Mr Purcell admits he initially bought his battery as a form of insurance against the volatility inherent in the spot market.
However, his thinking quickly changed when he saw the opportunities on offer, describing one instance in which he was able to fill up his 10-kilowatt-hour battery with electricity costing 1 cent per unit.
“That’s the opportunity and the risk on the very low prices,” he said.
"It cost me 10 cents to fill the battery during the middle of the day.
“And then at night-time the price went up over $10 a kilowatt hour, so I was able to export that same 10 kilowatts out of that battery for $100.”
When my solar is having a “bad day” it outputs 2kW instead of 5kW. Even in the afternoon when the sun is behind a massive tree that fully shades our panels (and our home, which is why I’m reluctant to cut it down) the panels still generate 600W and that’s far darker shade than any cloud (my home only uses more than 600W when we’re cooking by the way).
So yeah, filling your battery for 1c is a bit of a silly stat. It should be 0 cents to fill your battery. Selling the power back to the grid for a hundred bucks though? That’s totally possible right now.
And in the future I expect you’ll be able to do it with the battery in your car, which you could easily sell while still having enough power left over for the 30 minute drive to work in the morning (and then plug into solar at work).
Out of curiosity, what state are you in? A bad day for me sends my panels to near 0, but I am in Vic. A couple of rainy days and my battery will be empty. Good days will charge the battery and export 10-15kwh to the grid.
The big issue that I have is that my partner works from home, so on bad days her usage is swallowing a lot of the generated power. Not a lot i can do about that, i have made her setup as efficient as I can, but its always going to use more than just an idle house.