Thursday, December 31, 2009

I know this blog is about the VRB Energy Storage System, but...

I guess I'm one of those people who will step aside when the herd is all heading one way to look and make sure we're going the right way, and not off the cliff. Never been a lemming. I don't readily accept the "conventional wisdom". I've found out that usually, when some concept attains universal acceptance, it is probably due to some other reason than good logic, facts or common sense. So, I like to find the "other side of the story" - there is always one.

The VRB ESS fits in this concept. Popular sentiment is rushing toward renewable energy, like wind and solar, without truly considering the consequences. I believe we should develop distributed energy resources for many good reasons, including homeland security, energy independence, and local control v. centralized control. The VRB-ESS connected to solar PV or a wind turbine will provide all of that. And we'll need large energy storage facilities like the VRB to make large wind and solar PV installations useful and to prevent them from crashing the grid due to thier intermittant power output.

But I'm far from convinced that we need renewables to save our planet from global warming (opps! I mean climate change...) There, I've said it. But, even though I don't follow the climate change faith, I still have common ground for the reasons stated above.

All this so I could share these interesting bits:

ScienceDaily (2009-12-31) -- Most of the carbon dioxide emitted by human activity does not remain in the atmosphere, but is instead absorbed by the oceans and terrestrial ecosystems. However, some studies have suggested that the ability of oceans and plants to absorb carbon dioxide recently may have begun to decline and that the airborne fraction of anthropogenic carbon dioxide emissions is therefore beginning to increase. In contradiction to those studies, new research finds that the airborne fraction of carbon dioxide has not increased either during the past 150 years or during the most recent five decades.

And also:

ScienceDaily () -- A physicist from Colorado State University and his colleagues from the North American Carbon Program (NACP) have discerned and confirmed the unforeseen advantages of rising carbon dioxide levels. Through the processes of photosynthesis and respiration, scientists have been able to elucidate why plants are growing more rapidly than they are dying. The NACP is employing methods, such as the use of cell phone and aircraft towers to monitor and retrieve carbon data for their continuing study.

Tuesday, October 27, 2009

CAES - Lies and Damned Lies

With apologies to Mark Twain, I keep thinking of his categorization of whoppers when I hear the misleading, if not willfully false, claims made for Compressed Air Energy Storage - CAES.

The Wall Street Journal has a story on the DOE grants for CAES, due to be announced soon. $60 million is planned to "promote a patented technology that stores energy until it is needed".

First, referring to CAES as "energy storage", is a stretch, if not downright misleading. The WSJ doesn't mention that the compressed air is "stored" for the purpose of firing a natural gas generator! Yes, that's true - a natural gas, greenhouse gas emitting, fossil fueled generator.

Advocates of CAES are quick to point out that using compressed air increases the efficiency of natural gas generators, from about 33% to as much as 88%, so less GHG is emitted. That's great for fossil fueled generation, but don't call it energy storage. However, as discussed in an earlier blog, on an energy in - energy out basis, counting the energy used to compress the air, actual energy efficiency is about 54% or less. But I digress...

Second, how can anyone compare CAES to advanced batteries - like the VRB-ESS - and conclude that it's, "much cheaper than battery storage and far more durable"? The article quotes Robert Schainker of EPRI advising that batteries are too expensive. Elsewhere he is quoted as saying CAES costs about $700 per kWhr. If the PG&E project stays on budget - how likely is that? - then PG&E will get 10 hours at 300 MW, or 3,000 MWHrs for under $400 million, about $133 per kWhr? Wow, what a deal - if it happens. However, what about the cost of the natural gas? No information has been provided yet, but 8 million MMBtu per year seems in the ballpark. At $7 MMbtu, that's at least $560 million over 10 years. Twice that over 20 years. And what are the O&M costs? The generators are typically completely overhauled every 10,000 hours. We need more information...

By contrast, Prudent Energy is expecting the VRB-ESS to run about $500 per kWhr for 6 hours of storage within 2 years, and much cheaper for a 10 hour system. Refurbishment at 10 years, for about $60 kWhr for a 10 hour system, will allow the ESS to run another 10 years. And, wind power can be stored and delivered as needed, without emissions, with about 75% efficiency.

One final digression - if renewable energy, subsidized by taxpayers, is used to enhance a natural gas generator, is it still "renewable". Renewable wind power is consumed to run the air compressors. The compressed air is then released to enhance natural gas generation, turning "clean" energy into "dirty" energy. What does this do to the Renewable Portfolio Standards? Does wind energy, that is not delivered to consumers, but instead is consumed to produce natural gas fired electricity, count toward the 20% - 33% RPS?

