PowerSwitch

Need some advice and guidance.

As you know I am moving in 3 weeks (wahoo!) - and I want to explore the possibility of solar panels.

I have seen them on quite a few properties near to the house I am buying with similiar east/maybe slightly south east facing roofs.

The roof space looks easily big enough - but what I would like to know is what is the deal with the government subsidy?

If I approach one of these firms like first solar, what would be my initial outlay? Their brochures seem to imply its free, but they make money on the leccy sold back to the national grid? Sounds too good to be true?

Whats the deal?

Apologies for being lazy and not looking through existing threads

You pay for the panels and your electricity company pay you 43.3p for every kWhr you generate and an extra 3p for every kWhr you export to the grid. A big domestic system rated at 4kWp (that's the theoretical maximum you could get) might cost you £14k. Given a south-facing roof you might get a return on investment of close to 10% tax free. It's a contract for 25 years and the payment is index linked. A pretty good deal.

If you haven't got the cash there are firms that will put the panels on for you for free but they get all the 43.3 pences and you just get free electricity when the sun shines (i.e. when you're not at home and really don't need it). Not really a very good deal.

The firm I used are called Ethical Solar, and the name fits. If you go with them tell 'em I sent you and they will give a small donation to our Transition Town.

10% over how long?

I thought using solar energy to heat water directly is more efficient and will save you lots more money.

Cheers

ziggy12345 wrote:10% over how long?

I thought using solar energy to heat water directly is more efficient and will save you lots more money.

Cheers

The Feed in Tariff is a 25 year contract. The biggest threat to the 10% lasting over that whole period is inverter failure which might cause a ~£2000 bill at some stage.

Solar water heating is certainly a useful thing. I've got one too. But it doesn't give you the FiT so the electricity industry is not giving you money. In strict financial terms as far as the householder is concerned, solar pv is going to save you more money.

And remember everyone, your 43p per kwh is added on to the bills of poorest in society who themselves cannot afford solar panels.

To be more accurate, it is added to the bills of all electricity consumers, but mostly to the richest in society because they tend to have larger bills.

If you use a lot of hot water(I live in a female dominated household,nuff said) then solar hot water may be an idea? You could save more than you generate.

biffvernon wrote:

ziggy12345 wrote:10% over how long?

I thought using solar energy to heat water directly is more efficient and will save you lots more money.

Cheers

Solar water heating is certainly a useful thing. I've got one too. But it doesn't give you the FiT so the electricity industry is not giving you money. In strict financial terms as far as the householder is concerned, solar pv is going to save you more money.

Soon to change under the RHI, starts for domestic installs next year

I would go for hot water heating. The savings you get are not dependant on any government initiative that may disappear overnight. Installation is cheaper and the technology used is less complicated.

Evacuated glass tubes are the way to go apparently

What happens in the winter? Do you have to drain the system?

Cheers

Solar hot water is worthwhile if much hot water is used, the saving on gas or other fuel can be substantial.
Most systems do not need draining in the winter.
Most, though not all, solar water heating systems are reliant on a mains powered circulating pump, therefore not a disaster prep, unless you have a reliable standby source of electricity, and a spare pump.
Some systems use a small PV module to drive the pump.

Grid tied PV can be very worthwhile due to the high price paid for the output. Such systems DO NOT provide any backup power whatsoever, you will be just as grid reliant as before.

A stand alone PV battery charging system can be a very worthwhile disaster prep since it allows limited use of electricity almost indefinatly, no matter what happens to the grid.

If going down the grid tied route, consider a small battery charging system as well, there should be a useful saving by installing both at the same time on the same supports, and useing the same PV modules.

In the event of TEOTWAWKI, then the PV modules from the otherwise useless grid tied system could be re-purposed for battery charging or other uses. I would advise against so doing for routine power cuts whilst times are normal as there will be warrenty issues with any alteration, and such systems use lethal voltages.

biffvernon wrote:You pay for the panels and your electricity company pay you 43.3p for every kWhr you generate and an extra 3p for every kWhr you export to the grid. A big domestic system rated at 4kWp (that's the theoretical maximum you could get) might cost you £14k. Given a south-facing roof you might get a return on investment of close to 10% tax free. It's a contract for 25 years and the payment is index linked. A pretty good deal.

If you haven't got the cash there are firms that will put the panels on for you for free but they get all the 43.3 pences and you just get free electricity when the sun shines (i.e. when you're not at home and really don't need it). Not really a very good deal.

The firm I used are called Ethical Solar, and the name fits. If you go with them tell 'em I sent you and they will give a small donation to our Transition Town.

Thanks all for the advice.

Biff - I don't really have the cash - because of the risk of imminent financial/economic calamity I want to pay down debt asap.

But reference the free electricity when I am NOT home (ie during the day), my wife is part time, and works the white goods hard between thursday and sunday (amongst other things). So I guess I could get most from the free leccy?

Is it still worth doing in your view?

You could have the free set up and run a mains fed battery charger during the day to charge a battery bank and turn you lighting circuits over to 12V LEDs and a 12V fridge/freezer. Alternatively you could get an inverter/charger and run your fridge/freezer and central heating system off the batteries and inverter.

Totally_Baffled wrote: Is it still worth doing in your view?

It might be but check the small print carefully. Ken's idea of using batteries sounds a plan and you can achieve a lot just with careful deployment of time switches and a bit of lifestyle adjustment - Oh the sun's shining, time to put the washing on, rather than Oh the sun's shining time to hang the washing out.

It is certainly possible to use the "free electricity" to charge batteries, and then to use the stored electricity for lighting or refrigeration when the sun is not shining.
It may however not make economic sense.
Electricity produced, but not consumed within the house can be sold into the grid, though only for an additional 3p beyond the premium paid for producing it.
The battery charger, the battery, and the inverter, all have losses, that may in total approach 50%. Therefore electricity from the PV that is used to charge batteries, and then inverted for night time use, could cost 6 pence a unit. That is comparable with cost of buying it on economy 7 or similar tarrifs.

Remember also that batteries cost money and do not last forever.
A typical 12 volt 100 A/H deep cycle battery costs about £100 and has a useable capacity of about 0.5KWH (avoiding excessively deep discharge)
With a bit of luck the battery might last for 1,000 cycles, or a total of 500KWH cycled through the battery.
Therefore electricity that was free when put into the battery, costs as much as 20 pence a KWH when taken out of the battery.

Of course it might be argued that the battery was purchased as a disaster prep, and that having been purchased, might as well be used.
The economics are rather different in that case, since the battery might last 3 years in regular use, and 4 years in standby use.
Therefore only about 25% of the battery cost is due to useage, the rest would have been incurred anyway.

If the battery is only discharged by about 10%, then it might last as long in daily very shallow cycling, as it would just sitting there on float charge.