Renewable energy and storage

Myriad motives and interests drive California debate

Phil Carson | Apr 29, 2011


Energy storage is often hailed as the "holy grail" of the electric grid, but listening in on a California Energy Commission (CEC) workshop on the matter yesterday leads to several observations. This workshop was part of a CEC effort to gather input on the implications and potential implementations of energy storage in the state, for its Public Interest Energy Research (PIER) report on the topic, a somewhat parallel effort to one being explored by a proceeding opened by the California Public Utilities Commission on the topic.

Storage technologies and the business cases for them lie at the center of a tangled web composed of legislative directives, regulatory policies, specific grid applications, cost/benefit analyses, cost-effective alternatives, even basic philosophical views of the market—to name just a few strands in that web. 

Today I'll merely try to set the stage for further coverage of this multi-faceted issue. "Multi-faceted" is such an understated qualifier that I might suggest that this "holy grail" could prove to be as elusive as its biblical namesake.

That few will be satisfied with my exegesis underscores my point. Nevertheless, into the breach!

California has legislated for itself a hefty renewable energy portfolio (33 percent by 2020) and, subsequently, an energy storage portfolio directive (AB 2514) that beginning this year requires the state's utilities to develop five-year plans for energy storage and to begin procurement in 2014. The idea is to find a way to take increasing amounts of inexpensive, off-peak, variable wind and solar energy and store it to relieve expensive, on-peak demand. That presumably would preclude the need for more fossil fuel-fired base load and peak generating units, saving capital and lowering greenhouse gas emissions.

It appears that quite a variety of energy storage technologies can perform short-, medium and long-term storage, fulfilling various grid requirements from frequency regulation to renewable energy integration. Challenges arise over how to tailor a specific technology to a specific application in a cost-effective manner, while known, cost-effective alternatives remain in the toolkit.

Beyond the technical hurdles, many object that this approach ignores more cost-effective solutions, that costs and benefits cannot be properly allocated and that further tinkering with regulated markets only further delays the arrival of free market forces that would properly value everything about the grid and its commodity. Then there's the cost to ratepayers of pursuing renewable energy and the storage that could serve it. Not to mention a raft of unintended consequences.

I acknowledge that this is a somewhat brutally crafted summary, but let it serve to introduce aspects of yesterday's hearing that further illuminate the storage challenge.

The players who presented or participated in panels yesterday included utilities, vendors, federal and state policymakers, researchers, industry associations, industry research groups, attorneys, independent system operators (ISOs), system integrators and engineering firms, with a dash of citizen comments.

We're talking about the U.S. Department of Energy, the California Public Utilities Commission, the California Energy Commission, the California Independent System Operator, the University of California, the Electric Power Research Institute and the California Energy Storage Alliance, among others.

Those others included the state's largest utilities, such as Southern California Edison, Pacific Gas and Electric, San Diego Gas and Electric, Sacramento Municipal Utility District and Los Angeles Department of Water and Power. Most if not all of these utilities already have energy storage projects underway, at least in the demonstration phase.

But these lists and threads articulated above should give a sense of the disparity of interests, motives and viewpoints coming to bear on the storage issue.

Here are just a few of the questions that panelists sought to illuminate, if not answer:

  • How can storage help the state achieve its RPS?
  • How will storage help the state meet its self-imposed greenhouse gas emissions targets?
  • What can be done to better define energy storage's role?
  • What are cost estimates for energy storage?
  • How can its benefits be quantified?
  • How do utilities see the issue?


One citizen who commented on the record for this hearing had other questions:

  • Why is California's current fleet of pumped-hydro plants, in excess of 3,000 megawatts, inadequate?
  • How will subsidies for storage affect the availability of low-cost, off-peak energy for electric vehicles?
  • What policy and wholesale market changes, other than subsidies, narrow the cost-value gap for storage?


And one citizen commenter merely called for more coal-fired base load generation and descried the cost that storage and renewable energy would impose on ratepayers.

And this is just the set-up, sans details of the hearing itself. Like an addled spider and its web, the threads are many, not particularly straightforward and the playing field is full of competing interests.

We'll do our best to unravel it, thread by thread, issue by issue, in coming months.

Phil Carson
Intelligent Utility Daily





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Renewable energy and storage


April 29, 2011


Mr. Carson, Thank you for taking the time to summarize energy storage debate .


I have been following this debate in California since the Permanent Load Shifting Workshop #2 on 11/10/10 and as you say it lies “at the center of a tangled web”


We all know that whether a business is a retail store, such as Wal-Mart, or an electric utility, the consumer pays for everything. That fact should be a part of all cost alternates regardless of what side of the meter the storage is on. It is obvious, from the make-up of the panel, their questions and other comments that the focus is for energy storage on the utility side of the meter. Large commercial and industrial end-users should have representation along with the utility, government agencies, and lobbying groups participating in the discussions.


