R-Squared Energy Blog

Pure Energy

Overview of Electricity Storage Technology and India’s Renewable Energy Goals

There is a good overview in today’s Guardian regarding the status of affairs with respect to electricity storage technologies:

The challenge for green energy: how to store excess electricity

So with grid parity now looming, finding ways to store millions of watts of excess electricity for times when the wind doesn’t blow and the sun doesn’t shine is the new Holy Grail. And there are signs that this goal — the day when large-scale energy storage becomes practical and cost-effective — might be within reach, as well. Some technologies that can store sizeable amounts of intermittent power are already deployed. Others, including at least a few with great promise, lie somewhere over the technological horizon.

I have used the “Holy Grail” term several times to describe cost effective storage of electricity. I have also given “energy storage” as an answer when people ask what we should be focusing more attention on. While this article is perhaps overly optimistic, it provides a good overview of what people are working on.

I also read a good article last night on renewable energy in India:

A Growing India Sets Goal to Harness Renewable Energy

Despite the deepening energy crisis, renewable energy, predominantly wind and biomass, make up 3 percent of India’s total electricity production. Solar energy is not even a fraction of that, though India receives abundant sunshine throughout the year.

But India hopes to move from near-zero to 20,000 megawatts of solar electricity by 2020, as part of the National Action Plan on Climate Change. Announced in June 2008, the plan is a structured response to combat global warming and part of a proposal India intends to pitch at a climate change summit in Copenhagen this December.

If there is one thing the world desperately needs, it is for India and China to embrace renewable energy as their economies grow. If they do not, I think their growth is going to encounter fierce economic resistance as their growing energy needs start to put serious pressure on oil prices.

July 19, 2009 Posted by | China, energy storage, India, oil prices, The Guardian | 51 Comments

Investing in Energy Storage

I attended a presentation last year where a number of alternative energy technologies were discussed, and I was asked whether any major topic had been missed. I responded that I felt like the single most important topic had been missed: The enabling technology of energy storage. An efficient and cost effective energy storage solution is critical for smoothing out the intermittency of solar, wind, and tidal energy. This is the one advantage that biomass does have over these sources: Biomass may be inefficient at gathering solar energy, but it does store nicely.

How important is energy storage? I think it is absolutely crucial, but largely overlooked in alternative energy discussions. It simply isn’t as sexy as solar, but without a good storage solution, solar will never fulfill its potential. And it just hasn’t seemed to me that we are attacking the storage problem with a sense of urgency. So I was really glad to run across this story a couple of days ago:

Energy storage nears its day in the sun

MONACO (Reuters) – Energy storage is an unglamorous pillar of an expected revolution to clean up the world’s energy supply but will soon vie for investors attention with more alluring sources of energy like solar panels, manufacturers say.

The article sums up the problem:

While the supply of the wind and sun far exceeds humanity’s needs it doesn’t necessarily match the time when people need it: the sun may not be shining nor the wind blowing when we need to cook dinner or have a shower.

Soaring production of solar panel and wind turbines is now spurring a race to develop the winning energy storage technologies which will drive the electric cars and appliances of the future.

The race is heating up as manufacturers with entirely different solutions near the moment of commercial production.

Then it discusses a couple of storage solutions that are vying for supremacy, such as:

For example, UK-based ITM Power sees the future of energy storage in the explosive gas hydrogen. The company is developing a piece of kit called an electrolyzer which uses solar or wind power to split water into hydrogen and oxygen.

The hydrogen is then stored in a pressurized container until it is needed, whether to drive a car, produce electricity or for cooking.

“With batteries you’re taking enormous quantities of basic raw materials,” said Chief Executive Jim Heathcote, referring to cadmium in nickel cadmium varieties. His company won an award for research at the Monaco conference, organized by corporate finance advisers Innovator Capital.

“Two things we’re confident of is the supply of renewable energy and water,” he said.

ITM Power aims to start production later this year of electrolyzers and next year of hydrogen fuel cells which generate electricity.

