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Showing posts with label renewable energy. Show all posts
Showing posts with label renewable energy. Show all posts

Saturday, September 4, 2021

What future holds for energy and climate?

Energy industry is at a crossroad. It must now find a new direction to address the climate issue while to continue to supply energy to the world. The options are very clear. It can find new ways and means to genuinely address some of the mistakes of the past by inventing new methods to address the problem irrespective of the cost involved because time is not in our favour. Alternatively, one can redirect the issue using new terminologies and jargons and temporarily buy some time till finding an alternative and lasting solution to the problem. The first option will take time and cost more, and the second option may not take time and cost less. It seems most of the companies are choosing the second alternative. But how? Renewable energy is defined as “a source of energy that is available from the nature that can be constantly replenished”. This will guarantee the sustainability. But we are used to Carbon based fuels and technologies and therefore we also need a renewable Carbon that can substitute fossil fuels so that existing technologies for power and transportation can be used. Biomass is also derived from plants and animals like fossil fuels, but it is different in terms of time scale, and it can be replenished quickly unlike fossil fuels. It is basically made up of Carbon, Hydrogen and additionally oxygen, like fossil fuels such as coal, oil and gas but free from sulphur. Therefore, one can use the same technology such as combustion, gasification and pyrolysis etc and convert a biomass into energy, chemicals and fuels while claiming them as “renewables”. It will require oxy-combustion and gasification methods and unfortunately usage of pure Oxygen will be inevitable.Therefore, both Carbon as well as Hydrogen derived from biomass becomes “Green” and “renewable”. In addition "Green Hydrogen" using renewable energy sources such as solar and wind by water electrolysis will help decarbonisation by capturing and converting CO2 emissions into a Syngas. It requires a steep fall in the cost of renewable electricity to less than $20/Mwh and Carbon emission to be taxed at least @ $250/Mt to discourage fossil industry. Once we establish green and renewable Carbon and Hydrogen then it is only a matter of generating a syngas, combination of Hydrogen and Carbon monoxide with various ratios to synthesis various chemicals including bio crude oil that leads to refineries to produce petrol, diesel and aviation fuels. We will be back into the game but with different brand called “Green and renewable”; it is "an old wine in a new bottle" Everybody is happy and politicians can now heave a sigh of relief and feel comfortable. One can also use “blue hydrogen’ as a mix to green hydrogen and synthesis various downstream chemicals such as Ammonia, urea etc. Thus they can use them to decarbonise the fossil economy. In either way there is still an issue of CARBON EMISSION that needs to be addressed. They may claim biofuel as Carbon neutral, but it will not stop the increasing concentration of GHG into the atmosphere or climate change. Therefore Carbon tax will be inevitable. Bioenergy and renewable energy may increase the sustainability but will not address the issue of global warming and climate change. Nature does not discriminate between ‘bio-carbon’ and ‘fossil carbon’. Only “Carbon Recycling Technology” can address the problem of global warming and climate change. The simplest method will be to to collect CO2 emission from all petrol and diesel engines in a liquid form using a retrofittable device in the vehicle and convert them in a centralised facility to Syngas using renewable Hydrogen .The syngas can be converted into renewable crude using F-T reaction hat can be processed in a refinery for recycling into petrol, diesel and aviation fuel so that we can eliminate technologies such as large batteries and Fuel cells. By this way we can ensure the CO2 level in the atmosphere is stabilised and existing infrastructures are utilised. The availability of biomass for a radical change will be an issue especially in Asia where growing population requires more land for agriculture and deforestation is a common problem. Perhaps we need completely a new electricity generation technology that can "drive electrons to flow in a super conductor" and a magnetic storage using a cryogenic fluid. Unfortunately not many researchers are working in this direction.

Sunday, March 29, 2020

Renewable synthetic methane gas (RSMG) and Ramana Power Cycle (RPC) for Zero emission base load power.


RSMG is an abbreviation for ‘Renewable synthetic methane gas’ and it is a new form of a Carbon negative synthetic fuel to substitute natural gas. It is synthesized using  CO2 extracted from the sea or from power plant using Oxy combustion CO2 power cycle at the site such as CES, Graz cycle or Allam cycle (using supercritical CO2 as working fluid)  and Renewable Hydrogen (RH) by the following reactions using a renewable energy source.
1.    CO2=> CO + ½ O2 (electro-chemical reduction)
2.    CO + 3 H2=> CH4 + H2O (catalytic conversion)
There are other methods too can be applied but our patented process uses a unique method to synthesize RSMG from CO2 and renewable Hydrogen with a heating value (LHV) around 52 Mj/kg.
By using only, the sun and sea water, RSMG is continuously synthesized using continuous renewable energy such as OTE (ocean thermal energy) on 24 x 7 basis. Ocean is the largest reservoir for clean drinking water, Carbon dioxide, Hydrogen and thermal energy and it is imperative that the absorbed CO2 is extracted along with  stored thermal energy in order to restore the warming ocean to pre-industrial state to mitigate climate change. The success of the system depends on the availability of the lowest cost of renewable energy on 24 x7 basis such as Hydro or OTEC. Alternatively, the cost of renewable energy should be less than a $0.05/kwh.
What is RSMG?
RSMG is like natural gas with higher heating value consisting of pure methane and Hydrogen with no other impurities such as sulfur compounds or CO2. It is synthesized using a proprietary technology using CO2 extracted from seawater and renewable hydrogen (RH) using a renewable energy sources such as OTEC or Solar/wind etc. It can be compressed like CNG or liquified like LNG and can be transported or shipped to various destinations. RSMG is a Carbon negative fuel because it uses already absorbed CO2 from the sea and not from burning fossil fuel and it is also renewable because the O2 from CO2 emission is substituted with renewable Hydrogen (RH) constituting synthetic CH4. The purpose of this technology is to recycle Carbon indefinitely at the site of usage and that is why transportation in the form of CNG or LNG is discouraged.

Ramana Power Cycle (RPC)
RPC is a new patent (pending) technology to generate a base load power 24 x7 using a renewable synthetic methane gas (RSMG) with Zero emission. By constantly recycling CO2 in the form of RSMG during Oxy combustion CO2 power cycle we can eliminate usage of fossil fuel completely. Moreover, there will be no need to extract further CO2 from seawater for a specific power plant because Carbon is being recycled constantly. Only further RH will be required to run the base load power plant.
How RPC works?
RPC uses an Oxy combustion power cycle such as CES, Graz cycle or Allam cycle (using super critical CO2 as a working fluid) to generate a base load 24 x7 power. It uses 80% of CO2 generated internally leaving 20% high purity pipeline grade CO2 which is used to synthesize RSMG at site for recycling. That is why RSMG is renewable. Thus, RPC continues to generate a base load power with Zero emission. The electric efficiency of RPC is nearly 70 % and the cost of power is competitive to any other power source. By continuously generating RSMG and recycling CO2 it achieves Zero emission without any requirement of fossil fuel such as natural gas. Thus, the process can decarbonize the fossil fuel industry completely at the fastest time frame. Using 100% renewable hydrogen (RH) in gas turbine is still a long way off to achieve a commercial reality. Currently only up to 30% RH has been tested along natural gas (30:70) and there are several technical problems to be solved with combustor. Moreover, the maximum efficiency in Hydrogen based gas turbine will not exceed 35% at the maximum.

