Reposit Power Review: Does It Really Halve The Payback Time Of Your Battery?

Reposit pokie

Do you feel lucky? Maybe you can make a great return with Reposit by selling electricity to the grid, and maybe you can’t. Find out with our Reposit Power review.

Reposit is a Canberra based startup. They make software which optimizes the performance of a home battery system. The software is installed on a controller the size of a circuit breaker that sits in your switchboard.

reposit-box

The Reposit Box. It sits in your switchboard and controls your battery.

That in itself is nothing special. There are heaps of companies developing software to improve the financial performance of a home battery system.

The unique thing about Reposit is that it allows you to make some extra money when there is a surge in wholesale electricity prices. If you are with the right electricity retailer, you can get $1.00 per kWh for your exported electricity, during certain ‘high price’ events on your local grid.

Considering typical feed-in-tariffs are $0.06 to $0.10 per kWh, does this mean battery owners with Reposit have hit the jackpot? Reposit seem to think so.

If you install a Reposit box with a compatible battery, Reposit claims it will halve the time it takes to pay off it off.  Here’s a direct quote from their website:

“Reposit learns, adapts and predicts your energy usage so you’re getting the most from your solar. What’s more, you’ll save on your energy bills which means, on average, you’ll pay off your battery in half the time.”

And here is a video clip of Lachlan Blackhall, co-founder and Chief Technical Officer (CTO) of Reposit saying:

“Reposit minimizes your electricity bill and halves the payback time of an average battery.  When the price of energy in the wholesale market is high or when the grid needs extra energy to remain stable, Reposit can sell your energy back to the grid, earning you Grid-credits.”

 

In the full version of this video he goes on to say:

“Getting Reposit technology adds about 5% to the cost of a battery purchase, but the economic benefits alone mean that if you’re buying a battery and not adding Reposit you are absolutely crazy.”

It all sounds very impressive.  If I had known Reposit could halve the payback time of batteries I wouldn’t have spent the last year telling people, “No, they don’t pay for themselves yet, you’ll have to wait a while longer.”  Instead, I would have been saying, “Yeah man, batteries pay for themselves!  Just make sure you’ve got Reposit and you’re good to go!”

If Reposit had sent me information ages ago showing how great their product is, I could have happily let everyone know about it.  But they didn’t. And I can’t blame them – as I didn’t actually ask. To right that wrong, several weeks ago I asked them to provide me with historical information showing how well their technology performs.

They didn’t give it to me.

Because I didn’t have information from Reposit to work with, and because there is almost no information of substance on their website, I had to look into it on my own.

As a result, I have concluded that while installing Reposit may save people money and be an effective investment, it is very difficult to estimate what the return might be. Further, I just cannot see how Reposit can be correct when they say they can “halve the payback time of the average battery”.

Reposit Qualifies “Average Battery”

About a month ago now, I called Reposit, and asked if they could send me data showing the historical performance of home battery systems using their technology.  They promised to get it to me in 5-10 days.  After two weeks they let me know they’d been delayed but he would get back to me. After about three weeks from when I first contacted them they called me and told me they had looked into the historical data and said that Reposit would halve the payback time of batteries for people on time-of-use tariffs.  They also told me it would increase the average number of times the battery is cycled per day from 0.8 up to 1 to 1.3 times.

I thanked them for telling me this and asked them to email me the data. They didn’t send it.

But Reposit did kindly send me an email repeating what they had told me over the phone:

  1. For ToU customers Reposit doubles the savings (and halves the payback times) when compared to non-Reposit systems that only try to maximise self-consumption. The additional savings that Reposit achieves are based on intelligent pre-charging, ToU arbitrage and GridCredits.
  2. Reposit achieves average utilisations factors for ToU customers in excess of 1 and up to 1.3 (average utilisation for non-Reposit systems is approximately 0.8). On individual days Reposit is able to achieve utilisation factors up to 2 for some customers.
  3. Reposit is seeing an increasing amount of GridCredits opportunities nationally that will increase the savings that customers are able to achieve with Reposit technology.

