The guerrilla tactics allowing solar, storage to beat utilities

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(Note: An earlier version of this story was lost – along with the comments made by readers – because of our ongoing “technical difficulties”).

Last week, in response to a story about solar tariffs, one of our readers highlighted some of the ingenious ways installers are getting around the barriers imposed on distributed generation by many of incumbent utilities.

“Le Clair” described how he had installed a 5kW solar system on his household roof, and then, for just $99, added solar hot water – simply by diverting excess solar electricity during the day to the hot water element.  Instead of getting paid 8c.kWh for exporting excess power back into the grid, Le Clair saved on paying 30c/kWh on his hot water. It cut his quarterly bills from $180 to $20.

hot-waterAnd it used equipment as cheap and simple as $10 programmable timer switches (one for the meter box to divert the flow of current from the grid to the element in the water heater, and the second to connect the inverter output to either the house load or the supply for the water heater circuit).

Presto, you are now storing energy that would otherwise have been stolen by the grid,” he wrote. (And, it should be noted, that you are saving around 15kWh that customers may otherwise have had to store, or take from the grid).

It’s a fascinating insight into the sort of guerilla tactics being adopted to work around the barriers being imposed by utilities on households that have or want solar. Barriers that include preventing solar PV connections, preventing exports back to the grid, or paying little or nothing for those exports.

Ingenuity, and there seems to be little that the utilities can do about it, who have been desperate to protect their revenues in an environment of falling demand  and been largely allowed to get away with it by the regulatory settings.

As another RenewEconomy reader noted of the utility tactics:

“This is perfect example of unchecked capitalism, where a law allows a business charge the same amount to a declining customer base. We are already aware that those without solar are facing bigger bills (those with solar will still pay more for what the use from the grid, but it’s less than those without solar) . This kind of law has the potential to wreck the very business it hopes to protect. The irony of the situation is not lost on us. What we are seeing is self cannibalisation of a dirty business. Prices will get so out of hand that even the most reluctant person will be looking to install solar.”

Indeed, as an Ernst & Young survey found, 9 out of 10 Australian households have, are considering or will consider installing solar.

Glen Morris, an expert in small-scale renewables and storage with SolarQuip says Le Clair’s hot water solar work around, and the sort of programmable switches highlighted in our article last week, are just the tip of the iceberg of what some describe as the guerilla –  or hot PV – installations happening across the country.

Solar PV, he notes,  can be used to power stand alone appliances such as water heating, pool pumps, and lighting circuits – without ever needing to be connected to the grid.

Some network operators privately lament that they are unable to monitor the rollout of such installations, because they are not connected, and don’t require network approval (if they could get them).

Morris notes that these installations are being driven by the tariffs, which show little or no reward for solar exports, and network restrictions on solar modules.

“This technology is in its infancy – but there are products out there that do it. and early adopters are looking at these kind of products. We are on the slippery slope to grid defection,” Morris says, adding that some interesting innovations are occurring in battery storage as well.

“People just love solar – they are thinking about how can they can connect solar  –  and if they encounter opposition from networks, they find a way around.” That means finding more ways to “off-grid” parts of the home and part of home consumption.

“We are going through the massive revolution of energy networks. We will have multiple sources of energy, we will have “virtual net metering”, we will have energy distribution across various sites, and peer-to-peer trading.  We are seeing the equivalent of the mobile phone revolution.

Note: If you have any similar stories, please let us know editor at renew


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  • Pedro

    You could install a UPS system supplying power to the home, put in a change over switch for the grid fed battery charger and charge batteries using a DC coupled PV array. And no need for any paperwork/approvals.

    Individually powering non essential items is the way to go initially like pool heating, pumping and cleaning. How about solar electric lawnmowers, like those robot vacuums.

  • Macabre

    We may be a country of vested interests, but we are also a country of innovators. It is a shame for big businesses that they remains unable to tap into this innovation resource as it could yet save them.

  • Macabre

    PS Giles (in relation to your “technical difficulties”), a favourite business maxim I learnt is that “when you start drawing flak, you know you are over the target”. Despite the annoyance of these difficulties it shows that you are very much on target – and you are entitled to take that as a compliment.

