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Showing posts with label GHG emission. Show all posts
Showing posts with label GHG emission. Show all posts

Wednesday, January 6, 2016

Which car Hydrogen, Fuel cell or Electric that will win the race?


Automobile industry has come a long way since the time of Henry Ford. The internal combustion engine that drives the modern car is slowly but steadily evolving into an emission free engine. The carbon pollution has caused globe to warm and changed the climate and also caused respiratory illness for millions of people around the world for decades. The Carbon pollution was completely ignored in the past while other design features of the car have undergone massive changes. However, when the smog and deteriorating air quality of Delhi and Beijing was beamed around the world in our TV sets, people realized how vulnerable they are to carbon pollution. But how to eliminate the Carbon emission from our automobiles? 1.The simple answer is to substitute the fossil fuels we use every day such as Petrol and Diesel with Carbon free fuel such as Hydrogen. Hydrogen being a light gas it has to be compressed and liquefied so that it can occupy less space. However, it requires a special ‘cryogenic tank’ to store liquid Hydrogen at – 253 C. BMW has already produced a commercial vehicle and it is in the market. However, the Hydrogen dispensing stations are limited in numbers. It uses existing internal combustion engine suitably modified for Hydrogen fuel so that they can use existing infrastructure that produces their petrol engines. There is no carbon emission except for water vapour. However, Hydrogen should be generated using renewable energy sources such as solar or wind. Hydrogen generated by reformation of natural gas will still have a Carbon foot print. It can be classified as a Carbon free car depending upon how Hydrogen is generated. However, producing liquid hydrogen or filling in a cryogenic tank is not commercially feasible for individual household. Hydrogen supply will have to be a centralized filling station. BMW has recently focussing their attention towards Fuel cell car. While those early vehicles were fun to drive, they suffered from the inefficiencies of super-cooling the liquefied hydrogen, and the hydrogen vaporizing in storage. Around the turn of the century, BMW began to research the hydrogen-powered, fuel-cell electric vehicle as an alternative to the hydrogen-powered combustion engine. 2.The other alternative is to substitute fossil fuel with compressed Hydrogen that generates an electric power using Fuel cell that drives the motor and the car. Here both fossil fuel and internal combustion engine are substituted with Hydrogen fuel and Fuel cell. This is a marked deviation from a conventional car. Honda of Japan was the first to introduce a commercial car using a Fuel cell. It uses compressed Hydrogen at 70 Mpa pressure that supplies Hydrogen to PEM (proton exchange membrane) Fuel cell that generates power that drives the motor and the car. There is no emission except for water vapour. The car runs smoothly and silently because there is no mechanical engine or moving part. It is truly a Carbon free car if the Hydrogen is generated from a renewable energy source such as solar or wind. It is ideal for houses with roof top solar panels. However, one has to install a water purifier, an electrolyser, a compressor and a compressed tank for Hydrogen storage. If the Hydrogen is generated by steam reforming of Natural gas, then it will have a Carbon footprint and cannot be classified as carbon free car. Generation of Hydrogen using roof top solar panel, electrolysis and compression is possible by individual households but it involves still some risk due to the explosive nature of Hydrogen. A centralized Hydrogen dispensing is still a safer method. Toyota Mirai Fuel cell car is a new model introduced by Toyota motor Co of Japan. It too has certain additional features such as a power generator for a remote households or camps. 2.The third alternative is to eliminate fuel as well as the engine completely; instead supply power to the motor from a storage battery. Here there is no emission or noise because there is no engine or moving parts similar to Fuel cell car. However, the battery is heavy and occupies a large space and it requires frequent charging from an external power source. The power often comes from the main power grid which carries the power generated from a power station which invariably uses fossil fuel. Though there is no Carbon emission from the electric car it still has Carbon footprint. However, if the power is generated from a renewable energy source such as solar and wind then it can be classified as Carbon free car. It is ideal for houses with roof top solar panels. However, it should be connected to the power grid in parallel. Alternatively, it can be connected to a storage battery if there is no grid. The Lithium ion battery pack in Tesla Roadster weighs 990 pounds, stores 56 kWh of electric energy, and delivers up to 215 kW of electric power. Tesla battery packs have the highest energy density in the industry. To achieve this energy density, Tesla starts with thousands of best-in-class Lithium-ion cells and assembles them into a liquid-cooled battery pack, wrapped in a strong metal enclosure. The battery is optimized for performance, safety, longevity, and cost. The cells used in a Roadster employ an ideal chemistry for electric vehicles Nickel Metal Hydride (NiMH) batteries are commonly used in hybrid cars. However, a 56 kWh NiMH battery pack would weigh over twice as much as the Roadster battery. Instead, Tesla uses Li-ion battery cells which dramatically decrease the weight of the Roadster pack and improve acceleration, handling, and range.
With Lithium-ion chemistry, there is no need to drain the battery before recharging - there is no “memory effect”. Roadster owners simply "top-off" each night.However long term supply of Lithium is still an issue. Each of the above cars have their own advantages and disadvantages. However, Fuel cell cars have certain advantages over Electric cars in spite of the advancement in battery technology primarily due to the weight of the battery and frequency and time required to charge the battery. Fuel cell car has a capacity to store Hydrogen fuel as well as to generate power onsite and this advantage will go a long way to make fuel cell cars truly carbon free not only for transportation but also for stationery power generation in remote locations. A large scale deployment of renewable energy generation such as solar and wind around the world can deliver a Car that is truly carbon free. However fossil fuel power generation will continue for years to come as the new technologies are developed to generate power using fossil fuel without emitting Carbon emission such as Carbon recycling. The real winner of the car race will depend upon how a Carbon emission free power generation technology will emerge in the future. Whatever may the power technology Fuel cell will be here to stay and if a cheap alternative catalyst is developed for Fuel cell then the race will be well and truly on. (Ref : Honda, Toyota and Roadster websites)

