Sunday, September 27, 2015
Green storage for green energy
Rechargeable battery to power a home from rooftop solar panels
A team of Harvard scientists and engineers has demonstrated a rechargeable battery that could make storage of electricity from intermittent energy sources like solar and wind safe and cost-effective for both residential and commercial use. The new research builds on earlier work by members of the same team that could enable cheaper and more reliable electricity storage at the grid level.
The mismatch between the availability of intermittent wind or sunshine and the variability of demand is a great obstacle to getting a large fraction of our electricity from renewable sources. This problem could be solved by a cost-effective means of storing large amounts of electrical energy for delivery over the long periods when the wind isn't blowing and the sun isn't shining.
In the operation of the battery, electrons are picked up and released by compounds composed of inexpensive, earth-abundant elements (carbon, oxygen, nitrogen, hydrogen, iron and potassium) dissolved in water. The compounds are non-toxic, non-flammable, and widely available, making them safer and cheaper than other battery systems.
"This is chemistry I'd be happy to put in my basement," says Michael J. Aziz, Gene and Tracy Sykes Professor of Materials and Energy Technologies at Harvard Paulson School of Engineering and Applied Sciences (SEAS), and project Principal Investigator. "The non-toxicity and cheap, abundant materials placed in water solution mean that it's safe -- it can't catch on fire -- and that's huge when you're storing large amounts of electrical energy anywhere near people."
The research appears in a paper published in the journal Science.
This new battery chemistry was discovered by post-doctoral fellow Michael Marshak and graduate student Kaixiang Lin working together with co-lead author Roy Gordon, Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science at Harvard.
"We combined a common organic dye with an inexpensive food additive to increase our battery voltage by about 50 percent over our previous materials," says Gordon. The findings "deliver the first high-performance, non-flammable, non-toxic, non-corrosive, and low-cost chemicals for flow batteries."
Unlike solid-electrode batteries, flow batteries store energy in liquids contained in external tanks, similar to fuel cells. The tanks (which set the energy capacity), as well as the electrochemical conversion hardware through which the fluids are pumped (which sets peak power capacity), can be sized independently. Since the amount of energy that can be stored can be arbitrarily increased by scaling up only the size of the tanks, larger amounts of energy can be stored at lower cost than traditional battery systems.
The active components of electrolytes in most flow battery designs have been metal ions such as vanadium dissolved in acid. The metals can be expensive, corrosive, tricky to handle, and kinetically sluggish, leading to inefficiencies. Last year, Aziz and his Harvard colleagues demonstrated a flow battery that replaced metals with organic (carbon-based) molecules called quinones, which are abundant, naturally occurring chemicals that are integral to biological processes like photosynthesis and cellular respiration. While quinones in aqueous solution formed the negative electrolyte side of the battery, the positive side relied on a conventional bromine-bearing electrolyte that is used in several other batteries. The high performance and low cost of the technology, which Harvard has licensed to a company in Europe, hold the potential to provide scalable grid-level storage solutions to utilities.
But bromine's toxicity and volatility make it most suitable for settings where trained professionals can deal with it safely behind secure fences.
So the team began searching for a new recipe that would provide comparable storage advantages -- inexpensive, long lasting, efficient -- using chemicals that could be safely deployed in homes and businesses. Their new battery, described in a paper published today in the journal Science, replaces bromine with a non-toxic and non-corrosive ion called ferrocyanide.
"It sounds bad because it has the word 'cyanide' in it," explains co-lead author Marshak, who is now assistant professor of chemistry at the University of Colorado Boulder. "Cyanide kills you because it binds very tightly to iron in your body. In ferrocyanide, it's already bound to iron, so it's safe. In fact, ferrocyanide is commonly used as a food additive, and also as a fertilizer."
Because ferrocyanide is highly soluble and stable in alkaline rather than acidic solutions, the Harvard team paired it with a quinone compound that is soluble and stable under alkaline conditions, in contrast to the acidic environment of their original battery developed last year.
Marshak compares exposure to the concentrated alkaline solution to coming into contact with a damaged disposable AA battery. "It's not something you want to eat or splash around in, but outside of that it's really not a problem."
There are other advantages to using alkaline solution. Because it is non-corrosive, the flow battery system components can be constructed of simpler and much less expensive materials such as plastics.
