“When I purchased my current house, it was with an eye to solar efficiency – it had a North-facing aspect, so I was very keen to utilise that space for solar energy… I think I was customer number three in Canberra!”
As a retired scientist and engineer who worked in a nuclear power plant in the UK during the 70s and 80s, Ken has always been a very detailed individual. In fact, before purchasing an Evergen PV and Alpha Battery system, he first projected his potential savings by running his own spreadsheet.
“I was a very early adopter of solar PV, which were installed in 2011, and to this day, it is still performing.”
Based on an analysis of his roof space, solar panel hardware, and typical forecast in his location, Ken estimated the system would achieve a 73%-90% reduction in his current energy costs. But in fact, a year after installation, Ken’s savings exceeded even his own estimations.
Related story: How we estimate your savings
Over the last four bills, his system has generated an average of 107% savings, and earned him $50-$60 in surplus credit back from his electricity provider in the last two bills.
“We’re getting quite a good feed-in tariff – it’s a good littler earner.”
Of course, being the data-oriented man that he is, one of Ken’s favourite features of Evergen is the CSIRO-designed Energy Intelligence system – which he likes to check up on.
“I like to (use the app) to correlate the data; every week I collect the data from it, and I log the results in an excel spreadsheet, so I have a very good reference of how the sun is falling from my roof and I can check that the system is still performing as I expect given that amount of sun.”
So, what’s Ken’s secret to optimising his savings?
“We have a household policy of ‘use electricity when the PV panels are generating it’ – that is the most efficient use – charging the battery only gives us 80% efficiency, so using it in real-time gives us a lot higher efficiency, so we have modified our dishwashing, clothes-washing, ironing… all the heavy-use electricity (appliances are used) as much as possible during sunny, daylight hours.”
“That’s why the app is my favourite thing about the system. Number one, we use it to check that the system is functioning, because sometimes I look at the app, like yesterday, and that’s the first sign that something is not working, because it shows zero power coming from the roof, so the confirmation that all is well, all is working well is good.”
“The second thing is – is it performing as I think it should, given certain cloud conditions? So, that’s comforting as well. At the end of the day, I want to know am I surviving 100% off the grid, because that’s the aim – not to use any expensive electricity.”
“Unfortunately in the ACT, in suburbia, I can’t go off-grid – I would dearly love to go off-grid tomorrow to reduce greenhouse gasses and just be master of your own destiny. (It) is quite empowering, really.”
Even with these fantastic savings, Ken is optimistic that he can achieve even better results in the future.
Related story: 5 tips for cutting power use in your home
“My wife and I are ex public servants, so we did our due diligence and got three quotes for each form of system… but it was the future-proofing aspects of Evergen that turned me on. (Evergen) was the only company that admitted that, working with CSIRO, they were going to keep monitoring and optimise as time goes by.”
“Not only did the Lithium Iron Phosphate battery struck me as giving the best performance over time, I liked the idea that the software was remotely updatable. There was still quite a lot to learn about updating the algorithms, and I liked that that feature is a part of it.”
“People are complaining that their houses are too hot in summer, (but) they’re just throwing their energy away, really.
“Al Gore keeps quoting the rather hackneyed statement that one hour of the sun’s energy that falls on the earth is more than the electrical energy used in a year on the earth – so this huge, huge source of energy is largely wasted.”
“We’re all driven by money at the end of the day, and to me, if you’re going to stay in your house for ten years, it makes economic sense. I’m pleased with the system and I feel very lucky that I own one.”