  • Jan Veselý

    You should see what my father-in-law, the retired electrotechnician, created. He made whole control system which redistributes his PV energy to the big “energy eaters” (wash machine, dish washer, …) all turned on when ready and when sun is shining. The rest is sent to hot water boiler. And after all of that, the rest is sold to the grid for a trinket price. He is now over 60% of PV energy self-consumed (in summer). In winter it will be probably 100%. All in no-AC-needed country.
    Now he is making something similar to a friend, it should incorporate a heat pump.

    • Rob G

      There certainly would be a market for this smartening a renewable home. And with the way things are headed this could be hooked up to smart software apps that the likes of Google are already making. Electricians should be looking at this as part of their offering it could be as big as solar itself.

  • ChrisEcoSouth

    I’m all for ingenuity, but from experience I would suggest that ‘guerilla innovators’ find a solar technical person/business who understand what you are trying to do, and get them to implement it according to standards, which covers you for safety!
    Also, do NOT buy cheapo inverters from online mass-market sites – these are inevitably just not up to the daily rigours of running complex loads like pumps, vacuum cleaners, etc.

    • Patrick Ira DonEgan

      and then that professional is now liable for anything that happens in that whole house

  • Gongite

    Don’t forget the no-electricity alternatives such as solar ovens and BBQs. We have cut use of our regular oven and hotplates by a huge amount by using them. Good way to cook as well, gets you outdoors.

  • phred01

    The proverbial $**t hitting the fan will happen when there becomes low cost battery storage off grid will become very attractive. Secondly one can use an electric car that’s charged by solar. One of the proposals is some electric models have the option to swap batteries instead of recharging. The 2nd battery could be recharging @ home while one is out. There are many ways to skin a cat and this will hurt govn’t revenue eg GST & excise

  • Motorshack

    I’ve been applying this sort of approach, not just to my electricity consumption, but to my entire budget, so I buy nothing but absolute necessities from any corporation. As a result, my entire monthly budget for personal needs is only about $500 a month, and still dropping. I am retired now, and living on a pension, but even before I reached retirement age two years ago I was able to get by quite nicely working only a day or so a week, and at very modest wages, to boot. I literally had five and six day weekends.

    The One Percent, using corporate advertising, have brainwashed most people into thinking that they are completely helpless if they are not working for some big company, and buying their necessities from such companies. However, that is simply not true. My grandparents lived on farms and either made everything they needed, or bought from local craftsmen. Very little came into the local economy from any real distance.

    People think they need to be rich to be happy and secure, but that is not true. What is actually necessary is to have the little you really need in the way of material goods, and also to be able to avoid a job where you have to kiss ass all day.

    In the long run, it is the chronic ass-kissing that will ruin your day, not the lack of a giant bank balance.

    • Steve159


      “People think they need to be rich to be happy and secure”

      I think you’ll find George Monbiot’s article a worthwhile read …

      “The top 1% own 48% of global wealth, but even they aren’t happy. A survey by Boston College
      of people with an average net worth of $78m found that they too were
      assailed by anxiety, dissatisfaction and loneliness. Many of them
      reported feeling financially insecure: to reach safe ground, they
      believed, they would need, on average, about 25% more money. (And if
      they got it? They’d doubtless need another 25%). One respondent said he
      wouldn’t get there until he had $1bn in the bank.”

      • Motorshack

        Interesting essay from Monbiot, and I agree. Moreover, this is precisely what caused the breach between me and the mother of my children, as it happens.

        I used to make quite decent money as a freelance computer software designer, and I managed to make enough (by my standards) in six to eight months to last the whole year, so I was very happy to use the spare time between projects for more appealing things – spending time with the kids, reading lots of books, etc.

        In contrast, she is a self-made multi-millionaire, and she will simply never have enough. So, she was rather grievously offended to see me so blithely taking time off work, instead of grinding out endless extra dollars, and after five years she insisted that I get my lazy butt out of the house.

