When Sydneysider Nick Pfitzner agreed to be the first person in the world to have a Tesla Powerwall battery installed in his home four years ago, the sceptics were sure he’d be sorry.

But today, with the release of the first four-year study on the experiment, Mr Pfitzner’s having the last laugh all the way to the bank with the revelation that he’s paid an average of just 46 cents a day to power his four-bedroom home.

“And I have airconditioning, a pool and plenty of appliances,” he said, at his house in Kellyville Ridge. “I think, back then, the naysayers were waiting for something to go hideously wrong.

“They were saying the system would never pay for itself and that it was bad for the environment with everything it was made out of. But now I see them starting to walk backwards on their views, particularly as it becomes more common and gets such outstanding results.”

The study has further found that his saving over the past four years amounts to over $8400, with quarterly bills dropping from $572.29 to just $45.16 – a difference of 92 per cent.

In four years, the family has paid just $677.34, which is astonishing considering power prices are increasing by an average of 10 to 15 per cent per annum.

Sometimes, the quarterly bills have slumped as low as $19.47 for Mr Pfitzner, 43, his wife Danielle, 44, and their son Sam, 15, and daughter Hayley, 12.

“I would have been happy with even saving less!” said Mr Pfitzner. “But I knew the numbers were going to be pretty good. With the apps and software, you track how much energy you’re using with every appliance around the house and you start modifying your behaviour to save even more.

“We don’t ever go without, but we’re more aware of turning the lights off when we go out, and turning things on one appliance at a time. And a few years ago, we took a big family holiday to visit friends in the country, then Kosciuszko and then the beach, all paid for with the money we saved on energy, which the kids really appreciated too!”

Since the bushfires, the chief executive and founder of Australia’s largest solar and battery installer Natural Solar Chris Williams, who installed the battery for the Pfitzners, says there’s been a dramatic spike in demand for solar and batteries.

While the monetary savings are a factor, the major driver for people seems to be the desire not to be over-dependent on mainstream electricity supplies.

“I think the key word has become ‘resiliency’,” said Mr Williams. “People want to be more self-sufficient and less reliant on energy off the grid. The bushfire situation has been horrible but it seems to have really accelerated decisions about solar and batteries for households and business across Australia.

“Nick Pfitzner was an early adopter but people have now really embraced the technology. The financial savings haven’t been the main consideration, but they certainly help, and to see the numbers after four years shows the technology will only continue to grow with huge demand worldwide.”

Thousands of battery storage systems have been installed in houses around Australia, while worldwide over the past four years there’s been a 15,000 per cent increase in installations. Most pay for themselves, with the installation and technology costs, within seven years.

In addition, battery power can reduce a household’s carbon emissions by up to six tonnes per annum and, if the two million households in Australia with solar panels also installed a battery, emissions would be slashed by up to 13 million tonnes annually.