25-02-2025, 01:13 PM
(25-02-2025, 11:50 AM)harm_less Wrote:(25-02-2025, 09:10 AM)nzoomed Wrote: Yeah many forget solar is really fusion power, just extremely inefficient in the scheme of things, we are only collecting the smallest fraction of the suns energy that reaches us on earth.It's not only renewable energy that is driven by the sun. Fossil fuels are formed from plants that used the sun to grow millions of years ago.
Yet we still have over 1000W per square meter reach us, and our solar panels can only convert 20% or so of that to electricity, but we can still do alot with it!
All our renewable energy is in fact solar when you think of it, because the sun drives our climate that gives us hydro power and wind.
An EV would place quite a high demand on your solar power im guessing, Im hoping to install 10KW here, but I can probably squeeze a bit more on all sides of the roof, even though they dont get much sun, the panels are so cheap now.
I bought a 500W panel for only around $150 recently, and this was a big name brand from the electrical whoesaler.
cost is no barrier now, but I hope efficiency improves so I can get more watts per square metre on the roofspace available.
We're charging two EVs and battery garden tools from our 8.2kW of solar plus pumped water supply and usual home demands. We are currently seeing a credit on our Octopus account of $40 which will see us going back into debit by about Apr/May. To put the EV consumption into perspective our Polestar2 uses ~2,200kWh/year and the Leaf more like 1,300kWh. Our annual generation is around 12,000kWh/year and we export ~4,500kWh of that.
When we did our last upgrade we ended up with a redundant 5kW inverter which we're currently considering reinstalling with appropiate extra panels on our house roof as part of major renovations we're about to start. The plan is to export 100% of this extra generation which should return us about $1,300/year at Octopus's FIT. That would see us in constant and increasing credit all year so now in the process of approaching Octopus about how we could go about 'withdrawing' this credit from time to time. Planning stages at present but I'm confident of <5year ROI on the extra costs of getting this up and running. Adding battery or going V2G with our Leaf is another possibility I'm considering.
Yes thats a good point, especially given that fossil fuels are not considered a renewable fuel, its really just on the scale of a human lifetime that they are not when they take at least tens of thousands of years to millions of years to form.
V2G is a great option for a home battery, providing the car is available when you need to use that energy. I see that the returns from energy retailers varies dramatically, many dont want to credit you back in cash either, hopefully you can strike a good deal with Octopus.
I take it that you must have a high voltage DC inverter if you are considering V2G. Higher voltages also allow more efficiency and thinner cables, etc, plus there are a ton of cheap surplus EV batteries available from wrecked cars now that make a great second use as a solar bank.