Engineer readers differ on whether biomass can be considered a renewable energy resource
Last week’s poll proved inconclusive overall, with a wide spread of opinion and close results. Of the 577 readers responding to the poll, the largest group, 30 per cent, thought that the CO2 emitted from burning biomass took so long to be sunk back into new forestry growth that it could not be properly considered a renewable resource. But an only slightly smaller group, 28 per cent (just 13 fewer people) thought that it could be considered renewable if it were sourced close to the location where it was burned.
The next largest group, 18 per cent of voters, thought that it was possible that biomass was renewable, but that it shouldn’t be subsidised, while 13 per cent were more positive, concluding that biomass is renewable. A further 10 per cent declined to pick an option.
The comments section also reflected this diversity of views, with several people noting that forestry is a well-established industry. “So what if it takes 50 or 60 years to regrow?” asked Richard Annett. “It’s a short period in the scheme of things.” Another reader – Claire – argued that burning wood rather than much more energy-dense fossil fuels is a step backwards. “Tonne for tonne, much more wood is needed than coal to produce the same amount of energy. Given what a highly energy-demanding society we are, and that population and consumption are only growing worldwide, growing wood for energy will have a terrible impact on the world’s remaining forests.”
Robert Palgrave was also sceptical: “The carbon emitted to atmosphere by Drax warms the climate whether it has come from coal or biomass,” and pointed out that there is no requirement for power stations burning biomass to ensure that its emissions are balanced by regrowth. “Consequently there is no guarantee that biomass-originated carbon will ever be re-sequestered,” he added.

It’s particularly non-renewable when it turns out we can’t produce enough of it in the UK so we now bring this stuff in by ship from Canada! More expensive green nonsense.
When I embarked on our £40000 pellet CH system, I was told that Scotland had provided enough trees so pellets can be sourced locally. We’ll see!
This system was a start from scratch exercise, no plumbing , rads, tanks, electrics. It’s a 7 bed house.
So far so good.
I went for ‘None of the Above’ in the poll: I have concerns about the sustainability from the point of view of the regrowth: really new planting needs to at least replace what is harvested. My other concern (still from a sustainability standpoint) is the transport: again, ideally, the stuff should be grown locally – if not how much resource use (and CO2 that arises) as a result of the transport? How does this compare to the net CO2 saving by not burning fossil fuels? If we save 90% – then good. If the saving is 10%, then it’s not really very sustainable or renewable, is it? As for subsidies – well these do have a place to establish an infrastructure and a market – look at this week’s announcements in the fall in subsidy bids for offshore wind.
“Renewable subsidies”!! You just know there’s some really dodgy maths underlying it.
On a more positive point, yes, biomass should be one of the future green energy sources, sourced from forests where (for a like-for-like area) the wood biomass is not reducing.
Transport? I don’t know the relative kWh for that vs the biomass CHP output kWh, but let’s hope it’s not too bad. Meanwhile, what about reforesting more of the UK moorland which currently holds back insufficient flood water.
The AGW lobby are so powerful that they can get away with stories like burning wood produces renewable CO2 but coal does not. It was tragic to see Drax converted from a tremendous and efficient coal burning power station to a subsidy hungry wood burner. However, the wood cheat pails into insignificance compared with the wind subsidies.
Germany burns a lot of wood as part of the scam, but also burns loads of coal and lignite. These produce power at about 30€ / MWh, which at least subsidises their ruinous move into “unreliables”. How will the UK ever compete with such low cost producers?? The climate Change Act is a suicidal act that needs to be withdrawn, but the parliamentary brains to see that have long gone.
A much better source of biomass would be algae, since the production tonnage is far higher than any other plant species (on a per annum basis). Drying the algal mass sufficiently may pose a challenge, but one other means of processing is direct conversion to transportable liquid fuel.
I would think any such fuel far easier to burn in boiler or turbine or even ICE than wood pellets.
Tree or other plant growth depletes the soil of minerals. Yield will reduce after several cycles. At best it is a short term stop gap.