Friday, December 18, 2015

Decarbonizing Planet Earth with Carbon


“The method adopted in Vedanta to impart the knowledge of Brahman is known as the method of superimposition (adhyaaropa) and subsequent negation (apavaada). In the Bhashya, Bhagavatpada says, “The transmigrating self is indeed Brahman. He who knows the self as Brahman which is beyond fear becomes Brahman. This is the purport of the whole Upanishad put in a nutshell. It is to bring out this purport that the ideas of creation, maintenance and dissolution of the universe, as well as the ideas of action, its factors and results were superimposed on the Self. Then, by the negation of the superimposed attributes the true nature of Brahman as free from all attributes has been brought out. This is the method of adhyaaropa and apavaada, superimposition and negation, which is adopted by Vedanta.” (Ref: What are Upanishads? : An over view by S.N. Sastri on Luthur.com) The analogy that is often used to describe the process of superimposition and negation is that of ‘using a thorn to remove a thorn’. Finally, when the last thorn is removed, the thorn used to remove it is thrown away as well. Similarly, Carbon can be used to reduce carbon emission while power is generated! Let us consider the issues of Carbon emission and global warming resulting in climate change in the above context. Recent conference in Climate change held in Paris is acclaimed to be a success to the planet earth collectively adopted by 195 countries both developed and developing. In a nutshell they all have agreed to reduce their carbon emissions to limit the global warming to less than 2C or even 1.5 between 2030 and 2050. Is it really practical to achieve the above target given the nature of reduction and the complexity of imposing such a reduction within the time frame? It is a big question mark. The only practical method to reduce CO2 is by using Hydrogen CO2 + H2----> CO + H2O and then convert CO into a useful product such as Urea NH2CONH2 a fertilizer. Production of Urea requires additional Hydrogen which is again obtained by combustion of fossil fuel resulting in CO2 emission. Moreover, CO2 will eventually be released at the point of usage of urea later. While trying to reduce Carbon emission one will end up with more Carbon emission in the atmosphere.
The carbon emission from power plants can be substituted with renewable energy sources such as wind and solar at a very high cost but how the emissions from chemical plants such as urea or from automobile emissions, steel plants and cement plants be contained? We should also remember that silicon wafer to produce solar panels consume large amount of power which now comes invariably from fossil fuels. There is a long list of such plants emitting Carbon every day from all over the world. But there is a possibility to reduce emissions substantially by converting CO2 emissions from power plants into a synthetic fuel which can then substitute fossil fuel to continue power generation. The CO2 resulting from combustion of synthetic fuel will be recycled in the same manner mentioned above thus completing a cycle. To convert CO2 into a synthetic fuel we will require Hydrogen either by renewable sources or non-renewable sources. The non-renewable sources for Hydrogen cannot be a long term solution but renewable Hydrogen is very expensive at this stage. Therefore, Hydrogen is the only source which will not only help reduce Carbon emissions but also help eliminate Carbon completely from planet earth. Renewable Hydrogen is the key to decarbonize the planet earth. However, it may be possible to decarbonize the planet temporarily by using Hydrogen derived from fossil fuel without emitting CO2! It is not just a theory but practical because the technology has already been tested! In this process the Carbon will remain in the loop where it will neither be buried nor emitted into the atmosphere but constantly recycled.

