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How to beat the Energex “solar stitch-up”: Take part of your home off grid

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Energex’ recent submission to the Queensland Productivity Commission electricity pricing inquiry left a lot of solar system owners concerned about their systems and their plans to add batteries at a later stage.

Energex recently increased their supply charge from 91c/day to $1.28/day. The Off Peak Tariff and Night rate tariff are also to go up. The latest addition to this is a proposal to remove the 44ct feed-in tariff 265,000 solar system owners in Queensland have been enjoying if they add batteries to their existing system.

This proposal in particular has upset many system owners because it appears it directly targets those who try to make the most of their renewable energy without causing further harm to Energex’ network (or the planet). Energex’ concern is twofold:

  • Consumers could potentially storage energy in batteries at off peak rates and sell it back to the grid at 44ct/kwh.
  • If consumers store their solar energy in batteries they would then use this during later that day/evening. This is the exact time frame Energex has earmarked for newly planned demand-based tariffs. I.e. between 7am and 4pm you may pay 20ct/kwh, but during 4pm to 8pm you pay 40ct/kwh.

We are not the only ones who are concerned. Solar Citizens, a consumer advocated group has the same understanding of Energex’ proposal.

Whilst we don’t support the idea of charging the batteries at an offpeak rate and then selling it back at 44ct (it is against current regulations) we do obviously support storing solar energy in batteries for use at a later time.

We believe that proposals like these are more likely to come up over the next few months and years as utilities across the country come to terms with storage systems on their networks. Most experts now agree that the networks have been “overbuilt” and this is a key reason why we’re seeing such drastic proposals from utilities as they’re seeing their income stream disappear.

Given the state of flux the utilities are in currently and most likely will be for several years, purchasing a storage system comes with some risks. We advise our customers to consider reducing that risk by taking part of their home offgrid while leaving some of it connected. This means you can keep your 44ct feed in tariff, install batteries (completely separately from the existing system) and by taking part of your home offgrid you’re taking the first steps towards true independence.

Over the past 2 weeks we’ve received a number of questions from consumers relating to this.

I’d like to share those and our answers:

Energex argues the increased ability to keep large amounts of power for release back into the network would give those solar householders on the top rate an unfair advantage which was never intended by the bonus scheme?

  • GiantPower:  Any of the generated power directly from the solar panels or stored in the battery bank will never be exported to the grid. Our system simply does not have that capability.

Ergon does not call for eligibility to be removed in its submission, but argues that generous government rebates and feed-in tariffs have shifted the mindset of many customers from an environmental motivation to seeking a financial return. Am I not allowed to make the most of my feed-in tariff?

  • Giant Power: Whilst improved financial returns are a part of the outcome (and demand charges only make this better) there are 4 other reasons why you’d want to look at battery storage.
    1. Lock in your energy price against future price increases: By becoming your own power provider and spreading the initial system cost over time, you effectively lock in power for items on your off grid circuits at a far cheaper rate than is currently available.
    2. Store your solar power and use it at night: By being able to rely on the stored solar power in your system during evening and night, you can keep your peak power use low and avoid any future price markup / time of use tariff.
    3. Protect your essentials against blackouts and power outages: With automatic switching to stored power without interrupting supply, you might not even notice the grid is out.
    4. Improve your solar profits by exporting more power from existing solar system: By taking off the load from your essentials, your existing solar system can increase the amount of power that is exported to the grid. However, it can’t and won’t exceed the maximum approved capacity as no change is made to your existing system. This increase in exporting more energy into the grid is no different from you taking a 3 months holiday and reduce or eliminate any power usage in the house while you are away.

Tom Kuiper is wholesaling manager for Giant Power.

  

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  • Chris Fraser

    It is good to work towards energy independence. Although having part of a house on the grid still possibly creates problems. Consumers find they consume very little, but still have the dubious privilege of paying $1.28/day to connect. In that case, better keep the EV recharging socket on that circuit.

