[Closed] Seems that burning wood for power “is misguided”

Good article that, thanks for posting.

Could someone explain to me please why it is that the UK hasn't and doesn't invest in tidal HEP?

Seems a lot more reliable than Solar and to a large degree, wind power. The Solent gets 4 high waters' each day ( okay, pedant alert), the Bristol Channel, Western Isles are but three area where tidal flows are significant.

Could someone explain to me please why it is that the UK hasn't and doesn't invest in tidal HEP?

Hmmmm, thanks but I was hoping for an explanation using words with 2 syllables or less 😀

I'd think it obvious that wood burning isn't a scale-able option.

I don't get it?

The carbon intensity of the fuel is irrelevant as long as the same amount of trees are planted as are burnt?

If we are using up existing "stocks" of trees without replacing them, then yes, of course the net carbon release is higher than it otherwise would (wood?) be.

It's also worth noting that the building, and maintenance of other renewables, such as off shore wind, is also carbon intensive. For example, i watched a program where two techs were helicoptered to the top of an off-shore turbine to change the bearing greasers! Hardly zero carbon eh!

As coal was all formed millions of years ago, then replacing it with short term wood is directionally correct. Is it as good as replacing it with other renewables, probably not, but it's still much better than burning the coal in the same power station. The real answer is to limit our consumption of energy, perhaps Prof John Beddington should have cold baths from now on, and go to bed at 5.30pm when it gets dark to save energy? No? Thought not......

Ultimately, we need a mix of nuclear (base load) and renewable (with storage) but that will take 50 years to put in place. In the meantime, swapping our coal plants to wood (an easy change) is the right thing to do.

slackalice
Could someone explain to me please why it is that the UK hasn't and doesn't invest in tidal HEP?

Just off the top of my head:

1) Massive infrastructure costs
2) Relatively low energy density
3) Environmental concerns (loss of habitat, esp. marine bird population (mud flats lost etc)
4) Unknown effects on wider ecosystem (rivers silting up etc)
5) Barrier to shipping (requires locks to access our tidal river ports)

https://www.mottmac.com/article/2282/stevens-croft-biomass-power-station-uk

http://www.awjenkinson.co.uk/about/fp/lockerbie.php

https://www.cips.org/supply-management/news/2016/december/uk-facing-timber-shortages/

Fell vast areas of forests and plant a wind turbine ❓

Sorry maxtorque, it's not as simple as that. Firstly, unless you replace the tree you chopped down for power immediately with one containing the same carbon content, then you've a gap of the lifetime of the tree that needs filling. Then, you need to think about what you needed to grow that tree: fertiliser. There's only so much phosphorus on the planet, and whilst we can fix N, it's exceedingly energy intensive, and requires methane. After that, you need to consider the fact that far from all the carbon fixed by a tree ends up in its biomass: quite a lot ends up in the soil, where although a chunk may stay put, there's increasing evidence that in a warming and eCO2 will lead to more loss of C stored in the soil, exacerbated by fresh inputs.

But, more obviously, there simply isn't the space to grow energy: we need as much as we can for food. There was a reason we turned to coal in the first place, remember 😉

So, that's the problem outlined, how about a solution?

Well, number 1 is to use less energy. After that, renewables, backed up with pumped storage and batteries gets you a surprisingly long way, and these options are far more C neutral than conventional biomass energy. I accept in the UK that nuclear has a place, given the existing infrastructure and expertise, but it's a stop-gap, not a solution.

1) Massive infrastructure costs
2) Relatively low energy density
3) Environmental concerns (loss of habitat, esp. marine bird population (mud flats lost etc)
4) Unknown effects on wider ecosystem (rivers silting up etc)
5) Barrier to shipping (requires locks to access our tidal river ports)

My (albeit, limited ) understanding of hydro-electric is that it's one of the more efficient means by which to produce electrical energy. I'm happy to have my understanding corrected on this. So, taking my existing understanding and in response to above:

1) More massive than offshore windmills? I'm sceptical on that assertion.
2) ICBA to look up what relative energy density means, but sounds like it's not as efficient as I thought.
3) Loss of habitat? Check out some of the underwater hydro turbines, not sure their impact is that massive compared to the foundations required for the offshore windmills
4) Only unknown because we're not investing and thereby not undertaking any research.
5) Nope, St Malo doesn't have any restrictions to shipping AFAIAA

Next please. 😀

1) More massive than offshore windmills? I'm sceptical on that assertion.

I wouldn't be. Hydro requires vast amounts of concrete, which is hugely energy intensive.

One of the other issues with tidal is that whilst it's endlessly predictable, it's not always there when you need it. A big tide at 2am isn't much use to anyone.

But all that said, these discussions are as usual lacking a systems approach. We can pick each of these technologies off one at a time. Truth is we'll probably need all of them in some form or other.

