2kW system, is it worth bothering with

[Lee66]

I,m just trying to decide after reading many posts of here if a 2kW system will be worth bothering with? 

Refurbing and extending a 1960s bungalow which is on oil(no gas available). I only have available space for 6 maybe 7 solar panels.

Roof is 45 degree pitch and is South - South west facing (Southern England).

I have read about running appliances on timers, which sounds great and am considering if I go with panels to get a cylinder for hot water, that hopefully

this will help top up the temperatures.

Question is will i get enough energy through a small system to make this worth doing. I know it wont make money but i read people putting 6-8kW systems up to meet their needs.

2 person household and currently both out most of the working week day.  Thanks

[nod]

We didn’t have any PV on our first build

Partly because we hate the look of them 

and partly because we would have to live to a 100 before they will pay for themselves 

 

The consensus of opinion on here seems to be if you can buy them cheap and self install They will pay for themselves in a reasonable time 

You will need add batteries 

and there not cheap 

[Ferdinand]

I think we need some more information.

 

Your first step is to work out how you are going to renovate it and what your needs will be, before you decide if you need it.

 

It sounds as if you are looking at a Heat Pump, and I wonder if you can put more solar on the ground. The name of the game in investment-effectiveness in solar is saving money on the way in, and making sure you can maximise it. Remember that you may have an opportunity for charging car or supply-smoothing batteries in the future. In roof solar will save on new roof tiles if you have to replace these.

 

I renovated a 67sqm 60s bungalow 3 years ago to a high standard (EPC 74C) with no panels, and the tenants tell me that bills for a family of 3 ran at about £55-60 per month all in. The thread is here and has bits in it about building quality, heat control etc

 

 

[SteamyTea]

Energy and Power are different things.

You may well get enough energy to run most of your home from a 2kW_p system, but you will not very often get enough power from it to run much more than a few light loads.

Storing as DHW is a cheap and obvious method, but you will still be importing electricity at the same time.  Just that the unit cost will, in effect, be lower.

Using timers is a bit tricky.  Sod's Law says that the times you do draw a higher load i.e. washing machine, are the times it clouds over.

[A_L]

4 hours ago, Lee66 said:

Question is will i get enough energy through a small system to make this worth doing.

 

In your situation you can expect at least 1700kWh/yr with up to 14kWh on a cold cloudless day in April/May or Sept/Oct. A 250l DHW cylinder can absorb at least 18kWh from near cold. So with a solar diverter you could export very little.

.

[ProDave]

The key to solar PV now is cheap. I self installed a 4kW PV system a few years ago for about £1500 and self usage should give payback in 6 years.  2kW should be easy to self use if you divert excess to hot water heating almost nothing will get exported.  Self usage and the need for batteries only starts to become an issue above 4kW.