The Holy Grail of clean energy economy is in sight: Affordable storage for wind and solar

Enabling safe, clean energy that will never run out is a key to averting catastrophic climate change.  Roughly half the “solution” to global warming is solar and wind [see “How the world can (and will) stabilize at 350 to 450 ppm“].  Of course, many U.S. concentrated solar plants will use low-cost, high-efficiency thermal storage.  In the longer term, plug-in hybrids and electric cars are likely to play a key role in storage, if issues surrounding battery life can be solved and/or battery leasing strategies pan out (which would also create a large aftermarket for batteries that utilities could use).  Another strategy for grid integration is natural gas.  In this repost, guest blogger Craig A. Severance discusses what he learned about available technology from interviews with leading storage firmsSeverance is co-author of “The Economics of Nuclear and Coal Power” (Praeger 1976) and a former Assistant to the Chairman and to Commerce Counsel, Iowa State Commerce Commission.

As the world meets this December to set plans to halt global warming, it is expected America and other industrial nations will commit to a daunting task: reduce CO2 emissions 80% by 2050.  In just 40 years, a complete revolution in how we use and supply our power must happen, or the world will face catastrophic effects of runaway climate changes.

As a new power plant typically lasts 40-50 years, many scientists are now arguing we must simply stop building new power systems that use significant amounts of fossil fuels.  They argue we must move to a high reliance on the wind and the sun for our electricity.

Abundant Power. The U.S. has enormous wind resources, capable of generating over 20% of U.S. electricity from wind by 2030, according to the U.S. Department of Energy.

The sunlight  falling on our deserts, parking lots, and rooftops has even more power  — enough to supply 69% of U.S. electricity by 2050 according to published studies.

Other renewable power sources — such as geothermal energy, municipal waste-to-energy, and biomass — will also play a role, but they pale in size compared to the gargantuan resources of wind and sunlight.

How We Use Energy vs. How Nature Provides. Though nature provides all the energy we may need, there is a problem.  We demand power literally “at the flick of a switch”, not just when the wind is blowing or the sun is shining.

This basic fact about how we use power versus how nature supplies clean energy has caused many to discount the idea that wind or solar power can ever supply more than a small fraction of our electricity.  Critics of renewable electricity call it “intermittent” and “unreliable”.  They say we can’t “catch the wind”, nor can we command the sun to always shine.

These critics see two possible choices for the future. We can develop more stable supplies of renewable energy by coupling wind and solar projects with storage.  Failing that, they argue we should give up on renewables as a primary source of electricity, and instead build more nuclear power.

The flaw in the nuclear path, beyond its tremendous cost, long lead times, and imported fuel, is that nuclear is not actually “dispatchable” power.  Nuclear plants are designed to run all the time at fairly steady output — meaning nuclear power cannot provide the “peaking power” now provided by gas turbines.  Thus, a nuclear path would still rely heavily on fossil fuel power plants to “ramp up” on a daily basis to provide the power needed during these daily swings.

A truly dispatchable system providing over 80% reductions in carbon emissions, therefore, must rely on some form of energy storage.  The energy storage can allow us to fully utilize wind and sunlight as our main power sources — supplying both “base load” power and dispatchable daily peaking power with energy from these inexhaustible supplies.

Energy Storage and Today’s Grid.

Despite critics, wind farms and solar photovoltaics are already feeding zero-fuel-cost power into today’s electric grid with little or no energy storage.  At current levels, the fluctuations in wind and solar output are backed up by the same “load-following” and “peaker” natural gas power plants that already must handle wild fluctuations in customers’ demands for electricity.  Indeed, the DOE’s “20% Wind by 2030” scenario modeled how wind could supply this very significant portion of U.S. electricity needs even with no storage of the wind power.

As long as natural gas remains cheap and acceptable to use, many argue that developing ways to store wind or solar energy may be a case of “a solution in search of a problem”.  They note natural gas peaking plants are cheap to build and don’t need to operate much more than they already do, to provide firming power to renewables.

“Different sectors like to associate with wind power,” the NY TImes quoted Robert E. Gramlich, policy director at the American Wind Energy Association. “But we don’t want to give anyone the impression that storage is needed to integrate wind.  Even growing 20-fold, storage isn’t needed.”