“The one problem everyone’s had is how to store. The ability to take (surplus) renewable energy and make useful fuel out of it is almost priceless,” Heathcote said.

Investment Opportunities

The remainder of the article describes the investment opportunities in energy storage companies, which look attractive. I think in this next phase of my life, I will be more active at seeking out and acting on opportunities such as this. I have not done this in the past, even when I felt strongly about the direction of commodities or stock sectors. For instance, I just saw this comment from yesterday at The Oil Drum:

About four months ago Robert Rapier suggested that investors looking at energy commodities consider gasoline futures as a likly profit maker. That day I checked the price on http://www.bloomberg.com at $1.92 per gallon. I suggested to a relative that is heavy in the market to get into gasoline futures then as that commodity looked under priced. The person said it looked riskey and required too much diligents to handle.

Today gasoline closed at $2.55, up 33%. A $5000 investment in futures would have netted over $100,000 in following RR’s advice.

Did I act on my own advice? No. (I can already hear my wife asking “Why didn’t you act?”)

Did I act last spring when I was convinced gasoline prices were headed higher? No.

Did I invest in corn futures when I was predicting that because of the ethanol mandates they were headed much higher from their (then) $2/bu price? No. (Corn futures have more than doubled since then).

Did I short ethanol stocks when I wrote that they were overvalued? No. (I do know some who did just that based upon what I had written, and they made out quite well.)

And probably the best (worst?) example of all, did I short Xethanol when it was at $12 and I knew that a devastating exposé was about to be released by Sharesleuth? No. (XNL is now worth less than $0.50 a share).

I always advise people to invest in what they know. I got burned in 2000 investing in technology stocks that I didn’t properly understand. It is hard to do the proper due diligence if you really don’t grasp the important issues in the sector. In technology, it was hard for me to say which companies were poised, and which ones just thought they were poised (and fooled the analysts). But I do understand the energy sphere. I just have to start acting on my convictions. (I haven’t totally twiddled my thumbs on this issue. I have invested my 401K shares per my conviction on higher oil prices, and that has paid out quite well.)

Disclaimer: If you do act on anything you read here, you are on your own. I may change my mind tomorrow about whether something is still a good investment (with gasoline inventories where they are, gasoline futures are starting to look a lot riskier), and I don’t send out warnings to take profits and run. I am obviously not writing an investment blog, although clearly there are numerous financial implications based on developments in the energy markets.

February 25, 2008 Posted by | energy storage, investing, Xethanol, XNL | 570 Comments

Storing Renewable Energy

First, thanks to all who provided input for the renewable diesel essay. The comments were useful, and will help me to strengthen the chapter. Second, I had said that today I would comment on Benjamin Cole’s Seamless Transition to a Post-Fossil Economy. Frankly, I think other readers adequately addressed this, and even Benjamin realizes that a seamless transition is unlikely. So I will leave that one as is.

One of my major interests is storage systems for renewable energy options that would be characterized as intermittent. Solar and wind would fall into this category, and their intermittency really limits their ultimate potential. If wind turbines must be backed up by coal-fired power plants, it lessens the benefit. Therefore, the development of storage systems for intermittent sources of renewable energy is critical.

Previously, I wrote about Compressed Air Energy Storage (CAES). This is a system in which excess energy is used to pump compressed air into a storage cavern, which can then be bled off through a turbine when the wind is not blowing. There are clearly limitations to such a system. One must have access to both a good source of wind power, and a large, airtight cavern. This will limit CAES to specific niches.

However, this weekend I read about a system which, if successfully commercialize, would be more universally applicable. These ideas are to solar what CAES is to wind:

Groups Store Renewable Energy to Use on Rainy Days

First they frame the problem:

Scientists and engineers are struggling to find ways around a major obstacle to the growth of renewable energy: the fact that inexhaustible sources of energy, such as the sun and the wind, are undependable.

Solar power doesn’t work at night or on cloudy days. Wind is notoriously fickle, often dying down in the late afternoon just as electricity demand is peaking.

