Wood pellets or oil, ufh or rads

[FlipFlopGriff]

We're not on mains gas and they wanted £24k to connect us to the mains which was ridiculous. Looked at air source heat pumps but was unsure if it would work below 10-15 degree below and have to have the fans (look like an A/C unit) outside - listed property so external changes are more problematic than internal. Eventually went with a biomass boiler. 21kw Windhager so proven company and no issues other than emptying the ash in just over 12 months. Only to pup with bags with a pallet being c£250 for 96 25kg bags. The install was jut over £20k and that was just the biomass boiler, pipework tails and thermal store. I put the rads and pipework in and it powers 13 rads (just downstairs for now). Just applied for RHI and we'll get nearly double back spread over 7 years but this is very much dependant upon your EPC assessment on which the calcs are based.
The pellet cost has remained fairly constant over the last 10 years which can't be said for fossil fuels and the costs are only going one way in the long term. Using a bag a week to heat the water over the summer months on average and c3 bags a day on average in the coldest months.
House is 300+ years old, 225 square metres and all single glazed windows.
FFG

[FlipFlopGriff]

There is a RHI calculator here if that helps:
http://www.treco.co.uk/renewable-heat-incentive/in...
We used this as a guide for comparison against oil/LPG etc.
FFG

[Renovation]

FFG that's very interesting.

Can you tell me in very basic terms - is the grant 100% guaranteed - unlike some funding that dries up.
Presumably you want a better EPC to get more funding ?
I presume you have to load bags into a hopper - how often do you have to do this ?

Thanks

[CK11]

Is that 3 x 25kg bags per day in the winter months!

[jason61c]

As a side note, if I had a pellet stove fitted would that come under the deal?

[CK11]

Yes as long as it's in the rhi scheme list of approved stoves and fitted by an approved mcs installer

[FlipFlopGriff]

Installer has to be MCS approved as does the boiler which is easy to check. http://www.microgenerationcertification.org/consum...
http://www.microgenerationcertification.org/consum...
There are a few hoops to jump through but it should be a formality, until the funding runs out or they do as they did with PV and halve the pay out overnight. Biomass is 12.2p/KWh so for us we get the cost of the boiler an 8-9 years worth of fuel for free. Boiler isn't the smallest and we have to top up with bags (as no bulk store) which means topping up almost daily during the winter and weekly in the summer. Bags are 10kg each.
usually get them here:
http://www.woodpelletfuel.co.uk/woodlets---premium...
The Verdo ones seem to produce less ash, ie burn better so for a few quid more are better value.
FFG

[westberks]

On the question of rad or ufh I'd suggest ufh for living areas and bathrooms with rads for bedrooms. We have ufh throughout via concrete floors and its great everywhere but the bedrooms as you cannot get the heat quick enough and it takes too long to cool.

This leads to disagreements between me and swmbo as I'm always too bloody hot and she is too cold, for the record she wins the argument (especially since she found out that I turned off the floors at the fuseboard)

[Scuffers]

interesting thread,

efficiency wise, UF in a new build wins hands down, BUT (as said) it's not as quick to react to changes in demand.

as for heat source, looked at heat pumps, and although very cleaver etc, the costs just don't stack up, even if they are 4:1 (which seems like the holly grail that nobody actually achieves), the current price of electricity is high enough, and it's only going to go up (unlike oil/gas that do actually come down as well and are more pegged to world markets).

elec is what? some 12.9p/unit, and oil is some 4.7p/unit

other issue (with bigger houses) is the bigger heat pumps need 3 phase electric.

[RedLeicester]

clockworks said:

I'd go for oil for a wet heating system. No idea how much wood pellets cost compared to oil, but plenty of oil suppliers in this area, never seen a wood pellet truck?

UFH throughout for comfort and efficiency, and only go with oil if you don't like your bank balance.

We switched from oil to pellets/wood three years ago and our annual bills dropped from £5k on oil to £1800 on pellets.

You wouldn't "see" a pellet truck - unless they were bulk deliveries (over 6t blown) then they look just like any old other delivery truck from any old delivery company.

[CK11]

Could you give a little background as to your property and which make model pellet boiler you use?
How many ton per year of pellets?
Did you qualify for rhi?
Do you also use a separate wood burner?