Friday, March 21, 2014

It is time to switch over from Carbon to Hydrocarbon


When Carbon emission is high and the globe is warming due to such emissions then the simple and immediate solution to address this issue is to convert Carbon into Hydrocarbon, and the simplest Hydrocarbon is Methane (CH4).By simply introducing Hydrogen atom into Carbon atom the entire fuel property changes. For example the heating value of coal is only 5000-6500 kcal/kg at the maximum while the heating value of Methane (natural gas) increases to 9500 kcal/m3 by the above conversion. It means the same power generated by coal can be generated by using almost half the quantity of natural gas. Converting Carbon into substituted natural gas (SNG) is one way of addressing climate change in a short span of time. By switching over to SNG from coal will reduce the CO2 emission almost by 50%. Global warming due to GHG emission has become a serious environmental issue in recent times and more and more investments are made on renewable energy projects such as solar and wind etc. In spite of the major thrust on renewable energy projects the main source of power is still generated around the world using fossil fuel especially Coal due to its abundance and low cost. Moreover the investment already made on fossil fuel infrastructures are too big to be ignored and investment required to substitute coal-fired power plants by renewable energy are too large and gestation periods are too long to maintain the current electricity demand and to meet the future demands. The cost of renewable energy also is high and there is great resistance by consumers to switch over to renewable energy. Many Governments are reluctant to subsidize renewable energy due to their financial constraints. That is why countries like China which is growing at the rate of more than 8% pa are trying to decrease the ‘Carbon intensity’ rather than closing down the coal–fired power plants by setting up SNG (synthetic natural gas) plants by gasification of coal . This will reduce their Carbon emissions almost by 50% surpassing all other countries around the world in short span of time, thus meeting their emission targets agreed in “Kyoto protocol”. They can also meet the increasing electricity demand by using “syngas” generated by coal gasification plants, while reducing the Carbon pollution. They will also be able to produce Diesel and Gasoline from coal similar to the “SESOL” plant in South Africa which is already operating successfully for the past 50 years. “Leveraging Natural Gas to Reduce Greenhouse Gas Emissions” – a summary report by Center for Energy and Climate Solutions (C2ES) have highlighted the following in their report. “Recent technological advances have unleashed a boom in U.S. natural gas production, with expanded supplies and substantially lower prices projected well into the future. Because combusting natural gas yields fewer greenhouse gas emissions than coal or petroleum, the expanded use of natural gas offers significant opportunities to help address global climate change. The substitution of gas for coal in the power sector, for example, has contributed to a recent decline in U.S. greenhouse gas emissions. Natural gas, however, is not carbon-free. Apart from the emissions released by its combustion, natural gas is composed primarily of methane (CH4), a potent greenhouse gas, and the direct release of methane during production, transmission, and distribution may offset some of the potential climate benefits of its expanded use across the economy. This report explores the opportunities and challenges in leveraging the natural gas boom to achieve further reductions in U.S. greenhouse gas emissions. Examining the implications of expanded use in key sectors of the economy, it recommends policies and actions needed to maximize climate benefits of natural gas use in power generation, buildings, manufacturing, and transportation. More broadly, the report draws the following conclusions: •The expanded use of natural gas—as a replacement for coal and petroleum—can help our efforts to reduce greenhouse gas emissions in the near- to mid-term, even as the economy grows. In 2013, energy sector emissions are at the lowest levels since 1994, in part because of the substitution of natural gas for other fossil fuels, particularly coal. Total U.S. emissions are not expected to reach 2005 levels again until sometime after 2040. • Substitution of natural gas for other fossil fuels cannot be the