Then they cover the research under way:

The Department of Energy is researching ways to store energy at solar power plants that use thousands of mirrors to concentrate the sun’s rays on pipes filled with oil. The oil, heated to 750 degrees Fahrenheit, turns water into steam, which drives an electric power generator.

In one design from the Sandia National Laboratory in Albuquerque, N.M., excess heat is channeled into tanks of molten salt – a mixture of sodium, potassium and nitrogen that melts at 430 degrees Fahrenheit – where it can be stored for up to a week. The stored heat then can be transferred to a “heat exchanger” to boil water to make steam to run a generator at night or whenever necessary. Several power plants under construction in Spain plan to use this concept.

Another approach being tested at the University of Stuttgart in Germany would run pipes of fluid heated by the sun through a solid block of concrete. The concrete holds the heat for later use. To recover it, cold fluid is passed through the pipes, picking up heat on the way.

Molten salt is already used in some applications in the chemical industry to dampen temperature fluctuations in reactors. Even loss of power to a chemical plant would result in the reactor maintaining something close to reaction temperature, allowing a much quicker restart when power is restored. So, this is not pie-in-the-sky. These technologies are in use. I am glad to see that someone is attempting to use them to store solar energy, because I firmly believe it is the future.

In fact, I did a calculation this weekend for the book chapter I am writing that I believe demonstrates that there is no way we will be able to grow our way out of our petroleum dependence. The efficiency of photosynthesis is just too low to make that possible on the land we have available. So, in the long run it has to be solar, wind, and probably nuclear power.

July 16, 2007 Posted by | CAES, energy storage, solar power, wind power | 52 Comments

Storing Renewable Energy

First, thanks to all who provided input for the renewable diesel essay. The comments were useful, and will help me to strengthen the chapter. Second, I had said that today I would comment on Benjamin Cole’s Seamless Transition to a Post-Fossil Economy. Frankly, I think other readers adequately addressed this, and even Benjamin realizes that a seamless transition is unlikely. So I will leave that one as is.

One of my major interests is storage systems for renewable energy options that would be characterized as intermittent. Solar and wind would fall into this category, and their intermittency really limits their ultimate potential. If wind turbines must be backed up by coal-fired power plants, it lessens the benefit. Therefore, the development of storage systems for intermittent sources of renewable energy is critical.

Previously, I wrote about Compressed Air Energy Storage (CAES). This is a system in which excess energy is used to pump compressed air into a storage cavern, which can then be bled off through a turbine when the wind is not blowing. There are clearly limitations to such a system. One must have access to both a good source of wind power, and a large, airtight cavern. This will limit CAES to specific niches.

However, this weekend I read about a system which, if successfully commercialize, would be more universally applicable. These ideas are to solar what CAES is to wind:

Groups Store Renewable Energy to Use on Rainy Days

First they frame the problem:

Scientists and engineers are struggling to find ways around a major obstacle to the growth of renewable energy: the fact that inexhaustible sources of energy, such as the sun and the wind, are undependable.

Solar power doesn’t work at night or on cloudy days. Wind is notoriously fickle, often dying down in the late afternoon just as electricity demand is peaking.

Then they cover the research under way:

The Department of Energy is researching ways to store energy at solar power plants that use thousands of mirrors to concentrate the sun’s rays on pipes filled with oil. The oil, heated to 750 degrees Fahrenheit, turns water into steam, which drives an electric power generator.

In one design from the Sandia National Laboratory in Albuquerque, N.M., excess heat is channeled into tanks of molten salt – a mixture of sodium, potassium and nitrogen that melts at 430 degrees Fahrenheit – where it can be stored for up to a week. The stored heat then can be transferred to a “heat exchanger” to boil water to make steam to run a generator at night or whenever necessary. Several power plants under construction in Spain plan to use this concept.

Another approach being tested at the University of Stuttgart in Germany would run pipes of fluid heated by the sun through a solid block of concrete. The concrete holds the heat for later use. To recover it, cold fluid is passed through the pipes, picking up heat on the way.