If you are wondering what “ToU” means, it stands for “time-of-use tariff” where the amount people pay for grid electricity depends on the time they use it.  Time-of-use tariffs have a high “peak” price during weekday afternoons and evenings, a low “off peak” price late at night and early in the morning, and a moderate “shoulder” price the rest of the time.

There Is A Lot Of Variation In Time-Of-Use Tariffs

Reposit told me a time-of-use tariff is required to halve the payback time of a battery using Reposit.  Time-of-use tariffs can definitely improve the economics of battery storage, but I have wonder which one he means?  In Sydney and Perth the peak rate for a time-of-use tariff is around 48 cents a kilowatt-hour.  But Brisbane’s peak rate is about two-thirds that at around 34 cents.  And in Melbourne and Canberra it’s around 24 and 22 cents respectively.

If Reposit was more forthcoming with which time-of-use tariffs they are referring to then we would know which parts of the country they think they can halve battery payback times.

“Systems That Only Maximize Self Consumption”

Reposit told me that people on a time-of-use tariff can halve the payback time of their batteries compared to, “…non-Reposit systems that only try to maximise self-consumption.”

I find it very easy to believe a battery system equipped with Reposit could halve its payback time in places such as Sydney and Perth compared to, “…systems that only try to maximise self-consumption.”

But I find it very hard to believe the average battery installed in these places would, “…only try to maximise self-consumption,” because that would be a really primitive way to control a battery system.  So I don’t think Resposit is correct when they say they can halve the payback time of the average battery system because I don’t think the average battery system is controlled by such primitive software.

For example, if an original Tesla Powerwall is connected with a StorEdge Inverter and Interface the software in the battery inverter can take advantage of time-of-use tariffs.

But maybe Reposit has information that shows the average battery system does only try to maximise self-consumption.  If they do, I’d like to see it.

GridCredits Can Save You An Unknown Amount Of Money

If you are with the retailer Diamond Energy and have Reposit then it is possible to earn ‘GridCredits’ by selling electricity from your battery system to the grid.

As explained in the introduction, this very smart idea is Reposit’s ‘secret sauce’. It is the main reason people would choose to invest in Reposit instead of relying on the battery optimisation software that comes as standard with their battery.

Here’s how it works: When the wholesale price of electricity goes high enough, what Reposit calls a ‘grid event’ occurs. For each kilowatt-hour exported from your batteries to the grid during this time, you will receive one GridCredit.  GridCredits are worth $1 each.

It doesn’t matter how high the actual price of electricity goes, each kilowatt-hour your provide will still only be worth $1.  So if the wholesale price of grid electricity was $10 a kilowatt-hour during a grid event you would receive 10% of that amount.

I asked Reposit how often these grid events occur.  They didn’t tell me.

Their website FAQ states:

“Some parts of the grid will experience these events twice monthly – like in South Australia – while other parts of the grid are currently oversupplied with coal generators and are less volatile.”

This is not a lot of information to go on.  While it is not possible for Reposit to know how many grid events there will be in the future, they definitely could provide a state by state breakdown of how many grid events there have been in the past. Then people can decide whether or not they like the odds in their area.

Reposit say they are seeing an increasing number of grid events.  I’d like Reposit to quantify that. And I can’t understand why they are so hesitant to publish a list of historic ‘grid events’ to help people determine the value of this feature in their home state.

Potential Earnings From Grid Events

Reposit’s software will predict when a grid event is likely to occur and ensure your battery is adequately charged.  A battery won’t always be able to supply all its stored capacity in every grid event, but I am going to be very optimistic and assume that it will.

If, as their website suggests, South Australia can expect a grid event twice a month then someone with a brand new, original Powerwall who sends its maximum storage capacity into the grid each time would earn around 148 GridCredits over 12 months.  This would be worth $148.  But since electricity used for grid events isn’t available for household use, the amount saved would be less than this.  If it all had to be made up by electricity from the grid it would only save around $1041.  If instead of sending its full capacity during grid events the battery was only able to manage an average of half that then over a year it might only save as little as $52.