    • Humanitarian Solar

      With this approach the article raises about taking part of a house off grid, I think its to be avoided where possible as a summer solar system will be short in winter and one sized for winter will be over sized in summer, hence slower to pay back. I think we need to grasp in each State what rules we are responding to. Is the network discriminating against all solar systems? Just solar systems that feed back power to the grid? Just solar systems over a particular size? Just solar systems with storage? e.g.. if its just solar systems that feed back power to the grid (export) then I think the fastest payback would be installing a solar system with storage and setting the inverter to not feed back power to the grid and only use the grid for high power loads (inverter max output too small) and winter (PV too small). In this way the whole house still benefits from the solar system rather than taking half off the grid – in summer there would be parts of the days where the batteries are full resulting in the solar controller disconnecting the PV from the batteries (waisting power), while the other half of the house is still drawing power from the grid.
      In summary, I think as a community, in each state, we need to be very clear how we are designing for our chosen gear to give us the best and fastest payback. My suggestion where the rules are constantly changing, is designing to maximise for self consumption and not depending upon a FIT is a good fallback position. If a system pays itself back in a reasonable time in these circumstances, as far as I can see, it should do so in any policy context. So people short on cash, I think a small system designed for autonomy in summer, with enough batteries to be able to meaningfully use much of the PV power generated, is a good cost effective entry level strategy. This is the fastest way I can think of to achieve the best payback in any policy environment.

      • Ian

        In general you are right to say that household systems should be optimised for their individual circumstances and policies should reflect those household needs, however solar PV has become so cheap that optimisation is not such a big criterion, batteries are still expensive. It’s not unreasonable to slap solar panels on every available surface and allow any excess to be wasted, or to design for the worst case scenario so that for a few days in summer when the aircon needs to belt out cooling or in cloudy weather when the solar panels struggle to achieve a fraction of their rated output there is excess capacity to achieve adequate solar power. We are told networks ‘gold plate’ for this very reason. Once batteries become cheap then there may be a shift to a more balanced system. Again, regarding the poor utilisation inherent in having two separate PV systems on a house, with the advent of cheap solar that does not matter so much. The driving force here is the tariff structure of the utility. Consider this: if a house has a duplex supply system and the tariffs change so that integrating the systems becomes more beneficial there probably won’t be a huge cost to joint the off-grid array to the grid or vise versa .

        • Humanitarian Solar

          Hi Ian, I’m one of the households without a FIT. I designed the solar system to cope without a FIT. The inverter is classed by the regulators as a “remote inverter with charger capability” which means the inverter is not setup to export power to the grid and is setup to merely be a passive recipient of the grid, importing electricity when the load of the house exceeds its 3KW output or when the batteries are run down in winter. I haven’t tested the system as yet, as I’m still renovating a building to install the solar system. As you can see I’ve designed the system to not mess with utilities profits and merely meet my own electricity needs and so hopefully I won’t upset the monopoly of the grid, as I’m merely supplying me and no one else.

          • Ian

            As Joseph’s brothers sang ‘there’s one more angel in heaven, there’s one more star in the sky’ , every off grid system is one less place at Energex’s table. The vacuum left by an off grid system is almost as bad as ‘ self-consumption’ of a low FiTgrid tied system. Some would say selfish to hoard such a resource as solar panels and batteries, which could be used in all sorts of ways to stabilise the grid, but voting with your feet is the type of pressure needed to shake up the networks into creating a better prosumer – distributed network that we need as a country and as a community to decarbonise our energy supply. The value of that freedom of choice to the collective is greater than the value of a fully grid-integrated battery and solar system.

            With regards to your system, a 10 year payback is far too long, that must be the battery component. Since you’re still connected to the grid, be like South Australia and use that grid link as your ‘battery’ , rather spend your money on more solar panels , perhaps even to cover your summer peak demand or cloudy weather reduced power production. Have your system battery-ready though, so that when Elon Musk gets off his butt and makes lithium batteries as cheap as a Great Wall ute, you are then good to go.