How RPC is different from Allam cycle, for example?
Allam cycle has been selected by IEA (International energy agency) as the most efficient (electric efficiency at 55.4%) Oxy combustion power cycle to generate a base load power using natural gas. It generates 20% pipeline grade CO2 as by-product suitable for CCS applications. It requires natural gas as a fuel. It generates pure Oxygen from air using ASU (air separation unit) by cryogenic process. Air separation is an energy intensive process consuming as much as 15% generated power internally thereby reducing overall electric efficiency of the system. Moreover 20% CO2 discharged from the plant requires long distance piping and sequestration both are expensive thus increasing the cost of power.
RPC uses pure Oxygen generated as by-product of renewable hydrogen (RH) by electrolysis for Oxy combustion of RSMG and to continue to generate a base load power at highest electrical efficiency at competitive rate. Synthesis of RSMG is highly exothermic chemical reaction which generates superheated steam as a by-product which generates additional power using steam turbine thus enhancing the overall electric efficiency of RPC.
RPC is suitable only for large power generation such as 100 Mw and above. The process requires the cheapest and continuous renewable energy source such as OTEC, offshore wind turbines supplemented by PV solar. The main advantage of the system is it does not require large scale energy storage and the base load power can be exported directly to the grid using a substation as it has been done over several decades.
RPC has the potential to decarbonize the fossil economy at the fastest rate than any other methods currently used.
Any power generation technology should be able to meet the following seven criteria in order to be successful.
1.Power availability.
2.Power dispatchability.
3.Zero emissions.
4.Lowest levelized cost of power
5.Potential to decarbonize the fossil economy at the shortest time frame.
6.Potential to Completely eliminate fossil fuel
7. Sustainable and has a potential to achieve circular economy.
RPC can meet all the above seven criteria.

Tuesday, August 27, 2019

The real solution to Carbon problem

The real solution for Carbon problem:
When mother nature buried Carbon under the ground by way of fossil, we human beings mined them at enormous cost and added further value by combustion with air converting it into CO2 (carbon dioxide). In fact, we human beings added enormous value to carbon that remained buried (with zero value) for millennia. We were interested in the heat of combustion but forgotten about the CO2 emission. This is the fundamental flaw in the commercialization of thermal power using fossil fuels. Now there is a price to pay. There are only 2 options to overcome this problem.
1    We can completely ignore and ban fossil fuel all together at enormous cost (we have already invested in trillions in mining, processing, transporting and storing) and seek completely a new solution without any Carbon at all. This is unlikely to happen.
2      We can continue to use fossil fuel and generate base load power as we have been doing for decades but capture CO2 and convert it back into fuel so that it can be recycled with Zero CO2 emission. This is certainly feasible.
Many “so called innovators” are suggesting alternatives to fossil power generation using renewable source of energy. These sources were available with us from the beginning of the world as we know it, but they are intermittent. We are used to 24

x7 base load power using fossil fuels.
The real solution lies in using intermittent renewable energy to generate base load power (24 x 7) with zero Carbon emission. Renewable Hydrogen can achieve this goal. In doing so battery can also play a small role but not a major role. Couple of things should happen to achieve this goal.
1.     Capturing CO2 at the lowest cost. It can be best achieved using Oxy combustion of fossil fuel such as LNG (because it is a purified form of natural gas) using Brayton cycle with 100 % CO2 capture.
2.     Generate renewable Hydrogen (RH) using electrolysis using renewable energy source such as solar and wind etc. Technology is well proven and commercially available.
3.     Convert captured CO2 into CH4 using methanation reaction (which is already commercially practised) and recycling CH4 as a fuel to continue the base load power generation as usual. The newly generated CH4 becomes a renewable natural gas (RNG) by substituting fossil Hydrogen with renewable Hydrogen (RH). This technology developed by CEWT is known as Carbon Recycling Technology (CRT). It is a perfect example of a circular economy. Governments around the world should scrap fossil subsidies, tax Carbon @ $100.Mt ( at least) and offer liberal subsidies to renewable energy so that the cost of renewable hydrogen (RH) is at the lowest. CRT will allow Carbon to remain below ground as nature has done for several years. CRT will allow to run base load power (24 x 7) using RNG with ZERO CARBON EMISSION.

The above process is the only economical, commercial and environmental solution to the problem of global warming and climate change. All other methods will be expensive, time consuming with no guaranteed results and are unlikely to happen in the shortest time we have.
We at CEWT have the solution (not just theoretical but practically and commercially implementable immediately) and we seek like-minded partners and investors to team up with us so that we can show case the technology and implement them worldwide.








Friday, July 19, 2019

Renewable Hydrogen, an emerging alternative to fossil fuel


Fossil fuels such as coal, oil and gas have helped transformed our power and transport industries for decades till now. But recent geo-political situations, depleting fossil sources and Carbon pollution, global warming and climate change have raised serious questions about the future of fossil fuels. However, countries who have massively invested in fossil fuel infrastructure and who have been heavily relying on supply of fossil fuels have started realizing an inescapable truth that they are running out of time to find an alternative to fossil fuels. Recently Hydrogen has been suggested as an alternative source of energy and many countries are gearing up to promote Hydrogen on a massive scale. The countries who have been traditionally using fossil fuels are now focussing on generating hydrogen from fossil fuels as an easier option. But the basic problem with this approach is they still depend on fossil fuels which means they still contribute to Carbon emission and climate change. They can conveniently dispute or deny the fact that man-made Carbon emissions cause global warming in order to score political points among the ‘gullible public’. Democracy is all about numbers and as along as these number stack up the political parties will take advantage of the system and try to push their agenda. But all these efforts are only short term and they still cannot escape the truth that man made Carbon emission is transforming our world for the worst and the future looks bleak. However, there is a silver lining in the dark clouds of global warming and climate change in the form of renewable Hydrogen. It is now possible to generate Hydrogen using renewable energy sources such as Hydro, solar, wind, geothermal and OTEC (ocean thermal energy conversion systems) that can used not only decarbonize our present economy and also has the capacity to transform future energy and to a cleaner and more sustainable environment. It is now possible to achieve a circular economy in energy sector which means the CO2 emission from existing and operating power plants using fossil fuels can be reversed using renewable Hydrogen so that one can continue to generate power but with Zero Carbon emission. This is a huge transformation. However, the usage of fossil fuels will continue in other industries such as petrochemicals, polymers and additives, and other synthetic materials. But one can take advantage of using renewable Hydrogen even in such industries using Green Chemistry initiatives so that they can become more sustainable. However Renewable Hydrogen is currently very expensive though it is generated from abundantly available natural resources such as sun, wind and water because PV solar panels are made from high purity silicon material again made from simple sand. We cannot afford to take natural resources lightly because they are precious commodities. With limited usage of renewable energy at current levels the cost of PV solar panels is still very expensive but likely to come down as we deploy more and more solar panels in the future. We should also be careful how we use renewable Hydrogen. Our first and foremost usage of renewable Hydrogen should be to decarbonize the fossil economy and achieve a circular economy. It means we must convert CO2 emissions into renewable natural gas (RNG) using renewable Hydrogen so that the Carbon can be recycled indefinitely with Zero Carbon emission while power plants using fossil fuels can continue to generate a base load power. By this way we will be able to address two issues namely meeting the rising energy demand at a cheaper price while eliminating global warming and climate change. All other use of renewable hydrogen such as Hydrogen vehicles for transportation using fuel cell etc will be secondary because they are not our priority. If we can generate a base load power (24 x7) using renewable Hydrogen with zero Carbon emission, then that should be our focus whether we believe it climate science or not. This will also help us conserve fossil fuels that may be rarely used to meet certain critical needs while substantially reducing the carbon emission. Renewable hydrogen will require massive deployment of renewable energy projects all over the world. One can generate renewable energy and use it directly for domestic or commercial use. But they are intermittent and require large scale energy storage. Moreover, all HT transmission lines are old and designed for transmitting base load power. Such an approach will not help decarbonizing fossil economy currently widely used. That is why renewable Hydrogen will have to play a key role in the future energy mix. Renewable hydrogen can be used as a fuel for transport industries using fuel cell and Japan is leading the way in this field. But such an application has along way to go and it requires massive investment and creation of infrastructure by way of filling stations. Countries like Japan do not have vast land area for solar industries, and they are likely to use cheap nuclear power and sea water to generate large scale hydrogen infrastructure. By this way they can supply power to both hydrogen as well as electric (battery) vehicles. Alternatively, they are looking to import liquified hydrogen (LH2) from countries like Australia who are ready to use cheap brown coal to generate Hydrogen by gasification despite CO2 emissions. Currently Australian government is very keen to encourage LH2 from cheap coal. They have already approved a pilot plant in the state of Victoria and only future can tell whether such a decision is prudent or not. Japanese companies may prefer to invest in Australia to generate and export clean liquid hydrogen leaving behind all emissions including CO2 in Australia. They may generate LH2 from natural gas and export it to Japan, but it may not be acceptable by Japanese companies because it has a potential to poison the Platinum catalyst used in their Fuel cell cars. In fact, Australia has an enormous potential to generate renewable hydrogen and then use it locally as well as to export. This will be more sustainable in the long run.