There's no guarantee a 300 MW CAES will or can get built as expected, or that it will ultimately cost under $400 million. However, VRB systems can begin to be installed at wind farms and end-users now. It's more likely that 300 MW of VRB batteries can get installed in 5 years than CAES, and we won't have to substitute wind power for natural gas.

Tuesday, September 29, 2009

How Do You Value Grid Connected Energy Storage?

This is almost a part II to my earlier post, but I was reminded again of the problems we face when it comes to defining, and then valuing, Grid Connected Energy Storage (GCES).

The recent New York Times article, "Companies Race to Develop Utility-Scale Power Storage" pointed up the problems and potential for confusion. "Power storage" technologies listed included the Beacon flywheel, the NGK molton sodium-sulfur battery, the A123 lithim ion battery, and compressed air (again!). Quoting a report by GTM Research, this article made a very insightful distinction between "power oriented" technologies, used mainly to regulate short-term changes to grid frequency, and "energy oriented" storage -- in which energy use is shifted to other times of the day. However, the author could have done a better job applying this distinction and pointing out the difference in cost.

For example, the article discussed the $69 million Beacon project in New York, where they will install, "...hundreds of "flywheels" to store 20 megawatts of electricity, enough to power 200 homes for a day." In reality, the flywheel is designed to store only 15 minutes of power and falls into the "power oriented" category above. Its total energy storage will only be 5 MW hrs, about enough to power 40 homes for a day, although it will never be used for that purpose.

Also, the article reported on the $25 million requested by Southern California Edison for an A123 "32-megawatt-hour battery" - but is it really 32 MW hrs? I pose the question because the system will be designed as an 8 MW battery with 4 hours of storage (32 MW hr), but the application is at a wind farm, where multiple cycling is needed to firm wind - a "power oriented" application. Lithium ion batteries are good for about 500 - 600 complete charge and discharge cycles. If it is used in an "energy oriented" application, shifting wind power at night to the day, then it will only last about 2 years. However, in a "power" application, where the battery is barely discharged, it will last for many thousands of cycles. In fact, this is how it is currently applied. In this case it would be operated like an 8 MW flywheel, with usable energy storage of only about 2 MW hrs.

So how do you value these installations? If we value the flywheel and the li-ion systems by the MW hr, then their cost is $13.8 million and $12.5 million respectively. However, if all we care about is their power capacity, then the cost is $3.45 million and $3.125 per MW. (The NGK battery is the only energy oriented technology mentioned in the article, but no cost information was provided.)

By contrast, a VRB-ESS (vanadium redox flow battery - energy storage system) will provide both energy and power, with nearly unlimited cycles, full or partial, for about the same cost per MW of the flywheel or li-ion battery. However, the VRB-ESS will also include 4 - 8 hours of storage, dropping the cost per MW hr to a fraction of the cost for a "power oriented" system.

For example, a 5 MW system with 6 hours of storage would cost about $18 million, with all costs included - a complete turn-key system. That would provide 30 MW hrs of energy at a cost of about $600 thousand per MW hr. The cost of power is only $3.6 million per MW.

Although not directly relevant to the discussion, it's good to know that the VRB-ESS will last 10 years before needing refurbishment. This consists of replacing the PEM (proton exchange membrane) at a cost of about $3 million. The system is then good for another 10 years!

Bottom-line? - It's important to understand the application, whether energy, power or both, and then determine the cost per energy (MW) and/or the cost for power (MW hr), when evaluating the technology.

Friday, September 18, 2009

What is Grid Connected Energy Storage?

The California Energy Commission recently requested input on what the definition should be for "utility connected energy storage". Here are some of my thoughts:


1. How do you define utility scale energy storage?

I would suggest looking at several common sense issues to get a handle on what is utility scale or grid connected energy storage (GCES).

First, we should define energy storage as "electrical" energy storage. That means electrical energy storage in and electrical storage out. For utility or grid applications, we need to store electrical energy for use when needed; meaning excess electrical energy is shifted to a time when electric energy is scarce. This excludes some types of valuable energy storage, like thermal energy storage, but it clarifies what we are doing.

Thermal storage is a good thing and useful, but it cannot be used to produce electrical power for the grid, so it should be excluded from our consideration. This is not to single out thermal energy, but to illustrate the need to focus on electric energy storage. The distinctive of utility or grid energy storage should be the storage of electricity. Storing electricity energy for use as some other type of useful energy does not provide the grid with the electric energy when needed. It is load only. Electric energy storage should be a two way street, not a one way street.