A Better Way. Though wind and solar can be integrated without storage for a long time to come, energy storage proponents argue that coupling wind or solar power with utility scale energy storage is a “Better Way”.  If stored wind or solar energy instead of natural gas plants can be used to generate power when the wind is not blowing or the sun is not shining, less natural gas will be burned to provide dispatchable power.

Though storage will cost money, burning less natural gas will save money on fuel costs.  Also, there are now times when excess wind farm kWh’s have been sold onto the grid at extremely low prices or even given away, because they occurred in the middle of the night when there was very low demand for power.  Storing that wind energy, for sale of kWh’s the next day when prices are higher, would generate more revenue.   While less dramatic, solar power production can also be shifted to higher-demand periods, from solar noon to late afternoon/early evening when utilities typically experience maximum summer peak demands.

The most important motivator, however, to find a “Better Way” is the need to achieve phenomenal reductions in CO2 emissions.  While it may take until 2030 to reach a 20% contribution to the grid, what then?  Going beyond this level will require dispatchable renewable power.  Twenty years is within the lifetime of any new power plant built today, so storage proponents argue we should already be building to achieve minimum levels of fossil fuel use.

Compressed Air Energy Storage (CAES). A proven technology, ready to use now, for economical storage of massive amounts of renewable power is to compress air at very high pressures, and store this compressed air in large underground caverns, depleted wells, or acquifers.  When the wind turbines and solar plants reduce output, and power is needed,  the compressed air is released and run through turbines to generate power:

Source: Scientific American

Because the caverns or acquifers are so large,  hundreds of hours of output can be stored, providing the ability to cover very long “doldrum” wind periods or stretches of cloudy days. Most CAES turbines can also run in natural gas-only mode in the extreme event the cavern becomes fully depleted.   A reliable, fully dispatchable electricity generation system is provided.

CAES has a well established track record at scale.   A 280 MW plant in Hunthorf, Germany has run since 1978, and a 110 MW plant at McIntosh, Alabama  has been in continuous operation since 1991.

CAES systems use gas turbines almost identical to normal natural gas peaking turbines.  However, they only use about 1/3 the natural gas, because 2/3 of the natural gas energy in a regular turbine is used to compress air before it enters the turbines, and this compressed air would now be supplied by the stored air.  Natural gas would still be needed to heat the air before it enters the turbines.

CO2 Reductions. While not a 100% carbon free power system, a wind or solar coupled CAES power plant system can achieve >80% reductions in fossil fuel use.  A baseload CAES/wind system (designed to provide at least 85% Capacity Factor power to the grid) would typically provide half of its total power directly from the wind farm to the grid, without cycling through the CAES plant.  The other half of kWh’s supplied to the grid would come from stored energy in the CAES, at about 1/3 normal fossil fuel use.  Total fossil fuel use per delivered kWh would thus drop to roughly 1/6 of a normal fossil fuel plant, an over 80% reduction in CO2 output.

A carbon-free electric system is also possible, with CAES plants fitted with thermal storage.   The thermal storage would store heat from compressing the air, for later use to heat the air going to the turbines.  Known as “adiabatic” CAES plants, the stored thermal energy replaces the need for natural gas, causing the entire system to run on renewable power alone.  Because thermal storage is costly, it is not expected CAES plants installed in the next decade will include it.  However, a regular CAES plant can later be retrofitted with thermal storage, when it becomes more economical or society demands zero-carbon power.

Geological Formations Suitable for CAES. A nationwide network of CAES plants could use the same types of geological formations, and depleted gas wells, as are currently used to store most of the nation’s natural gas supplies.  Wide areas of the U.S. — most notably the wind-rich central states — have these formations and depleted wells:

Source: Coha and Louks (1991)

Cost of Renewable/CAES Power Systems. Because the caverns, aquifers, and wells are already there, CAES offers very economical energy storage.

Estimates for CAES plants range from $750/kW of generating capacity up to about $1,200/kW, with the difference being primarily the number of hours of energy storage.  A wind farm/CAES system (taken as a whole) capable of providing baseload capacity factors of 85% could be built for around $5,900/kW of equivalent baseload capacity, including the wind farm itself and the CAES facility.  While this is far more than a natural gas plant, it is comparable to a new coal fired power plant and at least 1/3 less costly than the same capacity if added through nuclear power.