Saturday, May 4, 2019

Can renewable technologies mitigate climate change?


Energy generation and usage is considered not only as a mark of progress of a nation but also security of a nation. That is why countries go to extraordinary lengths to achieve such a security and everything else becomes secondary in the path of their goal. That is why countries with high oil and gas reserves enjoy good relationship and privileges with powerful nations of the world. Countries who do not have their own oil and gas reserves and who completely rely on import of oil and gas have no choice but maintain a good relationship with oil rich countries despite their difference in ideologies and policies. But with warming globe and changing climate the dependence on fossil fuels is fast becoming unsustainable and countries look for alternatives. It is good news for the whole world especially for nations who depend completely on import of oil and gas because they can develop their own renewable energy sources to lower their emissions. But there is one major difference. Countries who depend on import of oil and gas required to develop only an infrastructure to store and distribute oil and gas, But with renewable energy they have to develop an infrastructure to produce the hardware necessary to use alternative energy sources such as solar, wind, geothermal but also energy storage such as batteries. The warming globe and changing climate have become a grave threat to the plant earth and a threat to lives of entire future generations. It is the greatest challenge of the industrialized world. One can view this as threat or as an opportunity. But it is time to act irrespective of our views and we must act now. It is an opportunity for scientists and engineers to view energy sources and their applications in a new perspective. It is an opportunity to understand how human activities affect our environment and how not to damage them but preserve them for our future generations while developing new alternatives. Humanity is just a part of a larger environment and any damage to planet earth is at our own peril. It is an ancient wisdom, but we neglected them. When an aboriginal of Australia said “we belong to earth and earth does not belong to us” we failed to listen to them. We(people) became bigger than They (environment). In pursuit of a new energy source one must be extremely careful in examining Nature and how she operates so that we do not make the same mistakes of the past. As we develop renewable energy as a potential energy source of the future, we should be aware of the life cycle of such a system and their impact on environment. Renewable energy requires hardware that uses exotic metals, catalysts, polymers, new Carbon sources and glasses. As we switch to Carbon free economy, we should make sure that there are no emissions in developing renewable energy sources and if necessary impose Carbon tax on such emissions and, to develop recycling technologies to recycle that hardware safely and environmentally friendly manner. It is critically important issue as we move forward. According to an article published in Chemical engineering News “The potential quantities of waste are enormous. By 2025, waste batteries removed from electric vehicles will total 95 Giga watt hours, according to an estimate by Bloomberg New Energy Finance. That pile will weigh roughly 600,000 metric tons. A similar amount of old solar panels will have accumulated by then, according to projections by the International Renewable Energy Agency. IRENA anticipates solar panel waste could reach 78 million metric tons by 2050. And Europe could see 300,000 metric tons per year of decommissioned wind turbine blades in the next two decades, says the trade association Wind Europe. Each year, approximately 300,000 metric tons of lithium-ion battery waste is generated around the world, says Sheetanshu Upadhyay, an analyst with India’s Esticast Research & Consulting. Most of those batteries come from mobile devices, but that waste will soon be overshadowed by old electric car batteries. Sales of plug-in electric vehicles are expected to surpass 2.6 million in 2020, according to Navigation Research.” The above data shows the amount of CO2 emission associated with implementation of renewable energy sources soon. There is a potential for large scale recycling industries on renewables, but it will come with a price and environmental issues. Right now, the main problem is the CO2 emission and the only way to tackle this problem is impose Carbon tax on emissions while encouraging industries with low emission technologies. It should be possible for UN to pass a unanimous resolution among the nations to address climate change by imposing Carbon tax uniformly across the nations. By such resolution UN can bring all those countries to the table who are currently reluctant to be a party to the Paris accord. Countries can use “Carbon rating” similar to “energy ratings” currently used for measuring energy efficiencies in appliances such as Heaters and air-conditioners. The lowest emitting technologies will get the highest Carbon rating while high emission technologies will get the lowest Carbon ratings. By using such a method countries who are reluctant to act on climate change will be disadvantaged; they will not be able to compete in international market or export their goods to low emitting countries based on Carbon ratings.

Monday, August 25, 2014

How sustainable is our sustainability?


Sustainability can be defined as the ability to meet present needs without disturbing Nature’s equilibrium by a holistic approach while not compromising the ability of the future generation to continue to meet their needs. Holistic is “Characterized by the belief that the parts of something are intimately interconnected and explicable only by reference to the whole” (Wikipedia). Mathematically and scientifically any exponential growth or consumption will not be sustainable and such growth will eventually be curtailed by forces of Nature. Unfortunately current models of sustainability do not take a holistic approach but focus only on a continuous growth or expansion to meet the demands of the growing human population thus disturbing the Nature’s equilibrium. The holistic approach is essential because our world is interconnected and any isolated growth or development in one part of the world will affect the other part of the world. Such a growth is counter-productive to human civilization as a whole. At the same time Nature’s equilibrium is critical for the survival of humanity and science should take into account this critical issue while developing solutions to problems. Otherwise such a solution will not be sustainable in the long run. Nature maintains a perfect equilibrium (dynamic equilibrium) while maintaining reversibility. Both are intricately linked. If the equilibrium is not maintained then it becomes an irreversible process and the entropy of such a system will only increase according to the second law of thermodynamics. The order will become disorder or lead to chaos. Moreover any human interference to nature’s irreversibility and equilibrium by human beings will require energy. Any energy generation process within the system will not be holistic and therefore will not be sustainable. For example, reverse osmosis (RO) is a major industrial process currently used to desalinate sea water/brackish water to potable water. This process is reversing the Nature’s osmotic process by applying a counter pressure over and above the osmotic pressure of the saline water using high pressure pump. This requires energy in the form of electrical energy or thermal energy in the case of distillation. When such energy is generated by burning fossil fuel then the entropy increases because combustion of fossil fuel is an irreversible process. It is clearly not sustainable. Energy is directly connected with economic growth of the world, but Governments and industries failed to adopt a holistic approach while generating energy by simply focusing only on economic growth. The fossil fuel power generation has resulted in the accumulation of GHG in the atmosphere and in the ocean changing the climate. Power generation by nuclear plant (Fukushima) has spilled radiation into the ocean and has crossed the Pacific Ocean to shores of North America. These are irreversible changes. The human and economic costs from such pollution will easily dwarf the ‘the economic growth’ of the world. It is not holistic because the emissions caused by one country affects the whole world; then it becomes the right of an individual to object to such pollution and it is the obligation of the Governments, United Nations and the industries to protect individuals from such pollution. Right now all these agencies are helplessly watching the deteriorating situation because they do not have the solution or means to reverse the situation whether it is an advanced country or a poor country; we always measure growth only by income and not by the quality of air we breathe in or water we drink or the environment we live in. The demand for energy and water are constantly increasing all over the world; and we are trying to meet these demands by expanding existing power plants or by setting up new plants. When we generate power using fossil fuel the heat energy is converted into electrical energy and the products of combustion are let out into the atmosphere in the form of CO2 and Oxides of Nitrogen. It is an irreversible process and we cannot recover back the fossil fuel already burnt. Similarly the electricity generated once used to do some useful work such as lighting or running a motor etc cannot be recovered back. The process of electricity generation as well as usage of electricity is irreversible. Similarly when it rains the water percolates into the ground dissolving all the minerals, sometimes excessively in some places making it unsuitable to drink or irrigate. This process can be reversed but it again requires energy. Both the above processes are irreversible and thermodynamically they will increase the entropy of the system. Any energy generation process will have cost implications and therefore irreversibility and entropy are directly linked with economics. Fortunately renewable energy sources offer hope to humanity. Even though the entropy is increased due to its irreversible nature there is no depletion of energy (sun shines everyday). Only Nature can come to human rescue to our sustainability. Science and powerful economies cannot guarantee sustainability irrespective of the size of the budget. There is a myth that billions of dollars can reverse the irreversibility with no consequences. It raises question on the very basis of science because science depends on “observation and reproduciability” as we know. The biggest question is: “Who is the Observer and what is observed”? When sages of the East such as Ramana Maharishi raises this question, the Science has clearly no answer and the world is blindly and inevitably following the West to the point of no return. .

