Going #offgrid may not be as green as it seems

Going #offgrid may not be as green as it seems

Going #offgrid may not be as green as it seems

Updated 20 November 2017, 16:00 AEDT

While Australians take to home batteries in their droves, some say there are better ways to save the environment.

So you're thinking of going off-grid. Disconnecting. Throwing off the shackles of the big energy providers and going it alone.

You'll be power-bill free, master of your domain — and best of all you'll be helping the planet. Right?

With the home battery revolution well and truly upon us, the potential for Australian households to disconnect from the grid has never been greater or more tempting.

"[It's] being able to stick two fingers up to the grid operator and say I don't need you anymore," Dr Richard Corkish, chief operating officer of the Australian Centre for Photovoltaics, says.

But as the number of home battery systems installed in 2017 is expected to triple the 7,000 batteries sold in 2016, are household batteries really the clean, green energy alternative we're led to believe?

Feeding solar into the grid 'greens' neighbourhood energy use

If helping the environment is your motivation, the $10,000 or so you'd spend on a battery could be better invested, director of ANU's Centre for Sustainable Systems Andrew Blakers says.

"If you have a grid connection, you're better off putting the extra money into more panels to feed more power back into the grid."

Professor Blakers says that while we are still reliant on non-renewables like coal, feeding your rooftop solar directly into the grid helps to reduce the use of fossil fuels in households that would otherwise be drawing power from a coal-fired plant.

"You're greening your neighbours down the road."

And although spurious claims persist online that solar panels never generate as much energy in their lifetime as is used in their production, the time it takes for a modern solar panel to recoup its "embodied energy" is minimal.

"It's between six and 18 months depending on where it's made and the way it's made, for a 25-year life. So for 95 per cent of the life of the PV system it's energy positive," Professor Blakers says.

As Australia's carbon emissions continue to rise, every household run on solar stands to reduce our carbon output by around 18 tonnes per year on average.

A connected grid essential for a renewable system

Dr Richard Corkish also has reservations about the rush to implement home battery storage.

"I think we have a marvellous resource in the grid in that when someone has some excess solar energy and their neighbour has insufficient, we actually have an interconnection — it's already there," he says.

He worries that a boom in home batteries may lead to issues with waste and disposal.

"There's obviously the resource consumption for the batteries and there's questions about what happens at the end-of-life of the batteries — whether they go into the recycling stream and how much gets recycled."

While they both agree that batteries are a crucial element of a renewable energy system, Dr Corkish believes that storage should occur on a broader scale.

"The storage should be at grid-level. And then bigger and cheaper per-unit-of-capacity is possible, rather than lots of little [batteries]," he says.

"Things then become possible like pumped-hydro storage, which is almost always cheaper than battery storage and it can be strategically located where it does the most good."

Abandoning the grid has 'doomsday potential'

Dr Corkish says there are other considerations besides the environment that need to be addressed if there is going to be a large-scale migration away from the grid.

"We've got this doomsday potential where everyone who is wealthy enough to have their own batteries [might go] off the grid … and all that's left on the grid is a few big users and poor people, who'll have to pay all the costs."

Under this scenario, electricity prices would be huge for anyone still using the grid. And if the grid were to be abandoned altogether, renewable energy couldn't be shared between generators.

Essentially, it would be every house and business for themselves.

But he doesn't blame people for wanting to opt out of the energy system.

"I don't think it's the consumers fault," he says.

"The problem's come about because of the way [the grid is] managed and the finances of it all. You've got to sell for very little and buy back for a much higher price."

He says that until grid operators offer the right financial incentives, people — including Dr Corkish himself — have a strong motivation to invest in their own home battery systems.