MSE News: EST cuts solar panels' bill savings estimate

MSE_Jenny

This is the discussion thread for the following MSE News Story:

"Energy Savings Trust cuts estimate of bill savings from solar panels."

Read the full story:
Energy Savings Trust cuts estimate of bill savings from solar panels

michaels

Yeah - I know people who have been forced to start using an air source heat pump to heat their swimming pool to maximise their savings...not sure subsidising heating for those able to afford a swimming pool was supposed to be the point of the scheme tho?!

[Deleted User]

I get a FIT payment of about £900 and save about £200 a year on elctricity but I am at home all day and stagger my usage so £70 a year sounds about right for the normal working person. The rent a roof businesses are laughing all the way to the bank

Cardew

The EST tests were caried out with export meters which is the only way to determine savings and they come up with £70.

Unless you have an export meter, you cannot say how much you are saving.

rhiwfield

Cardew wrote: »

The EST tests were caried out with export meters which is the only way to determine savings and they come up with £70.

Unless you have an export meter, you cannot say how much you are saving.

Even this doesnt tell the whole story. Part depends on how efficient you are in using electricity home generated up to the maximum beiong generated. e.g., using an immersion at 3kWp when you are generating 1kWp means you are using 100% of generation but having to import 2kWp for the privilege. Hardly a saving. But using the same immersion when generating 3kWp is a different story.

If you have already taken all reasonable steps to reduce consumption and then install pv, the resultant reduction in imports gives a rough guide to how much you are really saving. From a pre install benchmark of 4750 annual kWh we have gone to 2850 annual kWh, much of which saving appears to be usage of the c3000kWh we generate annualy, though as you say you'd need an export meter to be sure.

And even then you may need to consider whether you are using home pv generated to replace other fuel forms, such as oil or gas for summer hot water, which adds to the benefit.

I dont disagree with the broad conclusions of the EST report, but it certainly isnt one size fits all.

Cardew

rhiwfield wrote: »

Even this doesnt tell the whole story. Part depends on how efficient you are in using electricity home generated up to the maximum beiong generated. e.g., using an immersion at 3kWp when you are generating 1kWp means you are using 100% of generation but having to import 2kWp for the privilege. Hardly a saving. But using the same immersion when generating 3kWp is a different story.

I dont disagree with the broad conclusions of the EST report, but it certainly isnt one size fits all.

However very few people with a house big enough for solar PV panels will be using electricity on a 24/7 tariff.

They will heat and produce hot water by gas, oil, lpg or be on an Economy 7 tariff.

So taking your first case of generating 1kW and using an immersion heater, they will be losing money as they will be paying for two kWh at, say, 10p/kWh = 20p.

They could use 3kWh heating with gas for around 10p.

Even on the very rare times when they are generating 3kW(plus background consumption) they are only saving at the cost of that amount of gas/oil etc.

Pincher

Idea: National Grid electricity bank.

You deposit electricity at home using the export meter,
you withdraw electricity at home and at electric car charging points.

furndire

Where does this leave the people who have the free panels but have to pay £5 a month maintainance, or who paid £x to the rent a roof people for the panesl - mis- sold??? & how many of those schemes are out there?

Cardew

furndire wrote: »

Where does this leave the people who have the free panels but have to pay £5 a month maintainance, or who paid £x to the rent a roof people for the panesl - mis- sold??? & how many of those schemes are out there?

Some who paid £500 and £5 a month for maintenance(for 25 years) will actually be losing money.

Many of the 'Rent a Roof' companies are still stating that savings of £hundreds a year can be made.

The situation is made worse by some people, desparate to convince themselves that they made a wise decision, claim that they are saving unbelievable amounts; without any way of knowing how much they are saving, other than "last year I spent £xx this year £yy"

pawnbroker_2

One aspect that seems not to be covered is who checks that your roof is capable of carrying the extra weight ?

As far as I can see panels are quite heavy.

Also if someone has ahouse that is covered by NHBC and they put panels on after purchase does this invalidate the cover ?

lanstrom

pawnbroker wrote: »

One aspect that seems not to be covered is who checks that your roof is capable of carrying the extra weight ?

As far as I can see panels are quite heavy.

Also if someone has ahouse that is covered by NHBC and they put panels on after purchase does this invalidate the cover ?

It's a very valid question and there was a house on 'Help my house is falling down' the other night and Sarah Beeny said how bad it was that the tiles had been changed from slate to concrete tiles because of the extra weight. At least that extra load was on both sides of the roof. I would imagine that all that extra weight on just one side of the roof could be extremely bad news ?

Also .. I still can't find an answer to whether moss builds up under the panels since the rain can get to the tiles but the sun can't.