Unlike a nuclear or coal plant, the CAES plant would be fully dispatchable power, able to increase and decrease its output along with fluctuating customer demand.  This flexibility  is a major advantage for usefulness to the electric grid.

Total costs/kWh from this system would also be competitive.  Estimates indicate that if the wind farm is built with the 30% Federal Tax Credit (still available through 2012), a total wind/CAES system could deliver baseload power to the grid at about 10.5 cents/kWh.  This cost would rise to about 13.0 cents/kWh without the wind Tax Credit. (Effectively, the Tax Credit if used wisely could pay for the CAES plant to convert an intermittent wind farm into firm, dispatchable power.)

Though more expensive than kWh’s from a new baseload natural gas power plant (which would probably be about 9 cents/kWh), a wind/CAES system would be well protected from future fuel cost increases.  Also, at 10.5-13.0 cents/kWh, the baseload wind/CAES system would only be about half the cost/kWh  from a new nuclear power plant.

Pump Water Up and Let it Fall Back Down. Pumped hydro-electric storage is just that simple — when you want to store energy, use electricity to pump water to a high level.  Then, whenever power is needed, let the water fall through hydroelectric turbines to generate power.   You don’t get all your electricity back (about 22% is lost), but you get it when you need it.  This enables you to accept power from renewable sources when not needed, and store it for use later.

Pumped hydro storage is the largest utility energy storage method in the world, with 20,800 MW already in use in the U.S.  However,  its use has slowed because of limited sites for hydroelectric power dams.

Enter Riverbank Power Corporation, with its simple idea:  combine two well-established technologies into one.  First, use standard deep mining techniques to create a large cavern 2,000 feet deep, under a body of water such as a river or abandoned quarry.  Then, install 4 gigantic 250 MW hyrdroelectric turbines at the bottom of shafts, for a massive 1,000 MW power supply available on demand.  When power is needed, let water fall down the shafts and generate power.  When renewable power is available, pump the water back up.

Source: Riverbank Power

Riverbank Power is now actively exploring 15 sites in the U.S. and Canada, for selection of its first five 1,000 MW pumped hydro (AquabankTM) facilities.  Wiscasset, ME is high on the list, where Riverbank has already performed successful bore hole tests of the underlying rock.  The Wiscasset site is very symbolic, as it is the home of the former Maine Yankee nuclear power plant,  decommissioned more than a decade ago. A boon to Riverbank Power is the site is still set up to connect directly to the transmission grid.

Costs. Because Riverbank Power has to dig out its own cavern, its cost to construct is significantly higher than a CAES plant — estimated at $2 Billion for the 1,000 MW facilities, or roughly $2,000/kW. Also, instead of dozens or hundreds of hours of storage, Riverbank plants are designed to run for 6 continuous hours before the water would need to be pumped back up.  The timetable is good for hour-to-hour or minute-to-minute fluctuations but not long stretches with no wind or sun.

Riverbank is confident of its business plan, and is not asking for taxpayer or utility dollars.  Its turbines use no fossil fuels, and the facility should last 100 years.  The company plans to buy power at cheap prices, and sell power when it is needed more, at a higher price.

If it does that for 100 years, the Company feels it should pay for the initial $2 Billion investment many times over, while creating jobs and giving green energy developers a solid market for their power.

Batteries to Store Power When and Where Needed. While both CAES and pumped hydro storage plants hold the promise of very large scale economical storage, they both require special siting.   CAES requires an available underground cavern, well, or aquifer, while pumped hydro requires a water resource.  Batteries, however, can go virtually anywhere, and take almost no lead time compared to the larger projects.

Xtreme Power is a company out there today, already selling product, by identifying customers who have needs and who are willing to pay for solutions.  The company has a systems approach employing modular battery packs that can be scaled to provide Mwh of power storage, together with power electronics control systems.

Xtreme Power can shift  4 hours of power to a later time, for roughly 5-10 cents/kWh.  In many electricity markets, the difference in value between different times of the day can more than pay for this cost.