sole basis for long-term U.S. efforts to address climate change because natural gas is a fossil fuel and its combustion emits greenhouse gases. To avoid dangerous climate change, greater reductions will be necessary than natural gas alone can provide. Ensuring that low-carbon investment dramatically expands must be a priority. Zero-emission sources of energy, such as wind, nuclear and solar, are critical, as are the use of carbon capture-and-storage technologies at fossil fuel plants and continued improvements in energy efficiency. • Along with substituting natural gas for other fossil fuels, direct releases of methane into the atmosphere must be minimized. It is important to better understand and more accurately measure the greenhouse gas emissions from natural gas production and use in order to achieve emissions reductions along the entire natural gas value chain.” Countries like India should emulate the Chinese model and become self-sufficient in meeting their growing energy demand without relying completely on imported Petroleum products. Import of petroleum products is the single largest foreign exchange drain for India, restricting their economic growth to less than 5%. Countries that rely completely on coal-fired power plants can set up coal hydro-gasification and gasification plants to reduce their Carbon emissions in the immediate future while setting up renewable energy projects as a long-term solution. Transiting Carbon economy into Hydrogen economy is a bumpy road and it will not be easy to achieve in a short span of time. The logical path for such transition will be to switch coal based power generation into gas based power generation for the following reasons. The largest Carbon emissions are from power generation and transportation. Transportation industry is already going through a transition from fossil fuel to Hydrogen. More future cars will be based either on Fuel cell or Electric and in both cases the fuel is the critical issue. Battery technology also will be an issue for Electric cars. It is more practical to generate Hydrogen from natural gas and to set up Hydrogen fuel stations than generating Hydrogen from solar powered water electrolysis. With improvement on Fuel cell technology it is more likely that PEM Fuel cell may be able to operate on Hydrogen derived from natural gas that is completely free from any Sulphur compounds. Even for Electric cars, natural gas will play an important role as a fuel for power generation and distribution in the near future as we transit from Carbon economy to full fledged Hydrogen economy. Countries like India with highest economic growth will have to be pragmatic by setting up more SNG plants with indigenous coal than depending on imported LNG. India has only two LNG terminals currently in operation but do not have gas transmission infrastructure. With increasing demand for natural gas from all over the world and lack of LNG receiving terminals, India will have to face a serious fuel and power shortage in the future. By installing more coal gasification and SNG plants with down-stream products like like Diesel and petrol, India can overcome the fuel and power shortage. In fact India set up the first coal gasification and Ammonia and Urea plant in Neyveli (Neyveli Lignite Corporation) way back in Fifties after her independence and it is time to visit the past. Renewable energy is certainly the long term solution for energy demand but we have to consider the amount of GHG emission associated with production PV solar panels, wind turbines and batteries. There is no easy fix to reduce GHG emission in short span of time but switching Carbon to hydrocarbon will certainly reduce the emissions scientists are advocating and water (steam) is the key to introduce such Hydrogen atom into the Carbon atom. That is why we always believe “Water and Energy are two sides of the same coin” and renewable Hydrogen will be the key to our future energy. President Obama's recent announcement of Carbon reduction plan by coal-fired power plants in USA is a bold step in the right direction.A more ambitious plan may be required to avoid catastrophic climate change that might cost billions of dollar in health related issues and on rebuilding damaged infrastructure. For more information on the above topic please refer to the following link: Source: Harvard University Link: Coal to Natural gas Fuel switching and Carbon dioxide (CO2) emission reduction. Date: Apr 2011. Author: Jackson Salovaara.