Friday, January 3, 2014

Coal may be the Problem and the Solution too!


Can renewable energy really stop GHG emissions and global warming? Renewable energy is slowly but steadily becoming a choice of energy of the people due to its potential to reduce GHG emissions and global warming. The changing weather pattern around the world in recent times are testimony for such a warming globe. Can renewable energy really reduce the GHG emissions and reduce the global warming predicted by scientists? Thousands of large coal- fired power plants are already under implementation or planning stages. According to World’s resources institute, their key findings are : 1. According to IEA estimates, global coal consumption reached 7,238 million tonnes in 2010. China accounted for 46 percent of consumption, followed by the United States (13 percent), and India (9 percent). 2. According to WRI’s estimates, 1,199 new coal-fired plants, with a total installed capacity of 1,401,278 megawatts (MW), are being proposed globally. These projects are spread across 59 countries. China and India together account for 76 percent of the proposed new coal power capacities. 3. New coal-fired plants have been proposed in 10 developing countries: Cambodia, Dominican Republic, Guatemala, Laos, Morocco, Namibia, Oman, Senegal, Sri Lanka, and Uzbekistan. Currently, there is limited or no capacity for domestic coal production in any of these countries. 4. Our analysis found that 483 power companies have proposed new coal-fired plants. With 66 proposed projects, Huaneng (Chinese) has proposed the most, followed by Guodian (Chinese), and NTPC (Indian). 5. The “Big Five” Chinese power companies (Datang, Huaneng, Guodian, Huadian, and China Power Investment) are the world’s biggest coal-fired power producers, and are among the top developers of proposed new coal-fired plants. 6. State-owned power companies play a dominant role in proposing new coal-fired plant projects in China, Turkey, Indonesia, Vietnam, South Africa, Czech Republic and many other countries. 7. Chinese, German, and Indian power companies are notably increasingly active in transnational coal-fired project development. 8. According to IEA estimates, the global coal trade rose by 13.4 percent in 2010, reaching 1,083 million tonnes. 9. The demands of the global coal trade have shifted from the Atlantic market (driven by Germany, the United Kingdom, France and the United States) to the Pacific market (driven by Japan, China, South Korea, India and Taiwan). In response to this trend, many new infrastructure development projects have been proposed. 10. Motivated by the growing Pacific market, Australia is proposing to increase new mine and new port capacity up to 900 million tonnes per annum (Mtpa) — three times its current coal export capacity. The above statistics is a clear indication that GHG emissions by these new coal-fired power plants will increase substantially. A rough estimation indicates that these new plants will emit Carbon dioxide at the rate of 1.37 mil tons of CO2/hr or 9.90 billion tons of CO2 /yr in addition to the existing 36.31 Gigatons/yr (36.31 billion tons/yr) in 2009. (According to CO2now.org). If this is true, the total CO2 emissions will double in less than 4 years. If the capacity of new PV solar plants are also increased substantially then the CO2 emissions from PV solar plants will also contribute additionally to the above. There is no way the CO2 reduction to the 2002 level can be achieved and the world will be clearly heading for disastrous consequences due to climate change. The best option to reduce GHG emissions while meeting the increasing power demand around the world will be to recycle the Carbon emissions in the form of a Hydrocarbon with the help of Hydrogen. The cheapest source of Hydrogen is coal. The world has no better option than gasifying the coal instead of combusting the coal. Capturing Carbon and recycling it as a fuel : Solar power, wind power and other renewable energies generated 6.5% of the world’s power in 2012. This is part of a rising trend , but there is a very long way to go before renewable sources generate as much energy as coal and other fossil fuels. Solar panel of 1m2 size requires 2.4kg of high grade silica and Coke and it consumes 1050 Kwh of electricity, mostly generated by fossil fuel based power plants. But 1m2 solar panel can generate only 150kwh/yr and it will require at least 7 years to generate the power used to produce 1m2 solar panel in the first place. More solar panels mean more electricity consumption and more GREEN HOUSE GAS EMISSIONS.A large quantity of CO2 will have to be emitted into the atmosphere for the production of several GW (Giga- watts) of solar power.With thousands of newly planned and implemented coal fired power plants in the near future the greenhouse gas emission is likely to go up. It could take at least thirty years before renewable energy is as strong in the marketplace as non-renewable sources. In consequence, there is a need to use fossil fuels more effectively and less detrimentally until the renewables can play a major role in global energy production. One approach tried for more than a decade has been carbon capture, which stops polluting materials getting into the atmosphere; however subsequent storage of the collected materials can make this process expensive. Now an Australian based company has gone one step further and designed a process that not only collects CO2 emissions, but also turns it into a fuel by using the same coal! Clean Energy and Water Technologies has developed an innovative solution to avoid carbon emissions from power plants. The novel approach uses coal to capture carbon dioxide emissions (CO2 ) from coal-fired power plants and convert them into synthetic natural gas (SNG). Synthetic natural gas would then replace coal as a fuel for further power generation and the cycle would continue. No coal is required for further power generation. Through this method, the captured Carbon could be recycled again and again in the form of a Hydrocarbon fuel (SNG) with no harmful gas emissions. Carbon is an asset and not a liability. If Carbon is simply burnt away just to generate heat and power then it is a bad science, because the same Carbon can be used to generate several products by simply recycling it instead of venting out into the atmosphere. Carbon is the backbone of all valuable products we use every day from plastics to life saving drugs! As well as seeking a patent for this breakthrough innovation, Clean Energy and Water Technologies is seeking investment for a demonstration plant. Once demonstrated, it would then be possible to retrofit current coal-fired power stations with the new technology, increasing their economic sustainability and reducing their impact on the environment. 1. The Economic Pressures : Power is an integral part of human civilization. With the steady increase in human population and industrialization the demands for energy and clean water has reached unprecedented levels. The gap between the demand and supply is steadily pushing the cost of power and water higher, whilst the supply of coal, oil and gas is dwindling. The prospect of climate change has compounded problems. Many countries around the world have started to use renewable energy such as solar, wind, hydro and geo-thermal power; but emerging economies such as India and China are unable to meet their demands without using fossil fuels. At present, it is far cheaper to use the existing infrastructures associated with non-renewable energy, such as coal-fired power stations. Renewable energy sources are intermittent in nature and require large storage and large initial investment, with sophisticated technologies pushing the cost of investment higher. Governments could use environmental tariffs on power use to help make renewable energy more competitive, but politicians know that the public tend to not like such an approach. 2. Demonstration Plant: The estimated investment required for a demonstration plant is likely to be $10 million; however the potential for a good return on investment is high, as shown by the following estimation for a 100MW plant. • A 100MW coal-fired power plant will emit 98 Mt/hr CO2 • Coal consumption will be about 54Mt/hr • To convert 98Mt/hr CO2 into SNG, the plant needs to generate 390,000m3/hr syngas by coal gasification. • The gasification plant will require 336 Mt/hr coal and 371 m3/hr water. • The net water requirement will be : 95.70m3/hr • The SNG generated by the above plant will be : 95,700m3/hr and steam as by-product : 115Mt/hr. • Potentially SNG can generate a gross power of 500 MWS by a Gas turbine with combined cycle operation. • The plant can generate 500MW (five times more than the coal-fired plant) from CO2 emissions. • Existing 100MW coal fired power plant can use SNG in place of coal and sell the surplus SNG to consumers. • Surplus SNG will be about 75,000 m3/hr.( 2400 mm Btu/hr) with sale value of $36,000/hr. @ $15/mmBtu. • Annual sales revenue from sale of surplus SNG will be : $ 300 mil/yr. • The entire cost of coal gasification and SNG plant can be recovered back in less than 5 years. 3. Carbon Capture and Storage : Carbon capture and storage is the process of capturing waste carbon dioxide (CO2 ) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an underground geological formation. The aim is to prevent the release of large quantities of CO2 into the atmosphere. It is a potential means of mitigating the contribution of fossil fuel emissions to global warming and ocean acidification. The long term storage of CO2 is a relatively new concept. The first commercial example was Wey burn in 2000. Carbon capture and storage applied to a modern conventional power plant could reduce CO2 emissions to the atmosphere by approximately 80–90%, but may increase the fuel needs of a coal-fired plant by 25–40%. These and other system costs are estimated to increase the cost of the energy produced by 21–91% for purpose built plants. Applying the technology to existing plants could be even more expensive. 4. Global Warming : Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Scientists are more than 90% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels by coal-fired power plants. 5. Greenhouse Gases Without the earth's atmosphere the temperature across almost the entire surface of the earth would be below freezing. The major greenhouse gases are water vapour, which causes about 36–70% of the greenhouse effect; carbon dioxide (CO2 ), which causes 9–26%; methane (CH4), which causes 4–9%; and ozone (O3), which causes 3–7%. According to work published in 2007, the concentrations of CO2 and methane have increased by 36% and 148% respectively since 1750. These levels are much higher than at any time during the last 800,000 years, the period for which reliable data has been extracted from ice cores. 6. The Future of Global Warming?: Climate model projections were summarized in the 2007 Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC). They indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2 °F) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F) for their highest. 7. The Impact of Global Warming? : Future climate change and associated impacts will vary from region to region around the globe. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with the continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include a more frequent occurrence of extreme weather events including heat waves, droughts and heavy rainfall, ocean acidification and species extinctions due to shifting temperature regimes. There is a divided opinion among scientists on climate science. Major power consuming countries like the US, Europe, Japan and Australia are reluctant to sign the Kyoto Protocol and agree to a legally binding agreement. This has resulted in non-cooperation among the nations and the world is divided on this issue. Such disagreement has hampered development of non-renewable energy. Ahilan Raman is the inventor of the innovative process mentioned in the article. If you have any further questions or like to become a part of this innovative technology, please feel free to contact him directly by writing to this blog.