Logically, this also excludes electric energy generators. Again, this is an example of taking a different type of energy and converting it to electricity. Unless we define GCES as electricity in and electricity out, then a coal plant could be considered as GCES since it stores energy in the form of coal and provides energy as needed. If we do not specify electric in - electric out, then our discussion will be so broad as to be meaningless.

And, if we are careful to define GCES as electric in - electric out, then this will also exclude fuel driven compressed air energy storage systems. Such CAES systems are more clearly understood as highly efficient natural gas generators. Electric energy is used to run compressors. The compressed air is used to run natural gas generators more efficiently. Burning natural gas to produce electricity is not electric energy storage. It may be very desirable in some ways, but it should not be in the same box as other technologies that store electricity. If we include fuel driven technologies, then, again, our discussion becomes meaningless.

The second concept to address is the "storage" issue. The common sense expectation is that we are focused on storing and delivering useful amounts of electrical energy.

For example, there is a difference between delivering energy and providing power quality services. Various devices and technologies can store and deliver short bursts or pulses of power to balance short term variations in power quality. Utilities and energy users install various devices for this purpose. But their use is for power quality, not energy.

Similarly, the CAISO operates a market for frequency regulation that is considered a "capacity" market, as distinguished from their "energy" markets. Some ISO's are developing opportunities for Limited Energy Storage Resources (LESRs) to provide capacity - not energy - services, because they recognize the benefit from the quick response of such technologies. However, these systems are, by definition, limited in their energy and are not valued for their volume but for their capacity. Although valuable, they are not useful for energy delivery. At a minimum, a GCES facility should be able to store and deliver electric energy in hours, not minutes. We refer to the technical parameters used by the California Public Utilities Commission in their definition of advanced energy storage for the Self Generation Incentive Program. (Decision 08-11-044 November 21, 2008, page 12, “Ability to be discharged for at least four hours of its rated capacity to fully capture peak load reductions in most utility service territories (required AES duration of discharge will depend on each customer’s specific load shape, and the duration of its peak demand during peak utility periods).”)

LESRs should be in their own separate category for the valuable power quality benefits they provide to the grid, but they should be excluded from the GCES discussion because they cannot deliver energy in useful quantity.


Any comments?

Friday, August 28, 2009

PG&E Compressed Air Project - Quick Thoughts

Now that the deadline has passed to file for grid storage projects under the ARRA , we're beginning to see some of the concepts and projects that have applied for funds - see post below - including the 300 MW compressed air project by PG&E I believe PG&E will have to deal with some of the following issues on this project.
  • First, the $25 million requested is only for "initial analysis and design". The anticipated cost for the project will be $368 million. And that's before we see the cost over runs, delays and unexpected problems a huge project like this will invariably incur.
  • Then the utility will have to explain why they want to take "clean" wind energy and make it "dirty". Because, you see, the compressed air will be used for natural gas turbines! The argument is that the compressed air will make the natural gas turbines run more efficiently, requiring less natural gas - which is great if you're trying to make your natural gas turbines more efficient. But we thought the point of wind energy was to produce clean and renewable power - not more fossil fueled power.
  • And how much energy will we lose in this process? We create a certain amount of energy with wind and then burn it away by compressing it and burning natural gas. What is the net delivered energy when all of this is finished? I've seen reports of as little as 54%. So we take wind energy, throw away 40% or more, increase the price volatility through the natural gas market, and add emissions and GHGs. Why is this a good idea?
Utilities like CAES because it increases their power as a utility. They get to spend a bunch of ratepayer money on a huge central power plant which they control. This is why they have problems with distributed advanced batteries like the VRB-ESS. We could install 300 MW of the VRB-ESS in less time then they can get a CAES plant - if they ever get it built at all. And, the batteries would be built where it's needed, close to the load, reducing the need for more transmission wires, reducing the cost of distribution, improving energy security and power quality, and with greater efficiencies - less loss of wind energy - no emissions and no volatility on the cost of power.

Thursday, August 27, 2009

Largest Grid Battery Ever? What's the Real Story?

Southern California Edison has announced, apparently, that they have applied to the DOE, under the smart grid stimulus program, for $25 million to build the largest grid battery ever. I have many questions about this story and I'm hoping we'll get more clarification in the near future.

