Grid-tie solar PV in the United Kingdom

[sheddi]

All told I'm happy with it and have ordered another 60Ah / 3kWh of batteries to add in September/October when they arrive on a slow boat from China. (I'm not yet convinced that I use enough power in the summer, or generate enough in the winter, to justify more than 4kWh of battery storage.)

The 60Ah cells arrived yesterday! They need balancing which is going to take a couple of days of careful attention but with a bit of luck they'll be in operation by early next week. (I have a suspicion that they're not really 60Ah, more like 50Ah. We'll see.)

Hooked them up to the inverter for the first time this evening. I don't seem to have done a great job of balancing; I've got twelve cells at 3.1V and four at 3.2V. Oh well. They're working for now, I'll fix it in the morning (assuming the house doesn't burn down first).

[sheddi]

The house didn't burn down so it's a qualified success!

Looking at the voltages I think I've got one cell that's much weaker than the others, which is a bit of a pain. I'll keep an eye on it and see if it settles down.

Even so, for a total outlay of roughly US$420 ($260 for the cells and $60 for the BMS) I'm mostly happy.

Here's a bad photo from before I tidied up the balance leads.

[sheddi]

Today I did somerthing a bit different; I bought a wind turbine. A 400-ft-tall, 2.5GW wind turbine.

OK, I didn't buy a whole wind turbine (that would have cost about £4M) but a share in one through a co-operative administered by Ripple Energy. The idea is elegantly simple; the turbine generates electricity for £20/MWh, sells it to the grid for whatever the spot price is (the proposal is based on £60/MWh) and your share of the profit is credited to your electricity bill. For the 20-25-year-life of the wind turbine you get the the knowledge that your electricity* is being generated from wind and a roughly 5% ROI.

(For tax reasons you're limited to buying a share not greater than 120% of your expected electricity consumption, based on the capacity of the turbine and predicted load factor.)

This isn't the one I've bought a share in (this one is already fully subscribed) but it shows the general idea:


https://www.youtube.com/watch?v=-TORzLhjgfk

* Strictly, of course, the electricity from the turbine goes into the grid and is indistinguishable from all the other electricty. And sometimes the turbine will be generating more than the co-op members use, and other times it will be generating less. But your share of the turbine will generate a number of kWh and, if you buy the appropriate share, that number of kWh will be approximately equal to the ones you use.