The company has some large scale systems going in before the end of this year, and plans to deliver at least 75 – 100 Mwh of power storage in 2010, with more that can be delivered.  Most of its customers are large solar and wind developers, who are eager for a solution and ready to pay for it now.

NGK Insulators

Sodium Sulfur (NaS) Batteries. Another battery solution which is also already commercially available is sodium sulfur.  Xcel Energy has a 1 MW NaS battery installation underway from NGK Insulators to store up to 7.2 Mwh (in other words, over 7 hours of power), of wind energy for use when most needed.  The system will be adjacent to an 11-MW wind farm owned by Minwind Energy LLC, in Luverne, Minnesota.

Let’s Not Store These Ideas For Later. When renewable energy was still a long way off, the solution to energy storage seemed to be the unattainable “Holy Grail”.  It was always to be found, yet never found.

Now, however, the answers are actually here, and they are simpler and plainer than we expected,  Store air.  Pump water.  Use advanced batteries.   Like Indiana Jones in his Last Crusade, we need to know when the true Grail is right in front of us.

As Michael Breen from Xtreme Power told me, “Let’s stop jabbering about it, . . We just need more demonstration units so the industry can talk about this more intelligently.”

This is now happening.  Is the Holy Grail finally found?

25 Responses to The Holy Grail of clean energy economy is in sight: Affordable storage for wind and solar

  1. Rick Covert says:

    So if concentrated solar thermal is equvilant to 3 wedges how many wedges does wind turbined generated power and CAES make up for?

    [JR: Wind is 2 wedges. I’ve got plug ins for 1. Other wedge will use various strategies, including CAES.]

  2. David B. Benson says:

    Great. Now instead of using natural gas, a fossil fuel, make biomethane from wet biomass. There are a few such digesters in operation and no further research is required. These have the advantage that about 15-20% of the carbon is separated CO2, available for sequestration; carbon-negative.

  3. ecostew says:

    Yes, and corn grain/cellulosic biofuel (most ethanol and biodiesel) EROIs/environmental degradation/AGW mitigation are not sustainable. Use local biomass to generate electricity as appropriate based on EROI and the environment.

  4. Brewster says:

    Barry Brook from Brave New Climate in OZ claims that Nuclear (Particularly Gen IV) can be built cheaper than wind and solar…

    Any analysis going on as to why his numbers are so different from here?

  5. Bob Wallace says:

    “Pumped hydro storage is the largest utility energy storage method in the world, with 20,800 MW already in use in the U.S. However, its use has slowed because of limited sites for hydroelectric power dams.”

    From Wikipedia…

    “(I)n 2004, an extensive survey was conducted by the US-DOE which counted sources under 1 MW (mean annual average), and found that only 40% of the total hydropower potential had been developed. A total of 170 GW (mean annual average) remains available for development. …. In 2005, the US generated 10(12th) kilowatt hours of electricity. The total undeveloped hydropower resource is equivalent to about one-third of total US electricity generation in 2005.”

    Additionally there are many dams, particularlily in the western part of the country which are under utilized in the summer and fall during the dry season and when snow pack runoffs have slacked. With somewhat minor modifications they could possibly give us a lot of hot summer afternoon electricity production when we need it the most.

    Perhaps a new study of pump-up storage potential is in order.

  6. J.A. Turner says:

    Storage systems in urban areas could be used to provide load leveling and to make more efficient use of the transmission grid by allowing power to be moved from one area to another at times when the transmission grid has excess capacity. Imagine wind farms being able to provide steady output with storage to trim the highs and lows and to allow for timed flows of power to be sold to urban area storage companies when capacity is available on the grid and when power is cheapest. Local storage in demand centers could even help prevent blackouts and limit the spread of blackouts that do occur. Businesses could buy the next day’s power at off peak prices and be self-sufficient during peak hours. Cost-effective storage is game-changing even if we weren’t worried about CO2 emissions.

  7. Phillip Huggan says:

    I’m hoping some chemical storage batteries will exhibit some Moore’s Law style materials science innovations over the years enough to handle large electricty loads efficeintly.