The ash produced by biomass plants is a very good fertiliser many of the minerals pass through the combustion process – in my view CFD contracts should include a clause to return the ash and nutrients to the forest where the trees were harvested.
So all of the answers except one treat the biomass as a renewable.
So to answer fully we would need to know
* What biomass products are considered? – the image leads the reader to think wood pellet but there are way more types of biomass used for generation than this each with their own pros and cons
*Are we considering we have hit the usage plateau or still on the rising slope?
*What scale of useage is being considered? – Many small home plants may be viable but industrial scale may not be or vice versa
Most energy sources are renewable even oil and or gas but its the re-sinking period that takes the time. Oil and gas will be replaced if we can wait the several millions of years for the process to repeat. Where-as wood pellet (as imaged) is probably in the order of tens of years. if we discount the energy and resources used in processing and making the relevant plants (which are always discounted in most calculations).
In all another ‘Engineer Poll’ that has meaningless question and more meaningless results.
*
I agree with the problem of transporting the fuel – it should at least be included in any total energy saving calculation. Why not grow fuel more locally to the plant? OR build plants that are close to a fuel source?
Importing the fuel could work. Think battery or hydrogen powered freight ships /trucks. As usual the government will subsidise one aspect (in this case generation) when what should be subsidised is the whole cycle from raw wood fuel to the replanting and regrowing of the trees. If the whole cycle is carbon negative, then proceed -with a sensible subsidy if necessary. If not, don’t. It should be a level playing field across technologies though. Instead we have a government subsidising French and Chinese nuclear! You couldn’t make it up…
Well I went for maybe but it should not be subsidised. With Thorium salt reactors coming on line in a decade at $0.03/kWh heralding clean non polluting limitless energy availability, I think the bubble for quasi renewables and so called green energy projects, will burst. Finally bringing the nonsense economics surrounding such Green projects to a much appreciated end.
Cost is the only real test of whether so called “green energy” produces more energy than the fossil fuel consumed in its processing.
If costs 30 pence to make one KWh of electricity (what’s that 8 pence worth at wholesale prices), it’s bound to be absorbing several KWh of fossil fuel in it processing along the way.
There are renewables that cost less than 8 pence per KWh. They can’t be absorbing more fossil fuel than they produce or they would have to cost more.
Yes we should be using biomass, but it should not be subsidised. Use the low value bits of the tree (the bark and branches), not the trunk.
I suspect that it depends on the biomass and on what would happen if it were not burned. Cutting down large trees and planting saplings clearly increases CO2, it releases carbon that was captured before CO2 emissions were a concern against a promise to re-capture it later.
Burning short-lived fuel crops that were planted for the purpose, or byproducts of other crops such as straw, that closes an annual cycle puts the capture ahead of emission. Then the question is more what is emitted as well as CO2 (and water) that may be harmful vs what would have happened otherwise. Just letting waste biomass rot and emit methane is not a good option.
This is quite complex. It makes sense to use waste wood material from saw and pulp mills to produce electricity. It can be burnt to produce electricity or processed to make bio-fuels. It is not 100% renewable as energy is needed for transport and processing. To me it is wrong to subsidise this, the money would be better spent subsidising and developing other proper renewable energies such as solar , wind and hydro which will eventually be cost effective.
Yes of course it’s renewable.
It can be part of a truly circular system for both CO2 and the nutrient minerals.
That means properly managed biomass production locally to the power plant with the nutrient minerals being re-spread as ash on the ground before re-planting.
That system would work equally well with, woodland, coppicing, myscanthus or algae.
I did a large scale study of algae some years back and after a lot of feasibility scenarios concluded for a whole raft of reasons, that it is not viable except for high value outputs like pharmaceuticals and certainly not for biomass, sady.
I’m really pleased to see ‘The Engineer’ has suggested one way to view biomass energy is as “essentially a carbon-based fuel like coal that’s dressed up as a renewable”. That is spot on. I’m so glad you didn’t portray it as ‘carbon-neutral’ or ‘sustainable’ which is the fiction repeated ad-nauseam by Drax and others invested in this carbon accounting error.