But whether you’d actually average 2 grid events a month in South Australia is not clear and no real information is provided about other states – except it would be less.  Without actual historical data from Reposit showing how often grid events occur and how long they last, we really have no way to predict how much money could be saved. We can’t calculate how much money existing Reposit customers have saved by having Reposit’s unique GridCredits feature.

But More Batteries Means Fewer Grid Events

Reposit says they are seeing an increase in grid events. But if Australia installs 250,000 battery systems by 2020, as Reposit CTO Lachlan says he expects2, then this should be more than enough storage to reduce the incidence of grid events over the next three years.

If these 250,000 battery systems have an average output of 3.3 kilowatts of power they will be able to provide 825 megawatts3 in total which is almost 2% of the total generating capacity of the National Electricity Market.

By my reckoning, this should significantly reduce the number of grid events that people with Reposit may be relying upon to earn them GridCredits.  It should also reduce the difference between peak and off-peak rates for time-of-use tariffs, tariffs reducing the value of using stored energy during peak periods and reducing the value of electricity arbitrage.

I’m happy to be wrong on this, but at the very least Reposit should address what appears – to a layman like me – to be an issue with their business model. I’m sure Reposit have done the modelling – and it would be great if they could share it publicly.

Reposit Allows Energy Monitoring

Reposit works as an energy monitor for your home and through the use of an app allows energy consumption, solar electricity generation, and battery use to be tracked.  This can be a very useful tool for households to use to reduce their electricity bills by maximising their self consumption of solar electricity and reducing their peak grid electricity use.  A dedicated energy monitor without Reposit’s other benefits can cost from $220.

Reposit Chews A Lot Of Internet

The Reposit system is designed to work around occasionally losing access to the internet.  But it does use a crapload of bandwidth.  Reposit’s FAQ says:

“…the system will require about 1GB of data per month.”

That’s one billion characters.  Moby Dick4 has about one million characters.  So Reposit sends data equivalent to one thousand Moby Dicks a month.  That’s more than one Moby Dick an hour.  No matter how much you enjoy tales of seamen and sperm whales, that’s definitely going overboard.

The Cost Of Installing Reposit

It costs $500-$600 to install Reposit for a home with single phase power.  Currently there are three compatible battery systems listed on Reposit’s website – the original Tesla Powerwall, the LG Chem RESU6.4, and the Magellan RES1.

The replacement for the original Powerwall, the Powerwall 2 was recently announced.  The LG Chem RESU6.4 has been replaced by the LG Chem RESU6.5.  And Magellan no longer has the RES1 on their website.

I’m assuming Reposit are working on integrating their technology with the current battery models.

It Has A 10 Year Warranty

Reposit has a 10 year warranty on its system.  That’s not bad and matches the warranty of most new battery systems on the market.  Of course, as with any product, a company still has to be around to support a warranty.  Generally this would go without saying, but I mention it in this case because when a company goes belly up their products usually will still function.  But if Reposit’s servers stop working it’s game over.  As anyone who has played server based games can tell you.

 

This is a consideration when buying a Reposit system.

It Only Has To Pay For Itself

Reposit doesn’t need to halve the payback period of batteries to be worthwhile.  If they provided information that showed it would save an average of $70 or more a year, then at $600 or less to install, and assuming a lifespan of only 12 years, many people would be happy with the 3%+ return that would represent.

But I have no solid information I can use to estimate what kind of return it might give.  I have tried to get the information from Reposit, but they are hesitant to provide it. Naturally, that makes a cynical bugger like me question their bold payback claims.

I can say that if you are on a time-of-use tariff and you have a battery system that only tries to maximise self-consumption you really need to do something about that, but Reposit isn’t your only option.

We Need Software Like Reposit’s

The world needs the type of services Reposit provides. Services that both enable and encourage battery households to supply stored solar power in to the grid when needed.  This can reduce electricity transmission and distribution costs and help integrate clean renewable energy into the grid, reduce fossil fuel use and reduce grid outages.

But it is important to be fair and transparent to customers.  If claims are made about a product it can’t live up to, people can become disillusioned. That can hurt our industry. If someone believes Reposit when they say it, “…halves the payback time of an average battery,”  she might become very annoyed and seek a legal remedy if it doesn’t.