[jason61c]

CK11 said:

Could you give a little background as to your property and which make model pellet boiler you use?
How many ton per year of pellets?
Did you qualify for rhi?
Do you also use a separate wood burner?

I've been though it a few times today. Our house is a 4 bed detached old farm house, 198ish internal SQ m, or 2200 sq/ft. Going though the calculators it says 3.3tonnes on the boiler we've been quoted/the most interested in. I'm banking on £250 a tonne worse case. Say 4tonnes a year, £1000 a year...

[RedLeicester]

jason61c said:

I did look at pellet systems myself for the Feed in rates, however they're expensive to look after and not overly reliable yet.

In what way? They've been around for 20 years or more, and the UK has only just woken up to them.

[jason61c]

RedLeicester said:

In what way? They've been around for 20 years or more, and the UK has only just woken up to them.

I've now done a complete 180Deg turn on this. I looked a few years ago and had dealings with a few start up type companies. Now though it seems to make complete sense to me.

[clockworks]

Some seriously big heating bills here! I've got a 1960's 4-bed detached dormer bungalow.

I use about 650 litres of oil a year for the central heating, say £400.
Electricity (hot water and plenty of gadgets) is £75 a month.
A "load" of wood for the stove in the lounge each year, £120.
Some kindling, and the odd bag of smokeless coal.

Total energy bill around £1500 a year.

Pretty much the same cost as my last house - 1850's 3-bed end of terrace - which was all-electric.


I didn't realise that wood pellets were generally delivered in bags. I guess that's why they are relatively expensive?

[Renovation]

RedLeicester said:

We switched from oil to pellets/wood three years ago and our annual bills dropped from £5k on oil to £1800 on pellets.

£5k on oil !!!!

Can you give quick details - the two boilers, size of house, insulation, is that without taking any grants into account ?

My main sticking point is £14k for a pellet boiler V £3k for an oil combi fitted

Whilst there are grants, I don't trust the Gov't to stick to their deals as they haven't in the past and using an accredited boiler / installer adds massively to the cost.

[RedLeicester]

jason61c said:

RedLeicester said:

In what way? They've been around for 20 years or more, and the UK has only just woken up to them.

I've now done a complete 180Deg turn on this. I looked a few years ago and had dealings with a few start up type companies. Now though it seems to make complete sense to me.

Me too - my previous experience of any sort of log boiler was getting up at 5am in my grandparents cottage to rake out the coals and relight the boiler in order to get some tepid water come midday. Hell. Our architect at the time was pressing us to look into Biomass and I was determined to go down the GSHP route. I happened to be driving past the place that imports several of the big brand biomass systems and decided to drop in on spec to confirm my views of it being medieval technology. I called my wife on the way home to tell her we were having one!

[RedLeicester]

clockworks said:

I didn't realise that wood pellets were generally delivered in bags. I guess that's why they are relatively expensive?

Depends on one's definition of relatively expensive, these are old figures but:


Product Amount Required Unit Cost Annual Cost Incl. VAT Cost per kWh

Wood Pellets 137 Tonnes £180 £24,660 4.11p

Heating Oil 60,000 L 65p £39,000 6.50p

LPG 84600 L 49p £41,454 6.91p

Natural Gas 600,000kWh 3.711 £22,226 3.91p

Electricity 600,000kWh 10.112 £60,672 10.62p


Blown pellets are certainly cheaper than bags, but it depends on the volume you use as to whether it's worth the additional cost in hardware (big pellet storage hopper) for the saving in cost.

[RedLeicester]

Renovation said:

£5k on oil !!!!

Can you give quick details - the two boilers, size of house, insulation, is that without taking any grants into account ?

My main sticking point is £14k for a pellet boiler V £3k for an oil combi fitted

Whilst there are grants, I don't trust the Gov't to stick to their deals as they haven't in the past and using an accredited boiler / installer adds massively to the cost.

Boiler was a 30yr old thing though tested as still being 85% but parts were becoming trickier to get and breakdowns were increasingly common so we needed a change. It was hopelessly underpowered and heating a 5 bed detached house. Choice was to replace it and move on as is, or take the opportunity to do something a bit different.

