Affordable Housing Solar PV

silverwhistle

Does this happen via DC direct from the panels into a DC immersion element or just standard AC with the immersion just making use of the energy needed to keep exports at zero?

Sorry, just noticed a few more posts on this thread. The latter.

To the OP, 2kWp of panels would make a decent contribution to hot water although as to whether it would be worth installing a diverter is another matter but a difficult calculation. In view of the general dissatisfaction on the estate you might want to suggest they install them (or maybe in yours for a trial ;-) ).

My minimum usage is 52watts (possibly 37 occasionally) and then other things kick in (fridge etc.). My diverter sees that and then makes an allowance (of I'm not sure how much - 150w?) for error/delays and shoves everything left over into the HW tank. When the tank is hot, which would take longer in your case, export begins again.

If you're not in during the day at least make sure you start your washing machine via a cheap timeswitch to take advantage of the best daylight.

You might want to get hold of one of those infrared cameras for detecting thermal bridges and check the insulation in your houses. They can be bought or preferably borrowed.

pinnks

Subject to installation costs I would have thought a diverter would be a good investment. On sunny days like today, my systems generate between 1kW and 1.5kW before the WSW array comes into sun from about now until October any my water is hot before midday and stays hot from then on.

My 1.175kWp array (ESE facing) produces about 180 kWh per month from April to September with about 80 to 100 lost performance because of my shading issue. That is an average of 6kWh per day, or 9kWh if I didn't have shading. A 2kWp system should produce a bit more.

A 2kWp system should therefore be more than adequate to provide all or virtually all hot water from April to October, especially if there is little other draw on the system because people are at work. My 190L tank (with 2 of us) takes about 3kWh per day but a larger family or heavier water user might take more. If the system provides, say, 5kWh per day to heat the water for free for 7 months that would be about £150 saving on using imported electricity at 14p per unit. Over the rest of the year you might get another £40 or so. On that basis the diverter would take less than 2 years to repay the investment.

Just a thought...