According to The Australian Financial Review today, the battery-storage wars are breaking out, with Australia in the thick of it. Tesla, while the highest profile, will not be short of combatants.
Raghu Belur, co-founder of Silicon Valley start-up Enphase Energy, which will launch its home battery in Australia in early 2016, points to the wide gap between the typical "feed-in" tariff that a household in Australia will receive for its excess solar power and the price of power from the grid.
Prices for mains-supplied power more than four times as much as the feed-in tariff in some cases make battery storage worth a look.
No surprise, then, about Tesla's early focus on Australia for its Powerwall system, with its sleek, coloured wall-mounted 7-kilowatt-hour or 10kWh batteries to be available in 2016.
Bernstein Research, a bull on the lithium-ion battery space, describes Tesla's system as already "modestly attractive" in Australia – the 20¢ a kilowatt hour spread between wholesale and retail power prices gives a five-year payback.
But the Grattan Institute puts the realistic cost of a Tesla battery, including inverter, charger and installation, at more than $7000 in 2017, too expensive for most. It says the price would have to fall to about $1600 before it made economic sense in Brisbane, Adelaide and Perth, and by more in other cities.
Yet lithium-ion battery costs have fallen 94 per cent since 1991, while the energy packed into them per kilogram has increased. Bernstein sees usage costs continuing to fall by 20 per cent a year, cannibalising competing technologies for the next decade.
Meanwhile, a major Japanese company,Panasonic, a battery supplier for Powerwall and one of the "big three" lithium ion players alongside Samsung SDI and LG Chem, will launch next week an alliance with Australian electricity retailers targeting home storage.