Who will be first to offer easy-to-add-on storage for solar?

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Thousands of households with rooftop solar PV are getting only 8-10c/kWh for exports, while paying up to 30-50c for energy in peak periods.

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I wonder who will be first to actively promote an easy-to-add-on storage and smarts package for existing rooftop PV owners?

This makes good business sense because hundreds of thousands of PV owning households are getting only 8 to 10 cents per kilowatt-hour for their exports, while paying 30 to 50 cents for energy in peak periods. These people are already committed to PV and frustrated with the efforts of the electricity industry and its policy makers to undermine their financial returns.

A second area for storage that I haven’t seen discussed is at the micro-level, building storage into appliances, or integrating (or plugging in) storage into local wiring within a building. This limits peak demand charges, offers potential savings on upgrading wiring and reduces wiring resistance losses in existing buildings.

Advances in supercapacitors may play a key role here. New Mazda cars use them instead of batteries for energy recovery and storage, and the CSIRO-developed UltraBattery uses supercapacitors to mediate between the battery and the load, to extend battery life and reduce losses. Research on graphene also seems likely to improve supercapacitor performance.

One example of this potential is in the installation of induction cooktops in existing homes. Most induction cooktops have ‘boost’ modes that can use over 3 kilowatts per pot, so manufacturers can claim they heat up quicker than gas.

This potentially high peak demand can require upgrading of wiring back to the circuit breakers or even back to the street. But the amounts of energy required are not particularly large, so quite small amounts of storage would make a difference. For example, to boil two litres of water on an induction cooktop consumes less than a quarter of a kilowatt-hour.

A proviso is that the benefits must be balanced against the losses in the storage system.

When you look at the fine detail, the economics of appropriately designed distributed storage solutions could be much better than many expect.

Alan Pears teaches part time at RMIT University and is co-director of Sustainable Solutions, a small consultancy. This article is an excerpt from a large piece originally published in the Alternative Technology Association’s ReNew magazine.

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  1. Motorshack 5 years ago

    As a retired engineer, I have to say that I really like the style of thinking in this article.

    Most “revolutionary” technical improvements are actually the result of dozens, hundreds, or even thousands of small improvements made over fairly long periods of time. It is very rare for a large change to occur in a single step, much less completely out of the blue.

    The key point for individual householders and small business owners is that there are dozens of small changes that can be made in energy usage, none of which will seem like a big deal, but that collectively add up to a huge improvement.

    I particularly like the example of the induction cooker coupled to a big capacitor. The idea is not new, in that, for example, this is also how the flashbulbs in modern cameras are powered, but here we have a nice improvement in capabilities without needing to rebuild the circuit from end to end. Just redesign the last stage, and leave the rest as it was.

    I am, frankly, very pessimistic about the human ability to respond successfully to the challenge of climate change. However, if we do succeed in that, I think it will be the result of thousands of such small changes, adopted by billions of people.

    It will likely not be because the political and economic elite decided to lead the way in rational fashion. Those folks are too engrossed in very short-term thinking for that to be likely.

    So, our best bet is probably to solve the problem ourselves, simply by making every little change we can that takes us in the right direction, even if any given step is quite small.

    • wideEyedPupil 5 years ago

      Would be great if modest economic tools like FiTs, RETs and a price on Carbon could provide generalised support and acceleration-to-market for the improvements you are describing. Would it kill Abbott and Hunt to leave well-enough alone things they don’t have the intelligence and insight to understand?

  2. patb2009 5 years ago

    I’ve always thought a decent supercap put on the back of a Solar Cell would modulate small drop outs, and to put some decent sized parallel wired batteries would really let you ride out evening loads and let the inverter do double duty

    • Diego Matter 4 years ago

      well, Tesla with its powerwall announcement had the same idea!

  3. Moose 5 years ago

    Solar360 has trained 45 solar companies over the past month to be able to deliver exactly the opportunity you describe, at a LOCE of 19c PKWH using lithium.

  4. LM 5 years ago

    I like the Bosch BPT-S 5 batteries myself – nice look to it. I think people could see it in their garages but at $14-20K up front they really need to look at a few leasing models to make it more available or wouldn’t it be nice if the Australian Gov’t subsidized it like they do in Japan and USA? Not this government that’s for sure

  5. Pedro 5 years ago

    Laptop computers are a good example of a mini UPS system that could be adapted to many appliances, like TV’s, fridges and other white goods. There are also emergency lighting systems that are designed to come on in the event of a black out which could easily be modified.

    I also know a person that is experimenting with directly powering aircon with PV and controlled by a thermostat.

  6. Chris Fraser 5 years ago

    Sounds like the supercapacitors are very responsive to loads. Would we not also need one of these between us and the grid in case it suddenly browns out ?

  7. Petra Liverani 5 years ago

    The Indiegogo project, Solar Liberator, offers both easy-to-add panels and storage. https://www.indiegogo.com/projects/solar-liberator#home.

  8. Christophe 5 years ago

    You are absolutely right, and I think the same: we produce power from the house rooftop and store the surplus in house, locally, then we reuse this energy anytime when needed: cooking, cpvaccum, grey sky, evening. I built what did not exist yet few years ago and now it does the job. I called it DIY ESS – Energy Storage System –
    It has now 5kWh into Lithium ion LiFePO4 batteries, but can be doubled if necessary, and has been working fine for more than a year now. Google DIY ESS for more details.

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