          • Humanitarian Solar

            Hi Ian, a few decades ago I was an electronics and communications technician. I can see your versed in the paradigms of energy use at a macro level. With the micro level, solar panels, solar controllers and batteries all work on DC and DC appliances are slowly evolving. Tesla held sway over Edison because AC is the only way to transmit power over long distances. We then had no trouble putting power poles over one of the most low population density countries in the world, especially as last century we had cheap fossil fuel energy to pump it around. Australia is two thirds the size of America though we have one eighth the population density. In my view the grid will reverse and need a planned retreat. There aren’t really many appliances in a house that would need running on AC and so most future appliances could be removed from an inverter and work directly off DC. This would mean being mindful of the distances of wire runs, though the cost of the inverter, the next biggest cost after batteries, can be reduced by only running the minimum appliances through it that are necessary. If you look at the solar systems of developing countries they are much simpler and often use DC systems. For rural Australians, the advantage of communications gear and critical systems running directly off DC is only a battery failure would result in the system going down. Where possible, building in simplicity not complexity is best.

  • trackdaze

    The retailers wiuld be best to focus their energy in applying the blow torch to the network opertators.

  • Jacob

    When would the 44c/kWh FiT expire normally.

    • Humanitarian Solar

      I agree that’s a very important question so we know whether it’s worth taking the FIT into account for planning the solar system expansion.

    • Ray Miller

      1st July 2028 in Queensland. But of course this is always under review and could be revised, but judging by the 2,500 being removed each month it is likely only to be a few soles with this in 2028. And if the electricity prices continue to increase the value decreases with inflation etc as well. So in short the benefit/liability is ever reducing depending on your interest.

      • Jacob

        Why are 2500 houses being removed every month

        • Ray Miller

          If the property has a change of electricity account the 44c FiT is extinguished and is non transferable, with the a we seem to be a very mobile community.

  • Beat Odermatt

    There are several opportunities to increase the use of renewable energy in the home. Some residents may decide to have a secondary low voltage (12V) system installed which provides for all lighting (LED) and power to computers, TV sets etc. Such a system could take power from additional solar panels and battery storage. The camping industry provides for a large range of low voltage equipment which could be also used in a domestic situation.
    Smart meters can provide can provide energy companies with an opportunity to further reduce peak demand. There is no need for example for a hot water system, a dish washer, cloth dryer or washing machine to operate during peak demand times.

    • Humanitarian Solar

      http://WWW.springers.com.au are a low voltage specialist in Brisbane. Most DC appliances run on 12V and 24V so given a choice 24V is better as the cable diameters will be half the size.

      • Beat Odermatt

        We had recently a large scale blackout in SA because of interconnection trouble with Victoria. We were able to help ourselves and our neighbors in providing light and power to mobile phones because we had some fully charged batteries and LED lights. We are keen campers and it came in handy to have a bit of a backup.

        • Humanitarian Solar

          Fantastic, I have a 12V solar setup in a campervan and also have used the camping gear in a power outage. People can redeploy their 12V fridge and gas cooker and inverter in those emergencies.

      • Chris Fraser

        Not being electrically trained i suspect i’d be guessing cable diameter is proportional to the necessary amperes to power the appliance(s).

        • Humanitarian Solar

          I don’t have the formulae on hand though I think it’s an inverse square ratio, as in if the voltage is doubled and hence the amps half, the cable diameter is even less than half the previous diameter. So a 24V system requires much less diameter wire for the same distance between the battery and the DC appliance. the exact formulae can be found in Collyn River’s books.

        • Humanitarian Solar

          For a voltage drop of 2%:
          S = (L x I x 0.82) divided by V0 where:
          S = cable size required in mm2
          L = total conductor length in meters (eg. twice the distance between the batteries and appliance as the electrons have to get there and back)
          I = maximum current in amps
          VO = operating voltage
          “Solar Success: Complete Guide to home and property systems 2nd Ed. 2014, Collyn Rivers” and http://www.successfulsolarbooks.com and http://www.caravanandmotorhomebooks.com

          I found these calculations a little daunting at first though really its just plugging the numbers in. The books gave me enough knowledge to plan in consultation with the experts in the shop that supplied my gear. The books help me assess my needs and plan out stages fitting in with my budget. It’s a decent investment, so anyone interested will be rewarded just like researching a new car or real estate.

