In reply to SteveRi:
> Sounds a bit like you're putting the ethical cart before the practical horse.
Indeed - although on the practical side it seems quite a few people have reservations about the installation quality and long term effects of some rooftop PV installations.
> For any shortcomings of the FIT scheme the upshot is every kWh your panels produce is one less kWh demanded from the grid from alternative means (and quite probably fossil fuel).
Yes. It's not much of an upshot though as the kWh from solar onto the grid from domestic PV is not a significant fraction of demand when the sun is out in summer, let alone on average. It's never going to be either, this is not California.
> Buy the house you most like, leave the panels on, use the power where you sensibly can, pocket the offset in what you *would* have been paying to import from the grid.
It looks like one of the houses we're interested in has pre-installed panels from a "rent-a-roof" company. This basically puts the house off our list, as we'd not have proper access to the roof for maintenance (or skylights!) for 20 year, and would have trouble selling as it sounds like its very hard for buyers to get a mortgage under a "rent a roof" scheme.
> Interesting thread though, practical storage options have always been the missing link. Battery technology has changed so much in recent years, who knows what's next?
Batteries have an awfully long way to go before they can compete on cost grounds and store a sensible amount of energy. If they do reach the needed power densities, I imagine they'll have truly frightful explosion potential. My interest in batteries stops at lighting, a laptop charger, an efficient fridge/freezer and central heating pumps etc. To actually run electric cookers, big TVs, domestic appliances and so on from a renewable+battery system seems as much of a pipe dream as ever.
> Then do something that makes you feel good with the FIT payments - local CAB, something specifically to do with fuel poverty, whatever.
It seems I could just cancel the payments and avoid becoming a hypocrite on the issue.
Considering the various comments on the thread, the current "best" plan I have to add backup batteries to a house with pre-installed feed-in panels is to leave the panels as they are, but to add a separate battery bank and inverter (not connected to the grid, just "reserve" sockets), with the batteries being trickle charged from the mains, perhaps under relay control so they only charge when the panels are running. I could always then install some DC switch gear and a charge controller to divert the panels to the battery bank in a long power cut. As others have said, it's probably cheaper to have a generator though!
Post edited at 11:00