We are well aware of the DOE grant program because we are involved in several applications for the VRB-ESS. We'll provide more information as we have developments we can share.

Here are the issues and questions I have with the story:
  • First, I cannot find a press release from SCE. The story appears to based on an interview with Paul De Martini, Southern California Edison's vice president of advanced technologies. This makes it a bit difficult to get more detail or clarification. We'll ask Mr. De Martini for clarification.
  • Next, the story says the grant is for 32 megawatt hours of storage. Since the current A123 grid systems in place are for grid stabilization, with only about 15 minutes of storage, Edison would need to install 128 MW of capacity to get 32 hours of energy. That would make it a huge, unheard of capacity battery, but with very short term storage. So, I'm not sure what the application would be for wind energy. 4:1 capacity to energy storage is normally conceived for frequency regulation, which is the current application for A123. That type of application can be anywhere on the grid - there is no need to place it at a wind farm. We normally think of storage for wind for the purpose of shifting generation from night time production to the day - something you can't do with 15 min. of storage.
  • If the project is 32 MWHrs of storage, then it isn't the biggest project by a long shot. The 238 MWHr system by NGK in Japan wins that contest with their 34 MW by 7 hours of storage system. Sure, they can only use half the capacity at a time to avoid overcharging, but the total is still greater than the Edison project - if the story is correct.
  • The ARRA grant is a matching grant, so we assume Edison will need to seek approval from the California Public Utilities Commission for an additional $25 million, or more, for a total cost of $50 million. That's $1,500 per kilowatt hour! - pretty darn expensive. For comparison, the flow batteries and NGK are between $500 and $700. However, on a capacity basis, at 128 MW, it's only $390 per kW.
  • If the story meant to state a 32 MW capacity, then the economics make no sense.
I think the actual story is that Edison wants to install a large capacity system for grid stabilization, not an energy storage system to shift wind generation. Does it make sense? A 120 MW VRB-ESS with 6 hours of storage would cost around $300 million - 6X more expensive. However, along with fast response like the A123, you would also have 720 hours of energy storage! Is a 15 minute, fast response battery going to do the job, even if it is cheaper? This will be interesting to get the rest of the story and see how Edison presents the project to the CPUC.

Wednesday, August 5, 2009

VRB-ESS Government Incentives

This is a big month for us and many other energy storage companies. The American Recovery and Reinvestment Act - ARRA - a.k.a the Obama Stimulus Legislation - contains many incentives for energy storage and the smart grid. We're currently submitting several projects under the Smart Grid Demonstration Grant, which targets energy storage demonstrations. The deadline for submission is August 26th, and the total package will probably run to over 100 pages. We don't know how many projects will be submitted for the VRB-ESS - several sites are under evaluation - but, due to the complexity of the grant application process, we'll probably have to shut the door to additional projects around the 15th.

The Smart Grid Demonstration Grant is looking for several different types of demonstrations. The VRB-ESS is a good candidate for each category except one that is specifically set aside for compressed air energy storage. Grants are running from a couple million dollars for 1-3 MW installations to $25 million for 8-15 MW.

Here is the current breakdown of incentives for the VRB-ESS. We believe that the VRB-ESS specifically qualifies for these incentives in California - other energy storage technologies may not qualify.
  • ARRA - Under the current grant opportunity, the Department of Energy will fund 50% of an eligible project.
  • SGIP - the California Self Generation Incentive Program will provide a rebate of $2 Watt ($2 million per MW) for the VRB-ESS in association with on-site fuel cells or wind turbines. We believe the VRB-ESS will also qualify for an additional 20% ($2.40 per Watt) under a specific provision for California suppliers.
  • ITC - The Investment Tax Credit cash grant is equal to 30% of a project cost when integrated with other renewable energy projects. There are many conditions to this grant, but it's actually very liberal for the VRB-ESS. It will apply to VRB-ESS retrofits to existing cogeneration, fuel cells, biomass, hydro, wind, solar, etc. installations.
Bottom-line - a short term opportunity exists to fund up to 90% of the installation cost for a VRB-ESS system. Such a system would provide a generator or industrial site with many economic benefits, including load / generation shifting, power quality, energy security - and provide the potential to earn revenue from CAISO ancillary services or demand response programs. Most evaluations we've done show a payback in months. If you think your site could qualify, contact us at ctoca @ for an evaluation.

Friday, July 17, 2009

ITC Cash Grant for Storage

While the new guidelines from Treasury for the ITC grant are garnering headlines, a slightly overlooked item is the extension of the grant to energy storage!