The carbon emitted to atmosphere by Drax warms the climate whether it has come from coal or biomass. If carbon is taken out of the atmosphere by future growth of new biomass, that is a separate issue. Drax is not required under the terms of their subsidy to ensure such future re-growth. Consequently there is no guarantee that biomass-originated carbon will ever be re-sequestered. And even it if were, that will take decades at least, time we don’t have.
No one in this question/debate can provide any answers that are without alternative arguments. 15 years ago we had clients with large woods where thousands of tonnes of wood chip could be harvested. No subsidy existed, they used Oil, they purchased Biomass Boilers, and in some cases payback was less than two years.
Alternative to this the RHI pays huge sums of money to ill conceived projects, burning wood chip and pellets.
No one can win the environment arguments, but we still operate grossly uncontrolled heating and cooling in Major buildings throughout the UK.
Biomass in all its forms is but one fuel in many guises, contributing to spreading the load around all the alternative fuel solutions.
Not really an energy source, more greenwash, but a way of gaining some benefit from stuff that you have to get rid of. Better to use sewage to get some energy back than to dump it in the Thames.
Maybe renewable, but a terrible idea in this day and age. Wood is not as energy dense as fossil fuels so, tonne for tonne, much more wood is needed than coal to produce the same amount of energy. Given what a highly energy-demanding society we are, and population and consumption only growing worldwide, growing wood for energy will have a terrible impact on the world’s remaining forests. There is a reason many societies moved from burning biomass to burning fossil fuels in the first place! There also shouldn’t be much waste wood which can be used for this, “waste” wood could be a) turned into useful products like panel board or b) left in the forests to provide deadwood as an essential part of the ecosystem.
I also find it so hypocritical that when countries like Indonesia, and poor people in Africa are burning forests that is a climate issue but when it’s for rich people via power plants then it’s clean, green and sustainable.
Everyone needs to take into account the whole cost of Renewables’- from cradle to the grave. The US government made a huge mistake with Ethanol for adding to vehicle fuels instead of lead/MTBE- they left out of the cost equation all the fertilizers, CO2 generated, transport costs of everything involved in the process cycle and some labor/processing-equipment costs.
The UK needs not too, miss/leave out this part of the equation, unless the UK Forest Agency grow trees for local sourcing on exposed rainy sides of large moorlands and plant useful trees that meet the calorific values per KWh cost and the return of the ashes to the fields/ground instead of artificial fertilizers. Include waste building timbers,strand boards, engineered timbers, and corn/wheat/barley/Oats/and waste vegetation’s. They can be premixed and utilized in Hi-temp furnaces very easily and be part of CHP generation [even on a local scale like Battersee Power station was by providing heating/hot-water to the local area homes/industry-no cooling towers and place by a railway system for transport cost reduction].
Anything producing particulate pollution like pellets or burning wood do, and the answer has to be no. The disease burden on downwind population is high. Using the word renewable or sustainable on solid biomass is a treacherous former of greenwash. Pellet burners and wood burners should be banned at every scale.
It would make more sense to use fossil fuels and leave the trees to absorb CO2 not burn them
I think Biomass is sustainable and is green. Managed forestry is not new. Its been around for so long now. Several countries are on several regrowth of stands of trees. So what if it takes 50 or 60 years to regrow. It a short period in the scheme of things.
I work in Canada and know that forest fires are prevalent every year which burns up huge tracts of forest. Mature stands are prone to beetle kill and so you end up with forests of dead tress waiting for a lightning bolt to set it off. The latest forest fires in BC burnt more that a million hectares. 2.5 million hectares in Canada go up in smoke every year…(imagine cornwall and Devon being burnt every year). In my mind if the forest are managed and that forest fires are managed so that the fire is burnt to produce energy the planet is better off.
I guess if there is a choice between biomass and coal or other fossil fuels, then biomass wins hands over…….at the end of the energy transition period perhaps biomass will fade away too…..
