Hi
@Rooster6655 , I have had several quotes. The one I am now looking at is suggesting the following, which does seem eye-wateringly expensive (though so do the other quotes I have had). This setup has some nice parts to it:
17 x Longi 500W Solar Panels (21.5% efficiency, 84.8% performance after 25 years)
3 x GivEnergy 9.5 KwH Batteries
2 x GivEnergy HY5.0 Hybrid Inverters (to allow up to 10KW of power use at once)
Full Islanding electrical solution (to allow operation of the whole house from battery packs in case of Power Cut - as long as the batteries have power in them!)
COST: £25k
Their calculations have the system generating an expected 5,400 KwH per year. Our consumption is 11,500 KwH per year, and is subject to a Technical Survey at which time they will finalise the configuration (I have asked them to maximise the panels, even on the less-optimal North facing side of the house... They have assured me they will)
The company (Envo Energy / Bee Solar) are registered with various schemes including HIES, MCS, EPVS. And they are national in scale (part of a much larger group, so a company that is likely to be around for a while.)
I have been pushing to get a smart meter installed, so far stuck in the Customer services queue.
But the above system will apparently let me draw down 10KW at once from the batteries... and, even without a Smart Meter to prove it to myself, I do not expect to ever hit that level of drawdown at once, so I should be able to charge the batteries at low rate overnight (something like Intelligent Octopus) and then operate from solar and battery power during the day without dipping into the grid.
Payments would be made out of savings, so although there would be no financing involved, it would lose the opportunity cost of earning interest, which would eat into true benefit calculations.
But I am thinking this does make some financial sense (my primary concern) as well as being good for the environment. (an important secondary desire).
I am very happy to have another set of eyes review my thinking, and you kindly offered!
Thanks in advance!