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.

Sunday, December 2, 2012

Which is the best storage technology for Renewable energy?

The share of renewable energy is steadily increasing around the world. But storing such intermittent energy source and utilizing it when needed has been a challenge. In fact energy storage constitutes a significant portion of the cost in any renewable energy technology. Many storage technologies are currently available in the commercial market, but choosing a right type of technology has always been a difficult choice. In this article we will consider four types of storage technologies. The California Energy Commission conducted economic and environmental analyses of four energy storage options for a wind energy project: (1) lead acid batteries, (2) zinc bromine (flow) batteries, (3) a hydrogen electrolyzer and fuel cell storage system, and (4) a hydrogen storage option where the hydrogen was used for fueling hydrogen powered vehicle. Their conclusions were: ”Analysis with NREL’s (National Renewable Energy laboratory) HOMER model showed that, in most cases, energy storage systems were not well utilized until higher levels of wind penetration were modeled (i.e., 18% penetration in Southern California in 2020). In our scenarios, hydrogen storage became more cost-effective than battery storage at higher levels of wind power production, and using the hydrogen to refuel vehicles was more economically attractive than reconverting the hydrogen to electricity. The overall value proposition for energy storage used in conjunction with intermittent renewable power sources depends on multiple factors. Our initial qualitative assessment found the various energy storage systems to be environmentally benign, except for emissions from the manufacture of some battery materials. However, energy storage entails varying economic costs and environmental impacts depending on the specific location and type of generation involved, the energy storage technology used, and the other potential benefits that energy storage systems can provide (e.g., helping to optimize Transmission and distribution systems, local power quality support, potential provision of spinning reserves and grid frequency regulation, etc.)”. Key Assumptions Key assumptions guiding this analysis include the following: • Wind power will expand in California under the statewide RPS program to a level of approximately 10% of total energy provided in 2010 and 20% by 2020, with most of this expansion in Southern California. • Costs of flow battery systems are assumed to decline somewhat through 2020 and costs of hydrogen technologies (electrolyzers, fuel cell systems, and storage systems) are assumed to decline significantly through 2020. • In the case where hydrogen is produced, stored, and then reconverted to electricity using fuel cell systems, we assume that the hydrogen can be safely stored in modified wind turbine towers at relatively low pressure at lower costs than more conventional and higher-pressure storage. • In the case where hydrogen is produced and sold into transportation markets, we assume that there is demand for hydrogen for vehicles in 2010 and 2020, and that the Hydrogen is produced at the refueling station using the electricity produced from wind farms (in other words, we assume that transmission capacity is available for this when needed)? Key Project Findings Key findings from the HOMER model projections and analysis include the following: • Energy storage systems deployed in the context of greater wind power development were not particularly well utilized (based on the availability of “excess” off-peak electricity from wind power), especially in the 2010 time frame (which assumed 10% wind penetration statewide), but were better utilized–up to 1,600 hours of operation per year in some cases–with the greater (20%) wind penetration levels assumed for 2020. • The levelized costs of electricity from these energy storage systems ranged from a low of $0.41 per kWh—or near the marginal cost of generation during peak demand times—to many dollars per kWh (in cases where the storage was not well utilized). This suggests that in order for these systems to be economically attractive, it may be necessary to optimize their output to coincide with peak demand periods, and to identify additional value streams from their use (e.g., transmission and distribution system optimization, provision of power quality and grid ancillary services, etc.) • At low levels of wind penetration (1%–2%), the electrolyzer/fuel cell system was either inoperable or uneconomical (i.e., either no electricity was supplied by the energy storage system or the electricity provided carried a high cost per MWh). • In the 2010 scenarios, the flow battery system delivered the lowest cost per energy stored and delivered. • At higher levels of wind penetration, the hydrogen storage systems became more economical such that with the wind penetration levels in 2020 (18% from Southern California), the hydrogen systems delivered the least costly energy storage. • Projected decreases in capital costs and maintenance requirements along with a more durable fuel cell allowed the electrolyzer/fuel cell to gain a significant cost advantage over the battery systems in 2020. • Sizing the electrolyzer/fuel cell system to match the flow battery system’s relatively high instantaneous power output was found to increase the