Friday, January 4, 2013

Heating and cooling buildings with solar heat.

Air conditioning makes up bulk of the power usage especially in tropical countries where the sun is shining almost throughout the year and the humidity levels are high. It makes a perfect sense to use solar heat to cool homes, business and factories. Many air-conditioning systems are commercially available using simple roof top PV solar panels to generate electric power to run an electric window air-conditioners. This system uses commercially available solar panels and window air-conditioners and uses solar power to generate electricity to run the compressor and the blower in the air-con unit. This system requires large storage battery to store adequate electricity to run your air-conditioners for specified period of time. Otherwise it requires a large area of solar panels to meet the demand. The efficiency of such systems can be improved using DC operated compressors and fans. However, renewable energy such as solar is still expensive to run air-conditioners because of high initial investment cost, though it may be economical in the long run as the cost of solar panels and accessories slowly come down over a period of time. Moreover such systems are limited to small air condition capacities. For large air-conditioning requirements such as business and factories, we require a system that uses solar heat directly to air-condition the premises with higher efficiency and thermal storage capabilities. Designing such a system is not very difficult because most of the components necessary to install such a systems are readily available. One can install an air-conditioning system based on 100% solar thermal heat with molten salt thermal storage. Alternatively, a hybrid system can be installed based on solar heat without a thermal storage but using city gas supply. Many countries use gas for heating during winter seasons but do not use gas during summer. These countries can use a hybrid (solar-gas) system to air-condition their premises and avoid peak electric usage during summer seasons thereby avoiding electrical black-outs. The advantage with such system is they can also be used for heating the premises during winter season. With changing climate due to global warming many warm countries like India also experiences cold temperatures during winter season. For example New Delhi in India has experienced a sharp drop in temperature up to 15-20c during winter from earlier winters. Solar cooling systems to date have used waste heat gas absorption chiller heaters, which utilize the waste heat from co-
generation systems (CGS) for the cold water. However, these chiller heaters with their established technologies are devices designed for the effective use of stable CGS high-temperature waste heat, so they cannot accommodate the preferential use of solar heat when solar hot water temperatures suddenly change from large variations in the heat collector temperatures due to changes in the weather. The new solar absorption chiller heaters are now specially designed for the effective use of low-temperature solar heat to address this problem and improve the energy conservation effect from solar cooling system. Hot water at less than 90C can be used for such systems and typical chillers with their rated specification are shown in the figures. The efficiency of the system can be vastly improved by using parabolic solar concentrators, up to 27 times higher than ordinary flat plate solar collectors resulting in conversion efficiency up to 85% in heating and cooling. By selecting a natural refrigerant such as R717 we can save the environment from ozone depletion. Such systems offers flexibility to use exhaust heat, natural gas along with solar thermal storage up to 220C (phase transition temperature).The system offers an attractive return on investment, electricity savings and Carbon pollution reduction. The system can be designed from 5TR up to 200TR refrigeration capacity for 100% solar and up to 1000TR for a solar-gas hybrid systems. The solar thermal system with molten salt storage is versatile in its application because the same system can be designed for heating or cooling or on-site power generation for continuous applications. .

Friday, August 31, 2012

Indian black out and aftermath


The largest power outage that affected 650 million people in India recently was a major news around the world. Power outage is common in many countries including industrialized countries during the times of natural disasters such as cyclones, typhoons and flooding. But the power outage that happened in India was purely man-made. It was not just an accident but a culmination of series of failures as the result of many years of negligence, incompetency and wrong policies. Supplying an uninterrupted power for a democratic country like India with 1.2 billion people with 5-8% annual economic growth, mostly run by Governments of various political parties in various states is by no means an easy task. While one can understand the complexities of the problems involved in power generation and distribution, there are certain fundamental rules that can be followed to avoid such recurrence. The supply and demand gap for power in India is increasing at an accelerated rate due to economic growth but the power generation and distribution capacity do not match this growth. Most of the power infrastructures in India are owned by Governments who control the power generation, distribution, operation and maintenance, financing power projects, supplying power generation equipments, supplying consumables, supplying fuel, transportation of fuel and revenue collection. The entire system is based on the policy of ‘socialistic democracy’, after the independence from the British, though economic liberalization and globalization is relatively a new phenomenon in India. Since every department of power infrastructure is controlled by Government, there is a lack of accountability and competition. Many private companies and foreign companies do not participate in tendering process because it is a futile exercise. Some smart multinational companies set up their manufacturing facilities in India, often in collaboration with Governments in order to get an entry into one of the largest market in the world. Indigenous Coal is the dominant fuel widely used for power generation though the quality of coal is very low, with ash content as high as 30%.The calorific value of such coal hardly exceeds 3000 kcal/kg, which means more quantity of coal is required than any other fuel to generate same amount of power. Such coal generates not only low power but also generates huge amount of ‘fly ash’ (the ash content is the coal comes out as fly ash) causing pollution and waste disposal problems. Large piles of fly ash and age old cooling towers with a large pool of stagnant water are common sights in many power plants in India. Such low cost coal does not make any economic sense when considering the amount of fly ash disposal cost and environmental damages. Thanks to research institutions that have developed methods to utilize fly ash in production of Portland cement. The indigenous low grade coal is the fuel of choice by Indian power industries, though many plants have started importing coal recently from Indonesia and South Africa. Indigenous low grade coal and cooling water from rivers and underground sources are two major pollutants in India. Water is allocated for power plants at the cost of agriculture. There is a shortage of drinking water in many cities as well as irrigation water for agriculture. Since most of the power infrastructures are owned by Governments there is a tendency to adopt populace policies such as power subsidies, free water and power for farmers, low power tariffs etc, making such projects economically unviable in the long run. Most of the State Electricity boards in India are running at a loss and such accumulated losses amount to staggering figures. The Central electricity authority regulates the power tariff. They calculate the cost of power generation based on specific fuel and fix the power tariff that companies can charge their consumers even before the plant is set up. Most of such tariffs are based on their past experience using indigenous low grade coal and transport cost which are often impractical. Such low power tariffs are not remunerative for private companies and many foreign companies do not invest in large capital intensive power projects in India for the same reason. The best option for the Governments to solve energy problems in India will be to open to foreign investments and allow latest technologies in power generation and distribution. It is up to the investing companies to decide the right type of fuel, right type of equipments, source and procurement, power technology to be adopted and finally the tariff. India has come a long way since independence and Governments should focus on Governing rather than managing and controlling infrastructure projects. The latest scam widely debated in Indian media is 'Coal scam’. It is time India moves away from fossil fuel and allow foreign investments and technologies in renewable energy projects freely without any interference. India needs large investments in building power and water infrastructures and it will be possible to attract foreign investment only by infusing confidence in investing companies. It is not just the size of the market that is to be attractive for investors but they also need a conducive, fair and friendly environment for such investment.

