“One household at a time:” 50,000 homes with batteries could displace a gas peaker plant

Four years ago Mark Purcell sat in a Canberra café and watched as his diesel BMW was trashed by golf ball sized hailstones in a massive storm.

Faced with having to buy a new car, Purcell decided on a Tesla.

But he didn’t buy it for sustainability reasons, or for the electric drive.

“I got it for the technology, for the software updates, and the performance,” Purcell told the SwitchedOn Australia podcast.

Purcell’s purchase of a Tesla however kick-started his journey to fully electrify and decarbonise his home.

Every afternoon Purcell would drive home from work and plug in his new electric car.

“I charged it full bore, because I had a flat rate electricity plan,” Purcell says.

“I’ve now subsequently learned that’s the worst possible time because of the carbon intensity of the grid at five o’clock.”

“When the sun goes down, the carbon intensity shoots up.”

Purcell quickly found that his electricity bill had skyrocketed, and that was his motivation to install some solar panels.

“I had no idea how good solar panels were and what they did to your household energy profile.”

His Canberra household then copped “an absolutely shocking $4,000 gas bill.” That prompted Purcell to upgrade their hot water system and space heating with heat pumps.

His next move was to find a better energy plan.

“In my first year of doing all this – with the electric car, solar panels, heat pump for heating and heat pump for water – I saved $8,000 on my utility bills and that just blew me away.”

Purcell estimates that he covered the costs of his energy upgrade with the savings he made in three years.

When Purcell moved to Noosa he decided to electrify and decarbonise his new home from the get-go.

He replaced the bottled gas hot water system with a hot water heat pump, bought a second Tesla, upgraded the air conditioners, increased the solar system, bought home batteries and signed up to the wholesale energy retailer, Amber, so he could export energy back to the grid during the highest period of carbon intensity when it’s at the highest price.

“I’m saving about $15,000 a year now on my on my Noosa household,” Purcell says.

“I’ve got a big house, I’ve got a pool, I’ve got a heater, I’ve got lots of air conditioning, I’ve got two electric vehicles. But my electric bill every month is a credit.”

Finding a tradie though who was willing to install a hot water heat pump wasn’t so easy.

“This is one of the challenges with this transition,” Purcell says. “If you’ve been running gas hot water systems all your life and you’ve built a very successful business around that, that’s what good looks like to you.”

It was this issue that spurred Purcell to join his local community energy group, Zero Emissions Noosa.

“We’re looking at how can we break through some of these barriers and how we can get the local tradies upskilled in some of this new technology.”

Purcell is now on a mission to recruit other households to the electrification journey. His ambitious aim is to displace the power of a single gas peaker plant.

Purcell has calculated that 50,000 electrified households with batteries can do the same job of a gas peaker plant during the critical three or four hours of peak demand.

“For every 50,000 households that have batteries, that’s one less gas peaker plant that we need on the network,” Purcell says.

“I just need 50,000 other friends to come and join me. I’m literally recruiting one household at a time, both through my community advocacy, but also some online forums,” Purcell says.

You can hear the full interview with Mark Purcell on the SwitchedOn podcast.