Australia is at the dawn of a battery storage revolution. A recent report from US-based IHS Technology states that Australia’s energy storage market will grow from less than 500 battery installations in 2015 to 30,000 installations by 2018, while Morgan Stanley has found that half of all households in Australia are interested in installing solar panels with battery storage, with the market potential estimated to be $24bn.
However, one of the biggest gripes for those early adopters buying battery storage systems at the moment is the loss of efficiency of devices. For example, the Tesla Powerwall starts off with about 92% efficiency but, as the lithium cells degrade over time, these efficiencies, and its capacity, drop further.
But a new battery has come onto the Australian market that claims to not only maintain 100% of its storage capacity but also has a round trip DC-DC energy efficiency per cycle of 80% and is recyclable at its end of life. The ZCell is a zinc bromide flow battery designed by the Australian energy storage provider Redflowand is said to be the world’s smallest flow battery on the market. It could also have broad reaching implications for everyone’s electricity bills – if power grid operators take note.
Originally designed for the commercial, industrial and telecommunication sectors, the ZBM battery has now been repackaged as the ZCell for the residential market, allowing people to “timeshift” solar power from day to night, store off-peak power for peak demand periods and support off-grid systems. Bizarrely, Redflow thanks Tesla for ZCell’s realisation.
“Energy storage is having its moment in the sun as a concept and we have Tesla to thank for that, for really lighting the battery storage fire”, says Redflow’s executive chairman, Simon Hackett.
Hackett says that although Tesla has been the harbinger of household battery storage in Australia, there’s room for improvement.
“There are different batteries suited for different sorts of applications. While it’s absolutely logical for Tesla to be packaging their lithium batteries for home use, I think lithium batteries are better suited for cars while flow batteries are better for the residential market.”
Redflow has designed the outdoor battery ZCell, which is about the size of a standard air conditioner unit, stores 10 kW hours (kWh) of electricity and comes with a 10-year warranty. What makes the battery really stand out, says Hackett, is that it can store as much energy at its end of life as it does at the beginning.
“Lithium battery cells get worn out when worked hard, as lithium is a sprinter of a battery. What you need for your house is a marathon runner and that’s what our flow battery is. It’s an industrial-strength battery built to go from completely full to dead empty every day.
The first ZCells are expected to go to homes later this year (around June) and Hackett estimates that the final cost for the system, including installation, will be about $18,000.
“It’s not an entry-level price,” Hackett concedes. “But it’s a large battery.”
ZCell is also recyclable when it reaches its end of life, as the zinc bromide solution can be cleaned and put into a new battery, while the plastic casing and electrodes can be recycled into bottles.
Hackett suggests the unit would be most useful for householders using large amounts of energy – for example, those who have electric cars. Hackett himself is said to be Tesla’s biggest individual customer in Australia for electric cars – and he’s charging them with the ZCell battery.
However, he adds that everyone could benefit from battery storage as it could transform the way the power grid works, making it cheaper and more effective.
Last year, it was found that Australians are paying significantly more than people in other parts of the world in electricity network charges. These high charges cover the cost of electricity poles and wires and make up more than half of electricity bills.
In the last five-year period (running to 2015), networks recovered $44bn from our energy bills, which was used to replace ageing infrastructure (such as power lines, like those in Kilmore East which triggered fatal bushfires in 2009) and cover the forecast increase in energy demand.
But things didn’t quite go according to plan. The AER’s State of the Energy Market report 2015 revealed that, for the first time in Australian history, “demand for electricity declined or stayed flat for six consecutive years to 30 June 2015”, meaning that some of the investments weren’t needed.
The problem was exacerbated by the fact that, as network charges rose, customers used even less energy, thus making network prices increase further to cover losses.
Hackett argues that energy companies will continue to “drive people off the grid if they get too greedy about fixed network costs”, adding that if networks instead installed batteries into the grid and encouraged householders to do so by committing to purchase excess energy off them, then they could potentially save millions of dollars, make the grid more efficient, cheaper for consumers and therefore more attractive.
The concept is something that grid operators are looking into, Hackett says. “It’s just a question of how quickly the economics and batteries improve to make that business case stack up.”
He adds: “As batteries get cheaper in the near future, I expect that networks will increasingly move to this model.”