competitiveness of this system in low energy storage scenarios (2010 and Northern California in 2020), but in scenarios with higher levels of energy storage (Southern California in 2020), the Electrolyzer/fuel cell system sized to match the flow battery output became less competitive. • In our scenarios, the hydrogen production case was more economical than the Electrolyzer/fuel cell case with the same amount of electricity consumed (i.e., hydrogen production delivered greater revenue from hydrogen sales than the electrolyzer/fuel cell avoided the cost of electricity, once the process efficiencies are considered). • Furthermore, the hydrogen production system with a higher-capacity power converter and electrolyzer (sized to match the flow battery converter) was more cost-effective than the lower-capacity system that was sized to match the output of the solid-state battery. This is due to economies of scale found to produce lower-cost hydrogen in all cases. • In general, the energy storage systems themselves are fairly benign from an environmental perspective, with the exception of emissions from the manufacture of certain components (such as nickel, lead, cadmium, and vanadium for batteries). This is particularly true outside of the U.S., where battery plant emissions are less tightly controlled and potential contamination from improper disposal of these and other materials are more likely. The overall value proposition for energy storage systems used in conjunction with intermittent renewable energy systems depends on diverse factors. • The interaction of generation and storage system characteristics and grid and energy resource conditions at a particular location. • The potential use of energy storage for multiple purposes in addition to improving the dependability of intermittent renewable (e.g., peak/off-peak power price arbitrage, helping to optimize the transmission and distribution infrastructure, load-leveling the grid in general, helping to mitigate power quality issues, etc.) • The degree of future progress in improving forecasting techniques and reducing prediction errors for intermittent renewable energy systems • Electricity market design and rules for compensating renewable energy systems for their output Conclusions “This study was intended to compare the characteristics of several technologies for providing Energy storage for utility grids—in a general sense and also specifically for battery and Hydrogen storage systems—in the context of greater wind power development in California. While more detailed site-specific studies will be required to draw firm conclusions, we believe those energy storage systems have relatively limited application potential at present but may become of greater interest over the next several years, particularly for California and other areas that is experiencing significant growth in wind power and other intermittent renewable. Based on this study and others in the technical literature, we see a larger potential need for energy storage system services in the 2015–2020 time frames, when growth in renewable produced electricity is expected to reach levels of 20%–30% of electrical energy supplied. Depending on the success in improved wind forecasting techniques and electricity market designs, the role for energy storage in the modern electricity grids of the future may be significant. We suggest further and more comprehensive assessments of multiple energy storage technologies for comparison purposes, and additional site- and technology-specific project assessments to gain a better sense of the actual value propositions for these technologies in the California energy system. This project has helped to meet program objectives and to benefit California in the Following ways: • Providing environmentally sound electricity. Energy storage systems have the Potential to make environmentally attractive renewable energy systems more competitive by improving their performance and mitigating some of the technical issues associated with renewable energy/utility grid integration. This project has identified the potential costs associated with the use of various energy storage technologies as a step toward understanding the overall value proposition for energy storage as a means to help enable further development of wind power (and potentially other intermittent renewable resources as well). • Providing reliable electricity. The integration of energy storage with renewable energy esources can help to maintain grid stability and adequate reserve margins, thereby contributing to the overall reliability of the electricity grid. This study identified the potential costs of integrating various types of energy storage with wind power, against which the value of greater reliability can be assessed along with other potential benefits. • Providing affordable electricity. Upward pressure on natural gas prices, partly as a function of increased demand, has significantly contributed to higher electricity prices in California and other states. Diversification of electricity supplies with relatively low-cost sources, such as wind power, can provide a hedge against further natural gas price increases. Higher penetration of these other (non-natural-gas-based) electricity sources, Potentially enabled by the use of energy storage, can reduce the risks of future electricity.” (Source: California Energy Commission prepared by University of Berkeley).