New oil boiler was going to be around 4-5k + fitting. Equivalent pellet boilers came in around 10-12k, so assuming the circa 3k delta per annum would pay off in around 4 years - this was pre-RHI remember, so everyone was worked out on savings, rather than grants. The idea was any grant would be a bonus. Oh and we calculated on a steady uplift on oil of 10% per annum going forward which was ludicrously conservative - when we moved in oil was 32ppl, when we disconnected the boiler it was 76ppl.

However, we had an ace up our sleeve which the importer was quick to jump on: we have our own source of "free" wood. Now the choice became one of pellets versus wood versus combi - pellets could be bought in, wood meant "zero" heating bill, and combi was much more expensive, but offered the best of both worlds. After all wood boilers don't fill themselves and if I don't fell and split then there's nothing to put in it, and more to the point if we're away, the house freezes...

So we had:

Oil boiler - cheapest to fit, most expensive to run
Log boiler - next cheapest, potential "zero" running costs
Pellet boiler - medium capital cost, substantial saving over oil, but still "expensive"
Combination Log/Pellet boiler - greatest capital cost, choice and options on fuelling...

After much thought, we went down the final route - the combination boiler, with the intention we'd exploit it to the full - the higher capital cost was outweighed by the intention to use logs as much as possible, so as to reduce the fuelling bill to near zero, only falling back upon pellets when away or moments of can't-be-arsed-ness. We also chose to go with one of the big central players (at greater cost) with a long history of investment in biomass rather than some of the eastern or southern European ones which were often vastly cheaper but didn't have the pedigree (or in many cases as you mention, the MCS accreditation). Boy oh boy are we glad we did. "Sir, we're sending an engineer over to run a firmware update on your boiler..." Erm.... okay.... "Sir, there is now a Version 2 of your boiler and the manufacturers have decided your V1 simply isn't good enough, so they're sending someone out to retrofit the parts to make yours a V2".... erm..... okay... God bless the Austrians and their pseudo-teutonic efficiency.

Working on that equation, payoff extended to five years, but potential costs thereafter were whatever we chose to make them. The reality is we've boxed and coxed by buying around 2t of pellets a year, running the rest on logs. The more we have felled and processed the more we've adjusted to the rough time needed to generate enough logs (around 8t) to give us a year's supply, and we have this year experimented with buying freshfelled greenwood at about £1100-1200 for 27t (so just over 3 years supply, or circa £400pa). With RHI applications now finally opened to us "early adopters" we have gone for that too which will see the full cost of our installation back plus a further 50-75% on top. Either way it remains a bonus as the original calculation was on biomass vs oil. A very nice bonus though We're not worried about the government sticking to grants as we've seen no reason for them not to - like the early adopters to the FITs, the terms are still the same and still functioning now, so one would assume the RHI would function much the same way. Likewise the Green Deal hasn't been reneged so much as to have run out of money - there was a fixed pot set aside and it was used up. Having said that, the GD didn't exist when we installed, so all the capital came from us.

Have I become a convert? Yes very much so, but it comes with caveats - ours worked as we have the "free" wood, though the calculations still work assuming bought in wood, but again the latter becomes all the more appealing buying in greenwood but that relies upon having the space to put that sort of tonnage. Additionally once you move up to accumulator fed systems, the space take up by the boiler and sundry equipment increases massively - simple demand-fed pellet boilers are little bigger than an oil equivalent. Log boilers and accumulators are many times the size - ours has used up a single garage give or take a bit, so it's not something that will fit everywhere. Interestingly, our estate agent pal also commented that many townies were put off by the idea of having to touch nasty dirty logs, which was another driver to go for the combination system - if a townie wants to buy our place in years to come they hopefully won't be put off as they can just use pellets, but for us the real huge savings were on wood.

Oh and in terms of pellet cost, to be fair we've seen them come down they have come down as more suppliers have gone into the market and provided competition. How long this will last is anyone's guess as yes I'm sure their price will climb with time, but it hasn't happened.... yet.

[CK11]

Can I safely say I the grants were not available oil would win when not on mains gas
With the grants in place currently pellets. Win

Can the government stop the grants at any time they wish , ie install a pellet boiler at circa 10-12k and get the rhi payments
And in 6 months or whatever they can say we are no longer paying out and the scheme is over, even for existing customers or do they have to guarantee the 7 year payments

Is there a multi log and pellet boiler on this scheme?