I hope Reposit will have a successful future, because we need people writing the sort of software they make and who can adapt it as required to deal with things such as demand tariffs and other complexities the Australian electricity market frequently throws in the face of consumers.

But until they publish some of the data sitting on their servers, data that quantifies the payback of existing Reposit systems, consumers looking for a financial return won’t be able to judge for themselves if it is a good idea or not to invest $500-$600 in a Reposit box – so they can take advantage of $1 GridCredits.

As my father always used to say, “In business, whenever there is any doubt, there is no doubt.”

 

Even if it transpires that the GridCredits income is minimal, many consumers may still invest in the system simply because it supports the integration of renewables into the grid. But those consumers still have the right to see the data behind Reposit’s claims. I personally think it is a shame that such a small, innovative, important and nimble company appears so opaque.

Footnotes

  1. This assumes the household is on a standard tariff for Adelaide.
  2.  at 3 minutes and 43 seconds into the same video I linked to before
  3. When this article was first posted this figure was off by a factor of 10 as the result of a very careless mistake on my part.  Fortunately G F pointed this out in the comments almost immediately, so thank you for that, G F.
  4. If you don’t know what Moby Dick is, it is a classic novel your school teacher wanted you to read that has a school teacher sleeping with a sailor in the first few pages.
About Ronald Brakels

Many years ago now, Ronald Brakels was born in Toowoomba. He first rose to international prominence when his township took up a collection to send him to Japan, which was the furthest they could manage with the money they raised. He became passionately interested in environmental matters upon his return to Australia when the local Mayor met him at the airport and explained it was far too dangerous for him to return to Toowoomba on account of climate change and mutant attack goats. Ronald then moved to a property in the Adelaide Hills where he now lives with his horse, Tonto 23.

Comments

  1. Hi Ronald, I agree with what you say but believe that you are a decimal place out with your calculation of 250,000 x 3.3kw = .825 GW,? Keep pushing them for the data!

  2. Interesting article, Ronald. I wondered about their claims, too. It seems that anything to do with home batteries is shrouded in mystery.
    One error, I think. 250,000 batteries at 3.3kW is 825MW.

    • Ronald Brakels says:

      Thank you, yes, I made a mess of that, didn’t I? But almost 2% of the NEM’s generating capacity spread throughout the country and presumably instantly dispatchable, will still have quite a significant effect.

  3. G’day Ronald. Again, another great article mate! I too had engaged Reposit Power many moons ago now and I tried to get the business modelling, because well … good business demands it! Just like you, they never followed through. You are the first to point out the value of a ‘grid credit’ = $1.00. But does it actually translate into $1 back in your bank account or is it s credit that you draw down on, depending upon who holds that credit. I could not get them to cough up what that actually meant either.

    I suspect it might have some merit, but from where I sit at the moment, it’s a bit of a black box / buggery box setup with not enough detail. And on that note … you have nailed it spot on mate!

  4. PS Just watched the full video and a comment made by Lachlan does beg a serious question. And that is … if Reposit (or any other like platform for that matter) cycles your battery several times a day, then what implication does that have for one’s battery warranty?

  5. Good article and agree with the tone. Hard data is hard to get in solar and batteries.

    Regarding wholesale prices (expressed in kWh and referring to NSW):
    – average price is $0.06
    – its $0.31 right now (30 degrees in Sydney in the afternoon peak)
    – I cant post a pic but I have a chart in front of me from the AEMO which shows that the NSW wholesale price exceeds $0.20 for approx 50, 30 minute intervals each year. And yes, the same chart shows that these spikes are becoming less frequent. There were about 150 p.a. between 2001 and 2005.

    Obviously a grid event requires a price >$1.00. Based on the data above I’d guess this happens no more than one hour a month (being generous). So I’m making $12 month gross from Diamond (say $8 net). Fair to say I wont be an early adopter!

    QLD and SA are much more volatile. Multiply the above figures by approx 3-5 times to make a guess.

  6. Howard Patrick says:

    I too have followed Reposit, at a far shallower depth. You have helped me and I’m sure many others to better understand the product.