Saturday, October 20, 2012

Energy independent America

The recent debate between the presidential nominees in US election has revealed their respective positions on their policies for an energy independent America. Each of them have articulated how they will increase the oil and gas production to make America energy independent, which will also incidentally create number of jobs in an ailing economy. Each one of them will be spending a billion dollar first, in driving their messages to the voting public. Once elected, they will explore oil and gas aggressively that will make America energy independent. They will also explore solar and wind energy potentials simultaneously to bridge any shortfall. Their policies seem to be unconcerned with global warming and its impact due to emission of GHG but, rather aggressive in making America an energy independent by generating an unabated emission of GHG in the future. Does it mean an ‘energy independent America’ will spell a doom to the world including US? The best option for America to become energy independent will be to focus on energy efficiency of existing technologies and systems, combining renewable-fossil fuel energy mix, base load renewable power and storage technologies, substituting Gasoline with Hydrogen using renewable energy sources. The future investment should be based on sustainable renewable energy sources rather than fossil fuel. But current financial and unemployment situation in US will force the new president to increase the conventional and unconventional oil and gas production rather than renewable energy production, which will be initially expensive with long pay pack periods but will eventually meet the energy requirement in a sustainable way. The net result of their current policies will be an enhanced emission of GHG and acceleration of global warming. But the energy projections in the U.S. Energy Information Administration’s (EIA’s) Annual Energy Outlook 2012 (AEO2012) projects a reduced GHG emission. According to Annual Energy Outlook 2012 report: “The projections in the U.S. Energy Information Administration’s (EIA’s) Annual Energy Outlook 2012 (AEO2012) focus on the factors that shape the U.S. energy system over the long term. Under the assumption that current laws and regulations remain unchanged throughout the projections, the AEO2012 Reference case provides the basis for examination and discussion of energy production, consumption, technology, and market trends and the direction they may take in the future. It also serves as a starting point for analysis of potential changes in energy policies. But AEO2012 is not limited to the Reference case. It also includes 29 alternative cases, which explore important areas of uncertainty for markets, technologies, and policies in the U.S. energy economy. Many of the implications of the alternative cases are discussed in the “Issues in focus” section of this report. Key results highlighted in AEO2012 include continued modest growth in demand for energy over the next 25 years and increased domestic crude oil and natural gas production, largely driven by rising production from tight oil and shale resources. As a result, U.S. reliance on imported oil is reduced; domestic production of natural gas exceeds consumption, allowing for net exports; a growing share of U.S. electric power generation is met with natural gas and renewable; and energy-related carbon dioxide emissions remain below their 2005 level from 2010 to 2035, even in the absence of new Federal policies designed to mitigate greenhouse gas (GHG) emissions. The rate of growth in energy use slows over the projection period, reflecting moderate population growth, an extended economic recovery, and increasing energy efficiency in end-use applications. Overall U.S. energy consumption grows at an average annual rate of 0.3 percent from 2010 through 2035 in the AEO2012 Reference case. The U.S. does not return to the levels of energy demand growth experienced in the 20 years prior to the 2008- 2009 recession, because of more moderate projected economic growth and population growth, coupled with increasing levels of energy efficiency. For some end uses, current Federal and State energy requirements and incentives play a continuing role in requiring more efficient technologies. Projected energy demand for transportation grows at an annual rate of 0.1 percent from 2010 through 2035 in the Reference case, and electricity demand grows by 0.7 percent per year, primarily as a result of rising energy consumption in the buildings sector. Energy consumption per capita declines by an average of 0.6 percent per year from 2010 to 2035 (Figure 1). The energy intensity of the U.S. economy, measured as primary energy use in British thermal units (Btu) per dollar of gross domestic product (GDP) in 2005 dollars, declines by an average of 2.1 percent per year from 2010 to 2035. New Federal and State policies could lead to further reductions in energy consumption. The potential impact of technology change and the proposed vehicle fuel efficiency standards on energy consumption are discussed in “Issues in focus.” Domestic crude oil production increases Domestic crude oil production has increased over the past few years, reversing a decline that began in 1986. U.S. crude oil production increased from 5.0 million barrels per day in 2008 to 5.5 million barrels per day in 2010. Over the next 10 years, continued development of tight oil, in combination with the ongoing development of offshore resources in the Gulf of Mexico, pushes domestic crude oil production higher. Because the technology advances that have provided for recent increases in supply are still in the early stages of development, future U.S. crude oil production could vary significantly, depending on the outcomes of key uncertainties related to well placement and recovery rates. Those uncertainties are highlighted in this Annual Energy Outlook’s “Issues in focus” section, which includes an article examining impacts of uncertainty about current estimates of the crude oil and natural gas resources. The AEO2012 projections considering variations in these variables show total U.S. crude oil production in 2035 ranging from 5.5 million barrels per day to 7.8 million barrels per day, and projections for U.S. tight oil production from eight selected plays in 2035 ranging from 0.7 million barrels per day to 2.8 million barrels per day (Figure 2). With modest economic growth, increased efficiency, growing domestic production, and continued adoption of nonpetroleum liquids, net imports of petroleum and other liquids make up a smaller share of total U.S. energy consumption U.S. dependence on imported petroleum and other liquids declines in the AEO2012 Reference case, primarily as a result of rising energy prices; growth in domestic crude oil production to more than 1 million barrels per day above 2010 levels in 2020; an increase of 1.2 million barrels per day crude oil equivalent from 2010 to 2035 in the use of