Rooftop solar effectively eliminated grid demand in South Australia on Saturday as it accounted for all but a few megawatts of demand in the world’s most renewable grid.
I have an American based friend who recently visited and I discussed this with him.
His house has an asphalt shingle roof, which is beyond common, it's standard where he is.
This means the roof supports are light, and won't tolerate the load of solar panels (direct weight maybe, but not torque from wind).
Beyond that, his states power company have limited the accredited installers to a group that refuse to sell panels, they effectively lease them to you, with an insane payoff period.
If you go independent, you can't tie into the grid.
He's subject to a HOA, which means he can't build anything in his yard without approval.
And so, whilst he's paid for his dad here in Adelaide to have panels on his roof as a no brainer, he's given up in the US.
You might be able to shop around a bit as supply charges tend to vary (although some of it is tied to the underlying network) and of course feed in tariffs (although they are not massive in most states).
In US. I pay my co-op to source my energy from renewables. It's more economical for them to put up solar in fields than it is to have a bunch of tiny roof projects.
So, we have a "tiny roof project" on our rooftop. And it really is tiny since we have a two bedroom home
For 9 hours a day (in winter - 11 hours in summer) they produce four times more power than our peak consumption. When it's cloudy... it produces about twice our peak consumption. In hindsight, we probably could have saved money with an even smaller system... but a bit of headroom is nice and it wouldn't have saved much money, since wiring and the inverter were about the same (we installed the maximum number of panels our inverter can handle).
We also have power now even if the grid goes down during the day - doesn't happen often but it does happen occasionally.
It reduces our electricity bill by between $3 and $9 per day depending on the season.
If we're at home and use a lot of power, we sell between $1.50 and $2 to the grid. If we're out of town and use no power during the day (except the fridge, etc) we sell about $3 per day to the grid.
At that rate, it will only take two years to pay off the upfront installation cost... the inverter has a 10 year warranty and the solar panels have a 30 year warranty. So I'm fairly confident it will last longer than two years.
If we couldn't sell power to the grid, it'd still pay for itself in less than 3 years. Over the life of the system it should easily pay for itself ten times over.
Is it "more economical to put them in fields"? I haven't had quotes for that, we didn't consider it as there are no fields nearby. But our panels are screwed into the roof which took a couple hours. If we put them in fields they would've had to dig concrete footings, put posts in the ground, etc which likely would've been a much bigger project involving multiple contractors instead of just an electrician and two apprentices. There would also need to be underground or overhead wiring to our which, if you do it safely, is a major headache in it's own right.
I'm pretty sure you're wrong about placing them in the field being cheaper. You're underestimating cost and complexity of getting the power from the panels to your home.
The fact is rooftop solar is very simple and very cheap.
As for the "asphalt shingle and roof" being too weak... we have four aluminium bars almost the full length of the building screwed down on the outside of the roof, and the panels are screwed to that. The bars alone are more than strong enough and they spread the load evenly over the whole roof structure - there would be minimal load on the roof and I'm sure it'd work fine on shingles.
It’s pretty exciting seeing South Australia hit new records every year. On track to be a 100% renewable grid within my lifetime. Looking forward to seeing more storage capacity being added so they can go full days powered by renewable energy, then multiple days, then weeks and even months!
I managed to get a vehicle to grid (V2G) charger recently. When these make mass market it will be a huge deal.
My car has about 5x the energy storage of a standard house battery, so I can run the house for several days from the car.
A better option is to switch to wholesale prices. When the wholesale prices go negative (which happens fairly often in SA), I get paid to charge my car. When energy prices spike, I get paid a lot to discharge my car. My last energy bill was about -$190 for a month (not a typical month, I got $170 when the grid interconnecter was down for a day, which caused high prices all day).
I've never had any issues with running out of charge, and I don't think I'll ever pay for electricity again.
What puzzles me why house batteries are about $1000/kWh wile battery cells are about $100/kWh wholesale. Whole hi-tech part is in cells, test just packaging and wiring. Why we do not see house batteries for better prices? Car with battery will cost you less than house battery of same capacity as car has.
I’m in NSW and have total tree cover over my house, which is awesome for the shade and birds etc. I’d still like solar panels and thinking about some kind of rig in the bottom of the garden where the trees end. It’s a north facing slope so I’d get the sun pretty good. I’m investigating planning rules because I don’t know if the usual stuff about boundary set-backs and height limits count for solar panels. My neighbour will cop an eyeful of it instead of just vegetarian but I don’t care.
Bastard tortures me with the sound of his grandkids in his pool in the middle of summer. We just swelter.
My inlaws are similar, they have a system that uses a bunch of micro-inverters. More exxy, but they get good pull. Enough to run their house + heat pump + tesla battery
TBH we can’t afford the set up but at least now I know (got sent a NSW gov link) that it’s exempt development if it’s
<150m2, <5m above existing GL, and >3m to boundary. A few more items but those are the big ones.