Wood pellets for centeral heating.

Alycidon

Hi,

We live in a detached bugalow with an oil fired Ch system powering 14 radiators. We are fully insulated but are still amanging to get through 4,000 litres of heating oil per year.

We dont have gas, to remote, but do have electricity and an excellent Efel Harmony 3 log stove in our games room. This required regular reloading and gets so hot that we have to open the windows after about an hour to cool the room down.

Our oil fired Potterton boiler is about 30 years old and on its last legs. With the cost of oil at about 50p per litre and not likely to reduce much I am thinking about maybe running a pellet stove heating system either running on pellets or maybe crushed pelleted Miscanthus Grass (a plant has opened locally processing this stuff into pellets). Maybe we can then run an oil fired boiler as a back up should the wood one go out etc.

A long shot maybe but has anyone done this, if so views, comments etc would be welcome.

Failing that does anyone have current comparative energy generation costs for oil fired and wood pellets. I suspect that a pellet stove may attract a grant which helps. I have also seen that different model stoves put a different percentage of output into water heating for the rads and room heating.

Thanks for your help.

A

Canucklehead

Good morning: Good advice/links available at the Center for Alternative Technology website... http://www.cat.org.uk/information/info_content.tmpl?subdir=information&sku=info_is_renewables/ No personal experience with biomass in this country but used it extensively in Canada.

HTH

Canucklehead

Ken68

Welcome Alyc....so much in Google on this is SELLING..the best impartial advice I know is

http://www.selfsufficientish.com/

Several posters are/have put in wood pellet stoves.
Wood pellet stoves depend upon electricity to blow the fan, so no substitute for conventional stove.
p.s you want the forum section
pps...The Alternative Energy board.

peat

I think that bulk purchase of pellets at £140/tonne equates to about 3.3 pence per kWh.

Ken68

That's good peat, competitive, do you think could be used in a conventional stove.

peat

Doubt it. That figure assumes a boiler efficiancy of 90%. If you were to use a convential bolier rather that one specifically designed for pellets I don't know what the effeciency would be.

Alycidon

Pellets are to small for a normal log stove, they would tend to fall through into the ash pan unburnt maybe then leading to an ash pan fire. I have seen a pellet firebox that you could use on an open fire (and maybe a stove?) that will allow you to burn pellets this way. Strikes me as a bit of a waste though.

I have since seen on the welsh wood site the energy ratings for oil is 1 litre = 10KW and two KGs of pellets is also 10KW therefore if two kgs of pellets are cheaper than 1 litre of oil we should be getting somewhere. At £140 a ton then that makes 2kgs 28p if my maths are OK, oil is currently 49p.

I have now had a reply to my enquiry from one company supplying pellet boilers. They recon I need a 32KW boiler , the present oil one is 19kw but the bungalow has been extended twice since it was installed. Got no problem with that but they are saying pellets at £180 a tonne plus £40 delivery and I will need about 11 tonnes a year. So 15K for the set up plus base (1k?) plus installation for no savings at all !!.

I know their price is a bit high for pellets and I can source other fuels cheaper and maybe even make my own pellets from sawdust with one of those nice little US machines (about 2K) but maybe a bio fuel boiler is the way to go and not pellets. Pelleted Miscanthus has an energy output level slightly lower than wood pellets but it is available locally in bulk at about £130 a tonne collected.

Another point, can anyone tell me how these things smoke?. If I went for a stand alone boiler house set up it may have to be upwind of the house to allow easy refill of the fuel store.

Maybe a smaller in house pellet boiler running alongside the oil boiler is the optimum solution.

Thanks for your help and advice.

A

Just found this, seems to answer a few questions;

http://www.actionrenewables.org/uploads_documents/Biomassstepbystep.pdf

and this, just about sorts the job, just got to compare the Uk prices in pounds,

http://alternative-heating-info.com/fuel_comparison.html

Ken68

Talking to a farmer a few years ago.
He picked up an agricultural grant to install straw bale burning machinery to heat his house and workshops.
This was when the system first came out and despite the fuel and carting being free and some of the capital cost being recoverable, he still couldn't make it pay.
And it was a pain in the rear, often wanting to be unblocked to ensure smooth flow into the boiler.
He showed it to me, looked like a small combine harvester.
I figure anything with hoppers and tracks and belts and FLAMES is never going to be worry free.
Would this be the case with a wood pellet boiler do you think.?

Alycidon

They had a straw boiler at the big house on Woburn Estate but had to close it down due to smoke emissions.

Been to the NEC today at the home renovate/building show to look further at things, pellets are fed by augers so not much chance of those jamming given that you use the right size (6mm) pellets. They flow very much like a liquid.

Thought I had the solution with a Bosch air pump, takes heat out of the
air, being launched in June time but highest output is only 9.5kw and not the 32 kw I need. Also takes 3 kw to produce the 9.5kw !, Bosch guy though it would do as it uses a big water tank to store excess heat. Sounds iffy to me.

Think a plug and play type system is the best option (boiler+fuel store in a little shed), at this time a bio mass boiler looks favorite as it will burn anything I think but I have not really seen one of them in the flesh yet. They just had pellet boilers at the show.

A

mute_posting

Alycidon wrote: »

Also takes 3 kw to produce the 9.5kw !, Bosch guy though it would do as it uses a big water tank to store excess heat. Sounds iffy to me.

Why? the heat energy extracted form the air is stored in the water to be used as required.

i.e. if it is extracting 9kw from the air constantly, you may not need that much energy at the time so it is stored in a body of water - kind of like a battery to be used when u need it.
MP

Ken68

This chap fitted a wood pellet boiler as part of the project.As shown on television it took up an entire shed and Gryff Jones remarked 'bigger than I thought.'

http://www.mypembrokeshire.com/vnews/display.v/ART/2006/10/23/453d3d3d7a023