Developers and vendors have had mixed views over the potential application of the Investment Tax Credit to energy storage equipment at renewable energy facilities. Guidance was lacking and opinions were mixed, including those of government agencies. Storage would allow PV and other intermittent renewables to increase their revenue per kW by providing firm and dispatchable power, increased sales of energy during the highest paid peak period, and the ability to offer additional ancillary services of great value to the grid operator. But, without the assurance of a tax credit, developers were cautious about figuring storage into their calculations.

However, the Treasury has now issued guidance on the ITC cash grant in lieu of a credit, and storage facilities are included. (see page 11) Storage must be "integrated" into the project, but the guidance on that is not restrictive. Now, the additional revenue from using storage can be factored into a project, and the investors can benefit from the tax credit/grant.

Sunday, July 12, 2009

The Energy Storage Market is Like an Elephant

In my presentations to various government agencies, I often reference the story of the blind men and the elephant. This is a story with variations in many cultures, but it essentially involves several wise blind men coming upon an elephant for the first time. One grabs the trunk and exclaims that an elephant is like a snake! Another grabs the tusk and believes an elephant is like a spear, another the tail and believes the elephant is like a rope, another the side of the elephant and believes the elephant to be a wall, and so on. The blind men are accurate in their limited grasp of what an elephant "is", but they don't see the larger picture.

I use the analogy with energy storage and the VRB-ESS. Different players see the VRB energy storage system from their limited perspectives and they tend to have limited applications. Is the VRB-ESS a peak shifting resource, distributed energy resource, demand response, intermittent renewable energy integration, capital deferral of distribution / transmission assets, power quality, emergency power, on-site power, capacity, ancillary services - frequency regulation, and so on? The answer is yes, all of these, and we should "grasp" the greater value of multiple benefits.

Now Pike Research has a slightly different analogy regarding the market for energy storage, "The energy storage market is like a charging elephant: even if you can’t see what it looks like, you know it’s going to be big." They have a report out that projects a 10 fold increase in the "stationary utility" market from 2008 to 2018 to $4.1 billion. Most market projections for energy storage include vehicles and small applications - like laptop computers - so this is unique and interesting. Energy storage in general, and the flexible and powerful VRB-ESS in particular, have an important and profitable future. More information can be found at their website:

Thursday, July 9, 2009

Solar battery project unveiled in St. Petersburg

I thought this project was announced last year. See the video news report on our website at

"An example of Florida's expertise in energy storage is a demonstration project conducted by University of South Florida and partner Progress Energy Florida which combines renewable distributed energy generation and an advanced battery system to supply renewable energy generated in off-peak hours during peak power demand hours. One of the prototypes of the Sustainable Electric Energy Delivery System (SEEDS) is used on campus, the other at a nearby park to power lights at night."

However, this announcement was posted today, including this audio. Although the VRB-ESS wasn't mentioned by name, they discussed the battery system and the vanadium technology.

Wednesday, July 1, 2009

First Wind Energy Storage for Ireland

ZBB Energy has a press release out for their flow battery system at a wind farm in Ireland. Flow batteries are a great application at wind farms. The VRB-ESS has been used at wind farms for several years in Japan and Australia, and the Irish government published a report in 2007 about integrating a VRB-ESS into a wind farm, finding that the optimum size for that installation was a 2 MW system with 6 hours of storage (12 MWHrs).

Although the ZBB is a flow battery, there are significant differences between the ZBB and the VRB-ESS. These differences must be kept in mind when planning for an installation.

The ZBB is more energy dense than the VRB - which means it takes up less space. The folks at ZBB have standardized a containerized product - a 50 kWh system that can be linked in groups of 10 to make a 500 kWh system that fits on a truck trailer. This makes the system easily transportable and potentially mobile, allowing it to be trucked to one location and then another as needed. The downside is that there is no flexibility in configuration. The 500 kWh system will deliver a maximum of 250 kW (although it has the capability of exceeding this rating by 110%) for 2 hours. If you want more hours of storage, you must by more capacity, whether you need it or not. More technical information available here...

On the other hand, the VRB is less suited for mobile applications because it is less energy dense - it needs a larger footprint - which isn't a problem at wind farms and solar PV. Since it isn't restricted by the need for a smaller footprint, it can be configured separately for capacity and storage. For example, the Irish study determined an optimum configuration was 2 MW of capacity and 6 hours of storage. At the Hokkaido wind farm, Sumitomo installed a 4 MW system with 90 minutes of storage (this installation, as well as the Irish, is able to pulse up to 150% of capacity for 10 minutes each hour).