    The Riverbank idea is genius. Wow. I think if you cover the surface water source, it can even be relatively closed-system for arid areas through the world. That is, you don’t even need a nearby river or aquifer if you aren’t losing too much moisture to evaporation or subterranean leakage.

  8. Adelaideboy says:

    Barry Brook says that nuclear power can be built very cheaply and has quoted the low cost of a reactor that was built in Japan as evidence of this. This is odd, because all the reactors that are being built now are really really expensive. Which is a quite a pity, because if nuclear power companies wanted nuclear power to take off, then all they had to do was build a cheap reactor like the one Barry mentions, but apparently they all decided to build expensive ones instead. Even more strangely, even the Japanese have abandoned plans to build several nuclear reactors for cost reasons, which suggests they must have forgotten how to build cheap reactors themselves or decided not to for some reason.

    Barry also says that in the future modular construction will dramatically reduce the costs of nuclear power. This makes me wonder why, if it’s such a cost saving measure, nuclear plants weren’t constructed this way in the past? It’s not as if modular construction is a new invention. Perhaps the people building nuclear reactors in the past were a bit thick? I would also think that benefits from modular construction are likely to be greater for wind and solar power than nuclear due to the much smaller size of the modules involved, making economies of scale much more achiveable. The fact that the cost of wind and solar energy has been dropping by about 4% a year while nuclear has regretably been getting more expensive, suggests that this may be correct.

    Barry also says that a nuclear plant that reprocesses it’s own waste will be cheaper as it will save on fuel. However, fuel is only about 7% the cost of nuclear power and so even if reprocessing was free it would only cut costs by about 7%. Unfortunately, it’s not free as a reprocessing plant is quite expensive to build and run. France tried reprocessing fuel and it turned out more expensive than not reprocessing. Also, if for some reason we need to reprocess in the future, all the spent nuclear fuel from convential reactors will still be around. Fortunately that stuff lasts for millions years.

  9. BBHY says:


    There is a long, long history of extremely optimistic predictions of how cheap nuclear power will be.

    The nuclear industry has never come even remotely close to meeting any of those predictions. Instead nuclear is one of the most expensive sources of electric power.

  10. Michael Sun says:

    Wind and Solar energy represent the modern green tech compatible for diverse uses. Many countries have given big attention on building the infrastructure of both. Yet, socializing such green tech to people more closely will be contributing better to the future of this planet, solar energy especially. We need to support people to learn how to make a solar panel for their own and by themselves. WHy not?

  11. pete best says:

    Re #4, 4th generation nuclear power is not proven or as yet viable whilst the other technologies are. No one is saying that we should not go for 4th gen but its wedges in the future and not today.

  12. Eclipse Now says:

    Don’t forget that the Electric Car market will be both an extra demand on the grid, but also an extra “smoothing” capacity for the grid.

    For a long time the Electric Car market has been hampered by 2 things:
    * the price of buying a new battery for $4000 every 2 or 3 years,
    * the fact that a sudden ‘fuel up’ takes 4 or 5 hours. (No driving between Sydney and Melbourne in one hit!)

    Better Place have solved that.

    * You buy the car, they maintain ownership of the battery.
    * Many cars sit still 22 hours a day, so once charge points are installed everywhere you can charge at work, home, the shops or church.
    * Automated battery swap stations swap out your battery faster than you can refill your conventional car with petroleum!
    * But because charge points are everywhere, you’ll swap out batteries far less than you refill your current petroleum car.
    * The cars will be cheaper, faster, require less servicing, and be MORE convenient than gasoline/petroleum cars.
    * They are creating international standards for all car companies to follow and participate in this model!
    * These Better Place EV’s will be V2G (Vehicle to Grid), and so can sell energy back to the grid. In effect, they will act as a significant battery for the intermittent power supply of wind and solar! 50,000 cars = 1 gigawatt of power available for “grid smoothing”.
    * the batteries sort of follow a Moore’s law of their own and will become cheaper and more powerful.

    Israel will be the first country off oil, but others are following with city test applications before the country-wide roll out, such as San Francisco and Canberra.

    This does not solve the problem of oil dependency for airlines, agriculture, mining, and other applications. These areas will have to implement their own unique niche energy strategies. But at least it solves the main consumer of oil, us suburbanites!