Some negative comments here but each to their own I guess. Biomass has good qualities, naturally produces less NOx (a lot less), next to no SO2, equivalent PM. What you need to realize is forestry is an old industry, we’ve all used paper for years where do you think that came from? Well most biomass production is essentially filling gaps as the paper industry declines due to the new digital era. Its mainly waste wood, not hardwood or wood of any use i.e. furniture, waste, pelletized and used to produce energy in this way via generation of electric, CHP’s, domestic/commercial boilers. So if utilized in the right way it has a part to play.
We all take electricity for granted, the grid is tight and marginal in the UK, Inertia is a problem so we still need large spinning plant like Drax, frequency response can be achieved, voltage regulation etc. it allows grid to utilize the qualities of coal generation via a sustainable method while complimenting the ever expanding renewable energy sector of intermittent sources such as wind and solar.
As the grid expands with Electric Vehicles it definitely has its part to play and while ever the source of the wood is sustainable managed forestry why should it be an issue?
And the fact people complain about it being imported, where do you think most of Europe’s low sulphur high CV coal comes from? A high amount is not local!
If CO2 causes global warming and trees absorb CO2 then why would anyone in their right mind destroy (by cutting down and burning) the very thing that is helping the planet?
What percentage of the carbon in a tree comes from the air and what percentage comes from the ground? I heard it is about 50/50 but this could be rubbish. However, it would affect the argument.
At this moment in time, right now, 38.2% of the electricity being consumed in the U.K. is being generated from gas. Fact – the grid system needs flexible generation to ensure stable grid operation. So gas, coal or biomass will be needed to provide reliable and affordable power in the future. There is no doubt in my mind that converting old coal plants like Drax to generate biomass power is a better option than gas. Gas CCGT is marginally better than coal from a CO2 perspective because the conversion process is more efficient but they’re both releasing CO2 from ancient fossil sources. The wood used in biomass fuelled plants like Drax is sourced from sub tropical areas like the Southern US States because the trees grow so much quicker than in the U.K. absorbing CO2 at a much faster rates, this offsets the transport CO2 as does the means of transport using massive cargo ships from the US is better than using lorries locally in the U.K. on many environmental measures! The question I ask myself is can the subsidy needed to make biomass commercially viable be justified and my view is yes to provide the grid stability needed to facilitate zero carbon technologies like wind, solar, wave and tidal. I think the early biomass CFD contracts placed were high because of the government imposed 2027 time constraint, conversion projects had to pay back in around 15 years some in 10! There is no doubt in my mind that better deals could now be negotiated around the £70 to £80 per MWh for 25 year CFD contracts.
I won’t mention the 3200MW, £30Bn subsidy, 35 year CFD elephant in the room
If we look at using locally grown short rotation coppice (SRC), a power station requires around 1km2 of SRC for 1MW of power capacity. For Drax that equates to (3960MW / 242500 km2) 1.6% of Britains land area.
However, is it a good idea to use this land for SRC? If the land is used instead for solar farms, around 1km2 of PV is required for every 50MW of installation.
In terms of land use for power generation, the sooner we move to a decarbonised future the better. Subsidies for biomass only serve to delay the change.
There is not enough surface area on the planet to grow sufficient trees to provide the “renewable” biomass required to sustain this energy source or the energy required. Each tree in a commercial forest will take approximately 40 years to mature yet is consumed in minutes/hours releasing the captured carbon back into the atmosphere. The cycle is unsustainable.
In similar circumstances, and probably a less sustainable source of ‘green energy’ are the incinerators being dressed up as green. The PR of a newly proposed Knapton Green Energy at Malton suggests the plant emits no more CO2 than two HGV’s running at idle irrespective of the 65,000tons of non-recyclable land fill waste that will be delivered by truck to keep it running.
If we are to be serious about subsidising renewable energy with tax payers money we have to bypass the politicians intervention in this as they are clearly misinformed and choose to be uneducated in the technicalities. I fear many decisions on planning applications in these plants are swayed by local councillors with a vested interest in developing locally. The mere suggestion that this plant could provide energy for 16,000 new homes locally as opposed to putting it on the grid says it all.
