Calorific value of wood?

Mikex

My mate bought some bricks made out of waste wood yesterday and is considering burning them instead of coal. He does not have internet access so I said I would try to compare the calorific values of wood, briquettes & coal in order to compare prices.

I have been googling and have discovered calorific values as follows:

Seasoned logs 4.1 kW/KG

Briquettes 4.8 kW/KG

Coal 7.0 - 8.6 kW/KG

Before quoting these figues to him chapter & verse could someone confirm whether they are in the right area?

Thanks

Mike

rhiwfield

This might help

Mikex

Thanks,

The values seem to be correct.

He paid £3.50 for a 20kg bag which works out at 3.64p/kw.

Seems reasonable to me.

I do not know what he pays for coal. Anyone any ideas? Does £12.50 for 50 kg sound about right?

Mike

suki1964

Mikex wrote: »

Thanks,

The values seem to be correct.

He paid £3.50 for a 20kg bag which works out at 3.64p/kw.

Seems reasonable to me.

I do not know what he pays for coal. Anyone any ideas? Does £12.50 for 50 kg sound about right?

Mike

Well its not beyond the realms

Depends on where he lives and what hes buying and who hes buying it from

I pay £15 for smokeless

Household coal is a lot cheaper

andyelcomb

suki1964 wrote: »

Well its not beyond the realms

Depends on where he lives and what hes buying and who hes buying it from

I pay £15 for smokeless

Household coal is a lot cheaper

Wish I could get coal for £12.50 / 50kg.
Here in Kent the best online quote I've found for 1 tonne (delivered) is £13.45 / 50kg and my usual coal merchant charges £19-£25.50 / 50kg.

Can anyone point me in the direction of cheaper coal in the North Kent area?

Mikex

The £12.50 for 50kg was part guess and part from memory. I seem to remember him mentioning it in the summer. My mate buys 3 tons in the summer when prices are favourable although I understand his 3 ton heap is looking a bit sad after the recent weather.

However to continue with the comparison using the 1 tonne figure quoted above.

50kg = £13.45

1kg = 26.9p

Depending on the quality of the coal.

@ 7kW per kg = 3.84p/kW

@ 8.6 kW per kg = 3.12p/kW

Nothing in the price per kW between coal and heat logs.

Mike

grahamc2003

I've just been out for a bag of coal from our local farm shop (probably not the cheapest place to buy, but ok for the odd bag to top up my wood). That cost £10.20 for a 25kg bag of 'housecoal', the cheapest of the lot. Seems to work out at around 5p/kwh - a little more than I was expecting. Not many coal mines in Surrey though, so it's probably come a long way.

Mikex

Just spoken to my mate.

He bought 3 tonnes of best quality coal in the summer for £630. He still has the receipt. That works out at £10.50 for 50 kg.

Works out in the region of 2.5p per kW.

Mike

reeac

grahamc2003 wrote: »

I've just been out for a bag of coal from our local farm shop (probably not the cheapest place to buy, but ok for the odd bag to top up my wood). That cost £10.20 for a 25kg bag of 'housecoal', the cheapest of the lot. Seems to work out at around 5p/kwh - a little more than I was expecting. Not many coal mines in Surrey though, so it's probably come a long way.

Glad to see that someone is using the correct units for energy content - kWh. not kW. Using the latter is like quoting your car's fuel consumption in miles per horsepower. Might seem niggley but correct units avoid confusion.