PWR Bioheat. How are these IDIOTS so cheap?

[Stumpy Grinder]

That is an enormously inefficient way of drying logs so therefore hugely wasteful. Same as the guys who are the topic of the thread. Drying floor for logs is completely wrong. A few of our competitors do it locally and its crap.

 

 

 

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How can that be inefficient?

The heat is a bi-product of electricity production. Very dry woodchip is heated to produce wood gas which fuels an engine that drives a generator producing electricity. The heat given off is then used to dry wood, including the very same woodchip that fuels the electricity generation. All that is left is a black powder and all of the energy is used. How can that be inefficient?

SG

[matelot]

It's £70 a m3 for hardwood logs plus about £50 delivery. tbh, it doesn't seem that cheap....

[matelot]

How can that be inefficient?

The heat is a bi-product of electricity production. Very dry woodchip is heated to produce wood gas which fuels an engine that drives a generator producing electricity. The heat given off is then used to dry wood, including the very same woodchip that fuels the electricity generation. All that is left is a black powder and all of the energy is used. How can that be inefficient?

SG

 

I've looked at the website mentioned by the original poster and it makes no reference to electricity production?

 

To burn wood to dry wood just seems ludicrous to me. It seems obvious that kiln dried logs will have a far higher carbon footprint than logs dried in an open sided barn.

 

This is a perfect example of a government policy, which sounds good on paper, not meeting one of its prime objectives.

[SbTVF]

How can that be inefficient?

 

The heat is a bi-product of electricity production. Very dry woodchip is heated to produce wood gas which fuels an engine that drives a generator producing electricity. The heat given off is then used to dry wood, including the very same woodchip that fuels the electricity generation. All that is left is a black powder and all of the energy is used. How can that be inefficient?

 

SG

 

 

 

I was referring to their method of drying logs. Blasting hot air into a hangar without any recirculation or humidity control is a massive waste. It could be put to much better use for very little expense.

 

 

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[Stumpy Grinder]

That is an enormously inefficient way of drying logs so therefore hugely wasteful. Same as the guys who are the topic of the thread. Drying floor for logs is completely wrong. A few of our competitors do it locally and its crap.

 

 

 

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Have a look at how it can be done efficiently:

 

Borealis Wood Power generator uses wood chips to produce economical renewable thermal and electric power.

[SbTVF]

Have a look at how it can be done efficiently:

 

 

 

Borealis Wood Power generator uses wood chips to produce economical renewable thermal and electric power.

 

 

 

You're completely missing my point. I have no issue with CHP or biomass in general, I'm taking about using the heat generated as a side product being used in a totally inefficient way because it's not their objective. We have a biomass installation because we want just the heat and we use it as efficiently as possible, including for drying firewood in a properly designed insulated chamber/kiln. Our boiler went in for heating our livestock sheds and saving electricity. We save more in electric&gas that we get in RHI so the logs are just as side line.

 

Anyone blasting air into a hangar or shed to 'dry' logs, should have their RHI payments removed imho. (Grain drying floors excluded)

 

There are a few people I've heard of drying green waste with and to burn in their CHP systems, after already being paid to take it from the council, who are then being paid RHI. Now that's just burning wood for the sake of burning wood and is completely immoral.

 

 

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[TimberCutterDartmoor]

It's £70 a m3 for hardwood logs plus about £50 delivery. tbh, it doesn't seem that cheap....

 

Yeah the delivery kills it. Website says free delivery AKAICS.

[matelot]

Have a look at how it can be done efficiently:

 

Borealis Wood Power generator uses wood chips to produce economical renewable thermal and electric power.

 

That looks really interesting technology, however it doesn't seem that efficient in an environmental or financial sense...

 

It turns 1kg of wood chips into 1kWh of electricity, that means only about 25% of the energy in the wood is turned into electricity.... that's not particularly good, especially when you consider the amount of energy required to cut down the trees/ transport the trees/ chip the tree etc.

 

In a financial sense it doesn't seem that efficient either, I cant see a system like that costing much less than £500k by the time you include a new building & wood store etc. All for a system that produces 45kW of power. What does wholesale electricity cost? 5p a kWh? That means it only produces £2.25 of electricity an hour. Running 24/7 the system the system would produce £20k of electricity a year.

 

You might as well leave the trees standing, buy a £10k diesel generator and use the diesel that would have been used to transport and chip the trees in the generator.

[matelot]

Yeah the delivery kills it. Website says free delivery AKAICS.

 

I think it's free delivery if you are at the end of their street.

[Stumpy Grinder]

That looks really interesting technology, however it doesn't seem that efficient in an environmental or financial sense...

 

It turns 1kg of wood chips into 1kWh of electricity, that means only about 25% of the energy in the wood is turned into electricity.... that's not particularly good, especially when you consider the amount of energy required to cut down the trees/ transport the trees/ chip the tree etc.

 

In a financial sense it doesn't seem that efficient either, I cant see a system like that costing much less than £500k by the time you include a new building & wood store etc. All for a system that produces 45kW of power. What does wholesale electricity cost? 5p a kWh? That means it only produces £2.25 of electricity an hour. Running 24/7 the system the system would produce £20k of electricity a year.

 

You might as well leave the trees standing, buy a £10k diesel generator and use the diesel that would have been used to transport and chip the trees in the generator.

If they chipped and burned the entire tree, then your calculations are probably about right, but they aren't. We are talking about an estate with 2,500 acres of predominantly hardwood woodland! Most of it goes off whole to be milled. Anything not good enough for that gets logged and sold - about 1000 cubic metres a year! Anything not good enough for either gets chipped which is about another 1000 cubes a year! About 2/3 of that gets sold, and the rest goes in the generator which produces electric and dries the wood with the thermal. So they are effectively making the absolute most out of a tree by using what might otherwise get wasted to refine the product.

SG