Molten salt is already used in some applications in the chemical industry to dampen temperature fluctuations in reactors. Even loss of power to a chemical plant would result in the reactor maintaining something close to reaction temperature, allowing a much quicker restart when power is restored. So, this is not pie-in-the-sky. These technologies are in use. I am glad to see that someone is attempting to use them to store solar energy, because I firmly believe it is the future.

In fact, I did a calculation this weekend for the book chapter I am writing that I believe demonstrates that there is no way we will be able to grow our way out of our petroleum dependence. The efficiency of photosynthesis is just too low to make that possible on the land we have available. So, in the long run it has to be solar, wind, and probably nuclear power.

July 16, 2007 Posted by | CAES, energy storage, solar power, wind power | 52 Comments

Compressed Air Energy Storage

I have always been a big fan of wind power. But one of the knocks on wind is that it is intermittent. Since electrical demand probably won’t match up very well with wind fluctuations, installed wind capacity does not displace conventional power generation in a 1 to 1 ratio. For example, I have seen it claimed that 2,000 megawatts of installed wind energy still requires 1,800 megawatts of standby power for when the wind isn’t blowing. (1)

Clearly a storage system is needed. During times of high wind flow and low demand, the excess energy could be stored in something akin to a giant battery. When the wind isn’t blowing, users would pull from the “battery”. I have given a lot of thought over the past couple of years as to just what form such a storage system would take. I could envision several different options. One, air could be compressed into a storage system and then discharged through a turbine as needed. Two, water could be pumped uphill, and then be allowed to flow back through a turbine as needed. Three, water could be split to hydrogen and oxygen. I don’t like this option as much, because most electrolysis is inefficient and hydrogen storage is problematic.

(Incidentally, a variation of this third option was recently brought to my attention, in which excess wind power is used to make methanol, ethanol, or even ammonium nitrate fertilizer. For an excellent comprehensive overview of this option, combined with an impressive overview of wind energy potential in the Great Lakes area, see David Bradley’s report A Great Potential: The Great Lakes as a Regional Renewable Energy Source.)

Imagine my surprise this weekend to learn that while I have been daydreaming about a wind energy storage system, someone is in the process of doing it. Furthermore, others have previously blogged on it. I felt a bit like Rip van Winkle after waking up from his long nap. How could I have missed such an important development? The storage system is called compressed air energy storage (CAES). A January article from MSNBC explains the concept in Store wind power for later use? Cities bet on it:

A group of Iowa cities intends to not only harness the wind, but also capture it, store it underground and use it to help make electricity when demand peaks.

Members of the Iowa Association of Municipal Utilities have invested in a proposed power plant that would use wind turbines to drive compressed air into underground aquifers. The air would be released to generate electricity when needed.

The plant will use power from its own wind turbines, supplemented by cheaper electricity bought at off-peak times, to force air into rock formations at least 2,000 feet underground.

Current plans call for pressurized storage of tens of billions of cubic feet of air in rock formations deep underground. (2)

If you think I was surprised by that, imagine my surprise upon reading this from the same article:

Only two other underground compressed air plants are in operation. A plant in Huntorf, Germany, was built more than 23 years ago and a plant in McIntosh, Ala., is 11 years old. Both store compressed air in underground salt caverns.

Iowa’s project is unique in that it would use wind power to store the air and combine it with massive underground storage capacity.

The Germany and Alabama plants store hundreds of thousands of cubic feet of air in a thermos-bottle shaped container installed in the salt mines. The Iowa project would use naturally occurring pockets embedded in sand or sandstone formations sealed by shale or other rock.

So, a plant in Alabama has been using compressed air storage successfully for 11 years, and I didn’t know about it until this weekend. The only difference is that they aren’t using wind to do it. The Iowa plant will be the first to do that, but others will probably follow.

To be sure, such a storage system is not universally applicable. You need some kind of large, airtight, underground cavern. There are a lot of these in the United States, but they need to be located near a source of wind. Although, now that I think about it, I see no reason such a system couldn’t also be paired with solar or tidal generation systems, storing their excess energy using the same concept.

The plant is scheduled to come online in 2010. I wish them great success, and look forward to hearing reports after they start up.