As flow batteries, both the ZBB and the VRB can charge and discharge many times, ideal for intermittent renewable energy. However, the VRB will have a longer useful life. Both systems use a membrane that doesn't wear out from use, but will get old. As the ZBB membrane ages, the different solutions will come in contact and ruin the system. This doesn't happen with the VRB-ESS due to the single solution technology. If the membranes are replaced, usually in years 10 - 12, the system will last another 10 -12 years.

Charge Cycle:
As mentioned above, both systems can charge and discharge many times. However, the ZBB requires 4.5 hours to recharge it's 2 hour system, a 2.25:1 ratio. The VRB is closer to 1.3:1 and would take about 2.5 hours to "fill" a two hour tank.

Bottom-line, we are seeing many storage technologies becoming available for many storage applications. The growing awareness of the value of grid connected storage to integrate renewables and shave peak demand will increase the demand for flow batteries and the VRB-ESS.

Tuesday, June 30, 2009

Plug In Autos (PHEV) Grid Hero or Terror?

I saw this article about the New York Independent System Operator reporting that PHEVs won't cause a strain on the grid "as long as owners plug-in overnight". Funny, I keep hearing that PHEVs will be the savior of renewable energy, allowing for storage of wind and solar from the grid and from the home, transporting power to the workplace where they can be plugged in to run the office building on wind power stored from the grid at night, etc.. Now I see a statement about a potential strain on the grid?

Here's the problem: The typical home probably will not use more than 5 kW at any time during the day. Most of the time much less, with the peak demand around dinner time when everyone comes home and turns on the TV, the electric stove for dinner, the air conditioning during summer or the lights in winter. This causes a peak on the entire system, and the grid operator has to make sure there are enough generators - and enough distribution and transmission wires - to handle the load.

Now, it takes much more energy to move a car down the road then it does to light up a house. Most 8 cylinder cars will generate around 35 kw of power! If your PHEV has a 5 - 10 kW demand, and you plug it in when you get home - BAM - you just doubled or tripled your load on the grid!

"If vehicle batteries are charged during high-demand daytime hours, particularly in the summer, it could strain the grid and cause the need for costly new power plants, the report showed."

So the plan is to encourage millions of new battery powered cars or hybrids, and also set up a system that encourages consumers to act in ways that don't melt the grid.

Random question: How many folks want a plug-in electric car or hybrid? Now, how many of those people park their car in the garage? Oops - "there are only about 54 million garages for the 247 million registered passenger vehicles in the United States today." (pg 20 of the December 2008 report by the Electricity Advisory Committee). And of those 54 million garages - how many have room for a car? Better buy stock in extension cord companies.

Now here's an interesting dilemma - do the utilities install enough wires, generators and infrastructure to handle a potential peak from many PHEVs plugged in at one time - or do they hope that the incentives, etc., prevent that from happening?

Interesting irony - one solution to this dilemma, and many other potential grid issues, is to install large energy storage systems - like the VRB-ESS - on the local distribution circuit. This would increase capacity to handle a worst case scenario, without the need for more transmission wires, and allow for generation shifting from off-peak to peak.

The limits of energy storage technology | Bulletin of the Atomic Scientists

This obviously brilliant atomic scientist wrote a long and well researched article on the potential energy densities of energy storage v. hydrocarbon. He points out that there is much more energy per volume in hydrocarbon fuels then there can be in batteries or other forms of advanced storage.

"The maximum theoretical potential of advanced lithium-ion batteries that haven't yet been demonstrated to work is still only about 6 percent of crude oil."

However, he apparently ignores the fact that advanced storage technologies; like lithium ion, flywheels and the vanadium redox flow battery (VRB-ESS), can be used over and over! Storing wind, which is free and non-polluting energy, in energy storage that can be recycled - an unlimited number of times in the case of the VRB-ESS - should easily beat the hydrocarbons on energy v. volume, since the fossil fuel can only be used once! And, if the energy storage facility is in an area where space is not an issue - like a PV or Wind farm - then the discussion loses even more relevance.

His points may be more aimed at vehicles than grid connected storage. There's no opportunity to comment on his column where it was published, so I have to comment here.