For the same energy, You produce 4 times as much co2 burning biomass as gas.

The point these guys make in the article is that yes, in theory (if you ignore imbued energy cost such as transport and handling) biomass is co2 neautralbut it take approx 40 years for the equivalent co2 to be reduced by new biomass, and we're using it quicker than it can grow, thereby increasing the total atmospheric co2 anyway, whilst filling ourselves it's sustainable.

As an environmental scientist myself, I've been shaking my head about biomass for the last 15 years. It's in the same bracket as nuclear power not including the costs of is waste in its viability analysis. Just stupid.

I was at a conference and the ceo of draw power station was giving a talk. All their biomass was coming in from Canada/ America on ships. it used the existing docks/ rail link to draw that was used for coal to get the stuff in.

They couldn't rely on biomass from the uk as they needed such a massive volume.

oh - Zokes - its unlikely you'd be fertilising if you're growing conifers on the second rotation. Nutrient recycling and all that. Very few places need fertiliser in the first rotation apart from very impoverished ground.

oh - Zokes - its unlikely you'd be fertilising if you're growing conifers on the second rotation. Nutrient recycling and all that. Very few places need fertiliser in the first rotation apart from very impoverished ground.

You can't recycle the nutrients you remove, and most of them will be in the above ground biomass. If you don't fertilise, the trees will strip them from the soil, probably losing you more C from previously stable organic matter than in the biomass itself in the long term. (Quick hint, soil is a far greater store of C than plants)

As an environmental scientist myself, I've been shaking my head about biomass for the last 15 years. It's in the same bracket as nuclear power not including the costs of is waste in its viability analysis.

Couldn't agree more & also not to mention all the biomass boiler systems that are installed to get the eco points & are never actually used, or decommissioned due to fumes & faffage vs using the "standby/top up" gas boilers

why it is that the UK hasn't and doesn't invest in tidal HEP

Because they want a quick return on the money. Or like someone I know who sells online but refuses to fund an OpenReach survey to correct a line fault that kills his broadband, they want someone else to pay.

As an environmental scientist myself, I've been shaking my head about biomass for the last 15 years. It's in the same bracket as nuclear power not including the costs of is waste in its viability analysis.

We need to turn Mars into a solar panel planet with cables linking the power back to Earth, via cables or wirelessly. 😉

We could power the planet with PV panels covering a fraction of the Sahara. Bit more practical than mars

But think of the poor scorpions and Sidewinders! 😈

Many of the smaller biomass plants in the UK burn waste wood (that in the past would have gone to landfill) and generate both power into the distribution network and capture the heat for something useful.

That model has always made more sense than the Drax model of importing virgin wood by ship from across the Atlantic.

Tidal power is still in its infancy in the UK. It's expensive and risky and needs scarce Govt support to make it economically viable. Details of the Meygen demonstration project here:

https://www.atlantisresourcesltd.com/projects/meygen/

Thanks for the link curto it's good to see that at least something along the tidal power generation route is being done and feasibility studies to extend further south too.

As curto suggests, small local use of WASTE wood is surely good. Problem comes with a central and massive consumer like Drax which creates a demand and suddenly wood other than waste is being used.... And the numbers show that is bad.

We need to stop looking for the silver bullet, and exploit a wide range of solutions, making use of local resources, local waste and being sensitive to local issues as well as the wider global picture. Trouble is.... It's hard for the government to make large changes they way, easier to try with change to national infrastructure.

well know China has banned imports of waste plastic we will either drown in it or burn it. that's got help

As curto suggests, small local use of WASTE wood is surely good

It's still burning stuff though 😕

I don't think anyone is seriously suggesting that biomass is going to be a one stop green generation solution for more than a small proportion of our near future energy needs to be fair!

As the infrastructure exists (ie Drax already exists, so lets use it, rather than knock it down before it's worn out an build alternative generation infrastructure) and we can move to biomass on it (and similar plants) today that seems sensible to me. Better than coal, not as good as pure renewables, but accessible today, for a relatively low cost (both in terms of ££ and pollution)

It's worth remembering that all woods release there CO2 eventually. In fact, for a fast growing evergreen, something like a 50 to 100 year carbon cycle is typical (tree grows, tree dies, tree rots) so that amount of carbon is cycling quickly anyway.

Coal, oil and gas are all releasing CO2 that was sequestered millions of years ago by mother nature. Carbon that has been locked out of the atmosphere for all that time, and being released at a rate too fast for the natural balance of mother nature to respond to (more co2 in the atmosphere slowly drives extra absorption to remove that extra co2, by plants, and critically sea algae.

