But when he talks about his mission to get past the culture wars which have frustrated efforts to limit climate change in Australia, it's clear the hot tub is the perfect example.

Griffith's thesis is that by electrifying every facet of the domestic home, we can do more than reduce national emissions by a third, save more than $5000 per year by 2030, and create a boom in trade jobs - as if they weren't enough.

He says life can actually get better as we solve climate change; instead of sacrificing lifestyle to save the world, we can enjoy it more than ever.

In Griffith's words: "you can totally have a jet ski; it's just going to be electric".

The engineer is back home in the Illawarra after a few months in the USA, touring to promote his latest book Electrify: An Optimist's Playbook for Our Clean Energy Future. His next, The Big Switch: Australia's Electric Future, is published here next month.

His US trip included meetings in Washington, DC, with Biden Administration heavyweights, who he has been advising on energy policy for some years, including writing the Electrifying America's Future resolution, for a caucus he founded of Congress members which meets regularly to push the cause. He launched Mayors for Electrification, which he said has more than 200 city mayors signed on.

With Biden's climate agenda having had its "wings clipped" by recent votes, Griffith said it's Australia's time to lead.

"Somebody has to show the world how to do it, and we might as well," he said.

"I'm excited to be in Australia because there's significant headwinds still in the US to do as much climate action as is necessary in the timeline required. But there's still hope in Australia that we can strive to be the first country in the world to do a whole electrified suburb."

Clearly it wasn't his first rodeo. America had been home while Griffith studied at the Massachusetts Institute of Technology, where he graduated with a PhD before moving to San Francisco and founding several clean energy companies including Otherlab, and being awarded the MacArthur Foundation's fellowship, known as the "genius grant".

But Griffith told Weekender his main argument is relatively simple. As an engineer, he's not trying to lead adaptation to climate change. His project Rewiring Australia is trying to help solve it.

"Electrifying everything is a fairly simple idea," he said. "It cuts through the bull***t around hydrogen ... around clean coal ... around natural gas-led recoveries. Because none of those work. It's all about electrification, and if you electrify everything, that's how we will see the most benefit and the lowest energy prices."

Among the fault lines defining - or paralysing - the climate debate in Australia has been the threat to traditional fossil fuel jobs, fears for people's beloved big utes, and also whether individual or industrial action should be taking priority. For Griffith, there's 25 million reasons to concentrate on the domestic home economy.

"Actual voters experience the domestic economy - very few people apart from large corporations and overseas interests actually experience the iron industry, or the supposed hydrogen export industry," he said.

"That has been a traditional divide in the culture war, the threat of losing jobs in the regions because we'll stop digging coal or we'll stop fracking gas.

"But that doesn't let the other 25 million Australians who own homes and cars participate in the climate change solutions. Because Australia will realise the positive economics of that first in the world, we can be the global lighthouse that makes the world be more ambitious. I actually have hope, because so many Australians have realised the upside of cheap solar on their roof, and because I think so many Australians now are what we might call 'electric vehicle curious'.

"Of course there will be the holdouts who want the V8 or whatever it happens to be. But electric cars now are doing 400km, we'll see 1000km-range vehicles by 2023, 2024. The threat of losing your weekend will disappear.

"At that point, they've got more horsepower, they go faster, they climb better, the donuts are silent. I think that culture war will win itself, particularly as America makes things like the [Tesla] Cybertruck and the Ford F150 Lightning.

"It'll be quite hard to buy a petrol vehicle I suspect in 2028 Australia."

Griffith isn't anti-car - he loves cars, particularly old ones, and has several which he plans to electrify, including a Lincoln Continental, renowned as one the thirstiest gas guzzlers of all time.

While in San Francisco he electrified an old Fiat, using six electric skateboard motors, and resulting in a machine with triple the horsepower than the original petrol version.

Otherlab is his main US concern now, employing more than 50 people and having raised more than $100 million in funds for its energy innovation work, including grants from the US Navy and NASA.

Having taken care of business, Griffith is on a mission to tell Australia about the heroic task that awaits. He has the ear of local climate leaders Matt Kean, the NSW Treasurer, who called him a "sounding board" and "basically a genius" and Atlassian billionaire Mike Cannon-Brookes, whose words grace the cover of The Big Switch.

Australia will be hearing a lot more from Saul Griffith this year.

"What we need for the domestic economy, which is what the punters feel, already exists in electric vehicles, heat pumps, solar cells, batteries and induction cooking. The only thing that doesn't exist is an example where that's all deployed widely in one suburb to prove the grid won't crash.

"Ideally you would do an outer suburb of Sydney and you would do a regional town. It could be Penrith and Parkes or it could be Cabramatta and Broken Hill. I would like to prove that it's cost effective and improves people's lives."

Which brings us back to the hot tub. The solar system on his roof provides more electricity during the day than the family needs - so they "store" it in the water, keeping it warm for night or morning.

"Rather than get very little for selling that back to the grid, I just dump it into my hot tub. Basically it was free hot tub every day."

And a converted muscle car could be some kind of electric Trojan horse, able to cross lines and convince petrolheads that electric is OK.

"That's the utility of having the stories," Griffith said. "We'd had a narrative that climate change is going to be all about less of everything. But if we think about it, actually Australia is going to have more abundance than we ever had before, because the solar here is so cheap, and we're going to have these nice electric vehicles and heat pumps making your hot tub warm.

"We can fight back against the culture war by saying actually, you can totally have a jet ski. It's just going to be electric. Yeah. It's not just about looking forward to sacrificing things."