Tesla's Powerwall could be costly for those tied to the grid

As Australia prepares for the widespread launch of Tesla’s Powerwall home battery product, one local expert has said that the impact of the product could be negative for people who remain reliant on the grid. According to Ketan Joshi, research and communications officer at Infigen Energy, low-income earners and other grid-dependent taxpayers could face rising energy costs as they are forced to offset the costs of those who defect from the grid to use the Powerwall, stating that as "the utilisation of our transmission network decreases... Someone without enough money to afford solar/battery offset will have to face the consequences of network over-investment…”

The first residential Tesla Powerwall Battery was installed last month in the home of lucky customer number one, Nick Pfitzner, a computer programmer from Kellyville Ridge. He shelled out almost $16,000 for a 5 kilowatt photovoltaic (PV) system installed by Tesla reseller Natural Solar, with 20 250 watt solar panels with DC optimisers on his roof, along with a hybrid inverter and a 7kW Powerwall battery mounted on the side of his house.

In case you've been living under a rock, the Tesla Powerwall is a battery system which lets you do one of two things:

As Australia readies itself for the Tesla Powerwall "revolution", at least one expert says those dependent on the grid could face rising electricity, connection and maintenance costs.

Pfitzner says for the install to be successful, it will need to reduce his energy costs by around 85 per cent. Though he's been watching his energy metre daily since the install, he says it's too soon to tell. But with a 10-year warranty and a promise to refund the difference if the Powerwall doesn't live up to expectations, Pfitzner believes it's a worthwhile investment because it allows him to sell energy back to the grid, if needed.

"Ultimately, if I'm generating 25kW hours a day, storing some energy and using some, then getting a tariff for that at 5 cents but selling it for more, why wouldn't you?" he says.

"I still have to pay a connection fee (to the grid). If I can cover that cost it's fine, I don't need to be an energy baron."

Pfitzner is conservatively expecting it to take eight years before he can break even, but says there might be some potential to cut that number by a year or more. He put together a spreadsheet looking at the system's Return On Investment (ROI) at current prices.

"Every time I added 5-10 per cent to the energy tariff it cut the ROI by four to six months," he says.