    • Humanitarian Solar

      If you’re interested in DIY home/property systems and mobile systems as well Collyn Rivers has comprehensive books on these different solar system installs. Theres also info in the forums on the sister site called One Step Off the Grid.

  • Mike Day

    I fail to see the issue here. Anyone who is installing batteries, is I assume installing them to capture excess generation during the day, therefore, they are not exporting, or exporting at a greatly reduced rate. Thus the loss of the premium tariff is academic at best.

    In addition to this, given that the standard tariff is far below the 44c/kwh, I can’t see a situation where someone on the premium tariff could ever benefit by not exporting and the economics of batteries would not stack up. Even on the peak time of use tariff, you lose 4c/kwh, plus whatever it costs you for the batteries.

    Much ado about nothing really.

    • Humanitarian Solar

      I agree. A remaining issue is not having backup power in a grid outage though those are currently rare and would only apply to business’s with frozen food stock etc.

  • Humanitarian Solar

    I think Giant Power’s suggestions apply to people who are installing a new solar system without a generous FIT, except Point 4, as I can’t see it being worth exporting power, unless it’s only leftover power in summer which would otherwise be lost once the batteries are fully charged. a cheap conservative approach would be install a solar system big enough to be autonomous in summer and top up the batteries with the grid in winter with off peak electricity rates.

    • Chris Fraser

      Pity that the expiring FiTs will not be a consideration in solar design in the future. This will ensure that households keep finding ‘loads’ to keep their PV busy.

      • Humanitarian Solar

        Exactly. Using inverters or monitoring equipment to switch on loads like pool pumps, header tanks, hot water boosters etc. The alternative is only design the system so it’s big enough for summer, a good cost effective entry for a solar system.

  • Ray Miller

    Just a quick economic analysis show a couple of things;
    -those on 44cents would benefit by adding extra PV and keep the regulated inverter the same, add an western array to keep a higher PV output later in the day to cover a greater proportion of household loads. This also reduces the peak demand on the network.
    – the cost of battery systems at present is very high, amounting to many times the current electricity price
    – the value in a battery system is that of resilience, when the grid may not be present to provide a level of backup energy, which should be encouraged. Higher battery backup costs can be justified under these circumstances.

    • Humanitarian Solar

      Yes I think last I talked with a Qld installer, people needed to keep the same size inverter or the rules were such they would lose their generous fit, however it appears people can increase PV without losing their Fit. I’d always check the rules prior to the install as they seem to be changing.
      I don’t understand the reason for a western oriented PV if they have a generous FIT as there’s no benefit to use the power as they produce it for dinner. north facing will give more power overall and work best if people can get a good price for it if they can’t immediately use it or if they don’t have a FIT they are best to get a few batteries.

      • Ian

        Sorry to chase your tail like this, but you raise excellent issues. I am just restating your comments and expanding on them to try get a better understanding of the situation.

        As I see it, an inverter will output to a maximum and then no more. If rated 5KW that is what it will maximally export to the grid. Having 10KW of solar panels connected to a 5KW inverter, for arguments sake, would keep the maximal 5 KW output going for a much longer proportion of the day, (say 5hrs at 5 KW as opposed to 1 hr at 5KW) and thus benefitting more from the generous FIT. Is that the idea? Is a special export limiting device needed or does the inverter do the job adequately? If the inverter limits the output capacity of the solar array, in the above case to 5KW, how would the household use that ” wasted energy” as well as continuing to export the full 5KW to the grid? Perhaps a bigger inverter attached to a bigger array with an export limiting device to prevent excessive power export to the grid. Such a set-up would probably break the rules and negate the generous 44c/KW tariff though.

        By the way, and for what it’s worth,extra PV added to the western facing roof would prolong the maximal output of 5 KW into the afternoon, so the North facing array would peak at mid day and the western array would peak sometime in the afternoon. Together you might get an extra hour of maximal solar output which can be shot off to the grid, obviously to maximise exports the household should have to minimise its electricity loads for that time in the usual way of the 44c net feed in tariff.