My expertise has been in the application of Thermal Energy Storage (TES) installed at the end-users site. In an effort to level the playing field, I would like to review the reasons why TES should be get more attention:


  1. TES reduces the stress on the grid and does not add to it.
  2. TES focuses on peak demand reduction and the shifting of energy use to non-peak hours where wind power is more available.
  3. The largest items that increase peak demand are air-conditioning and process cooling- both of which are excellent TES candidates.
  4. TES can be very competitive when designed for new and retrofit chilled water cooling plants.
  5. TES adds local jobs for A&E Firms, contractors and American equipment manufacturers.
  6. Overall greenhouse gas emissions  are lower on TES applications than with wind power.
  7. The peak demand reduction is a permanent reduction as compared to the temporary reductions available from demand response programs.
  8. Utility incentives could be less than those presently being offered for demand response.
  9. TES can be varied to compliment the variations in wind and solar energies.
  10. TES is extremely reliable.
  11. TES systems can be designed to provide both permanent demand reduction and, when required, demand response.
  12. After the 30 to 40 year life expectancy, there will not be a hazard battery waste site for our grandchildren to clean up.
  13. TES is a proven technology that can provide demand reduction almost immediately.


There is no single right answer to the energy problem, and all options should be evaluated. End-users can play a significant role and are vital to the success of any energy or thermal energy storage system.


Lou Clark, Columbia, MD.     



Cost Matters

I was at the workshop until the start of the first panel.  The Chairman asked a couple of key questions.  One Phil mentioned was whether and how storage might be in conflict with other policy priorities like demand response.  Another was whether the problem was whether getting the cost of storage down was a matter of technology (yes according to one respondent) or production economies of scale (no).  If that's borne out, then subsidies and set-asides to build storage will be good for the manufacturers and a bad deal for consumers.

I agree with Phil's thesis that storage has its place, especially at the right price.  The presence or absence of renewable energy is largely irrelevant.  However those applications are few in number and represent small volumes at the moment.

Jack Ellis, Tahoe City, CA

Thanks for the comments

Thanks to all for taking the time to share your thinking.

Looks like a good representation of the gamut of thinking on storage and, by extension, renewable energy.

We have 1) rejection on the face of it, 2) anger over electricity rate increases and 3) someone willing to consider the business case, while realizing that it's complicated.

Personally, I think that RE and storage should get its due consideration, especially at the local, homeowner or neighborhood scale.

California may not move as swiftly as one reader would like, but it still serves as a crucible worth our attention.

Thanks to all for reading and writing in,

Phil Carson

Renewable Energy and Storage

Mr. Carson, some of the concepts sound great but lets face it, it's just wishul thinking. Calionia does not move quickly.


I participated in listen only mode and agree that the over tone was just how to assign a value to the benefits of storage; there is no denying that storage, at all levels will help create a truly smart grid but just what is the cost of that service?

As in any supply and demand business, having a inventory available thru storage or warehousing of product makes or breaks a business. Imagine if a gas station didn't have adequate product on hand when demand was up; they'd go broke.

Now think about all the future renewable energy hubs that will be built to get the country away from fossil fuels and emissions; storage is an absolute necessity to turn that product into a firm, dispatchable resource. The down side is storage will remove the need for building more natural gas peakers for load following, frequency control, etc. The cost of using gas for variable energy integration has been modeled; the cost of extra capacity noted, and the cost of transmission buildup necessary to integrate wind. There is a baseline to apply a value for the benefits at least on a large scale. (Compressed air and pumped storage) but at the distribution side things are still muddled.

Storage is the "black swan " and without it the US will not reach grid parity. However it will change the grid as we know it.

How money is made in solar energy

'Then there's the cost to ratepayers of pursuing renewable energy and the storage that could serve it. "

Albuquerque Journal report Michael Hartranft article is summarized

  1. 30,000 solar panels
  2. two megawatts
  3. enough power to supply 640 homes
  4. first of five pnm solar plants
  5. four additional utility-scale solar pojrects
  6. Los Lunas, Alamagordo, Deming, Las Vegas
  7. each will have a five megawatt capaciity
  8. generate about 51 million kilowatt hours
  9. cost about $191,7 million
  10. enough power for about 7,000 homes

Here are the  computations

2,000,000 watts takes 30,000 solar panels
5,000,000 watts each at four additional plants for total of 20,000,000 watts

fast neutron
Santa Fe, NM
January 12, 2009

From actual experience, wind farms produce 1.2 watts per square meter. Solar Thermal and Photovoltaic methods capture 5 to 6 watts per square meter. There is no economy of size in either technology. Dividing the watts you need by those values gives the land area in square meters needed to produce the juice. The numbers are astronomical
If both are correct, 300,000 solar panels are at least required for the additional 4 installations?


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