Last week the energy products VP of Tesla (supported by CEO Elon Musk) proposed the installation of 100 to 300 megawatt hours (MWh) centralised battery capacity in South Australia, consisting of banks of PowerWall 2 lithium batteries.
Based on figures from SolarQuotes, this represents a rough maximum of 37 to 111 megawatts (MW) of output for about 2 hours and 40 minutes. The amount of MWhs and MWs are very different quantities, routinely confused in commentary and the news; some articles have reported “100 MW”, and GetUp has appropriated the excitement in support of its questionable 100% national renewable energy ambitions:
Elon Musk has pledged to help fix South Australia’s power crisis by installing a 100 megawatt battery system in 100 days, or it’s free!
Exactly how it will fix a state’s power crisis hasn’t been quantified. The example cited in California, the recent Mira Loma facility (20 MW, 80 MWh):
will charge using electricity from the grid during off-peak hours, when demand is low, and then deliver electricity during peak hours to help maintain the reliability and lower SCE’s dependence on natural gas peaker plants.
Expert analysis of the broader Californian battery experience can be read about here.
While the excitement around the news was gripping social media on Friday, South Australian electricity demand looked like this:
The blue line is AEMO 30-minute demand data; the green line annotations simplify the day’s demand into an unseen bottom rectangle of baseload (1,200 MW for 24 hours: 28,800 MWh) and a peaky 7,200 MWh triangle corresponding to the normal daily demand fluctuation. Rooftop PV “behind the meter” consumption is added from APVI data, and is the estimated contribution from about 700 MW of total distributed capacity. The $/MWh price roughly follows this demand curve.
The advantages of battery storage are that it can be installed rapidly (regulations permitting) and can be switched on and off pretty much instantly. Based on the capabilities of a 100 MWh installation in South Australia, and the stated operation of the Californian example, no more than 37 MW could be suddenly supplied over the 2 hour 40 minutes of evening peak, as represented by the red line.
Does this look like it’s fixing a power crisis?
If this proceeds, the manner in which it will help keep state power prices from rising, or even begin to lower them, and how it will relieve the ever-growing reliance on South Australia’s interconnection with Victoria, must be primary considerations. As detailed in the SolarQuotes article, the 30% degradation in battery capacity from only 10 years of use and the limited operational lifespan thereafter needs to be highlighted: no other electricity grid infrastructure is expected to last such a short time. And perhaps most glaringly for many proponents, the potential environmental and social impacts from lithium production in other countries would never be tolerated here. If we’re were instead to pursue an Australian Made battery storage solution to our national power sector’s challenges, many vocal battery supporters need to work out why they prefer one massive foreign-owned hole gouged out of the earth to any other.