‘Clean Energy and Water Technologies’ is now a social enterprise based in Melbourne, Australia. The purpose of this enterprise is to introduce a zero emission technology developed and patented by Ahilan Raman, the inventor of the technology. A 25 Mw demonstration plant will be installed to show case the above technology. This platform also used as a blog will publish articles relevant to Zero emission technologies for power and Zero liquid discharge technologies for water industries.
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Showing posts with label Batteries. Show all posts
Showing posts with label Batteries. Show all posts
Saturday, May 4, 2019
Can renewable technologies mitigate climate change?
Thursday, April 27, 2017
Battery versus Hydrogen
Monday, August 19, 2013
Clean power and water for remote island communities
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).
Friday, March 23, 2012
Why PV solar is still considered expensive?
Photovoltaic solar industry has started expanding in recent years in US and Europe and the rest of the world also started following. Still solar energy is considered expensive in many parts of the world for various reasons. In most of these countries, energy is predominantly managed by Governments with age old technologies and transmission systems. Coal is still the major fuel used for power generation and their distribution infrastructures are old and inefficient. Transmission losses, power pilferring, subsidized power tariffs and even free power for farmers, are some of the issues that compound the problems. Energy and water are considered more of social issues rather than business issues. For example in India, frequent power failures are common and sometimes people do not have power even up to 8 to 12 hours a day, especially in country sides. Standby diesel generators are integral part of an industry or business. The heavily subsidized power supply by Government from coal fired power plants is underrated. The average power tariff in India is still less than $0.07/kwhr.But the reality is they will be using diesel generated power for equal number of hours in a day and the cost of diesel power varies from $0.24 up to $0.36/kwhrs, almost in par with solar power. The average power cost will amount to $0.18 to $0.20 /kwhrs.
Any slight increase in oil price will have a dramatic effect in energy cost in India and their balance of payment situation.Governments are in a precarious situation and they have to make a balancing act between subsidizing the energy cost and winning the elections. They often subsidize the power resulting in heavy revenue losses for Government run electricity boards. Most of the electricity boards in India are in red .People are used to low power tariffs for several decades and any increase in the tariff will make the Government unpopular. Greenhouse effect and global warming are secondary issues. With an average economic growth rate at 7% year after year, their energy requirements have gone up substantially. They may require several hundred thousands of MW power in the next 5 to 10 years. They have opened up energy sector to private only in recent years.
Renewable energy industry is relatively new and there are very few large commercial scale solar and wind power plants in India. Majority of residents and businesses cannot afford high cost of PV solar installation. Even if they install, there is no ‘power- in tariff’ mechanism by Government where consumers can export surplus energy at a higher tariff to the grid. With current power failures lasting 8-12 hours/day, such mechanisms will have no value. The situation is the same in many Asian countries.
The solar panel costs are high due to lack of local production of silicon wafers, batteries and inverters and most of them are still imported. State electricity boards do not have funds to buy power at higher tariffs. Import duties and taxes on imported components are still high making renewable industries uncompetitive against cheap coal fired, subsidized power cost of $0.07/kwhrs .India requires massive investment on renewable energy industries. But most of the power projects which are under planning stage or under implementation are based on either coal or oil or LNG.There is no sign that India will soon become a major player in renewable energy.
In PV solar projects, the cost of storage batteries are higher than the solar panel during the life cycle of 25 years. If the life of a battery is 8 years then you will need 3 batteries during the life cycle. For example, if you use 100 watts solar panel with a life span of 20 years, the initial cost of solar panel may be $300 which will generate an average power of 140 watt.hrs /day. If you plan to store 5 days energy using a battery, you will enquire 5x 140= 700 watt.hrs battery, costing about $175.If you have to replace batteries 3 times during the life span of 20 years then the cost of battery is 3x175= $525.You have to add operation and maintenance cost, in addition to it. Therefore, your investment on batteries is 1.75 times more than solar panels. This cost will substantially add up to your energy cost.
In most of the Asian countries where they cannot export surplus power to the grid, they have to rely only on batteries. This high cost of stored energy is not remunerative because they cannot export this surplus to the grid at a higher tariff. This situation is not likely to change at least in the short term.
Sunday, March 18, 2012
Tame the Renewable with Hydrogen
The sun is bright and warm and your roof top solar panels and solar heaters are working hard to generate power and hot water. But the rate of power generated is too small to use immediately. The hot water is not hot enough for your shower. Your 200watt rooftop solar panel generates only 0.12 kwhrs after 5 hours of hard work. It does not meet your expectations. You expect 200 watts solar panel to generate about 1000 watt.hrs (1kwhr) in 5 hours. It is not happening. You don’t think renewable energy can meet your electricity demand.
There is a strong wind in the island and the wind turbines are rotating faster than usual but there are hardly any people living there. Wind turbine generates good power when the wind velocity is above certain level. But the electricity generated by the wind has no immediate takers.
There is a good rain this year and the dams are overflowing and the Hydro is generating surplus power but not many people are living near the catchment area. The power has to be transmitted hundred of kilometers to the nearby town through a sub-station. When the dams are dry there is hardly any power generation and power supply is rationed to the town.
When there is a demand for power Mother Nature does not offer the resources for power generation. When Mother Nature offers the resource we do not need power. This anomalous situation is the single largest obstacle that is undermining the potential of renewable energy. Of course, the high initial cost and half-hearted approach by Governments to offer subsidies or grants for renewable energy are other factors that add to the anomaly.
The only option to get over this situation is to store the energy 24x7 when it is generated and use them when we need them. It requires good storage technology, automation and information technology that can communicate with Natures energy resources and harness them, store them and deploy them judiciously and intelligently to meet our demands.
Current battery technology cannot be a long term sustainable solution; it is expensive, requires constant maintenance and replacement, which adds to the expensive initial investment on renewable systems. The best option is to generate Hydrogen on-site whenever sun shines or wind blows and store them under pressure that can be used as and when we require electricity using Fuel cell. It is easier to handle gas than stored electricity in batteries. Batteries are very heavy, has a limited life cycle and poses health hazard and not suitable for large scale power storage and not sustainable in the long run.
An Elecrolyzer can generate Hydrogen from water onsite whenever there is a sun or wind energy available and they can operate from 10% to 100% capacity depending upon the availability of renewable resources. The surplus power from Hydro can be converted into Hydrogen and stored. With so much advancement in information and communication technology, harnessing nature’s energy, storing them and deploying them in a timely manner is not major issue. Hydrogen can bridge the gap between Natural resource availability and human demand. This is what science is all about. We developed science by learning from Nature or duplicating Nature and Renewable energy is nothing different.
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