        • Humanitarian Solar

          Hi Ian, if its possible to add more PV without negating the 44cKWH FIT, yes the PV would power the inverter to export its maximum output more often, though yes there would be waisted power if the PV output exceeded the inverter output. In a hybrid or remote solar system, the PV often directly feeds the batteries and so only when they are fully charged, the PV is either disconnected from the batteries or some inverters can be programmed to export the extra power over and above what the household needs once the batteries are full. The inverter is the brains of the solar system and how intelligent it is depends on how many configurations it can be programmed to do.
          With west facing arrays, http://www.solarchoice.net.au say in their article on tilt and orientation that a west facing array will only ever produce up to 85% of its rated output. They also have a really neat diagram showing power output for tilt and orientation. I believe we previously only thought of using west oriented arrays when we were cooperating with a cooperative grid which often needed the power in the afternoon in summer when people switched their AC on, though designing for the household, its best to orient north whenever possible, especially as we adopt batteries, as they don’t care what time of the day the power goes in, they just need the PV dishing out as much power as possible, especially in winter.

      • Ray Miller

        Yes the solar inverter will self regulate to the maximum level and may also derate its output in elevated temperatures to keep the unit within safe operating limits.
        Adding a western array is all about increasing the average power delivered to the grid (the peak is limited by the inverter) and increasing self useage. The ideal would be a fully tracking system but is seldom implemented due to cost, reliability and complexity takes the gloss off. The next best is to add (if suitable full sun location is available) a western bias PV array as an auxiliary one. As households tend to have higher loads in the late afternoon, kids with computers, electric cooking, air conditioners it benefits both the 44c systems and those on much lower rates. Everyone then self consumes more at the retail price and exports at a time of higher wholesale prices. If the dwelling was on TOU with the peak price being 4-8pm the solar benefit is even larger.
        Yes the western array will not deliver the year round output a northern one will but as PV prices are coming down it is more than justified as a way of lifting the average power and total energy delivered from solar. Of course the array needs to be engineered to be comparable with the overall system design. Also then if batteries are included importantly it gives more opportunity to charge the batteries and/or reduces the work load on the batteries making them last longer.

  • Ian

    Just to clarify,Tom, are you saying that to retain your current 44c/ KWH FiT and get the benefits of battery storage on this energex network, all that is needed is having two PV arrays the existing one on the generous tarriff still connected to the grid in the old way and a new one completely off grid with solar panels ,invertors, MPPT’s, Chargers, batteries etc. Is there no way that Energex can use this as an excuse to renegade on the locked- in 44c/ KWH tariff? We all know that they have spat the dummy on this tariff, and look for the tiniest out to their commitment.

    What I had in mind as an example for a second off grid system was an off grid PV kit powering a pool circulation pump plus pool solar heater with excess power going into a small subsidiary air conditioner with a small deep cycle battery completing the system. The whole system ,power generation and load completely separate from the grid.

    Others might choose to have an off grid system power the regular domestic appliances like fridge, TV, computers, lights , washing machines etc using the off grid PV array and powering the same devices using the grid connected system when the off grid array fails through lack of sunlight on prolonged cloudy days. The only separation between power supplies and domestic loads being a switch.

    The first example has a off grid system subsidiary or extraneous to the current on- grid system whilst the second is more sketchy in its separation of the two systems.

    What do others think?

    Here are some reductio ad absurdum arguments: I have a grid connected solar array on the 44c/ KWH tariff and as a separate system have some garden lights with solar and battery storage. Minute power requirements but still a second off grid solar system, can Energex refuse to honour their commitments because of this? At what point does the size of an off grid system constitute a breach in the customer’s contract? Here’s another example in a similar vain: same grid connected array but with laptop computers charging batteries from a mains outlet? Is that acceptable? Or maybe an EV doing the same thing, charging from the household mains power, but in this example having the ability to return power to the grid?

    • Humanitarian Solar

      The article says it is only a “proposal” to discriminate against people on the generous FIT – who add batteries to their PV. In my opinion such a proposal would be unfair, as not all Inverters feed back power to the grid. Additionally as Mike Day says below, what is the point in adding batteries if the household has a generous FIT? Those with a generous FIT are effectively using the grid as a cheap or profitable battery. Only those without a generous FIT should consider adding batteries. So those with a generous FIT should abide by the rules to keep it and those without a FIT are in a position to get quotes on the payback of various batteries.