"First generation flow batteries were single-element couples -- transition metals like vanadium or iron or chrome," says Michael Perry, Project Leader for Electrochemical Systems at United Technologies Research Center, who was not involved in the work. "Now we're seeing the possibility of engineered molecules giving us the properties and attributes that we want in one complete system. More work is required and justified but the Harvard team is really demonstrating the promise of next-generation chemistries."
Robert F. Savinell, Distinguished University Professor and George S. Dively Professor of Engineering at Case Western Reserve University, another battery expert who was not part of the Harvard research, agrees that the new technology offers significant advantages over other flow batteries concepts, including "potential very low costs with sustainable materials, high efficiencies at practical power densities, and safe and simple operation." He adds: "It should be expected that this flow battery approach will have a short development and scale-up path for fast commercial introduction."
Harvard's Office of Technology Development has been working closely with the research team to navigate the shifting complexities of the energy storage market and build relationships with companies well positioned to commercialize the new chemistries.
The Big Question: Where Are the Major Geothermal Opportunities Around the World Today and What Should the Industry Do to Take Advantage of Them
Geothermal technology offers renewable energy that comes from under the earth. The energy is baseload, dispatchable, and 100-percent renewable. The industry is making slow-but-steady progress in various regions of the world. As attendees head to the Geothermal Energy Expo and Geothermal Resources Council Annual Meeting in this week, we ask our readers this issue’s Big Question.
Director of Communications, Geothermal Resources Council
In organizing the biggest annual event in the industry (the GRC Annual Meeting & the GEA Geothermal Energy Expo), the Geothermal Resources Council (GRC) gets an insight into current trends. From these, we can see that the biggest opportunities remain in Indonesia and The Philippines in Asia and in Kenya and Ethiopia in Africa.
However, the recent news that the Japanese government will allow drilling for geothermal resources in parts of national parks bodes well for the industry there. Also, new legislation in Mexico will potentially be a boon for geothermal energy.
I hope legislation will be passed to restore the Salton Sea in Southern California. This would involve the development of more than a GW of geothermal energy, providing a much-needed push for the industry in the United States.
In addition, the research into Enhanced Geothermal Resources (EGS) here in the United States, in particular at the Frontier Observatory for Research in Geothermal Energy (FORGE) program, might provide the breakthrough for the industry that will make geothermal energy available anywhere in the world.
There are probably many untapped areas. But in Kenya, they have enough geothermal potential to possibly power a major part of East Africa. The added bonus is that the transmission lines that are being installed for the Lake Turkana Wind Project pass close by allowing connection points and substations to be built. External companies should be encouraged to invest and be a part of Kenya’s 5,000-MW vision for future energy provision.
The age-old issue for geothermal power generation is proving resources and developing risk with a utility rate of return on completing a successful project. This single issue has sidelined potential projects for decades. Sponsor Energy Capital is forming a fund to solve this issue for worthy projects.
Geothermal is abundant in many places around the globe. I see the real problem as that in most areas where geothermal is present, there is insufficient grid capacity to handle the load that can be generated.
If you closely examine the geothermal domes that exist throughout the southwestern United States, for example, you will find that the grid necessary to support larger amounts of energy is not present or is dedicated to the transfer of energy from areas supplied by larger fossil-fuel generation plants.
The costs to upgrade this power structure and to connect these plants to the grid end up being higher than the developers of the projects can bear.
Craig Immel
Founder, Steady State Asset Partners
There are two important trends in geothermal energy that have the opportunity to drive new growth in the ground-source heat pump industry. First, the development of innovative geothermal HVAC-financing models will enable many more buildings to keep their occupants comfortable while conserving energy and keeping operating costs low.
These new business models are allowing property owners to avoid large upfront cash outlays for upgrading to geothermal while still keeping monthly cash payments below their properties’ previous monthly heating and cooling bills.
The geothermal industry is following in the footsteps of successful solar PV financing models, which are growing rapidly by selling no-money-down solar installations.
Second, there is a growing recognition that geothermal heat pump systems can be used for thermal energy storage. While there is a lot excitement around solar PV and grid storage, much of that electricity is ultimately used to provide thermal comfort and water heating.
Storing BTUs underground and simply pumping them into or out of buildings as needed is a smart way to use electricity and heat energy. It is also a great opportunity for utilities to comply with the Clean Power Plan by reducing overall energy loads on the grid.
