Tesla Powerwall, Solar and Network Power Generation

Good opinion piece from Gizmodo's Campbell Simpson on Tesla Powerwall, solar and energy market in Australia:

Opinion: Tesla’s Powerwall battery is coming to Australia later this year, and it promises to lower your power bills by charging from your house’s solar panels or when off-peak energy generation tariffs are in effect. But it may face competition and obstruction from Australia’s existing energy suppliers and retailers, whose current businesses are built around power generation and consumption, not storage.

RenewEconomy says that in the end, consumers may suffer. The fundamental idea of Powerwall, and of residental or small-scale battery energy storage in general, runs counter to the way electricity is generated and used around Australia. In Australia, as in any country around the world, large-scale power is generated relatively consistently from baseline generators like coal- and gas-fired power plants, with supplementary power and peak boost coming from sources like wind, industrial solar and hydroelectric. Power demands fluctuate based on industrial and residential requirements.

In the merit order, nuclear (of which Australia has none) and coal-fired power plants are relatively cheap to run due to low fuel costs, but take a long time to heat up and reach operating temperature — they are therefore suitable for generating a pre-set, fixed amount of power but are not able to adjust dynamically to daily fluctuations in consumer demand. Wind power contributes to baseload, but only at a proportion of its maximum power — it is changeable with regional weather.

Mid-merit generation plants like hydroelectric, diesel and gas turbines are more responsive to demand, but comparatively more expensive. In a traditional energy generation system, there’s a baseload and a peak for production, and largely similar peaks and troughs that coincide in consumption. That means, thanks to the principles of supply and demand, that there are expensive times to buy electricity — these are the peak and off-peak tariffs we’re all aware of on our quarterly energy bills.

In the scheme of things, solar — especially on a distributed, rooftop-scale model — is surprisingly close to a baseline level of power generation, although only during daylight hours (and especially peak daylight hours). Australia has excellent rooftop solar penetration — over 4400MW on 1.4 million homes — and generally excellent sun (thanks, giant hole in the ozone layer), as well an existing time-of-use tariff system from electricity companies. 

It’s those three things that make Australia attractive to Tesla Energy and the Powerwall. There’s a huge market of people with solar energy generation already installed on their rooftops, and a population opento the idea of rooftop solar, as well as a traditional energy generation infrastructure and retailers that charge users based on when they use their electricity. Battery energy storage — through a device like the Powerwall, which has the Tesla factor even though BES has been available for some time already through — means that houses with solar can store that midday energy rather than feeding it back into the grid.

Read more here.