    (I still prefer New Urbanism and eco-cities to suburbia as a more economically viable and socially attractive town plan, but that is another story).

  13. Samir Succar says:

    Another important benefit of energy storage worth mentioning is its ability to decrease the amount of transmission capacity needed to deploy large (Gt-scale) quantities of wind. Better utilization of transmission infrastructure, together with other non-wires solutions like demand response, energy efficiency and distributed generation can have important land conservation benefits and help reduce what some refer to as the “energy sprawl” associated with new energy development. I touch on some of these issues in my blog on this topic from a few days ago

  14. Rockfish says:

    The costs of nuclear are particularly high in North America because we have a very high price on risk. The costs of failure with nukes are immediate and perceptible, and therefore incredibly high, and they get built into the equation. (The costs of coal are diffuse and invisible, thus they are not perceived as high and are priced accordingly).

    America also lacks any institution with the integrity to construct something as critical as nuclear plants. You can’t trust private industry – profit motive will corrupt any enterprise. You can’t trust government, because absent any performance incentive (and with the prevalence of corruption) corners will be cut, too. No trust = high risk = high cost.

    I personally would not trust any private enterprise or public entity to build a nuke in my backyard….

    [JR: Nukes are pricey everywhere.]

  15. jack cadogan says:

    As a 35 year energy research supporter and analyst, I’m always struck by stories such as posted above that “Economic storage for electricity is around the corner.” Many of these concepts have been talked about, and even operated as pilot plants, for 20 years or more. For one reason or another, they have not become commercial.

    No doubt, economic electric storage would help move off-peak wind to on peak, but except for the potential for Vehicle to Grid (v2g) and the reality of pumped hydro, economic applications do not yet exist, in my opinion. A major point of the recent Department of Energy study that wind could provide 20 percent of the lower 48’s electricity by 2030 is that storage is not necessary. However, ultracapacitors may offer a promising option not discussed in the post.

    Let’s be blunt: Proponents of wind and storage have different points of view for the near term. I’m a long time “wind weenie”. Any “answer” to the wind storage question depends on relevant economics. A rational and informative discussion of this can be found in the review of the recent Energy Storage Association meeting in the article “Ill Wind Blows over Storage Market” by John Gartner at Matter Network. Find this at:

    I believe that the electric storage holy grail is yet to be found.

  16. alexy says:

    In describing the CAES option, the author correctly indicates that natural gas would be consumed to warm the compressed air prior to it entering the combustion turbine. Possibly an alternative approach would be to use the natural gas to generate electricity, a more valuable product than heat, in MW scale fuel cells first. The fuel cell waste heat could then be used to heat the compressed air prior to entry into the combustion turbine. Fuel Cell Energy offers a similar product to heat natural gas exiting pipeline turbo-expanders.

    Separately, Hybrid Power Technologies has proposed a hybrid nuclear power plant concept in which a small, modular nuke is used to compress the air used by a fossil fuel power plant. The company claims this avoids many of the problems of the current nuclear power plants while also improving the fuel efficiency of the fossil plants.

    Fluidic Energy is developing a large format rechargeable Zinc-air battery targeted for storage of wind/solar energy. They claim initial tests are planned for later this year and appear to hope for commercial availability in 2 years.

    Finally, China is working on several gen 3+ nuclear reactors with claims of costs around $4 billion. We shall see. But even if correct, with Chinese labor rates / economics / policies, this will surely represent the minimum cost.

  17. Mark says:

    Eclipse Now in #12 writes about Shai Agassi’s idea on infrastructure for an electric car where you don’t own the batteries. I really like Shai’s approach. But larger scale adoption especially in places like North America won’t happen until the batteries have larger energy densities. Many won’t buy until the cars are larger and this requires battery advances so as large amounts of batteries aren’t required.

    I’d like to know if batteries advances follow Moore’s Law. I don’t think they do. Shai mentions Moore’s law but I’m not sure what he’s referring to.

  18. Bob Wallace says:

    Mark, I really don’t agree that EVs won’t find a market in North America (and I assume you really mean the US) until “the batteries have larger energy densities”. And by that I assume you mean more range between charging.

