There are various levels of consensus on storage in the clean energy sector. A lot of people agree pumped hydro sounds like a good way to store cheap energy generated by renewables, but not everyone agrees the enormous Snowy 2.0 project is a great way to do it. Pretty much everyone also agrees storage is a great way to squeeze the most value out of a residential solar PV system, but a lot of the people who install and sell batteries will privately admit it’s an expensive proposition.

For many owners of systems with storage, however, there’s no question. They saw the opportunity, they bit the bullet and now they’re largely free from the grid. In many cases this is happening on the edges of networks, where electricity is costly. As a consequence, city folk don’t get to hear many battery stories.

George Zombori has a few to share, though, because as CEO of Tesvolt Australia he’s been involved in fixing energy problems for clients in far flung spots such as Christmas Island (14.4kWh installed in a seed-cleaning shed) and the outreaches of Western Australia (48kWh at an avocado farm). Tesvolt also has form around the world, with projects as large as 4MWh on-grid in the UK and 2.68MWh off-grid in Rwanda.

Networks want storage

The case for storage is being heard. As far as he’s aware, Zombori tells EcoGeneration, most of the network operators are insisting that battery storage be included in plans for large-scale solar PV plants to provide frequency control, peak-shaving and to inject additional energy into the grid when it’s needed.

When cloud cover interferes with generation networks appreciate if a solar plant can fill the void with stored energy, he says. “The idea is to have a very continuous injection into the grid as opposed to fluctuations – 100MW … 20MW … 100MW … 20MW – this is one of the drivers that could be leading to good results,” Zombori says.

Miners have been cautious about committing to renewable energy, he says, but any shift in government policy which sees companies effectively charged for their own emissions should see them using clean energy – and storage – to replace existing providers. “Some of the mining companies are starting to look at these opportunities.”

The biggest hurdle has been outright reluctance by the federal government to attempt an objective opinion on clean energy generation and how it might replace the nation’s ageing coal plants.

From the outside in

Tesvolt is approaching the Australian market from its fringes, and Zombori says he is very keen to find applications in the agriculture sector, particularly in remote reaches. “All of them are struggling with energy,” he says. “The grid is very unreliable and any time they need poles and wires extended to them they have to pay a fortune.” Tesvolt has systems installed at three Australian farms, Zombori tells EcoGeneration.

A system installed at an avocado farm in Pemberton, West Australia, saw Tesvolt and developer Unlimited Energy awarded The smarter E Award last year. The off-grid system includes 53kW of solar PV, a 160kWh saltwater battery system and 48kWh of Tesvolt storage.

The tipping point where commercial and industrial energy users with solar charge into a frenzy of battery purchases is just around the corner, or so we’ve been told for a while now. It all will happen when prices pass some magical benchmark of affordability. When will that be? Zombori smiles. “I am planning to give a lecture: How to find your way out of the battery maze,” he says. “The poor audience has a million choices and it is very hard to compare apples with apples.”

The CSIRO battery guidelines will be welcome, he says, as dodgy manufacturers will find it harder to conceal their sins. On his numbers, Zombori says solar and storage below 100kW can be bought for 6-8 cents/kWh, which is compelling. “That magic number tells you battery storage is already reaching its potential.”

Installed Tesvolt systems are generally cycled once a day, Zombori says, calling up some client load profiles on an ipad while manning a booth at the Smart Energy Conference in Sydney in April. The concept for the client in the example he shows is to charge as much as possible from PV in the morning and use that energy up to a 10pm knock off time. Most of the time the operation runs without any input from the grid, he says.

Another happy customer. But there is still so much ground to cover. “Anyone who is using diesel should be knocking on our door,” he says.