      • Ian

        Sorry but this article is primarily about the 260 000 home owners with the generous 44c/KWH tariff. Not much is about the more recent installations of solar PV. The whole point of the 44c/ KWH tariff is that it encourages export of as much solar power generated as possible . It’s not about storage, anyone with this tariff would want to maximise their export of power. The original idea behind the tariff was to encourage the uptake of solar at the time when solar panels were expensive. There was no mechanism to tail this off as the price dropped and the draconian measures slashing the FiT coupled with the vote winning grace period saw a massive uptake of solar. Energy networks in Queensland are now locked-in to this 44c tariff for those people. There is obviously an attrition rate as people’s circumstance changes, but for those that choose to stay in the same premises and hang onto the same tariff this article is addressed to their needs. It’s not a question of fairness or otherwise, it’s a question of government and energy network honouring their commitments. Times continue to change and people want to add to their solar PV systems. If this proposal to deny people the 44c/KWH tariff they already have if they add storage is made law then what are these people’s options? The author Tom Kuiper says yes there are options, namely install an independent and second PV system with battery storage that does not and cannot feed into the network’s grid. In such a scenario Energex in particular could not legally revoke that household’s 44c/KWH tariff. In effect these households can still enjoy a decent return on their original ( and often ) expensive investment in Gridtied PV and move ahead with the times and add storage. I don’t think he is really too concerned about the abstract ” greater good” or what’s good for the ” people ” or the ” collective’s energy supply system” that’s for philosophers and university professors. I think he is addressing the individual who has a household and needs to use whatever means legal to maximise his or her investment to best improve his or her lot. One cannot blame Energex for doing the same thing it’s just that the two clash badly. Householder wants to add storage and keep the premium tariff, energy company wants to sell as much product for as much money as it can get, and eliminate the consumer/ producer competition. If it came to choosing sides I would go with the consumer/ producer simply because
        I am one of them!

        • Humanitarian Solar

          Hi Ian, ok I will be more on topic. If I were in your shoes, I would want to see the Energex proposal to know exactly under what circumstances Energex wish to take the 44c/KWH tariff away. I personally see their argument, which I think is correct, people with an export tariff that is higher than an off peak electricity rate, could unscrupulously install batteries and design a system to import electricity at an off peak rate and export at their higher rate, thus making a profit out of the network, or perhaps rather other consumers on the network. As you pointed out, the tariff was originally intended to kick start grid connect systems and not for the purpose of making an income from the difference between import and export rates. In my view, Energex have a point to somehow set a boundary with people who may wish to do this. While the 44c/KWH tariff remains, people can enjoy this and reap the benefits of adding PV to their roof and there is little point adding batteries. However if people did wish to add a few batteries as a backup in the event of a grid outage, then in my view those batteries should not be allowed to discharge electricity into the grid and the inverter should be set to keep the batteries on float, so they are fully charged in the event the grid goes down. In this way, people like yourself could update your system to include storage, while addressing Energex’s concern to not make a profit by exporting electricity at 44cKWH then importing it back for 20cKWH. If we find a way to address Energex’s concern, then you can move ahead with storage while addressing their fears.

          • Ian

            Awesome analysis, perhaps we should do some thinking for the utilities, for free of course. Is buying a grid connected storage system worth while to get that most depraved and unfair arbitrage between off peak power and the 44c FiT? A tesla Powerwall 7 KWH battery pack has a life of 5000 cycles and costs about $9500 to install into an existing solar grid tied system. The round trip efficiency from grid to charger to battery to inverter and back to grid is about 87% so the cost of getting the equipment to achieve this arbitrage is $9500/(0.87 x 7 x 5000) = 31c/KWH. Seriously, is anyone really going to bother with this whole arbitrage thing? The fuss the network operators make about arbitrage makes them look like right royal nobs.

  • Humanitarian Solar

    The chief threat arising in this article is not to those on a generous FIT as they are already on a good deal and that won’t change if Energex get their proposal through. The real threat is getting a precedent where a network can discriminate against a solar system that adds storage – even if that solar system does not feed back power to the grid. What people do behind the meter on their property should be up to them as it involves nobody else. If the solar system does not feed back power to the grid (export) then what does it have to do with Energex??????????????????????????????????