        Ironically, when the court determined the child support I would pay, it was a substantial reduction from what I had been kicking in to the household budget voluntarily as a marriage partner.

        Anyway, my overall point is that I am much more likely to be happy living on my pension (of which I only spend about one third) than she is living on her millions (and still grinding out the hours in some corporate job, to boot).

        • Steve159

          There’s a couple of interesting dimensions to your story (which was a great read 🙂

          You may have heard of the corporate heavyweight going south to some South American village by the sea, advising the villager to do this, do that to be wealthy.
          Villager: what would I do with all that money?
          Corporate dude: retire, live by the sea, go fishing …
          Villager: I’m already doing that (smiling).

          Another is that it’s a woman’s prerogative to complain …”if a man stands in the middle of a forest talking, and there are NO women around, is he still wrong?”.

          Ask that of women and many (in my experience) will yell, “YES, OF COURSE! what a stupid question”

          In other words, you’ll be wrong whatever you do, so go your own way (as you’ve done) and enjoy (which you’re doing).

          Good on you.

      • patb2009

        it’s an addiction…

  • Rob G

    Even the smallest pleasures are enhanced by generating your own power. I cooked a slow roasted lamb this last Sunday for 5 hours (did a couple of loads of washing and made several cups of tea too) all this was powered by the sun. I just wanted to find a useful way to use my power so I geared my dinner around my power generation time.

  • Michel Syna Rahme

    How cool! More tips please!

    Shame, because if utilities and retailers chose facts and progressive forward looking business models instead of ideological freak-out reactions behind puppets such as Abbott, they probably would have found prosumers willing to work with them to safeguard long-term profits and the viability of the grid. But na – so stuff them!

  • Doug Cutler

    Is anyone working on a fridge or a fridge add-on that makes ice during hi-sun of midday enough to cool the fridge through a 24hr cycle?

    • Motorshack

      Check out Sundanzer, among others. They don’t use your particular idea, but they are efficient enough to run round the clock on the power stored in a relatively small battery. They are, however, both small and expensive, although reputedly very efficient.

      There are also a number of AC systems in commercial buildings that use cheap grid-supplied electricity during the night to make enough ice to cool the building during the day.

      Also, refrigerators using the ammonia cycle are actually driven by heat, not compressors, so perhaps a solar thermal collector of some kind could store enough heat to run such a system round the clock. The problem with these systems is that ammonia leaks can be dangerously nasty, so, while still used in off-grid situations, they are not very popular.

      • Doug Cutler

        I’m not an engineer. I guess a lot would depend on the relative efficiency of using electricity to make ice factoring in the heat loss of your fridge vs storing the electricity in a battery.

        • Motorshack

          Yes, lots of careful calculations to work out the real effectiveness of the idea.

          However, as an engineer, I also want to say that the hardest part of the job is coming up with novel ideas for solving problems, because that requires the ability to look at things from unusual points of view. You seem to have that knack, so good for you. Keep thinking.

          As for the ideas that I mentioned, that is obviously not my personal creativity. I’m just a guy who reads a lot, and then keeps track of the useful ideas that I run across.

          • Doug Cutler

            I can’t take credit for the basic concept of fridges that store their own ice for long cycle cooling. I think I first saw it roundabout these pages – likely related to links others are suggesting here. But, yes, I do like to try to think outside the box when I can but I can only do it for low-tech.

            So, once again as a non-engineer thinking out loud here is what I might try: purchase a small chest freezer – cost from $350 to $500 here in Canada. During peak sun use the freezer to make as much ice as possible with picnic cooler type ice packs. At sundown, turn off the freezer and transfer the ice packs to your regular fridge turning it into an old fashioned ice box for overnight. A bit of a pain but for die-hards perhaps a way to significantly reduce your fridge’s 24hr draw on the grid.

            Now, what I have no idea of is how efficient or cost effective this might be or what the payback time is.

            Here in Ontario Canada we have smart meters and cheaper power at night. I could reverse the process and use cheap overnight energy to make ice for daytime. I think the payback cycle might be very long though since price difference between day and night electricity is not overwhelming.