    Seems some of us need to be patient and wait for the time when battery costs have come down and systems that enable PV generated energy to the sent directly to EV batteries, to reduce cycling of home storage batteries, have been developed.

    The PowerWall 4 and its equivalents.

  7. I too have been following, and speaking to Reposit to try to understand the economic benefits. And I greatly value your article to further my understanding. I would value further articles in this area as I suspect smarter energy manage systems is an area where there is lots of room for development and improvement in the economics of solar and batteries.

    I too have been disappointed that they have not been able to offer any hard data to substantiate their claims. I too also think the “halve the time to payoff” is exaggeration, certainly for me, and that is despite that fact that I have TOU metering in Sydney with a large difference between the off peak and peak times, with a large potential to use battery in peak times.
    The most optimistic calculation I can come up with based on their numbers (assuming 24 grid events a year AND assuming you can full discharge your battery every grid event AND assuming you then recharge from the cheapest solar (8c) electricity AND raising the average number of cycles / day from 0.8 to their upper end claim of 1.3 AND all these cycles happening from the cheapest solar electricity and offsetting the peak TOU rate(48.48C)), is payback 1.8 times quicker. But I guess maybe they have thought this is close enough to round up to halving the payback time if you then also forecast for increasing number of grid events, and a widening of the gap between solar feed in tariff and peak TOU tariff. BUT, to me this all look wildly optimistic at best. My guess is for vast majority of people will not come close to this for various reasons. For me, by my calculations, it is not even worth me being with Diamond Energy to get the grid credits, because it is better for me to go to another provider who can provide cheaper overall electricity rates (calculation outlined below). But if you are getting a battery, I does look like you can more easily justify the addition cost of Reposit ($500-$600), and this is without the grid credits, and purely based on smarter system allowing better utilisation of the battery. For me, even on a more pessimistic set of assumptions (no grid credits AND only raising battery utilisation from 0.8 to 1 cycle per day, and only getting tariff arbitrage from off peak to shoulder, or shoulder to peak) I get a payback on Reposit in about 5 years. It is probably reasonable to assume that these assumptions are on the pessimistic end, and I would guess the payback is probably significantly better than this. So if you have any faith in Reposits data on increase in battery utilisation, it looks sensible to get Reposit if you are thinking about battery. Note : I would be very happy for Reposit or anyone else to come on and correct/improve these calculations and assumptions.

    HOWEVER, having said that, a smarter energy management system similar to Reposit, is on my “mandatory” list of requirements for any battery system, as I do think that it will improve the economics today, AND don’t want to be locked out of future benefits that I assume are likely to continue to develop. So I suspect it might be a case of undermining their own credibility with the exaggerated claims (at least in the eyes of the more savvy buyer), rather than being more conservative, but being able to put up a real case that does support the economics of Reposit being able to pay for itself, and improve the economics of the battery. Reposit might be doing this to further propagate the myth of “justifying battery installs purely based on hard economic payback” rather than aiming at the market of battery buyers like myself who have it partially justified by other reasons.

    From my investigation, it would appear that Reposit has a significant lead in this space. As far as I am aware, they are the only people who have got the “Grid credits” going. HOWEVER, I strongly believe that too much is made of the Grid Credits, and at this stage, the other things they are doing which might be more important are not getting enough analysis. At least according to their marketing claims, they also have developed smart algorithms to maximise the battery usage based on solar and demand forecasting. Eg understanding your demand profile, putting this together with weather and solar generation forecast for your individual setup and demand pattern, and recharging and discharging the battery at the appropriate times to minimise the overall cost of electricity. This might mean that they might charge the battery during off peak to cover usage requirements through shoulder/peak for the coming overcast day (or even charge in shoulder to offset peak). So for me any systems that does learn, adapt and take into account your specific usage and generation patterns, tariffs as well as improve this with weather data, and factor in cost of battery degradation with discharge/recharge etc is not going to be able to maximise the economics of the battery. Reposit claim to be able to do all of this, though again, I would like to see more detailed analysis of their algorithm to understand any gaps between the marketing and the reality. Though I guess they would argue they have done this in their claims at being able to raise the average number of cycles from 0.8 to 1 or 1.3 cycles per day.