The real problem is that the bunker fuel needed to power the ships that make transport of biomass across the Atlantic feasible is un-taxed. This filthy stuff is massively polluting too.
I’m not sure if it can be called renewable but it’s certainly green 🙂 !
The only green aspect of the gallop into subsidised electricity generation from unreliable sources and biomass is the government’s lack of appreciation that the UK has been changed from competing with the other major economies on industrial electricity prices in 2004, to being double that of the USA and among the highest in OECD and all to have no effect on the world’s CO2 emissions.
Lunatics and asylums come to mind.
Unless you can consult an independent expert it is very hard to assess all the data, everyone thinks they know the answers and the maths.
Without a published and truly independent table of comparisons showing all the methods of renewable sources with a real set of standard comparisons it is very hard to judge just what is the best method. The fear is that everything we see published is skewed by those with an interest in making one method look good and another look bad. What exactly is the truth? – I for one do not know. The only thing that can be said is that everything is relative, like saying a Euro Dot5 engine is ‘clean’, it isn’t ‘clean’ it is ‘cleaner’ than an engine from a previous generation.
We must surely embrace the basic facts regarding biomass burning for provision of energy in the UK. DECC/Arup report that burning of millions of tonnes of the low energy content material requires 90% import thousands of miles. Typical 34 day sea journey using ageing polluting bulk carriers is reported to result in 47% of the energy content being lost before the fuel reaches low efficiency power plants , Delloite report 25-30% energy loss in pelleting and processing the timber and large biomass burners such as Drax sadly deliberately waste most of the energy in cooling towers .
Hazardous pollution per unit of useful energy produced is many times higher than alternative burning , a Scottish report published in 2008 detailed deadly fine particle pollution 30-105 times higher than equivalent gas and many times higher than oil. I cannot find a biomass power plant specifying hazardous pollution less than 30 times higher than equivalent gas and unfortunately the emissions inversion characteristics ensure local ground level impact. Pass through any community and the wood burner becomes obvious, you can smell it. Subsidising deliberate degradation of air quality defies logic especially when aware there are cleaner and far more efficient alternatives.
Renewable energy claims require serious scrutiny when aware of time scale and local impact especially in Country of origin, we are aware it takes 10 years of growth to compensate GHG released during planting and a recent report details serious impact on Canadian wildlife due to deforestation and this is known as a major source of biomass for UK burning. Where is the due diligence and duty of care in our energy policy?
Regards Brian Wilson
The due diligence and even common sense behind the UKs energy policy over the last decade has been carbon reduction (except for trees of course as they are green) only. There is no sensible way that unreliable power would have been over-subsidised other than to prove conclusively to the world that our political class is as green as grass.
Subsidies are the main issue here as everyone is competing for them as money is key, by presenting a good case (the good salesman syndrome) it seems that the one presenting the best case wins and taxpayer funding goes to systems which never meet their predicted figures, or have numerous other failings. What do Government do about it? nothing, they spew out drivel to convinve people they are correct when in many cases they are wrong, and power company receiving the subsidy knows this is fixed under contractual conditions. Government stops subsidy and company sues Government, in either case the taxpayer loses.
I run my own HHO system, it powers six homes solely from wind power, water from the sky, and a set of 12 volt batteries, this will produce over 3000 litres of HHO for less than 30 minutes of battery use. If I can do it all myself having NO subsidies and pay for it out of my own pocket with a return on investment in less that a year then why can’t industry, they can but they need subsidies to produce such small scale systems, so do they work.
lets assume a power intensive industry such as steel production, by running a series of large generation sources such as wind, solar, or even water turbines, sufficient power can be produced to make huge quantities of electricity to power HHO generators, and the gas is stored in large tanks. HHO can then be used to provide to power gas furnaces to make steel cheaply as fuel costs are very high.
How about a modern housing development with its own water collection, a wind turbine or solar system or even a water turbine to produce electricity to store in batteries, a single HHO generator could power entire housing estates with much hotter gas so people use less.