Actual usefulness of solar panels

Laconic

Next week, I'll be moving into a rented house that has a 4kWh system of solar panels installed. Needless to say, I will not be seeing any of the feed-in tariff from the system (not my investment to recoup) and I've no say in whether it's been placed well or badly.

My question is simply this: how much of a difference will this make to my electricity bill? A precise answer is, of course, impossible to give but it's surprising how hard it is to find out whether it'd be practical to expect to be able to set the dishwasher to run during the day. Assuming that after losses, the average daytime power output is 2kWh, what sort of things could run?


Thanks for any help in wrapping my mind around this system.

martinsurrey

a 13 amp fuse will give at most 3kw draw, and if a standard plug was drawing this for an extended time you would know about it.

the most expensive things to run are things that heat up, so kettle, washing machine set at 80degrees, dishwasher on the hottest setting.

on a sunny day you should be able to power one high draw item at a time for free.

Furts

I have a 4kW system. This is the limit allowed by the electric companies. The panels regularly exceed 4kW reaching the maximum of 4028Watts. There appears to be some limit switch to restrict output.

Thus on a sunny day I know I can heat my water on electricity, and power the house office, with surplus electricity going back into the grid.

I also run oil filled radiators from September to April powered by the panels. This reduces my gas fired boiler use.

In financial terms it depends how well insulated the house and hot water cylinder are. In my case, both are good. The result is my household costs are ridiculously low.

Furts

To add to my previous post the cost savings are impossible to predict accurately.

IIRR when panels were becoming popular the sales people were saying £150 per year. The Energy Saving Trust challenged this, saying a typical house, with people not there in the day, would be £50.

In my experience £50 is easy to achieve, £150 is easy with some organisation and thought, £250 may be achievable if one is at home in the day with a family and giving thought to the electric use.