        • patb2009

          i’ts not about efficiency it’s about cost. If it’s cheaper, it may be a lot better

      • adam

        Re: ammonia cycle – how does that work? In order to move heat from a cold to a hot reservoir we need work which is through compression.

        I thought Ammonia was just a different refrigerant so just has different thermodynamic properties but the cycle still needs compression so heat can be removed.

        • Motorshack

          No, ammonia is not just a different refrigerant, the cycle itself is different. To see the details, you can check out this Wikipedia article. They explain it better than I would, having not really thought about it for 20 years, or so.

          I was intrigued in reading the article to see that even Albert Einstein once got involved in the design and marketing of a variant of this kind of refrigerator.

          • adam

            wow thanks!

          • JonathanMaddox

            Or read The Mosquito Coast.

        • Ian

          Ammonia refrigeration uses the absorptive cycle. Ammonia is absorbed into water creating a low pressure environment and cooling effect and then boiled out of the water using heat. The heat required is relatively high and causes a technical barrier as far as solar providing a sufficiently hot energy source. Solar powered refrigeration is the holy grail, maybe the next Elon Musk is out there somewhere ready to make a mint!

    • Pedro

      There is a eutectic chest fridge/freezer on the market which from what I believe has a non freezing coolant in the walls. They were about the size of 100 litre ice box. This is going back about 15 years where people on quite modest off grid systems would run the fridge during the day and turn off at night. And the stored coolness in the walls is enough to keep you food cold overnight.

      I am not aware if they have made a more domestic model. the one I was familiar with was much more a camping style unit.

    • ChrisEcoSouth

      Have a look at the Ammonia Cycle Thermal Generation/Storage system that ANU has been working on for quite some time – sounds great, why not fund it better so sunny hot Australia can use it?

  • Roger Brown

    I installed a solar hot water system ( Frost model )about 21 yrs ago when my gas guzzler heater died. Its still going and with a 3 kw solar power system and .44 cents + 6 cents from Energex , I don’t have to worry about a bill , just a small credit .

  • juxx0r

    A thermostat that’s only active when you’re exporting power.
    A heat pump water heater that runs a variable inverter that talks to your solar inverter to consume all the power that would be exported.
    Hydronic underfloor cooling that runs via a tiny cooling tower to eliminate A/C.

  • patb2009

    I’ve thought setting up a couple of solar panels to run a chest freezer, to make ice and use the ice at night to run a small A/C Heat exchanger.

  • Guerrilla solar was first a movement to illegally interconnect off grid solar equipment with the grid. A lot of legitimate safety concerns resulted from this and, thus, in the US UL1741 was born (grid-tied inverters must disconnect from grid when voltage moves outside an acceptable window). I wrote about a resurgence in guerrilla solar “plug and play” solar products a few years ago:

    This latest incarnation of guerrilla solar is intriguing in such that it points out how savings-focused most individuals who go solar are and how economic pressure and energy prices (including the low price of PV modules) are working together to push these solutions to move to guerrilla implementation and commercialization faster.

    From an efficiency standpoint, you’re losing a lot when you turn high grade energy into low grade energy when you convert solar electric power into heat. It’s thermodynamics. It’s fascinating how market pressures such as the battle over the transition to distributed generation will push people to develop intriguing schemes like described above to take control of their energy destiny. History repeats itself!

  • Kevin Brown

    Who/where are the solar installers who can set this up?

  • Steve Fuller

    Could the lighting circuit of a standard domestic supply go off-grid?

    If the lighting circuit was decoupled from the grid connection and replaced with solar elec input and the smallest appropriate battery for storing day time solar elec then off grid lighting would be possible. The installation of LED for efficiency and movement sensors to turn off unused lights would minimise the battery size requirement.

    In the event of battery depletion emergency on-grid power circuit lamps could be turned on.

    Thus the lighting circuit would be totally off grid with grid emergency back up.

    I am interested in the economics and efficiency of such an idea.

    It seems to me that the grid will remain an essential service for a rational, efficient and fair society for the foreseeable future but we need to come up with as many solutions as possible to make a 24/7/’365 renewables powered grid feasible.