In California, we need the California Independent System Operator (CAISO) to recognize the importance of geothermal energy and eliminate barriers to its development.
There is something wrong when geothermal is only 4 percent of California’s renewable energy portfolio. The area around the southern end of the Salton Sea is the richest deposit of geothermal energy in North America and has resources to replace the shuttering of San Onofre.
Today there are almost 80 countries around the world at some stage of exploring or developing their geothermal resources, so there are opportunities on every continent. The best scenarios for success and growth are those where there is an understanding of the resource and geology, the governments support its development and the economies needs power. All three of these factors are found in East Africa, particularly in Kenya and Ethiopia, making this a leading region for geothermal opportunities.
Equally strong potential exists for new geothermal development in Mexico and Indonesia as these governments each move forward on geothermal initiatives and open doors for new investment. Opportunities also abound in the ripening geothermal markets of Central American countries, Caribbean Islands, and Pacific Islands.
But don’t write off the United States. As climate emissions become a market driver, the firm and flexible attributes of geothermal power make it an essential part of any greenhouse gas emissions reduction plan. Only a small fraction of geothermal resources are developed, so it’s still a pioneer industry with a lot of room for advancement.
To take advantage of the opportunities, first support GEA as it works to open and promote new markets and to keep companies informed of new opportunities. Second, develop the best technology and the best team. Then prepare your plans knowing the risks...and seeking to reap rewards.
Karl Gawell
Geothermal Energy Association
Geothermal opportunities are best capitalized upon in physical locations where the potential exists. Such opportunities are greatest on or near major volcanic activities or tectonic plate underlap areas. The entire tectono-magmatic activities around the Red Sea gave rise to several geothermal provinces over the continents surrounding the Red Sea, represented by thermal springs and fumaroles at several locations in the State of Eretria, Djibouti, Ethiopia, Yemen and Saudi Arabia.
Ideally, an offshore system in the Red Sea could provide a major source of steam energy for electrical production. A high-voltage DC undersea cable could carry this energy ashore for mass storage or immediate use.
The United States Navy Operates the COSO Geothermal Well in California. The energy produced from this facility powers an entire base plus overcapacity for adjoining communities.
Geothermal planning requires high-quality research on understanding location, technology, environmental impact, the cost of feeder transmission lines, mass storage, maintenance and operation.
Most geothermal systems require extensive maintenance and lifecycle support which must be factored into the business case for any such project.
The perspectives on what constitutes a great geothermal opportunity differ. For developers and investors, it is about accessibility and supporting schemes. For suppliers, it is about the market structure, openness and competitiveness.
Overall, the key markets for suppliers are Indonesia, Philippines, Kenya, Turkey, Mexico, and the several smaller nations with smaller projects. For investors supporting schemes such as the Geothermal Risk Mitigation Facility in Eastern Africa, a new insurance scheme in Mexico and Latin America, as well as good feed-in-tariffs, are helpful.
Germany, for that matter, still is likely one of the better return opportunities, despite its smaller project size and higher perceived risk.
There are some good geothermal resources in East Texas.
One of the things that concerns me the most about geothermal is the water withdrawal and consumption. I know that a lot of companies are looking for ways to reduce their water impact (in particular by using recycled water - much like in the natural gas industry), but the water component is still one I think needs to be part of any discussion.
If the geothermal potential is in areas that are predicted to see an increase in drought or heatwaves in the coming decades, I think that water availability should be part of the calculus of whether it is worth harvesting those resources. At the very least, developers should consider how to be smart about reducing their freshwater use.
When we talk about geothermal energy development, we should not forget geothermal, or ground-source, heat pumps (GHPs). This technology for the past few decades has been quietly building its contribution to pollution reduction, job creation, and energy/cost savings for millions of people around the world.
Here in the United States, it’s a “50-state” technology that is not dependent on ideal natural conditions of heat source availability and permeable rock.
Around 700 MWt of capacity is installed every year in the United States alone, by far outpacing development of “hot rocks” on an equivalency basis with electrical production. Best of all, GHPs eliminate onsite use of fossil fuels like fuel oil, natural gas, and propane that are not only pollutants, but are hazardous as they are burned by conventional equipment.
The GHP industry is still nascent in the United States, primarily because of its higher upfront installation cost. This cost is due to the need for excavation or drilling to install ground-loop heat-exchange systems.