As long as we aren't burning old oak trees (that have spent 100's of years growing) then we are only releasing recently sequestered Co2, and critically the system is self limiting (ie you cannot burn more trees than you can grow)

It's worth remembering that all woods release there CO2 eventually. In fact, for a fast growing evergreen, something like a 50 to 100 year carbon cycle is typical (tree grows, tree dies, tree rots) so that amount of carbon is cycling quickly anyway.

That's not at all true. You might not be able to see much of the rotted tree, but a lot of it will still be there in the soil, and unless you mess about with it, it'll stay there for a lot longer than 50-100 years

zokes - Still not a customer
That's not at all true. You might not be able to see much of the rotted tree, but a lot of it will still be there in the soil, and unless you mess about with it, it'll stay there for a lot longer than 50-100 years

Canny mind, just remember seeing something yonks ago that if there were no mushrooms and the like then we'd be knee deep in dead trees! I'm sure someone more knowledgeable will be able to explain!

Anyhow, I think the general point might be(I dunno, I'm speculating) that a tree rotting doesn't equate to a tree being burned, in atmospheric terms.

And how many saplings are required to fix the same amount of carbon on a daily basis as a felled adult tree?

Dickyboy - Member
It's still burning stuff though

true, but if you have wood waste, and we do, making use of it as we dispose of it seems good. open to consider other uses though.`

as for saplings vs adult tree, no idea, although younger trees in a managed forest grow and absorb more carbon than older trees apparently.

zokes - Still not a customer

Sorry maxtorque, it's not as simple as that. Firstly, unless you replace the tree you chopped down for power immediately with one containing the same carbon content, then you've a gap of the lifetime of the tree that needs filling

Well, no, because you "replace" the tree you cut today, with the tree that was planted the day after it was planted- it's a rolling cycle, thinking about it it in terms of direct replacement doesn't work.

Well, no, because you "replace" the tree you cut today, with the tree that was planted the day after it was planted- it's a rolling cycle, thinking about it it in terms of direct replacement doesn't work.

You miss the point, you have to think about it in terms of direct replacement as that's what the atmosphere sees. The (say) 20 tonnes of carbon liberated when you burned the tree remains there contributing to climate change until the new tree eventually over decades absorbs an equivalent amount.

Yep, I think I said earlier the better idea is to plant trees and not burn them. Though not sure how to make that one well enough incentivised.
Burning things for fuel is bad as it releases CO2, no matter what you do it will still be a negative impact. We need methods that don't include burning stuff to generate power.

zokes - Still not a customer

You miss the point, you have to think about it in terms of direct replacement as that's what the atmosphere sees. The (say) 20 tonnes of carbon liberated when you burned the tree remains there contributing to climate change until the new tree eventually over decades absorbs an equivalent amount.

No, it just doesn't work like that- the trees have a lifespan and have already been planted, replacements are planted daily and have been for decades, and they get bigger by themselves. Stop thinking about the tree and think about the forest as a resource

That's assuming you're cutting managed forestry of course but since that's the only way it makes any sense I think it's a fair assumption. Cutting virgin forest for power is pretty much criminal- but here we have a pretty high volume of pretty shitty trees, in manmade tree factories that are already on a sustainable replacement loop. FC forests were created as a strategic resource- not for this job but they can do it.

The issues are that as Mike says, it's better not to cut them- because just being closed loop neutral isn't enough, we want carbon sinks not carbon neutral. And if you cut them, it's best to do something non-burny with them. And also that large scale generation isn't feasible on a closed loop. But that doesn't stop it from being a useful part of generation.

No, northwind, it works exactly like that. If you put 20 tonnes of C into the atmosphere as CO2, then you need to offset that immediately with 20 tonnes of C being sequestered [u]at the same time[/u]. It doesn't matter whether you burn a tree, coal, or your gran's undies, inputs to the atmosphere need to be offset simultaneously and that offset needs to be of an equivalent longevity to be carbon neutral. If not, you're effectively taking a 'loan' on the atmosphere for the life of the tree that's replacing the one you just burned.

Whilst it doesn't solve the immediacy requirement, biochar in conjunction with biogas or bio-oil production has the possibility to at least produce a residue with greater stability than what went in.

The idea of planting forest as a carbon sink just doesn't work. The planet isn't big enough and there isn't enough farmland to sacrifice. The oceans do a good job and so long as we don't disturb the balance between silca and carbonate organisms in favour of (which we are doing) will continue to mop up the carbon from volcanicity and possibly a bit of man-released carbon as well. Climbers and cavers will be familiar with limestone rocks - that's the planet's major carbon sink.

As for forests, think about it, for the carbon sink idea to work you'd have to stock the same amout of carbon in wood as is released from the fossil fuel you burn - you'd be better to just burn the wood and replant as you go. But that's not possible because we use too much.

