Just imagine if a politician would be so silly to suggest that a Tesla big battery was not much use because it could only power the nation for a few minutes, or a portion of South Australia for less than an episode of Ninja Warriors.
Or that you would need thousands more such batteries to have enough storage to provide electricity for the country when the sun don’t shine or the wind don’t blow.
Well, just imagine this. Put those batteries on wheels. Inside electric vehicles.
And then measure the capacity of those batteries if there were 10 million such EVs on the road, as the Australian Energy Market Operator has imagined in its scenario planning for the future grid.
According to Tritium, an Australian company specialising in EV fast-chargers, those batteries combined would provide some 500 gigawatt hours of stored electricity.
That equals to nearly 5,000 times the size of the Tesla big battery – enough, if it was ever needed, to power the nation for a day.
Not that Tritium is suggesting that is way the country should go – a whole bunch of wind and solar, and relying on a fleet of EVs for back-up, but it makes the point that EVs have enormous potential to make better use of networks, and better use of renewables.
And the investment in these batteries would essentially be for free, because for most buyers they would be amortised in the purchase of the EV, which in itself will be a cheaper option than their current petrol or diesel powered vehicle.
‘This is quite a big deal,’ says Tritium’s engineering director James Kennedy, while presenting the above chart at the Renewable Cities conference in Adelaide this week.
‘With that number of vehicles, that translates into a 500GWh distributed battery. It’s equivalent to 5,000 times the storage of the Tesla big battery.
‘It could run the entire country for a day …. it means that we could go to 100 per cent renewable energy.’
Electric vehicle batteries are already being used in trials to provide storage and support to the grid, and BMW batteries were recently installed as back-up to a wind farm in Germany.
Kennedy says that for the battery resources to be used, they would need to inter-connected, and there would need to be bio-directional charging.
And the EV manufacturers need to be more comfortable about having the batteries used in such a way. The concern is around degradation, but continued improvements in battery efficiency in coming years should see that become less of an issue.
Kennedy says that most EVs will have way more capacity than they need on a daily basis – the average daily car trip is 30-50kms, and most EVs will have a range of at least 200kms and up to 500kms or more in some cases.
That creates a big resource that – with smart software and management – can be tapped into in a future grid that relies heavily on wind and solar, along with other storage such as solar thermal, pumped hydro, and household and grid scale batteries.
‘It sounds a bit science fiction,’ Kennedy says. ‘But we are actually quite close.’
Even if the EV battery capacity was not used to power the whole grid for a day, Kennedy says that it could be used as a resource to manage peaks, store excess renewables, and be used by employers to reduce demand charges.
‘There are all kinds of possibilities,’ for EV batteries to be integrated into a grid, he says.
Certainly, AEMO is looking seriously at the impact – and benefits – of EVs as it puts together its Integrated System Plan that will place a special focus on the role of distributed energy, which includes rooftop solar, battery storage, virtual power plants and EVs.
As we reported last month, AEMO recently sharply increased its scenario planning for EVs, suggesting a 50 per cent market share, or 10 million vehicles, in one scenario by 2037.
Certainly, nearly everyone barring a few die-hard conservatives predict that the EV revolution is upon us. Environment and energy minister Josh Frydenberg predicts one million EVs on the road by 2030, Beyond Zero Emissions says all new car sales will be EVs by then.
Whether it occurs slowly or quickly may depend on the availability of low cost models in Australia, and that may depend on what sort of policies are in place to encourage that.
Tritium’s Kennedy points to the experience of Norway, where the introduction of EVs was heavily subsidised.
‘It was seen as a subsidy for rich people. But what it did do was provide the volume and the price parity between an EV and an internal combustion vehicle. That subsidy is mostly disappeared, and the rate of uptake is still accelerating.’
The share of EVs on the road is now nearly equal to that of petrol cars, and of diesels, whose share has plunged from 75 per cent to 35 per cent in the last six years.
EVs, of course, will not just have benefits in supporting renewables, decarbonising the transport sector and improving air quality, they will also reduce Australia’s perilous dependence on important fossil fuels for transport.
The country’s reserves have fallen as low as 42 days. But the reality for the consumer is that means just about two weeks, possibly less, or fuel available for cars. Just imagine the queues, and the angst.
For a fact check on Tritium’s claims about EV storage, we went to Andrew Blakers, a leading energy and storage specialist from the ANU, and the author of numerous reports about the transition to 100 per cent renewables, and the role of storage.
Blakers agrees that about 450 GWh is needed to cover 100 per cent renewables, and this can be in the form of car or stationary batteries, demand management or pumped hydro (or combination thereof).
And he agrees that 10 million EVs equals about 500GWh.
But, he says, and this is a big but – the stress period in a 100 per cent renewable energy scenario is not necessarily on a hot summer afternoon (which is mostly covered by tens of gigawatts of solar PV, and where EVs could fill that backup.
The major problem shifts to a wet windless week in winter. ‘It’s questionable whether EV batteries will last through such a week if they are being used for transport and if they are also delivering to the grid. So, EVs can help but are not the whole solution.’