  • Ken Fabian

    Whilst I agree that buying off peak and selling it back at a price that has a subsidy included is unethical, buying cheap – or withholding excess – and selling back when wholesale electricity prices are high – with no subsidy component – looks perfectly ethical to me. I’m fairly sure the off-peak supply we get is tied to specific uses – a hot water system on granny flat – and it would be illegal, as things stand, to connect it to a battery charger, but that kind of limitation should be reviewed; much as our electricity big players would prefer that climate change and transition to low emissions be entirely separate to discussion of electricity supply and pricing in the presence of intermittent renewables, that transition looks necessary and urgent and protecting the profitability of fossil fuel plant should not have precedence.

    The potential to purchase off peak with the use of solar and batteries is something offerring possibilities I find very interesting. Mostly they are variants of what I’d expect power companies to do or at least be considering – prepurchasing ahead of predictions of extended overcast conditions for own use; load shifting between periods of high and low use; shifting between high and low prices.

    Smart systems can be set up to maximise self use, but they could also maximise buying and selling to the electricity market. Going on holidays? Program the system for maximising returns from export rather than maximising home use and let those batteries run low. Could we see retailers bypassed completely and solar and battery fitted households buy and sell directly via wholesale electricity markets? Surely the overall cost for a household should be less if they aren’t paying that middleman’s cut.

    Power companies can also get creative and see all those batteries and solar panels as opportunities – contracts that give them access to a proportion of those stored kWhrs, for load levelling, load shifting, blackouts and emergencies? I think they will have to because the way it’s going they will be left with old plant that’s forced into ever greater intermittency, forced to up prices to stay financial and creating the ideal conditions for attracting new technologies and new players.

    • Humanitarian Solar

      With para 1, I’m in the process of setting the system up so it can charge batteries during off peak electricity rates. The FIT is only 4cKWH regardless of when the power is exported, so I didn’t even bother designing for power to be exported as it would have involved extra costs that aren’t worth it for the amount the system would ever have excess. I’m low on cash so the cheapest way for me is design for autonomous summer use and hit the charger button on the inverter/charger in winter or when the batteries run low. So the system is purely a passive recipient of the grid and I’m doing my best not to make any waves to get the grid off side.
      In the future when solar households are a bigger lobby group and voting group, I hope big battles can be won where a truly cooperative grid can be had for all.

  • Humanitarian Solar

    To satisfy Energex’s concern about not “storing energy in batteries at off peak times and sell it back to the grid at 44cKWH” inverters can be chosen or configured to not do this. An example is the Victron Brand has an option called “Keep Batteries Charged” where:
    The inverter will stand alone or switch to mains power as soon as it is available.
    No DC power will be drawn from the batteries to feed the AC loads, so when generated Solar Power is insufficient, power will be drawn from the mains in order to supply the loads.
    Solar power will be fed to the AC loads and/or into the mains.
    Use this option when you want to be sure that the batteries will be full when a mains failure occurs. http://www.victronenergy.com searching on Self Consumption Hub 1.

    In this way people on the 44cKWH feed in tariff could add batteries as a backup to mains power and the solar system would import and export power the same as it did prior to the installation of batteries, not adversely effecting Energex. I’m sure all inverter brands would have this option.

  • Miles Harding

    Interesting how the needs and greeds of the network operators translate into complete nonsense in this story.

    Charging batteries off-peak and supplying the grid at peak is exactly what we should be going as we transition to renewably sourced electricity. From this point of view, it doesn’t matter whether the energy comes from local solar panels or a distant generator, although the line losses may make this less attractive. What is important is that the batteries are not charged from fossil fuel sources.

    Our over-built networks have to be written down and the bureaucrats responsible stood against the wall, or this sort of distortion will continue to suppress any transition to the Renewable Economy we urgently require.

    Without near-total decarbonisation, it is difficult to see how organised civilization will make it past the end of the century. It really is a matter of life and death.