A brain for your battery storage system: Q&A with Reposit Power

Reposit Power is a Canberra-based start-up that promises to be one of the key facilitators of Australia’s battery storage revolution. Their product is an $800 battery storage system control system (a ‘Reposit Box’) that could spell the difference between a home’s saving a little and saving a lot on an energy bill – all through intelligent software that maximises the ‘energy effectiveness’ of a home.

Although the company has made a name for itself through its innovative GridCredits product, which allows battery system owners to trade their stored energy at premium rates, it also does a lot more. We wanted to know more about exactly what value proposition Reposit Power’s innovative technology offers, so we asked them some questions about the specifics of how their system works. 

1. The basic idea with Reposit Power’s GridCredits is that households who have energy storage systems will be paid a premium rate for exporting electricity to the grid during peak pricing events, when electricity is expensive.

How would you explain the value proposition of GridCredits to the average solar homeowner who is considering installing a battery bank?

The Reposit Box is like a smart brain for your battery. It turns off the basic control system that ships with your battery/inverter and puts a smarter one in its place. It helps you get a lower bill in two main ways.

First, it uses machine learning to become predictive about your use of energy, and it uses weather models to predict solar. With this information it can do a better job of making your battery anticipate your needs in the day ahead – and keep you in the loop by sending you notifications.

Second, it links you up with the wider electricity system so you can sell back when the energy market is willing to pay you worthwhile amount for your stored energy. You access this by switching to a retailer offering GridCredits – which are earnings a bit like a feed-in tariff.

The Reposit Box doesn’t cost a lot more in the context of buying a battery system – we think it would be silly to make such an investment without getting the best control system available.

Reposit Power screenshots

2. In addition to peak pricing rates, will households also be eligible for lower daily rates roughly equivalent to their retail tariff rates?

Right now you can shop around to get the best electricity plan. It’s the same when you have a battery, except that you will be able to have a plan that is ‘transactive’ with rates for both buying and selling electricity. The first company to offer such a plan is Diamond Energy with their GridCredits 100 product, but more companies have products in development.

3. Reposit’s ability to let battery owners sell their electricity at a premium during peak time is based on the idea that retailers will be willing to pay for their contribution to the grid.

Given the size of the grid and the huge amounts of energy and power during peak events, it seems clear that there would need to be a lot of battery-owning households with Reposit Power systems to make it worthwhile for a retailer to consider making payments to them.

Would there therefore need to be a ‘critical mass’ of thousands of distributed Reposit-equipped energy storage systems deployed before customers started seeing benefits from GridCredits? Or could households start benefiting immediately?

When you get a battery, you are like a power station; a really good power station. Most traditional power stations take anything from half an hour to several hours to start. Yours is super fast – acting in as little as 2 seconds. And your power station goes in both directions; it can generate AND it can consume. This is just the sort of power station we need as our grid becomes more renewable – with wind and solar ramping power up and down.

The issue is that you are a TINY power station when compared to traditional electricity generation. Our national grid management systems were well designed in the 1990s despite the fact the designers could not have anticipated the present wave of ‘decentralisation’. Reposit has been able to develop software that aggregates households and allows them to participate in these ‘spot’ markets right now.

4. The customer’s choice of electricity retailer is another important part of this puzzle. Obviously households with Reposit-equipped batteries will want to sell their peak electricity at a premium, but only if doing so makes sense in the scheme of their overall retail electricity plan. This might require some shopping around. Will these Reposit-equipeed customers have the same range of electricity retailer choice as those without Reposit systems?

Yes – the first product is out there: Diamond Energy’s GridCredits 100. And more products are being trialled right now.

5. How much control will Reposit-equipped households have over when and how much of their stored energy they sell into the grid?

A Reposit Box does the work for you. It watches the weather, learns your patterns and looks for opportunities to earn in wholesale markets. Our app tells you what is likely to happen in the coming day so you can act accordingly if you want to – for example, it will predict your battery becoming full allowing you to use excess solar if you can. The main thing is that the customer chooses an energy plan that they like – this will determine how often you sell back and for what price.

6. Would a Reposit-equipped battery bank cost more to a household than a non-Reposit equivalent? (If so, how is this justified?)

Yes a Reposit Box is a small additional investment at around $800 more than a standard setup. We think its a no-brainer. It makes your solar and battery investment work harder, and allows you to choose an energy plan that works to get your bill as low as possible.

7. How many energy storage products currently available in Australia are compatible with Reposit’s GridCredits? Any more on the horizon?

We are mainly supporting batteries from LG and Tesla with a range of inverters including SolarEdge, SMA and SunGrow. There are a lot more in testing.

© 2016 Solar Choice Pty Ltd

Jeff Sykes


  1. Would a battery system with the reposit system make any sense if you are on the premium feed in tariff of 68c/Kwh?

    1. Hi David,

      Generally speaking, it’s not in the interest of people with a premium feed-in tariff like yours to get batteries, full stop. Battery storage works best for homes that doesn’t get paid much for solar that they put into the grid.

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