Thursday, August 9, 2012

Irreversibility leads to unsustainability


People in the chemical field will understand the concept of ‘irreversibility’. Certain chemical reactions can go only in one direction and but not in the reverse direction. But some reactions can go on either direction and we can manipulate such reactions to our advantages. This concept has been successfully used in designing many chemical reactions in the past and many innovative industrial and consumer products emerged out of it. But such irreversible reactions also have irreversible consequences because it can irreversibly damage the environment we live in. There is no way such damage can be reversed. That is why a new branch of science called ‘Green Chemistry’ is now emerging to address some of the damages caused by irreversible chemical reactions. It also helps to substitute many synthetic products with natural products. In the past many food colors were made out of coal tar known as coal tar dyes. These dyes are used even now in many commercial products. Most of such applications were merely based on commercial attractiveness rather than health issues. Many such products have deleterious health effects and few of them are carcinogenic. We learnt from past mistakes and moved on to new products with less health hazards. But the commercial world has grown into a power lobby who can even determine the fate of a country by influencing political leaders. Today our commercial and financial world has grown so powerful that they can even decides who can be the next president of a country rather than people and policies. They can even manipulate people’s opinion with powerful advertisements and propaganda tactics by flexing their financial muscles. Combustion of fossil fuel is one such example of ‘irreversibility’ because once we combust coal, oil or gas, it will be decomposed into oxides of Carbon, oxide of Nitrogen and also oxides of Sulfur and Phosphorous depending upon the source of fossil fuel and purification methods used. These greenhouse gases once emitted into the atmosphere we cannot recover them back. Coal once combusted it is no longer a coal. This critical fact is going to determine our future world for generations to come. Can we bring back billions of tons of Carbon we already emitted into the atmosphere from the time of our industrial revolution? Politicians will pretend not to answer these question and financial and industries lobby will evade these question by highlighting the ‘advancement made by industrial revolutions’. People need electricity and they have neither time nor resources to find an alternative on their own. It is open and free for all. People can be skeptical about these issues because it is ‘inconvenient for them’ to change But can we sustain such a situation? Irreversibility does not confine only to chemical reactions but also applies for the environment and sustainability because all are intricately interconnected.Minig industries have scared the earth, power plants polluted the air with greenhouse emission and chemical industries polluted water and these damages are irreversible. When minerals become metals, buried coal becomes power and water becomes toxic effluent then we leave behind an earth that will be uninhabitable for our future generations and all the living species in the world. Is it sustainable and can we call it progress and prosperity? Once we lose
pristine Nature by our irreversible actions then that is a perfect recipe for a disaster and no science or technology can save human species from extinction. One need not be scientist to understand these simple facts of life. Each traditional land owners such as Aborigines of Australia or Indians of America and shamans of Indonesia have traditionally known and passed on their knowledge for generations. They too are slowly becoming extinct species in our scientific world because of our irreversible actions. Renewability is the key to sustainability because renewability does not cause irreversible damage to Nature.

Monday, August 6, 2012

Base load power generation with Solar thermal


All existing power generation technologies including nuclear power plants uses heat generation as a starting point. The heat is used to generate steam which acts as a motive force to run an alternator to produces electricity. We combust fossil fuels such as coal oil and gas to generate above heat which also emits greenhouse gases such as oxides of Carbon and Nitrogen. As I have disused in my previous article, we did not develop a technology to generate heat without combusting a fossil fuel earlier. This was due to cheap and easy availability of fossil fuel. The potential danger of emitting greenhouse gases into the atmosphere was not realized until recently when scientists pointed out the consequences of carbon build up in the atmosphere. The growth of population and industries around the world pushed the demand for fossil fuels over a period of time which enhanced the Carbon build up in the atmosphere. But now Concentrated Solar Power (CSP) systems have been developed to capture the heat of the sun more efficiently and the potential temperature of solar thermal can reach up to 550C. This dramatic improvement is the efficiency of solar thermal has opened up new avenues of power generation as well as other applications. “CSP is being widely commercialized and the CSP market has seen about 740 MW of generating capacity added between 2007 and the end of 2010. More than half of this (about 478 MW) was installed during 2010, bringing the global total to 1095 MW. Spain added 400 MW in 2010, taking the global lead with a total of 632 MW, while the US ended the year with 509 MW after adding 78 MW, including two fossil–CSP hybrid plants”. (Ref: Wikipedia) “CSP growth is expected to continue at a fast pace. As of April 2011, another 946 MW of capacity was under construction in Spain with total new capacity of 1,789 MW expected to be in operation by the end of 2013. A further 1.5 GW of parabolic-trough and power-tower plants were under construction in the US, and contracts signed for at least another 6.2 GW. Interest is also notable in North Africa and the Middle East, as well as India and China. The global market has been dominated by parabolic-trough plants, which account for 90 percent of CSP plants. As of 9 September 2009, the cost of building a CSP station was typically about US$2.50 to $4 per watt while the fuel (the sun's radiation) is free. Thus a 250 MW CSP station would have cost $600–1000 million to build. That works out to $0.12 to $0.18/kwt. New CSP stations may be economically competitive with fossil fuels. Nathaniel Bullard,” a solar analyst at Bloomberg “New Energy Finance, has calculated that the cost of electricity at the Ivanpah Solar Power Facility, a project under construction in Southern California, will be lower than that from photovoltaic power and about the same as that from natural gas However, in November 2011, Google announced that they would not invest further in CSP projects due to the rapid price decline of photovoltaics. Google spent $168 million on Bright Source IRENA has published on June 2012 a series of studies titled: "Renewable Energy Cost Analysis". The CSP study shows the cost of both building and operation of CSP plants. Costs are expected to decrease, but there are insufficient installations to clearly establish the learning curve. As of March 2012, there was 1.9 GW of CSP installed, with 1.8 GW of that being parabolic trough” Ref: Wikiedia. One Canadian company has demonstrated to generate Hydrogen from water using a catalytic thermolysis using sun’s high temepertaure.The same company has also demonstrated generating base load power using conventional steam turbine by CSP using parabolic troughs. They store sun’s thermal energy using a proprietary thermic fluid and use them during night times to generate continuous power. The company offers to set up CSP plants of various capacities from 15Mw up to 500Mw.

Thursday, August 2, 2012

Solar Hydrogen for homes and cars.


Renewable Hydrogen offers the most potential energy source of the future for the following reasons. Hydrogen has the highest heat value compared to rest of the fossil fuels such as Diesel, petrol or butane. It does not emit any greenhouse gases on combustion. It can readily be generated from water using your roof mounted solar panels. The electrical efficiency of fuel cell using Hydrogen as a fuel is more than 55% compared to 35% with diesel or petrol engine. It is an ideal fuel that can be used for CHP applications. By properly designing a system for a home, one can generate power as well as use the waste heat to heat or air-condition your home. It offers complete independence from the grid and offers complete insulation from fluctuating oil and gas prices. By installing a renewable Hydrogen facility at your home, you can not only generate Electricity for your home but also fuel your Hydrogen car. The system can be easily automated so that it can take care of your complete power requirement as well as your fuel requirement for your Hydrogen car. Unlike Electric cars, you can fill two cylinders of a Hydrogen car which will give a mileage of 270miles.You can also charge your electric car with Fuel cell DC power. Renewable Hydrogen can address all the problems we are currently facing with fossil fuel using centralized power generation and distribution. It will not generate any noise or create any pollution to the environment. It does not require large amount of water. With increasing efficiency of solar panels coming into the market the cost of renewable Hydrogen power will become competitive to grid power. Unlike photovoltaic power, the excess solar power is stored in the form of Hydrogen and there is no need for deep cycle batteries and its maintenance and disposal. It is a one step solution for all the energy problems each one of us is facing. The only drawback with any renewable energy source is its intermittent nature and it can be easily addressed by building enough storage capacity for Hydrogen. Storing large amount of energy is easy compared to battery storage. The attached ‘You Tube’ video footages show how Solar Hydrogen can be used to power your home and fuel your Hydrogen car. Individual homes and business can be specifically designed based on their power and fuel requirements.