    Toyota and GM combined to do a study on US driving habits and found that something like 90% of daily US driver trips were under 40 miles. The Nissan LEAF is expected to have a 100 mile range. When one looks at the cost of fueling an EV I think we are going to see a lot of people buying an EV as “one of the family cars”.

    Additionally many people take few long trips by car. They are probably going to be willing to drive a 100 mile range car and rent something else for their 1x a year big trip.

    Furthermore eTec has already started building rapid charging stations which Nissan expects to be plentiful by the time their EVs are in full production.

    What is promised by eTec/Nissan is a 10-20 minute recharge and I assume that’s an 80% charge. So drive ~100, stop for 20 minutes, drive 80, stop for 20, …. Many people are going to be OK with that if their long distance driving is not very frequent and not extremely long.

    And you might want to visit the US sometime, especially the west coast. Lots of us don’t drive great big cars.

  19. Mark says:

    Bob Wallace #18.

    There will always be some market for EV’s in North America but for a large market the EV’s will need to be bigger. I’m not focusing on the range issue but the volume of batteries needed and their weight for the larger cars. Currently, EV’s are kept small/light so the volume and weight of the batteries does not become a problem. However, I fully expect this to change as battery technology advances.

  20. Bob Wallace says:

    Mark, the Nissan LEAF is “mid-sized hatchback which seats five adults”. It’s about the size of a Ford Focus, which sells very well in the US.

    I’m not sure where your size concerns come from. Lots and lots of us drive cars this size in the US.

    People who genuinely need large vehicles (such as my neighbor, the rancher) will likely choose PHEVs rather than EVs.

  21. Bob Wallace says:

    Back to green energy and storage…

    We need the Big Model for our energy future.

    A nice “SimCity” program that lets us plug in the current cost of wind, solar PV/thermal, etc. and the current cost of pump-up, battery, etc. and see how the problem is most economically solved.

    Something that could be continuously revised to include siting/transmission costs, current green energy supplies, current and future needs, conservation savings, etc.

    I do think that one of the very largest needs is for a clearly presented path forward.

    People are aware of the climate change problem and what is causing it. People are ready for change. What they need, I think, is a map. Show the public the way and they will start pushing and supporting the politics.

  22. Mike#22 says:

    An excellent post Craig.

    EPRI associate Dan Rastler has this ppt on storage options. His data supports the cost effectivness of Xtreme’s lead battery. slide 19.

    SAFT has this product Li-ion for distributed storage:

  23. Mark says:

    Bob Wallace post #20.

    Nissan LEAF! Are you kidding?

    This car size has a market in the US and Canada but if you want large adoption you’ll have to get bigger than a Nissan LEAF.

  24. Bob Wallace says:

    No,not kidding. But I think we’re on slightly different pages. Somewhere between 15% and 20% of new car sales in the US are sub compact and compact. Lots of people buying these sorts of cars are looking for high mileage/environmentally friendly cars and I suspect they are going to be the EV buyers for the first few years.

    I suspect EV manufacturers are going to need a few years to build production levels to saturate this small car market.

    By then batteries probably will have improved to begin to allow larger EVs with a decent range. And remember that the critical issues for good mileage/range is not size, but weight and aerodynamics.

    Due to the high cost of batteries which may continue for several years manufacturers may decide that it’s better to use more expensive but lighter materials in order to minimize battery pack weight.

    It’s going to be interesting to see the dimensions of the Tesla S with its 300 mile range. At this point Tesla is describing it as having “passenger carrying capacity and versatility rivaling SUVs and minivans”. It’s going to be too expensive for lots of us but it should show us what is possible with current technology.

  25. Mike Keller says:

    Update on Hybrid Nuclear Energy.
    We will be shortly publishing a paper describing how hybrid nuclear energy can be combined with solar energy as well as compressed air storage. These new members of the hybrid/nuclear family will sling-shot renewable energy into a highly competitive position. Government subsidies for renewable energy will be unnecessary; the hybrid-nuclear/solar technology handily beats the competition. Greenhouse gas emissions are also stunningly low.

    Summary should be available on our website ( in early December)

    Mike Keller
    President & CEO
    Hybrid Power Technologies LLC