I’ve been mulling over this dilemma.
Is our energy budget better balanced by being independent from the grid, so we’re not adding to demand or drawing power from any non-renewable generating capacity?
Or, taking a bigger view, is it better to hook up to the grid as a micro-generator and contribute renewable energy to a communal resource?
Using the grid instead of battery storage makes a lot of sense. Electricity doesn’t store very well and batteries are not hugely efficient, have limited lifespan, and are expensive. But it also seems slightly daft to be exporting all our capacity to the grid only to take it back again, since a lot of energy is lost in transmission.
It’s kind of like our situation in Scotland where water from the local reservoir now travels all the way to the outskirts of Edinburgh (where it’s subjected to all kinds of abuse) before being piped all the way back out to us again, a round trip of about 60 miles, a fair bit of energy used in construction and operation, and water that doesn’t taste anything like as good as it used to.
Maybe some sort of hybrid is the thing? A relatively self-contained system that only exports surplus power to the grid (instead of dumping it, which the hydro generator I’m looking at is designed to do) and draws power down only when demand temporarily exceeds generation and storage capacity? This might give us the best of both worlds. On the one hand, enough oomph for wielding the odd power tool plus power to keep us going when the water’s low and the sun’s hiding. On the other, minimal transmission losses, power during power cuts, and contributing our surplus to the community instead of wasting it.
I’m not sure I have the definitive answer to this yet. For one thing I have to find out how much it would cost to connect us to the grid, and cost that out in various permutations with batteries. And I think somewhere at the back of my mind I don’t quite trust myself not to get more careless with power usage if I’ve always got unlimited supplies on tap …