Wednesday, July 11, 2012

Fuelcell power using Biogas


Fuel cell technology is emerging as a base-load power generation technology as well as back-up power for intermittent renewable energy such as solar and wind, substituting conventional storage batteries. However, Fuelcell requires a Fuel in the form of Hydrogen of high purity. The advantage of Fuel cell is, its high electrical efficiency compared to conventional fossil fuel power generation technology, using Carnot cycle. Fuel cell is an electro-chemical device similar to a battery and generates power using electro-chemical redox reaction silently with no gaseous emission, unlike engines and turbines with combustion, rotary movements and gaseous emissions. The fuel Hydrogen can be generated using a renewable energy sources such as solar and wind as described in my previous articles, “Solar Hydrogen for cleaner future” dated 4 July 2012, and “Renewable Hydrogen for remote power supply “dated 28 June 2012. Alternatively, Hydrogen can also be generated using biomass through Biogas. Biogas is an important source of renewable energy in the carbon constrained economy of today’s world. The biogas can be generated from waste water and agro-waste by anaerobic digestion using enzymes. Biomass such as wood waste can also be gasified to get syngas, a mixture of Hydrogen and Carbon dioxide. In anaerobic digestion, the main product will be methane gas accompanied by carbon dioxide and nitrogen while the main product in gasification will be Hydrogen, cabon monoxide and carbon dioxide and oxides of Nitrogen. Whatever may be the composition of the resulting gas mixture, our focus will be to separate methane or Hydrogen from the above mixture. In anaerobic digestion, the resulting Methane gas has to be steam reformed to get Hydrogen gas suitable for Fuel cell application. In gasification, the resulting Syngas has to be separated into pure Hydrogen and Carbon dioxide so that pure Hydrogen can be used as a fuel in Fuel cell applications. As I have outlined in many of my previous articles, Hydrogen was the only fuel we have been using all these years and we are still using it in the form of Hydrocarbons and it will continue to be the fuel in the future also. The only difference is future Hydrogen will be free from carbon. We have to address two issues to mitigate Carbon emission, and it can be done by 1.Elimination of Carbon from the fuel source. 2. Generation of Renewable and Carbon free clean energy directly from solar and wind. One option to eliminate Carbon from the fuel source is to use Biomass as the raw material to generate Hydrogen so that fresh Carbon will not be added into the atmosphere by emissions .The second option is to generate pure Hydrogen from water by electrolysis using renewable energy such as wind and solar. Environmentally friendly waste-to-energy projects are becoming popular all over the world. But currently most of these waste-to-energy projects generate either Biogas (Methane) by anaerobic digestion or Syngas (Hydrogen and Carbon dioxide) by gasification. Both these gases require further purification before they can be used as a fuel for power generation. The Methane content in the Biogas (about 60% methane and 40% Carbon dioxide with other impurities) needs to be enriched to 90% Methane and free from other impurities. The composition of a typical Biogas is shown in table1. The resulting purified methane gas will be reformed using steam reformation in presence of a catalyst to obtain syngas; finally Hydrogen should be separated from resulting syngas so that it can be used directly into the Fuelcell.The common Fuel cell used for this application is invariably Phosphoric acid fuel cell. PAFC uses 100% Phosphoric acid in Silicon carbide matrix as an electrolyte. PAFC is a self contained unit completely enclosed in a cabin consisting of a gas reformer, Fuellcell power generator, Power conditioning unit and other auxiliaries. The PAFC is of modular construction with capacities ranging from 100Kw up to 500Kw as a single unit. It can be installed outdoor in the open and it can be readily connected to a piped Biogas. It can also be connected to existing piped natural gas or LPG bullet as a stand-by fuel. Any waste-to energy project can be integrated with Fuel cell power generation with CHP application to get maximum economic and environmental benefits. Hydrogen derived from biomass will be an important source of fuel in the future of clean energy; and Fuel cell will become an alternative power generation technology for both stationary power generation and transportation such as Fuel cell car or Hybrid cars. PAFC is a compact, self-contained power generation unit that is used even for base load power. The electrical efficiency of PAFC is about 42% .It is suitable for CHP applications so that the total energy efficiency can reach up to 85%.It is ideal for supplying continuous power 24x7 and also to use waste heat for space heating or space air-conditioning with an absorption chiller in CHP applications. The ideal candidates for PAFC power generation using CHP will be hospitals, super markets, Data centers, Universities or any continuous process industry.PAFC is currently used as a backup power for large scale renewable energy project with an access to piped natural gas. A schematic flow diagram of a fuel cell power generation is shown in Fig 3 using biogas at Yamagata sewage treatment plant in Japan. Biomass based Fuecell power generation has a great potential all over the world irrespective of location and size of the country.

Sunday, July 8, 2012

Fuelcell or battery for Renewable energy back-up?


