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New Study: Battery Storage “Not An Economic Prospect

April 16, 2018

By Paul Homewood


A new technical paper from GWPF proves that battery storage systems to work with rooftop solar are a waste of money:



New Study: Battery Storage “Not An Economic Prospect”

Consumers warned to avoid battery storage for rooftop solar systems

Rechargeable batteries are said to be a way to extend the appeal of rooftop solar installations, storing the energy generated during the day for use at night. Home energy storage looks set to become big business: Tesla has already entered the marketplace, looking to apply its expertise in batteries to generate a new source of income. Other big-name motor manufacturers are expected to follow.

However, a new paper published by the Global Warming Policy Foundation (GWPF) reveals that consumers are in danger of being fleeced. The paper’s author, power engineer Dr Capell Aris, has examined the economics of battery stores and finds that in the UK their high cost means that they will never pay for themselves. As he explains:

“The price of  batteries is relatively high, but the possible savings from adding them to a rooftop solar installation are quite limited, particularly as a fraction of the typical electricity bill.  When you add up the costs and benefits, it is quite clear that they are a waste of money.”

That could change if the price of batteries were to fall dramatically, but the gap between costs and benefits is currently so wide that this is unlikely in the near term. As Aris explains:

“There is no doubt that battery prices are falling, but even if we make some fairly optimistic assumptions about performance, prices would have to fall by another 50% just to break even. They would need to come down even further than that to give a financial return. It’s hard to see this happening any time soon. Battery storage for rooftop solar is simply not an economic prospect, and will likely remain that way.”

  1. Jonathan Bensted permalink
    April 16, 2018 1:29 pm

    that is true for the UK, although the picture is rather more attractive for sunnier climbs..

    • Graeme No.3 permalink
      April 16, 2018 10:56 pm

      Not so true. In Australia the Alternative Energy Association (A.T.A.) has an on-line calculator which advises that a home storage battery rarely pays for itself. The ATA even made it onto the ABC (dare I call it a carbon copy of the BBC) with that advice.

      • Duker permalink
        April 21, 2018 3:18 am

        Not so sure about ATA ?
        “The Alternative Technology Association (ATA) has traditionally advised people to consider this carefully based on their household’s electricity consumption. Now, however, the ATA recommends a big solar system, even if consumption is low.”

        A big system even if consumption is low ? I think they have turned from guarding the henhouse to providing leads for the foxes

  2. April 16, 2018 2:10 pm

    Reblogged this on Climate Collections.

  3. Max Sawyer permalink
    April 16, 2018 3:14 pm

    Are there any signs of a much-needed breakthrough in battery technology – cheaper, lighter, greater capacity, faster charging time, longer life etc? Or does the answer lie with a form of capacitor that doesn’t leak charge?

  4. April 16, 2018 3:36 pm

    I had the privilege and pleasure of reviewing an early draft of the paper, so what can I say? Excellent. Will anybody take any notice of this, or will they just fall for the hype and buy a battery storage system regardless of the facts?

    • April 16, 2018 3:49 pm

      Anyone fearful of power cuts may think the cost is secondary to the benefit.

  5. markl permalink
    April 16, 2018 4:01 pm

    Given the initial cost, upkeep, and lifespan of rooftop PV panels those savings are questionable as well. Selling a home with decade old panels will reduce the value unless the new owner just ignores and disconnects them at EOL and who wants that on their roof when it will increase roof repair and replacement costs as well as look bad?

  6. Phoenix44 permalink
    April 16, 2018 4:06 pm

    Electricity is a rubbish thing to try and store. Why we are wasting so much effort trying to store something that is so easy to generate using really great stores of proto-electricity is utterly beyond me.

    It’s like trying to find a new way to store food calories when we already have cows.

  7. April 16, 2018 5:20 pm

    O/T We already know Eggborough power station is to close in September cos it didn’t win a CfD bid
    But today BBC North has been covering this story :
    \\ Warning power station closure ‘will hike electricity prices’
    … Union leaders are warning the cost of electricity could go up next winter because of the closure of a Yorkshire power station.
    The government says that won’t cause a supply risk. But the Prospect Union has raised concerns. // (So seems to me it originates out of Union PR)
    A similar story ran in 2013

  8. Joe Public permalink
    April 16, 2018 5:27 pm

    A chart, but no mention of the pathetic performance of solar during months of peak demand – 5%-6% during the entire winter quarter.

    Then, guess when those with smart meters will incur maximum peak time-of-day charges per kWh.

    • Joe Public permalink
      April 16, 2018 5:29 pm

      “A chart, …” – the one in the study.

  9. John permalink
    April 16, 2018 6:58 pm

    Took them a while to come to this conclusion.
    Hence why electric cars have problems.
    They may be barking up the wrong tree on this one & need to move on

  10. john cooknell permalink
    April 16, 2018 8:27 pm

    My experience with large battery storage systems is that they cost a lot up front and then you have to replace every 5-10 years, even if you don’t use them a lot.

    Also to work efficiently and reliably the batteries need to be kept in good environmental conditions, not too hot and not too cold.

    They do get very hot when discharging.

    • Paddy permalink
      April 17, 2018 6:47 am

      I don’t fancy an electric car in a winter like last. What happens when you use the heater?!

      • Gerry, England permalink
        April 17, 2018 12:55 pm

        You get to walk places instead of drive.

  11. Ian permalink
    April 17, 2018 11:54 am

    Would the calculation be different for large installations like the new one attached to the Blackburn Meadows (Sheffield) waste energy recovery system? It’s to be hoped so looking at the above.

    • April 17, 2018 6:10 pm

      Interesting Ian

      This new storage will be eligible for capacity market auctions, which will probably cover most of the cost.

  12. Tom O permalink
    April 19, 2018 6:40 pm

    I find this an intriguing concept. I have often thought about having solar panels, but not once have I ever considered having them without battery storage. I think it lies in WHY you consider solar. If you are thinking of solar to save money, then that is one thing. If you are thinking solar as backing up the power grid when it goes down – local accident or storm takes down power lines, then panels without batteries are as useless as teets on a bull. I have never considered selling power to the power company, I just want to be able to keep my beer cold when they fail to deliver power. I never once thought of starting up the “Tom O Power Supply Co, an LLC.”

    Regarding the suggestion of a generator and fuel. Consider a grid failure that lasts, say, 2 weeks. How are you going to supply your generator with fuel, keep 10,000 liters in reserve? I’d rather have a bank of batteries and an inverter, cut back what I can’t use, and still be able to read at night or use my computer while “the beer stays cold in the frig.” And I am talking about a grid failure, blown transformer in a solar storm comes to mind, not just a local failure where power is out for a day or two.

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