The industry is working to overcome that initial cost barrier through innovative financing that secures cost savings immediately for building owners. It is also seeking to apply government incentives resulting from amendments to energy-efficiency laws and renewable-energy portfolio standards.
The industry also advocates renewal of its tax credits for residential and commercial installations at the federal level, which are set to expire next year. Several business tax incentives are now under scrutiny by a cost-conscious Congress.
Most of all, the GHP industry must continue its efforts to inform the public about its economic and environmental advantages, especially carbon emission reduction, at a time when climate change is on everyone’s minds.
Geothermal technology offers renewable energy that comes from under the earth. The energy is baseload, dispatchable, and 100-percent renewable. The industry is making slow-but-steady progress in various regions of the world. As attendees head to the Geothermal Energy Expo and Geothermal Resources Council Annual Meeting in this week, we ask our readers this issue’s Big Question.
Director of Communications, Geothermal Resources Council
In organizing the biggest annual event in the industry (the GRC Annual Meeting & the GEA Geothermal Energy Expo), the Geothermal Resources Council (GRC) gets an insight into current trends. From these, we can see that the biggest opportunities remain in Indonesia and The Philippines in Asia and in Kenya and Ethiopia in Africa.
However, the recent news that the Japanese government will allow drilling for geothermal resources in parts of national parks bodes well for the industry there. Also, new legislation in Mexico will potentially be a boon for geothermal energy.
I hope legislation will be passed to restore the Salton Sea in Southern California. This would involve the development of more than a GW of geothermal energy, providing a much-needed push for the industry in the United States.
In addition, the research into Enhanced Geothermal Resources (EGS) here in the United States, in particular at the Frontier Observatory for Research in Geothermal Energy (FORGE) program, might provide the breakthrough for the industry that will make geothermal energy available anywhere in the world.
There are probably many untapped areas. But in Kenya, they have enough geothermal potential to possibly power a major part of East Africa. The added bonus is that the transmission lines that are being installed for the Lake Turkana Wind Project pass close by allowing connection points and substations to be built. External companies should be encouraged to invest and be a part of Kenya’s 5,000-MW vision for future energy provision.
The age-old issue for geothermal power generation is proving resources and developing risk with a utility rate of return on completing a successful project. This single issue has sidelined potential projects for decades. Sponsor Energy Capital is forming a fund to solve this issue for worthy projects.
Geothermal is abundant in many places around the globe. I see the real problem as that in most areas where geothermal is present, there is insufficient grid capacity to handle the load that can be generated.
If you closely examine the geothermal domes that exist throughout the southwestern United States, for example, you will find that the grid necessary to support larger amounts of energy is not present or is dedicated to the transfer of energy from areas supplied by larger fossil-fuel generation plants.
The costs to upgrade this power structure and to connect these plants to the grid end up being higher than the developers of the projects can bear.
Craig Immel
Founder, Steady State Asset Partners
There are two important trends in geothermal energy that have the opportunity to drive new growth in the ground-source heat pump industry. First, the development of innovative geothermal HVAC-financing models will enable many more buildings to keep their occupants comfortable while conserving energy and keeping operating costs low.
These new business models are allowing property owners to avoid large upfront cash outlays for upgrading to geothermal while still keeping monthly cash payments below their properties’ previous monthly heating and cooling bills.
The geothermal industry is following in the footsteps of successful solar PV financing models, which are growing rapidly by selling no-money-down solar installations.
Second, there is a growing recognition that geothermal heat pump systems can be used for thermal energy storage. While there is a lot excitement around solar PV and grid storage, much of that electricity is ultimately used to provide thermal comfort and water heating.
Storing BTUs underground and simply pumping them into or out of buildings as needed is a smart way to use electricity and heat energy. It is also a great opportunity for utilities to comply with the Clean Power Plan by reducing overall energy loads on the grid.
In California, we need the California Independent System Operator (CAISO) to recognize the importance of geothermal energy and eliminate barriers to its development.
There is something wrong when geothermal is only 4 percent of California’s renewable energy portfolio. The area around the southern end of the Salton Sea is the richest deposit of geothermal energy in North America and has resources to replace the shuttering of San Onofre.
Today there are almost 80 countries around the world at some stage of exploring or developing their geothermal resources, so there are opportunities on every continent. The best scenarios for success and growth are those where there is an understanding of the resource and geology, the governments support its development and the economies needs power. All three of these factors are found in East Africa, particularly in Kenya and Ethiopia, making this a leading region for geothermal opportunities.