Batteries have become indispensable for energy storage in renewable energy systems such as solar and wind. In fact the cost of battery bank, replacements, operation and maintenance will exceed the cost of PV solar panels for off grid applications during the life cycle of 20 years. However, batteries are continued to be used by electric power utilities for the benefits of peak shaving and load leveling. Battery energy storage facilities provide the dynamic benefits such as voltage and frequency regulation, load following, spinning reserve and power factor correction along with the ability to provide peak power. Fuel cell power generation is another attractive option for providing power for electric utilities and commercial buildings due its high efficiency and environmentally friendly nature. This type of power production is especially economical, where potential users are faced with high cost in electric power generation from coal or oil, or where environmental constraints are stringent, or where load constraints of transmission and distribution systems are so tight that their new installations are not possible. Both batteries and fuel cells have their own unique advantages to electric power systems. They also contain a great potential to back up severe PV power fluctuations under varying weather conditions. Photovoltaic power outputs vary depending mainly upon solar insolation and cell temperature. PV power generator may sometimes experience sharp fluctuations owing to intermittent weather conditions, which causes control problems such as load frequency control, generator voltage control and even system stability. Therefore there is a need for backup power facilities in the PV power generation. Fuel cells and batteries are able to respond very fast to load changes because their electricity is generated by chemical reactions. A 14.4kW lead acid battery running at 600A has maximum load gradient of 300 A/sec, a phosphoric-acid fuel cell system can match a demand that varies by more than half its rated output within 0.1 second. The dynamic response time of a 20kW solid-oxide fuel cell power plant is less than 4 second when a load increases from 1 to 100%, and it is less than 2 msec when a load decreases from 100 to 1%. Factory assembled units provides fuel cell and battery power plants with short lead-time from planning to installation. This modular production enables them to be added in varying increments of capacity, to match the power plant capacity to expected load growth. In contrast, the installation of a single large conventional power plant may produce excess capacity for several years, especially if the load growth rate is low. Due to their multiple parallel modular units and absence of combustion and electromechanical rotary devices, fuel cell and battery power plants are more reliable than any other forms of power generation. Fuel cells are expected to attain performance reliability near 85%. Consequently, a utility that installs a number of fuel cell or battery power plants is able to reduce its reserve margin capacity while maintaining a constant level of the system reliability. The electrochemical conversion processes of fuel cells and batteries are silent because they do not have any major rotating devices or combustion. Water requirement for their operation is very little while conventional power plants require massive amount of water for system cooling. Therefore, they can eliminate water quality problems created by the conventional plants’ thermal discharges. Air pollutant emission levels of fuel cells and batteries are none or very little. Emissions of SO2 and NOx in the fuel cell power plant are 0.003 lb/MWh and 0.0004 lb/MWh respectively. Those values are projected to be about 1,000 times smaller than those of fossil-fuel power plants since fuel cells do not rely on combustion process. These environmentally friendly characteristics make it possible for those power plants to be located close to load centers in urban and suburban area. It can also reduce energy losses and costs associated with transmission and distribution equipment. Their location near load centers may also reduce the likelihood of power outage. Electricity is produced in a storage battery by electro-chemical reactions. Similar chemical reactions take place in a fuel cell, but there is a difference between them with respect to fuel storage. In storage batteries chemical energy is stored in the positive/negative electrodes of the batteries. In fuel cells, however, the fuels are stored externally and need to be fed into the electrodes continuously when the fuel cells are operated to generate electricity. Power generation in fuel cells is not limited by the Carnot Cycle in the view that they directly convert available chemical free energy to electrical energy than going through combustion processes. Therefore fuel cell is a more efficient power conversion technology than the conventional steam-applying power generations. Fuel cell is a one-step process to generate electricity, the conventional power generator has several steps for electricity generation and each step incurs certain amount of energy loss. Fuel cell power systems have around 40-60% efficiencies depending on the type of electrolytes. For example, the efficiencies of phosphoric-acid fuel cells and molten-carbonate fuel cells are 40-45% and 50-60%, respectively. Furthermore, the fuel cell efficiency is usually independent of size; small power plants operate as efficiently as large ones. Battery power systems themselves have high energy efficiencies of nearly 80%, but their overall system efficiencies from fuel through the batteries to converted ac power are reduced to below 30%. This is due to energy losses taking place whenever one energy form is converted to another A battery with a rated capacity of 200Ah battery will provide less than 200 Ah. At less than 20A of discharge rates, the battery will provide more that 200 Ah. The capacity of a battery is specified by their time rate of discharge. As the battery discharges, its terminal voltage, the product of the load current and the battery internal resistance gradually decreases. There is also a reduction in battery capacity with increasing rate of discharge. At 1-hr discharge rate, the available capacity is only 55% of that obtained at 20-hr rate. This is because there is insufficient time for the stronger acid to replace the weak acid inside the battery as the discharge proceeds. For fuel cell power systems, they have equally high efficiency at both partial and full loads. The customer’s demand for electrical energy is not always constant. So for a power utility to keep adjustment to this changing demand, either large base-load power plants must sometimes operate at part load, or smaller peaking units must be used during periods of high demand. Either way, efficiency suffers or pollution increases. Fuel cell systems have a greater efficiency at full load and this high efficiency is retained as load diminishes, so inefficient peaking generators may not be needed. Fuel cells have an advantage over storage batteries in the respect of operational flexibility. Batteries need several hours for recharging after they are fully discharged. During discharge the batteries’ electrode materials are lost to the electrolyte, and the electrode materials can be recovered during the recharging process. Over time there is a net loss of such materials, which may be permanently lost when the battery goes through a deep discharge. The limited storage capacity of the batteries implies that it is impossible for them to run beyond several hours. Fuel cells do not undergo such material changes. The fuel stored outside the cells can quickly be replenished, so they do not run down as long as the fuel can be supplied. The fuel cells show higher energy density than the batteries when they operate for more than 2 hours. It means that fuel cell power systems with relatively small weight and volume can produce large energy outputs. That will provide the operators in central control centers for the flexibility needed for more efficient utilization of the capital-intensive fuel cell power plants. In addition, where hydrogen storage is feasible, renewable power sources can drive an electrolysis process to produce hydrogen gas during off-peak periods that will be used to operate the fuel cells during peak demands. The usage of storage batteries in an electric utility industry is expected to increase for the purposes of load leveling at peak loads, real-time frequency control, and stabilizing transmission lines. When integrated with photovoltaic systems, the batteries are required to suppress the PV power fluctuations due to the changes of solar intensity and cell temperature. The fact that the PV power outputs change sharply under cloudy weather conditions makes it hard to decide the capacity of the battery power plants since their discharging rates are not constant. For a lead-acid battery, the most applicable battery technology for photovoltaic applications to date, the depth of discharge should not exceed 80% because the deep discharge cycle reduces its effective lifetime. In order to prevent the deep discharge and to supplement varying the PV powers generated on cloudy weather days, the battery capacity must be large. Moreover, the large battery capacity is usually not fully utilized, but for only several days. Fuel cells integrated with photovoltaic systems can provide smoother operation. The fuel cell system is capable of responding quickly enough to level the combined power output of the hybrid PV-fuel cell system in case of severe changes in PV power output. Such a fast time response capability allows a utility to lower its need for on-line spinning reserve. The flexibility of longer daily operation also makes it possible for the fuel cells to perform more than the roles of gas-fired power plants. Gas turbines are not economical for a purpose of load following because their efficiencies become lower and operating costs get higher at less than full load conditions Fuel cell does not emit any emission except water vapor and there is absolutely no carbon emission. However, storage batteries themselves do not contain any environmental impacts even though the battery charging sources produce various emissions and solid wastes. When an Electrolyzer is used to generate Hydrogen onsite to fuel the Fuel cell, the cost of the system comes down due to considerable reduction in the capacity of the battery. The specific cost of energy and NPC is lower than fully backed battery system. During dismantling, battery power plants require significant amount of care for their disposal to prevent toxic materials from spreading around. All batteries that are commercially viable or under development for power system applications contain hazardous and toxic materials such as lead, cadmium, sodium, sulfur, bromine, etc. Since the batteries have no salvage value and must be treated as hazardous wastes, disposal of spent batteries is an issue. Recycling batteries is encouraged rather than placing them in a landfill. One method favoring recycling of spent batteries is regulation. Thermal treatment for the lead-acid and cadmium-containing batteries is needed to recover lead and cadmium. Sodium-sulfur and zinc bromine batteries are also required to be treated before disposal. Both batteries and fuel cells are able to respond very fast to system load changes because they produce electricity by chemical reactions inside them. Their fast load-response capability can nicely support the sharp PV power variations resulted from weather changes. However, there are subtle different attributes between batteries and fuel cells when they are applied to a PV power backup option. Power generation in fuel cell power plants is not limited by the Carnot Cycle, so they can achieve high power conversion efficiency. Even taking into account the losses due to activation over potential and ohmic losses, the fuel cells still have high efficiencies from 40% to 60%. For example, efficiencies of PAFCs and MCFCs are 40-45% and 50-60% respectively. Battery power plants, on the other hand, themselves have high energy efficiency of nearly 80%, but the overall system efficiency from raw fuel through the batteries to the converted ac power is reduced to about 30%. A battery’s terminal voltage gradually decreases as the battery discharges due to a proportional decrease of its current. A battery capacity reduces with increasing rate of discharge, so its full capacity cannot be utilized when it discharges at high rates. On the other hand, fuel cell power plants have equally high efficiency at both partial and full loads. This feature allows the fuel cells to be able to follow a changing demand without losing efficiency. The limited storage capacity of batteries indicates that it is impossible for them to run beyond several hours. The batteries when fully discharged need several hours to be recharged. For its use in PV power connections, it is as hard to estimate the exact capacity of the batteries. In order to prevent the batteries’ deep discharge and to supplement the varying PV powers on some cloudy weather days, the battery capacity should be large, but that large capacity is not fully utilized on shiny days. For fuel cells, they do not contain such an operational time restriction as long as the fuel can be supplied. Thus, the fuel cell power plants can provide operational flexibility with the operators in central control centers by utilizing them efficiently. As intermediate power generation sources, fuel cell power plants may replace coal-fired or nuclear units under forced outage or on maintenance. For the PV power backup the batteries’ discharge rate is irregular and their full capacity may usually not be consumed. So, it is difficult to design an optimal capacity of the battery systems for support of the PV power variations and to economically operate them. Instead of batteries fuel cell power plants exhibit diverse operational flexibility for either a PV power backup or a support of power system operation.