The limits of energy storage technology | Bulletin of the Atomic Scientists

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Tuesday, June 23, 2009

Utility-Scale (Grid) Energy Storage Development – Increased Demand Results in Industry Innovation

Fairly extensive presentation on the market opportunities and suppliers for large grid connected energy storage. Plenty of opportunity for many technologies.

Wednesday, June 17, 2009

Duke Energy Smart Grid Demonstration Uses Storage

Someone said that a smart grid without storage is like a computer without a hard drive. Duke Energy seems to agree.

While much of the discussion about the the smart grid has focused on cool demand side gadgets to control thermostats, air conditioning and refrigerators - and the software and incentives (or forced compliance) to control them, the most effective "smart" appliance is an energy storage system. Energy storage on a distribution grid allows for the most efficient use of renewable energy - like PV systems on residences - and peak demand that occurs from air conditioning (and future hybrid plug-in cars) without intrusive monitoring of residential power use. What a concept - one robust and dispatchable grid connected battery - like the VRB-ESS - instead of multitudes of residential controllers, software and regulations.

Duke Energy plans to demonstrate such a common sense approach. Their system will utilize an advanced flow battery to balance PV, shift generation to cover peak, and provide power quality. Residential customers will be given the option to change power consumption by providing them with information and incentives - not by forcing remotely monitored / controlled motion sensors (to turn lights and power off and on) and thermostats on customers.

The advanced energy storage system (battery) allows Duke to work cooperatively with their customers without forcing compliance or intruding into their privacy. Customers can chose to respond to price signals or other data provided by Duke. However, the battery fills in any gaps and provides a truly "smart" addition to the grid.

Tuesday, June 9, 2009

Storage Technology of Renewable and Green Energy Act of 2009

U.S. Senator Ron Wyden (D-Ore.) has proposed legislation to provide tax incentives for energy storage. This is a first - providing energy storage with incentives similar to renewable energy, demand response and energy efficiency.

Press Release:

"In an effort to increase infrastructure supporting renewable fuels, the STORAGE Act provides investment tax credits for energy storage facilities and equipment that temporarily store energy for delivery or use at a later time. Currently tax incentives are only available for the generation of renewable energy, but output from wind, solar, and wave and tidal energy projects literally rises and falls with natural conditions. Storage technologies can help harness the output of renewable energy sources and allow them to be used when they are most needed. The bill encourages innovation by providing tax credits for a broad range of storage technologies, from water reservoirs to flywheels to hydrogen production to batteries when connected to the nation’s electricity transmission and distribution system and when installed in homes, businesses, and factories."

Although mentioning flywheels and hydrogen production, the language of the bill seems to be more oriented to advanced batteries like the VRB-ESS.

For example, the definition of ‘qualified energy storage property’ includes a minimum requirement to store at least 2 megawatt hours of energy, and output 500 kilowatts of electricity for 4 hours. On the face of it, this 4:1 storage v. capacity ratio would seem to rule out a flywheel that only has 15 minutes of storage. However, a flywheel system could provide 4 hours of electricity at 500 kW if the storage was oversized to 8 MWHrs. The conceptual grid-connected flywheel system, like that of Beacon Power, as well as the lithium ion systems, like Altairnano (see anuual shareholders presentation), are planned to provide short pulses of energy for grid stability, not sustained electricity delivery of more than 4 hours. So, a large flywheel/li-ion system could qualify, but it would seem to go against the conceptual definition in the bill. Looks like a loophole that Senator Wyden may want to tighten.

Also, the bill requires the energy storage to store and deliver electricity. For hydrogen production to qualify, a system would have to be designed to use electricity to generate hydrogen - say through electrolysis of water - and then convert the hydrogen to electricity - perhaps through a fuel cell. The problem is that this wastes a tremendous amount of energy. Taking 100 units of electricity through this cycle only returns about 20 - 30 units of delivered power. By comparison, storing electricity in the VRB-ESS is about 75% efficient. This may be another area for Senator Wyden to be more specific. Does he want to incentivize grossly inefficient electric storage systems?

We'll continue to follow this bill and comment.

Friday, May 29, 2009

Energy Storage Association Annual Meeting

The ESA held its annual meeting this past May 20-22 in Washington DC. According to the ESA, the meeting was well attended, with 13 exhibitors and over 300 attendees. It may not sound like much, but this is a big increase for an industry event that has begged to be noticed in the past.

Much interest was engendered by the smart grid stimulus money. According to the ESA, there were over 40 presentations from 10 panels.

Although we did not attend, we had our sources. We learned that the VRB-ESS is still well perceived.