References

1. “Airtricity’s rise and rise leaves criticism blowing in the wind”, Irish Examiner, April 30, 2005.

2. “Store wind power for later use? Cities bet on it”, MSNBC.com, January 4, 2006.

May 15, 2006 Posted by | CAES, energy storage, wind power | 41 Comments

Compressed Air Energy Storage

I have always been a big fan of wind power. But one of the knocks on wind is that it is intermittent. Since electrical demand probably won’t match up very well with wind fluctuations, installed wind capacity does not displace conventional power generation in a 1 to 1 ratio. For example, I have seen it claimed that 2,000 megawatts of installed wind energy still requires 1,800 megawatts of standby power for when the wind isn’t blowing. (1)

Clearly a storage system is needed. During times of high wind flow and low demand, the excess energy could be stored in something akin to a giant battery. When the wind isn’t blowing, users would pull from the “battery”. I have given a lot of thought over the past couple of years as to just what form such a storage system would take. I could envision several different options. One, air could be compressed into a storage system and then discharged through a turbine as needed. Two, water could be pumped uphill, and then be allowed to flow back through a turbine as needed. Three, water could be split to hydrogen and oxygen. I don’t like this option as much, because most electrolysis is inefficient and hydrogen storage is problematic.

(Incidentally, a variation of this third option was recently brought to my attention, in which excess wind power is used to make methanol, ethanol, or even ammonium nitrate fertilizer. For an excellent comprehensive overview of this option, combined with an impressive overview of wind energy potential in the Great Lakes area, see David Bradley’s report A Great Potential: The Great Lakes as a Regional Renewable Energy Source.)

Imagine my surprise this weekend to learn that while I have been daydreaming about a wind energy storage system, someone is in the process of doing it. Furthermore, others have previously blogged on it. I felt a bit like Rip van Winkle after waking up from his long nap. How could I have missed such an important development? The storage system is called compressed air energy storage (CAES). A January article from MSNBC explains the concept in Store wind power for later use? Cities bet on it:

A group of Iowa cities intends to not only harness the wind, but also capture it, store it underground and use it to help make electricity when demand peaks.

Members of the Iowa Association of Municipal Utilities have invested in a proposed power plant that would use wind turbines to drive compressed air into underground aquifers. The air would be released to generate electricity when needed.

The plant will use power from its own wind turbines, supplemented by cheaper electricity bought at off-peak times, to force air into rock formations at least 2,000 feet underground.

Current plans call for pressurized storage of tens of billions of cubic feet of air in rock formations deep underground. (2)

If you think I was surprised by that, imagine my surprise upon reading this from the same article:

Only two other underground compressed air plants are in operation. A plant in Huntorf, Germany, was built more than 23 years ago and a plant in McIntosh, Ala., is 11 years old. Both store compressed air in underground salt caverns.

Iowa’s project is unique in that it would use wind power to store the air and combine it with massive underground storage capacity.

The Germany and Alabama plants store hundreds of thousands of cubic feet of air in a thermos-bottle shaped container installed in the salt mines. The Iowa project would use naturally occurring pockets embedded in sand or sandstone formations sealed by shale or other rock.

So, a plant in Alabama has been using compressed air storage successfully for 11 years, and I didn’t know about it until this weekend. The only difference is that they aren’t using wind to do it. The Iowa plant will be the first to do that, but others will probably follow.

To be sure, such a storage system is not universally applicable. You need some kind of large, airtight, underground cavern. There are a lot of these in the United States, but they need to be located near a source of wind. Although, now that I think about it, I see no reason such a system couldn’t also be paired with solar or tidal generation systems, storing their excess energy using the same concept.

The plant is scheduled to come online in 2010. I wish them great success, and look forward to hearing reports after they start up.

References

1. “Airtricity’s rise and rise leaves criticism blowing in the wind”, Irish Examiner, April 30, 2005.

2. “Store wind power for later use? Cities bet on it”, MSNBC.com, January 4, 2006.

May 15, 2006 Posted by | CAES, energy storage, wind power | 20 Comments