Domestic Solar - would it pay me ?

[Clive]

Should be under £1000/kw installed now for what your looking at. I know somebody who looked at putting them on a barn conversion very recently and instead opted for ground source heat pump instead for the heating. I've seen that in action and it's very efficient for that side of things. He's left his elec requirement to come off the grid due to his main use being at night. This was for around 8k sq ft property.

ive got heating covered, not a fan of ground source though, have spoke to several with it and all wished they hadn't although if they had solar to power the immersions maybe it wouldnt be so bad - best return on heating is massive over spec of insulation

wouldn't even consider solar on the house (listed people wouldn't let me anyway) but with this barn 100m away it seemed like a possibility, as prices seem to be falling all the time maybe best to wait until all this daft FIT is out the way and they stand on their own feet though I reckon

 

[Clive]

In theory, and I suspect reality, it should be possible to buy panels and inverters, much cheaper , that are not licensed for FIT use. Or alternatively buy second hand panels , which have little or no value.
This licensing requirement has always put a large premium on prices and was a typical EU reg gold plated by DECC to ensure everyone gets a crack of the whip.
You will need local Area Network Provider, approval of course as it will still be feeding into the main

why do people sell used panels ? (if they are not nicked !)

 

[Exfarmer]

no idea but am aware some are available, never chased them up.

 

[f0ster]

the problem is that when you need the battery power the most the sun shine is the poorest, but if you have overcapacity of solar then you stand a chance of always having battery power available. on a very good sunny day you might get 3 to 3.5 kw out of a 4KW system but that drops down to a few hundred watts on an overcast day.

 

[Greenbeast]

regarding earlier battery talk....

 

[Pasty]

Also interested in this. Could get 10kw on my barn which is 50m or so from the house and already connected to my domestic supply, just for lighting and a few sockets down there. Plenty of room for batteries. I'm just not sure on the cost / benefits of going for it.

 

[Greenbeast]

i'm gonna budget for a 12kw array on the house when we build. got 3 phase here so i can go to just over 11kW export with no changes on the DNO side

 

[f0ster]

we usually install 12 kw and use a 10kw inverter, the inverter manufacturer is ok with this arrangement. this way the inverter does not exceed 16A per phase.

 

[Exfarmer]

Also interested in this. Could get 10kw on my barn which is 50m or so from the house and already connected to my domestic supply, just for lighting and a few sockets down there. Plenty of room for batteries. I'm just not sure on the cost / benefits of going for it.

Pasty, it very much depends on how much power , you think you can use, particularly in the summer when you will produce most.
The bigger your supply the lower proportion you will use but the best chance of catching winter sun .

 

[Pasty]

i'm gonna budget for a 12kw array on the house when we build. got 3 phase here so i can go to just over 11kW export with no changes on the DNO side

We've got 11Kva lines directly over the barn and over the house garden with a transformer on the pole in my garden. Would that give us any advantage if we could go straight into the 11KVa lines?

 

[f0ster]

even with 11kva lines right by you if you do not have three phase on your property it will still cost a lot to get three phase,

 

[Courier]

even with 11kva lines right by you if you do not have three phase on your property it will still cost a lot to get three phase,

Never mind 3 phase - nothing with 11,000 volts involved comes cheap [emoji33]

 

[Bloders]

weve 11KV and DNO would not allow over 4KW due to us being near the end of the line and the two farms between us and end of line having 4KW of solar each, so 11KV doesnt really help much

 

[Exfarmer]

We've got 11Kva lines directly over the barn and over the house garden with a transformer on the pole in my garden. Would that give us any advantage if we could go straight into the 11KVa lines?

You should have no issues at all putting 10KW on the roof, in your situation
if you have 3 phase, it may work against your ability to use the power as you are unlikely to be able to take the power off the 3 phases, in a manner to efficiently utilise it, for domestic purposes.
The payback on all the new tariffs rely on you being able to utilise the bilk of that power which is unlikely in most cases.
However you may feel that for green reasons, or your belief that power prices will surge, that you wish to do the install anyway

 

[renewablejohn]

Thermal solar is another alternative for 24/7 power production as an alternative to batteries

 

[Pasty]

You should have no issues at all putting 10KW on the roof, in your situation
if you have 3 phase, it may work against your ability to use the power as you are unlikely to be able to take the power off the 3 phases, in a manner to efficiently utilise it, for domestic purposes.
The payback on all the new tariffs rely on you being able to utilise the bilk of that power which is unlikely in most cases.
However you may feel that for green reasons, or your belief that power prices will surge, that you wish to do the install anyway

We only have a single phase supply but the transformer is in my garden. Would only really be for domestic supply and part of my reasoning would be to fix my domestic electricity costs for hopefully most of the rest of my days. I suspect we will be moving to more electric vehicles and machinery so all that will need charging. Even things like chainsaws / mowers etc. are starting to become viable so all that could be charged during the day.

I'm not entirely sure which way electricity prices are going to go. I don't necessarily subscribe to the view that they will keep rising. In fact I think the opposite may be true but who knows?

 

[Pasty]

Thermal solar is another alternative for 24/7 power production as an alternative to batteries

We would probably fit a few thermal panels on the house as we already have a solar thermal store hooked up to a wood stove (Esse W23 bah) and a gas boiler. So that would be good for summer time hot water and boosting in the winter. In time we will replace the Esse with something which can cook and heat the whole house or at least provide much more heat to water.

 

[Greenbeast]

We would probably fit a few thermal panels on the house as we already have a solar thermal store hooked up to a wood stove (Esse W23 bah) and a gas boiler. So that would be good for summer time hot water and boosting in the winter. In time we will replace the Esse with something which can cook and heat the whole house or at least provide much more heat to water.

Although i have fitted solar thermal twice in the past and do have a fondness for it, i gather most people now just reckon you should just spend the money on more pv, you can always divert the leccy to immersion heaters using many of the available load diverters

 

[Pasty]

Although i have fitted solar thermal twice in the past and do have a fondness for it, i gather most people now just reckon you should just spend the money on more pv, you can alwasy divert the leccy toimmersion heaters using many of the available load diverters

Yes, that would be possible too. I saw one in an install in Cornwall. Immersun or something. I suppose the cost of a thermal install would buy a lot more capacity in an existing or new PV install.

 

[Greenbeast]

Yeah, my last 40 tube system cost me about £3k i think, including the cylinder and pipework (DIY install), proabbly cheaper now but man alive £3k buys you a good bit of PV and it's more flexible....