    In the ideal world I would also like them to extend this further to being able to control loads to further improve the optimisation that can be done. Eg control when to turn on hot water heaters, pool pumps etc so these are using the cheapest electricity. This could be further extended to run air conditioners automatically, based on forecast and inside temperatures etc. This would be like being able to buy a bigger battery, for what I assume will be a cost that is a fraction of the price of an actual battery. This level of integration does not seem to be here yet. But with a system like Reposit, it seems to me that this is just a matter of software development, with some fairly basic hardware and this should all be possible. And if they can encourage integration with hot water/pool manufacturers, this level of integration can be even more powerful. Reposit have shown they have a track record in the ideas and software development, as well as bringing other stakeholders into partnering in their vision (Eg energy retailers, battery and inverter manufacturers etc). So I think they are as good a bet to back as anyone to be able to further improve the economic.

    A few of my thoughts questions on all of this as follows :-
    1. I would be interested in more review on what other players are offering in the smart energy management systems. As near as I can tell 1) most of the battery/inverter manufacturers seem to be pretty dumb, and looking to 3rd parties like Reposit to improve their capabilities 2) Evergen seem to be claiming similar capabilities to Reposit, but without the Grid Credits (I am guessing this might be relatively easy for them to add, if and and when grid credits are worth it) 3) A couple of others (Sunverge and Sonnenbatterie) suggest they have software that competes, but I have not been able to get any specific information. Would a future article reviewing some of these other options be in the pipeline 🙂 ??

    2. for me at this stage, I suspect the $1 grid credits might be of little benefit for a lot of people interested in finding the cheapest overall electricity rather than focusing on headline $1 Grid credits. From my analysis, Diamond Energy prices are more expensive than the cheapest electricity retailer I can get, and even the most optimistic forecast for the value of the grid credits falls short of the extra I would pay to get them. In my case, their off peak rate is more than 25% more than the other provider making it better to stick with the cheaper provider until prices change to justify the benefits of the grid credits. The other thing is I assume it is likely is that if I install a battery and Reposit, my off peak usage is actually going to rising due to charging battery off peak to offset peak/shoulder usage. So I suspect the off peak rate needs to be competitive to justify the grid credits.

    4. For the post above from DickHunt, that talks about the NSW wholesale price, I am not sure this market is the whole story???. From early conversation with Reposit (which I might have misunderstood), I think they suggested about 3 potential markets that might justify a grid credit event (apologies to Reposit if I have misunderstood anything from this conversation). Obviously the wholesale market is 1, but I think he suggested that there was another market for standby generators that are responsible for stabilising the grid when load causes a frequency shift. I got the idea that this was separate to the wholesale market I think you might be looking at, and I think there might have been a 3rd market he suggested that I can’t remember the details of. But given my complete lack of knowledge, and potential complete misunderstanding, it would be nice for someone who really knows to give us all a more detailed understanding on how this all works, and correct any mistakes I have likely made with this.
    3. for the battery/solar industry, what Reposit (and others) are pioneering is an important and very interesting development. I believe even today, and despite what I can only assume are exaggerated claims, what they offer would does appear to justify the purchase of a Reposit box with a battery purchase for a lot of people. For some people it might even change the economics of batteries just enough for them to justify the cost, especially if part of the justification is not purely about economic payback. In addition, I believe there is lots of potential in the future to expand this. So it is a bit of a shame that it appears balanced coverage has to have a negative component to try to explain the exaggerated claims. Unfortunately this leaves less time to focus on what I believe are the very real economic benefits of adding Reposit to any battery purchase. Let’s hope that Reposit and others can provide more data to support their claims, and if necessary scale back their claims, so future articles can focus on the positives. I suspect it is a very good product, so pity to have some exaggerated claims throwing question marks over its viability.

    Keep up the excellent work you do in this blog.

    • Really good post and extremely comprehensive. I also have TOU metering in Sydney (via Mojo). A couple of comments:

      1. Smart, integrated systems are definitely the way to go. Need to be really smart though … for example my pool pump runs off peak at 0.094c kWh. FIT is 0.073 kWh. The arbitrage of switching the pool pump is very small for me. I appreciate that this is just a tiny example and that other applications e.g. switching on and off aircon while remotely closing shutters or blinds and running a roof extraction fan could be a big winner.

