Harness the power of the sun

YOU may have noticed quite a ripple of excitement around batteries lately.

The ripple seems to grow every time Elon Musk takes the stage, announcing some new plans for his now rather famous Tesla battery.

You can be excused, by the way, for not realising that Tesla is offering just one of the many models of household battery systems available in the Australian market today.

It’s fair to say Tesla’s share of the media outweighs their share of the market by a pretty clear margin.

One thing we can expect, regardless of which battery brands dominate, is that we are likely to see a lot of them in years to come. And many will be in your garages and sheds and porches.

Australia is gearing up to be one of the hottest destinations for residential battery systems, with Bloomberg New Energy Finance and the CSIRO both suggesting up to four million Australian households being equipped with a battery within the next couple of decades.

Tasmanian households are going to be a part of that picture. So, what is everyone so excited about?

Batteries are of course the answer to the age-old question around rooftop solar generation: “what happens when the sun don’t shine?”

With lithium-ion battery technology continually improving and large-scale commercial production pushing down costs rapidly, that answer is soon going to start making sense for many households. More batteries means more solar.

It now costs less, in almost any location in the world, to generate your own electricity from rooftop solar than it does to buy it from the grid — yes, even in Tasmania, where we have more sunshine hours than Germany where the solar revolution kicked off.

But for now this is true only if you can use it when it is actually being generated.

This is where batteries come in, storing energy as you produce it to use when you need it later. A so-called smart battery will do an even better job, predicting how much solar you are going to generate, how much energy you are going to use and when you will use it, and thus making smarter decisions about how much energy to store and when to release it.

Batteries and their electronics typically lose about 15 per cent to 20 per cent of the energy you store, so making smart decisions is especially important.

Batteries can do much more than just store solar.

Utilities (generators, network operators and retailers, such as Hydro Tasmania, TasNetworks and Aurora) meanwhile are viewing the looming battery revolution with a mix of nervousness and excitement — nervousness because there are so many unknowns about how it will all unfold and what the impacts will be on their businesses and excitement because there is growing realisation that a large fleet of batteries in households can help them address challenges associated with increasing levels of variable renewable generation in the grid.

Batteries can be used to smooth out the intermittency of some forms of generation, even if the generation is located far away. They can be used to store and trade energy with nearby householders or electricity consumers, or they can be used to mitigate the impact of price volatility in the wholesale energy market.

Batteries can be used to more efficiently operate and manage distribution networks,

Evan Franklin

similar to what is being trialled by the University of Tasmania, TasNetworks and partner organisations in a world-first research project on Bruny Island.

Household batteries may play a key role in helping to maintain power system stability and security, something for which South Australia’s recent “big battery” has been primarily installed.

All this can be good news for households too, extending the usefulness of their batteries and unlocking additional value too (and hence additional bill savings).

So, would you like batteries with that?

The technology is steadily progressing and prices are coming down, but the battery market is still very much in its infancy. So far, uptake has largely been driven by highly incentivised trials or programs, or by “tech nerds”, often more politely referred to as early adopters. This makes it very hard to know just how the proliferation of batteries is actually going to pan out.

We do not yet know, for instance, what factors will motivate households to install batteries? How rapid the uptake will be? How much people will be prepared to pay for batteries, and what they expect in return? What functionality will they value most highly in their battery: storing solar, providing backup, earning bill savings, or something else? How willing will households be to share their battery’s functionality with third parties such as utilities?

All this, and more, is still unknown. Yet the answers could be critical in helping us understand the impact that household decision-making will have on the way our electricity system is planned and operated in future.

With colleagues from the UTAS School of Social Science, we are aiming to

It now costs less, in almost any location in the world, to generate your own electricity from rooftop solar than it does to buy it from the grid — yes, even in Tasmania.