"In general, people seem keen on the VRB technology and happy that Prudent has chosen to pick up where VRB left off in developing the technology. While the competitive environment is getting more well-populated, flow batteries in general and the VRB technology in particular are still noted in many of the presentations. Consensus seems to be that they definitely have a part to play in the energy storage industry."

NGK's molten sodium sulfur NAS battery is well accepted in Japan. According to one pr
esentation, they have over 270 MW located at 190 sites in Japan. In fact, they are "sold out" through 2010. (Which means, apparently, that it will not be possible to install a large energy storage facility with the NAS battery under the smart grid stimulus grants?)

My comment - I wonder how a large installation of NAS would be accepted in the USA? I personally think the Japanese are much less sensitive to such things. I saw a peaker plant go down in flames from neighborhood activism in S. Orange County, California. This natural gas plant was nowhere near any houses, out of sight, and no one would ever know when it was running. However, a few activists were able to shut down the "smokestack power plant". I have to believe there would be some real reaction to a molten sodium/sulfur plant of any size near a neighborhood, even though NGK has engineered substantial safeguards into the system.

I also received this report on the NGK system in New York: "
One interesting note is that there was a complete failure of the NGK system in New York this past year, requiring that the entire storage system be replaced. Apparently the NaS system cannot be completely discharged without suffering irreparable damage" I didn't find any news on the internet about the failure - anyone have a reference?

Lithium batteries of various types received substantial attention - and why not, they're getting all the money! But they aren't ready et for long term storage - most applications are for quick response, short term storage - like flywheels.

The VRB-ESS still looks good for large, grid connected storage.

Thursday, May 21, 2009

Energy Storage Vaporware

From the earliest days of personal computing, companies would announce, to much fanfare, a new piece of software that would do wonderful things, be user friendly, the next killer app., etc.. Then, after awhile, the buzz and hype would fade away, deployment would be delayed - and then forgotten. This phenomenon became know as "vaporware".

I see the same cycle being repeated with energy storage. Now that energy storage is seen as crucial to integrating renewable energy, the press and media seem to be looking for any new and exciting concept or R&D that could result in a story, without really evaluating the potential for practical success or application to our need for storage.

For example, I have seen articles recently about storage from "bug farts", "air fueled batteries", and a new flow battery that is safer and more reliable, costs less, and would be a good fit for solar and wind farms- but they won't talk about how it works.

I can't say that all or any of these technologies will be the energy storage equivalent of vaporware, and some seem to have some pretty serious and knowledgeable people behind them. However, it seems easy to get a lot of press on a concept or technology that is years away from any practical application.

We should continue our R&D and enjoy discussing new and creative energy storage ideas - but we also need to be realistic about our need for energy storage, and our need to begin deploying those technologies that are available now. Vaporware isn't going to solve our problems!

Why Blog about the VRB-ESS?

This is my initial post to the US&R Energy Storage blog. I started this blog so I could share my thoughts on grid energy storage and the VRB-ESS. Although there are many different energy storage technologies, and each has a potential application in the energy management toolbox, I wanted a forum where I could focus on the VRB system and its applications.

First, some background - the VRB-ESS is the vanadium redox flow battery (VRB) energy storage system (ESS) by Prudent Energy. More information on the technology is available at our website, My comments on this blog are my own and do not necessarily represent those of Prudent Energy or anyone else connected with the company.

The VRB technology is decades old and installed around the world in various sizes from 5 kW to 6 megawatts. It's ready for mass deployment for smart grid and wind/solar energy integration. We are looking for opportunities, such as provided by the smart grid stimulus funding, to deploy large installations and bring the cost down through economies of scale. Just like photovoltaic technology (PV), the cost for this technology has been significant, limiting installation to demonstrations and niche applications. However, the deployment of intermittent renewables, like solar and wind, is focusing attention on the need for massive energy storage, and incentives are being created to reduce installation costs and build the pipeline. Thus, like PV, greater deployment, due to these financial incentives, will result in cost reduction through economies of scale, resulting in even greater penetration and benefit to the grid.

Utility Savings & Refund, LLC (US&R) is my company and we are a sales affiliate for the system. We saw the possibilities for this amazing technology back in 2006, and we've been promoting it ever since. I'll be discussing some of the potential applications and benefits in later posts. However, my plan for this blog is to comment on current developments in energy storage, not to use the blog as a long infomercial for the VRB-ESS. That being said, please keep in mind that I will feel free to comment from the perspective of one that is most familiar with one specific and practical energy storage solution.