Hi,
I'd like to expand our grid-tie PV system once again to take up the remaining space on our small roof.
This would get us to over 5kWp of PV driving over 4.4kWp of inverters, though as the panels are on east- and west- facing roof surfaces it's virtually impossible for everything to be maxed out at once.
However, this expansion takes us over the 'G83' UK threshold where the local Distribution Network Operator (DNO) cannot refuse an installation, which stands at 16A per phase, 230V/240V.
So we've asked them nicely (well, the installer who's put in my first and second rounds did) and the DNO has given us the OK today.
Next up I have to convince my other half, the council because of covenants in our deeds rather than planning permission (though we might be getting big enough to have to consider that), my electricity supplier, and consider the complications of the new Feed-in-Tariffs coming in and the effect on a system spanning old and new schemes. Indeed the new one might have to be considered entirely separate for simplicity.
However, at over 4kWp inverter output on a sunny day and (eventually) an 'instant' (air-to-water) heat-pump with a decent CoP, I reckon that we could match our current natural-gas hot water delivery (~24kW in, maybe 18kW out) directly from our panels with no grid draw and no carbon footprint! Of course, at the other end of the year in winter, we might draw as much as 9kW from the grid to match our combi, but that's still OK.
So I'm very strongly leaning to finishing off with PV rather than doing any solar thermal, and also a bunch of 'Kingspan K-18' dry-lining. My aim remains zero-carbon for primary energy.
Rgds
Damon
PS. I may also try to sneak a bit extra PV onto the roof for my off-grid system. That may be tricky for various reasons though...