      2. Reposit needs to come clean as how it works. No doubt they are working like crazy under the surface on both their technology and their marketing. I don’t believe they have a competitive advantage currently – this space is going to be very dynamic and exciting.

      3. Diamond needs to come clean as how these grid credits work. You bring up a good point – it could be based on any price >1,000MWh in any of the states forming the national market. Makes it quite a bit better for the consumer. Mind you, Diamond are not exactly altruistic – they are buying electricity for $1 kWh, and selling for the spot price which will be at least $1kWh, and possibly over $10kWh. Which goes to your point that the overall deal needs to be attractive….

      4. Promoting the grid credits is great marketing. It relies on consumers greatly overstating the frequency of rare events (grid credit events). This is a common psychological bias.

      5. There is going to be a lot of dynamism, and it could be at retailer level. I think we are going to see a lot of smart new products. I think the economics are going to improve substantially for the consumer, driven by lower cost of battery storage and to a lesser extent solar.

      • Howard Patrick says:

        Seems the big advances will come when EVs become a substantial component of the transport sector and a large proportion of off-peak power finds its way into EV batteries.

        Unfortunately the current Australian Government, and, probably the Opposition, have difficulty looking very far into the future. This is especially the case when so many in the Government are anthropogenic climate change deniers.

        Hopefully R&D advances and the market will lead our Government by the nose.

  8. I don’t understand why batteries are only cycling about 1 time unless it is a very broad average.
    I would have thought that with Sydney TOU pricing, batteries would be discharged once in the evening from accumulated excess solar and once in the morning from overnight grid charging at off peak rates, for an average recycling of say 1.5 times per day.
    Perhaps a lot of people even on TOU tolling don’t have sufficiently big solar systems to charge the battery during the day for use in the later end of the day peak or even shoulder TOU tolling periods.
    What do you think?

    • Ronald Brakels says:

      In Sydney there is no peak time-of-use period in the morning. It’s only from 3pm to 9pm on weekdays. The shoulder period starts at 7am, but the latest the sun rises in Sydney is about 7:01am so solar will be producing at least some electricity and reducing the need for power from other sources, whether from batteries or the grid. And charging an 89% efficient battery system with off-peak power is only going to save about 7 cents a kilowatt-hour if that power is used in a shoulder period, which is not worth the battery degradation it will result in under any normal circumstances. As a result, even in places such as Sydney and Perth with a large gap between peak and off-peak electricity rates, people trying to maximize the economic return from their battery systems aren’t likely to have a high average daily cycle rate.

      But if something like Reposit knows there is going to be cloudy weather and the battery won’t be able to fully charge off solar electricity, then it can charge it using off-peak power and use it during the late afternoon and evening peak.

  9. I spoke briefly with Reposit at the C4CE (Community Energy Conference) in Melbourne. I am an Enova Community energy retailer shareholder, so I am interested in assisting Enova to help their aim of being 100% renewable asap.
    The Reposit box could help companies such as Enova manage their peak demand, the Enova management must have plans for a system such as the Reposit to assist management of the Peak demand, such as happened early this year in the heat wave.

    Reposit is also part of a pilot study into a marketplace for excess power, as is seen in this recent article:
    http://reneweconomy.com.au/greensync-launches-world-first-exchange-trade-stored-household-solar-power-49889/

    I too would like to see the data that backs the Reposir claim for pay-back period. I wonder if this would come under the ‘truth in advertising’ legislation??
    I do know that Reposit is considering a Hot water system switch to supplement the optimum energy use. This would also allow the retailer to manage demand to some extent if the customer allowed. In my case, I am using simple element type storage Hot Water Services (for 2 units) that I will be heating with Solar PV excess or if on TOU, the low rate, which is almost equivalent to the Grid-feed Enova is paying for PV grid feed at 12c/KwH.

  10. For what it’s worth 1Gb per month of data costs a minimum of $70 per month from Telstra.

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