It is a rubbish idea and should be dropped as soon as possible. Give the people they have made a promise to a couple of thousand and tell them to go away.

I've done a guide to the RHI implications for solar water heating systems here

http://www.leeds-solar.co.uk/blog/entry/renewable-heat-incentive-consultation-solar-water-heating-guide

it's going to be based on deemed / sap, so you can run the tank cold all you like.

excluding inflation, for a fairly standard 4.8m2 / 2 panel system producing 1000kWh a year according to SAP (best case scenario), will get £175 a year, or £1225 over 7 years from RHI.

On gas (condensing boiler) you'd maybe be saving around £50 a year, or £350 over 7 years, on oil £90 a year, or £630 over the 7 years.

so a total of £1575 over 7 years on gas, or £1855 on oil.

These figures are probably a bit conservative, as I think the efficiencies of the boilers are over estimated for the summer water heating only use, particularly if the tank temperature is above 55, when the condensing impact stops working, but the difference isn't going to be that big, maybe £60 for gas. Assumptions about the rate of fuel price increases is going to be pretty significant as well I think.

I think we're going to struggle to make this economically viable, though I guess it's better than the previous £400 LCBP grant, or the current £300 RHPP grant... sort of.

Actually, add in the RHPP grant and it's almost looking viable at the very cheapest end of the spectrum. Maybe.

I can't help thinking that just a decent sized grant would be a whole lot simpler all round, possibly still based on the SAP output estimates.

How does that compare to the FITs for same area of PV panels?

Still faintly hoping to be eligible for 7 p / kwhth for our Ashp as including cop that would more than cover the running costs, if not the finance.

I still haven't had time to read the consultation documents in detail, but my understanding is that DECC are proposing to deem the 20 year generation kWh and then pay that over a 7 year period. (see 139, 144 and q25)

Deeming will be based on calculations from SAP/RdSAP/or some other equivalent software to be used by the installer. (181)

If you have a GSHP or ASHP and want to keep a fossil system as back-up then you must have a heat meter installed. RHI payments will then be based on the HP meter and not deeming and with a cap based on the total calculated heat demand. (187, 188)

Ted you could well be right.

I did read that bit but didn't understand it, and thought they'd maybe tried to just cover the costs of the system over the 7 year period via the per kWh rate.

I'm baffled about how they're intending to split up the payments then, and why they feel the need to stick with the 20 year payback period even though they want to pay it over 7 years. surely you'd at least make the numbers divisible by each other, eg 20 years split across 5 years of payback = 4 x payback rate per year. over 7 years it must equal 2.8 or something.

That really applies to the entire thing though, everything seems to be up in the air / open to question, but 7 seems to be the current suggestion, which is what I was trying to outline.

having thought about it, this thing about concentrating 20 years of payments into 7 years is a total recipe for long term problems. Effectively, someone who replaces their system in 15 years time because it's broken, could end up with the government trying to reclaim 1/4 of the RHI money they'd paid them (if they found out).

If they want to make it pay back in 7 years they need to just make that the case without this sort of unnecessary complexity IMO... or just give it as an up front grant and be done with it instead of adding all this unnecessary complexity.

I just tried explaining this idea to a few reasonably competent people (SSE power station engineer and teacher), and they couldn't get their heads around it, so I really don't fancy trying to have to explain this to potential customers.

I've not been reading the Forum for some months so have only just seen the comments gustyturbine made in April. If you read my post in full you will see that I went down the road of using an MCS installer in the hope of getting RHI payments and could probably have saved myself £2-3000 if I had not bothered: however the installation, even having paid that extra money, was a worthwhile investment given the then (and current) price of oil and the alternative returns in the investment market. If it had not been so I would not have spent the money. If I had needed to borrow the money it would probably not have been worthwhile. I am simply saying that anyone who spends money in the expectation that it will be re-imbursed by some uncertain scheme in the future, is asking for disappointment. Maybe past experience in trying to get Grants for Agriculture and Forestry has made my wary of Government promises. I'm still hoping for some sort of domestic RHI but I'm not holding my breath

Mine was not a money-grabbing decision either - it was a money saving exercise. In my case I installed a biomass boiler and hot water accumulator as I have plentiful supplies of firewood. Some argue on this forum that burning wood is not environmentally friendly because of particulates but some research suggests that a modern Austrian gasification boiler (mine is a Froling) burning dry wood is little more polluting than a gas boiler and as my only sensible alternatives are oil or electricity, biomass is best for me. Frighteningly, and maybe unnecessarily, my previous oil bill for heating was about £3,000 a year. My firewood is free apart from harvesting costs but if I had to buy on the open market I could probably buy a cube of seasoned hardwood for about £100 and I reckon I would burn about 12 of those a year so my costs have reduced by £1800. The system, MCS approved and including flues and all plumbing into the existing under-floor heating system and DHW cylinder, cost about £15,000 so the return is already 12%. I then got the RHPP of £950 because I was MCS certificated. If I had foregone MCS I could have saved at least £2000 but considered that the extra cost was justified in that there was a possibility of getting RHI in due course. Perhaps that's greedy but it does expose the flaws of the RHI and any grant system that is designed to the lowest common denominator.

Waddonvale - there is a section in the consultation about having to buy wood fuel from an approved source, and having to retain invoices to prove that you have done so. Like you I have a plentiful supply of 'free' wood, which is well seasoned, but it looks as if I will not be able to use it and claim RHI.

Posted By: martintLike you I have a plentiful supply of 'free' wood, which is well seasoned, but it looks as if I will not be able to use it and claim RHI.

We are still burning wood salvaged from our build since we only light the stove occasionally. Are we saying this will impinge on our ability to claim RHI for the ASHP unless we have a meter? How much would such a meter cost? Presumably because of this we can't back date our payments?

Umm, ST, there was a lot of shuttering and bits and I don't really know what but they're mostly stove sized. I'm sure we did get too much in places but by not having a skip (for all but a week) we salvaged lots of materials that would otherwise have gone to landfill.

Shocking what gets chucked in a skip when it's the easy option and easily buried by something else!

tbf, their house is clad in larch cladding IIRC, which I think was seasoned on site after installation, so I can imagine there would have been a lot of off cuts of perfectly good timber for burning, and very little ply.

Robin, the consultation proposed they wont pay Rhi for wood stoves, only for certain approved biomass boilers using approved supplies of 'sustainable' fuel. But they wont deduct it from the payments for your ashp, they would only deduct heatingby oil or gas. But not electric.

Hope we understood that right...

If you want to have your say on RHI please see link

https://econsultation.decc.gov.uk/decc-policy/rhi_domestic/consultation/intro/view