biofuels, much of which is produced domestically; and slower growth of energy consumption in the transportation sector as a result of existing corporate average fuel economy standards. Proposed fuel economy standards covering vehicle model years (MY) 2017 through 2025 that are not included in the Reference case would further reduce projected need for liquid imports. Although U.S. consumption of petroleum and other liquid fuels continues to grow through 2035 in the Reference case, the reliance on imports of petroleum and other liquids as a share of total consumption decline. Total U.S. consumption of petroleum and other liquids, including both fossil fuels and biofuels, rises from 19.2 million barrels per day in 2010 to 19.9 million barrels per day in 2035 in the Reference case. The net import share of domestic consumption, which reached 60 percent in 2005 and 2006 before falling to 49 percent in 2010, continues falling in the Reference case to 36 percent in 2035 (Figure 3). Proposed light-duty vehicles (LDV) fuel economy standards covering vehicle MY 2017 through 2025, which are not included in the Reference case, could further reduce demand for petroleum and other liquids and the need for imports, and increased supplies from U.S. tight oil deposits could also significantly decrease the need for imports, as discussed in more detail in “Issues in focus.” Natural gas production increases throughout the projection period, allowing the United States to transition from a net importer to a net exporter of natural gas Much of the growth in natural gas production in the AEO2012 Reference case results from the application of recent technological advances and continued drilling in shale plays with high concentrations of natural gas liquids and crude oil, which have a higher value than dry natural gas in energy equivalent terms. Shale gas production increases in the Reference case from 5.0 trillion cubic feet per year in 2010 (23 percent of total U.S. dry gas production) to 13.6 trillion cubic feet per year in 2035 (49 percent of total U.S. dry gas production). As with tight oil, when looking forward to 2035, there are unresolved uncertainties surrounding the technological advances that have made shale gas production a reality. The potential impact of those uncertainties results in a range of outcomes for U.S. shale gas production from 9.7 to 20.5 trillion cubic feet per year when looking forward to 2035. As a result of the projected growth in production, U.S. natural gas production exceeds consumption early in the next decade in the Reference case (Figure 4). The outlook reflects increased use of liquefied natural gas in markets outside North America, strong growth in domestic natural gas production, reduced pipeline imports and increased pipeline exports, and relatively low natural gas prices in the United States. Power generation from renewable and natural gas continues to increase In the Reference case, the natural gas share of electric power generation increases from 24 percent in 2010 to 28 percent in 2035, while the renewable share grows from 10 percent to 15 percent. In contrast, the share of generation from coal-fired power plants declines. The historical reliance on coal-fired power plants in the U.S. electric power sector has begun to wane in recent years. Over the next 25 years, the share of electricity generation from coal falls to 38 percent, well below the 48-percent share seen as recently as 2008, due to slow growth in electricity demand, increased competition from natural gas and renewable generation, and the need to comply with new environmental regulations. Although the current trend toward increased use of natural gas and renewable appears fairly robust, there is uncertainty about the factors influencing the fuel mix for electricity generation. AEO2012 includes several cases examining the impacts on coal-fired plant generation and retirements resulting from different paths for electricity demand growth, coal and natural gas prices, and compliance with upcoming environmental rules. While the Reference case projects 49 gigawatts of coal-fired generation retirements over the 2011 to 2035 period, nearly all of which occurs over the next 10 years, the range for cumulative retirements of coal-fired power plants over the projection period varies considerably across the alternative cases (Figure 5), from a low of 34 gigawatts (11 percent of the coal-fired generator fleet) to a high of 70 gigawatts (22 percent of the fleet). The high end of the range is based on much lower natural gas prices than those assumed in the Reference case; the lower end of the range is based on stronger economic growth, leading to stronger growth in electricity demand and higher natural gas prices. Other alternative cases, with varying assumptions about coal prices and the length of the period over which environmental compliance costs will be recovered, but no assumption of new policies to limit GHG emissions from existing plants, also yield cumulative retirements within a range of 34 to 70 gigawatts. Retirements of coal-fired capacity exceed the high end of the range (70 gigawatts) when a significant GHG policy is assumed (for further description of the cases and results, see “Issues in focus”). Total energy-related emissions of carbon dioxide in the United States remain below their 2005 level through 2035 Energy-related carbon dioxide (CO2) emissions grow slowly in the AEO2012 Reference case, due to a combination of modest economic growth, growing use of renewable technologies and fuels, efficiency improvements, slow growth in electricity demand, and increased use of natural gas, which is less carbon-intensive than other fossil fuels. In the Reference case, which assumes no explicit Federal regulations to limit GHG emissions beyond vehicle GHG standards (although State programs and renewable portfolio standards are included), energy-related CO2 emissions grow by just over 2 percent from 2010 to 2035, to a total of 5,758 million metric tons in 2035 (Figure 6). CO2 emissions in 2020 in the Reference case are more than 9 percent below the 2005 level of 5,996 million metric tons, and they still are below the 2005 level at the end of the projection period. Emissions per capita fall by an average of 1.0 percent per year from 2005 to 2035. Projections for CO2 emissions are sensitive to such economic and regulatory factors due to the pervasiveness of fossil fuel use in the economy. These linkages result in a range of potential GHG emissions scenarios. In the AEO2012 Low and High Economic Growth cases, projections for total primary energy consumption in 2035 are, respectively, 100.0 quadrillion Btu (6.4 percent below the Reference case) and 114.4 quadrillion Btu (7.0 percent above the Reference case), and projections for energy-related CO2 emissions in 2035 are 5,356 million metric tons (7.0 percent below the Reference case) and 6,117 million metric tons (6.2 percent above the Reference case)”. (Ref:U.S. Energy Information Administration).