![Just connect to grid: A Tesla Powerwall - or other such battery - could boost Australia's energy supply faster than a ...](/content/dam/images/g/s/3/r/v/1/image.related.afrArticleLead.620x350.gv4p1c.png/1490251254040.jpg)
Australia could get an extra 2 gigawatts of electricity – the boost Prime Minister Malcolm Turnbull wants from an expanded Snowy Mountains hydroelectricity scheme – through batteries and connecting a quarter of the houses that already have solar panels.
The same increase in power could come from equipping 400,000 solar homes with a battery such as a 5-kilowatt Tesla Powerwall 2, a Tesla spokesman said on Thursday.
It would be a quicker process than expanding the hydro dam, which could take at least four years.
"If you were to take one quarter of the Australian households with solar and apply a Powerwall, allowing half of that Powerwall to be aggregated into the grid, you'd have the same amount of power as would come from the boost of an expanded Snowy Mountains hydro at a fraction of the cost and a time frame of one to two years," the spokesman said.
![A slower fix: Snowy Hydro Tumut 3 power station in Talbingo, NSW, is in line for a $2 billion expansion.](/content/dam/images/g/u/z/j/v/7/image.imgtype.afrArticleInline.620x0.png/1490247726676.jpg)
The notion of using batteries to stabilise power grids got a boost this month when Tesla founder Elon Musk offered to build a $100 million, 100MWh battery farm in 100 days. But it's not a major leap. A CSIRO report for industry association Energy Networks last year predicted that by 2027 electricity customers would be generating 29 gigawatts of rooftop solar, up from about 5GW in 2015 and that battery storage would have grown to 34GWh from zero.
Co-ordinating batteries
The technology to coordinate batteries and let households sell their output into the grid is newer than the long-established practice of feeding solar-generated power directly into networks, but is already happening.
"All it needs is a co-ordination and market interaction layer, which we provide for $600," said Dean Spaccavento, a co-founder of energy management group Reposit Power, which has been doing it for 15 months and operates in NSW, Queensland, Victoria and SA.
An advantage of batteries is that they offer a distributed energy source. New transmission lines aren't needed and the network is resilient – a storm in one location may knock out an area, but not necessarily others.
The upfront $4 billion collective price tag of purchasing and installing nearly half a million Powerwalls – at a price of about $8000 apiece and $2000 for installation – is more than the $2 billion Mr Turnbull said it would cost to boost the current 4.1GW capacity of the Snowy Mountains scheme by 50 per cent, or another 2GW. However, the cost would be paid by individuals – rather than the public purse – who would also benefit from lower power bills as well as credits from the grid.
"It's an absolute no-brainer," Mr Spaccavento said.