Equally strong potential exists for new geothermal development in Mexico and Indonesia as these governments each move forward on geothermal initiatives and open doors for new investment. Opportunities also abound in the ripening geothermal markets of Central American countries, Caribbean Islands, and Pacific Islands.
But don’t write off the United States. As climate emissions become a market driver, the firm and flexible attributes of geothermal power make it an essential part of any greenhouse gas emissions reduction plan. Only a small fraction of geothermal resources are developed, so it’s still a pioneer industry with a lot of room for advancement.
To take advantage of the opportunities, first support GEA as it works to open and promote new markets and to keep companies informed of new opportunities. Second, develop the best technology and the best team. Then prepare your plans knowing the risks...and seeking to reap rewards.
Karl Gawell
Geothermal Energy Association
Geothermal opportunities are best capitalized upon in physical locations where the potential exists. Such opportunities are greatest on or near major volcanic activities or tectonic plate underlap areas. The entire tectono-magmatic activities around the Red Sea gave rise to several geothermal provinces over the continents surrounding the Red Sea, represented by thermal springs and fumaroles at several locations in the State of Eretria, Djibouti, Ethiopia, Yemen and Saudi Arabia.
Ideally, an offshore system in the Red Sea could provide a major source of steam energy for electrical production. A high-voltage DC undersea cable could carry this energy ashore for mass storage or immediate use.
The United States Navy Operates the COSO Geothermal Well in California. The energy produced from this facility powers an entire base plus overcapacity for adjoining communities.
Geothermal planning requires high-quality research on understanding location, technology, environmental impact, the cost of feeder transmission lines, mass storage, maintenance and operation.
Most geothermal systems require extensive maintenance and lifecycle support which must be factored into the business case for any such project.
The perspectives on what constitutes a great geothermal opportunity differ. For developers and investors, it is about accessibility and supporting schemes. For suppliers, it is about the market structure, openness and competitiveness.
Overall, the key markets for suppliers are Indonesia, Philippines, Kenya, Turkey, Mexico, and the several smaller nations with smaller projects. For investors supporting schemes such as the Geothermal Risk Mitigation Facility in Eastern Africa, a new insurance scheme in Mexico and Latin America, as well as good feed-in-tariffs, are helpful.
Germany, for that matter, still is likely one of the better return opportunities, despite its smaller project size and higher perceived risk.
There are some good geothermal resources in East Texas.
One of the things that concerns me the most about geothermal is the water withdrawal and consumption. I know that a lot of companies are looking for ways to reduce their water impact (in particular by using recycled water - much like in the natural gas industry), but the water component is still one I think needs to be part of any discussion.
If the geothermal potential is in areas that are predicted to see an increase in drought or heatwaves in the coming decades, I think that water availability should be part of the calculus of whether it is worth harvesting those resources. At the very least, developers should consider how to be smart about reducing their freshwater use.
When we talk about geothermal energy development, we should not forget geothermal, or ground-source, heat pumps (GHPs). This technology for the past few decades has been quietly building its contribution to pollution reduction, job creation, and energy/cost savings for millions of people around the world.
Here in the United States, it’s a “50-state” technology that is not dependent on ideal natural conditions of heat source availability and permeable rock.
Around 700 MWt of capacity is installed every year in the United States alone, by far outpacing development of “hot rocks” on an equivalency basis with electrical production. Best of all, GHPs eliminate onsite use of fossil fuels like fuel oil, natural gas, and propane that are not only pollutants, but are hazardous as they are burned by conventional equipment.
The GHP industry is still nascent in the United States, primarily because of its higher upfront installation cost. This cost is due to the need for excavation or drilling to install ground-loop heat-exchange systems.
The industry is working to overcome that initial cost barrier through innovative financing that secures cost savings immediately for building owners. It is also seeking to apply government incentives resulting from amendments to energy-efficiency laws and renewable-energy portfolio standards.
The industry also advocates renewal of its tax credits for residential and commercial installations at the federal level, which are set to expire next year. Several business tax incentives are now under scrutiny by a cost-conscious Congress.
Most of all, the GHP industry must continue its efforts to inform the public about its economic and environmental advantages, especially carbon emission reduction, at a time when climate change is on everyone’s minds.
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