Man started buring fossil fuels because he ran out of wood. By the Napoleonic wars Europe had run out of wood for building and burning. Wood had become a rare, expensive commodity and a cheap alternative to burn was needed: coal, then oil.

The only way to slow climatic change is stop burning fossil fuels. Burning wood from managed woodland is carbon neutral and has it's place in the energy mix. Wood should preferably be burned close to the point of production to reduce the use of fossil fuels in harvesting and transport. Burning the waste from wood yards to produce energy is a very good idea, burning wood grown specifically for burning not such a good idea. Burning windfall, wood from tree surgery, dried garden waste etc. an excellent idea.

Burning wood from managed woodland is carbon neutral

No it's not.

I agree that it's better than burning fossil fuels, but any process that emits more CO2 than whatever would have happened to that C had we not got involved is not neutral. As I've said already, don't dismiss inputs that would have made their way into the soil as "free" CO2. They're not. A good chunk of them, around 40-50%, would contribute to increasing soil organic matter levels, which can be much more stable than the wood was originally. Further, they contribute to a more healthy soil than can sustain greater ecosystem function and potentially greater plant production, in turn inputting more C to the soil.

Sure can be.

Local wood, cut with an electric chain saw, slpit with an electric splitter (both powered by solar panels that produce a lot more than we use). All barrowed by hand to the point of use. No I don't use an axe made from wood-smelted iron and forged in a wood-fired forge - I could.

"carbon neutral" is true for the wood burning in many parts of the world. One forester in France has gone back to using horses to get wood out of his forest - carbon neutral transport and less damage to the soil so the forest is more productive. In much of the developing world wood really is carbon neutral fuel - hand cut and transported to the point of use. And even with fossil fuel powered harvesting it's as close to carbon neutral as any alternative energy in terms of embedded energy.

Ultimately the objective is produce so much alternative energy that oil is only used for things where there is no natural alternative; pharma, plastics etc. where bio-oils don't contain the necessary molecules.

Some of the carbon in plants goes into the soil when they rot. That's what makes soil.

As for forests - I've also read that outside the tropics the climate stabilising effect of the carbon sequestration of forest is more than cancelled out by the reduced albedo of forest covered land - so forests actually make the earth warmer. In the tropics growth is so vigorous and so much carbon is sequestered that it still works.

Local wood, cut with an electric chain saw, slpit with an electric splitter (both powered by solar panels that produce a lot more than we use). All barrowed by hand to the point of use. No I don't use an axe made from wood-smelted iron and forged in a wood-fired forge - I could.

Low carbon, certainly. But it's not carbon neutral.

Biochar seems interesting, I was looking at stuff about that recently. Potential to improve soil greatly and sequester carbon for the long term, but could it be viable on a large scale? Seems almost hobbiest scale currently.

At present it's a carbon sink, Ransos.

I'm pretty sure that there's more carbon stocked in my wood piles than in the embedded carbon in the tools used. As the wood has all grown back the bit of the planet that my wood comes from is stocking more wood than it was when I started harvesting.

You wanna be a dick about it so can I. You're falling into the trap laid by the climatic skeptics who denigrate any form of alternative energy as having huge amounts of embedded carbon while minimising the damage caused by fossil fuels. People want a western lifestyle and in the long term the best way to achieve that without turning the planet into a Devonian desert.

The onjective should be energy froms that have low forms of embedded carbon. Reforesting part of a tropical island to provide fuel for the locals is better than carbon neutral as it provides a sink at the same time as properly carbon neutral fuel.

In Europe machanisation means that doesn't happen but when you compare with the embedded energy in solar panels, wind turbines, tidal or any other high tech solution then burning wood, especially waste wood, is still very low carbon and a valid part of a sustainable energy supply mix.

You wanna be a dick about it so can I.

No, I was pointing out your mistake. But I see that once again you've turned this discussion into one all about you. Congratulations.

And one thing for the pontificating do-nothings on this thread. I've noted that the bigger the car, the less-well insulated the house, the more ridiculous that flash keosene burning holiday, the pig eaten - the more of an arse people are when talking about climatic chnage so for the record:

Electricity positive house (even with an electric car)
No gas, wood for heating but about 2.5 m3/year as house is
Well-insulated house
Solar water heater
triple glazing
Madame walks to work
7500km a year by electric car
We use bikes for shopping and many local journeys
We use the bus and train for holidays
I've flown less than once per ten years (mainly because I dislike flying)
Local produce bought in preference and where possible

But we ski and I have some flash music kit and we live well.

So rather than joining in with the dicks criticising laudable attempts to do something because there's a tiny proportion of embedded carbon rejoice in the fact taht someone is trying to do something and succeeding rather than pissing in their shoes whislt sitting with the gas central heating set at whatever it's set at (too high).