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Britain has gone two months without burning coal to generate power

bbc.com

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Re: Britain has gone two months without burning coal to generate power

#51

Post by skybrian »

hn23 wrote: post #40
renegading wrote: post #35

Earlier quoted context omitted.

The carbon is captured when the tree grows and then released when the wood is burned. This is different from fossil fuels where it is underground.

The reason wood is considered neutral is, that most of the wood is used for construction and other stuff. If you burn it and happen to burn fossil fuel as well, nothing is neutral.

Growing a tree removes carbon from the air. That's carbon-negative. Cutting it down and using it in construction is still net-negative for the wood itself. (Though probably not when you take other energy usage into account.) In the very long run, the building might be torn down and the wood might rot or burn bringing things back to zero again.

Growing a tree, cutting it down, and burning the wood is carbon-neutral. But it's very dirty when it comes to other pollutants. A catalytic converter can help.

Re: Britain has gone two months without burning coal to generate power

#52

Post by rsynnott »

praveen9920 wrote: post #15

Bhutan is actually carbon-negative for a while but this is significant. A complete country going off coal. To compare this with one of the biggest contributors to pollution, India, has around 50% of electricity generated by coal. Of course, Britain's electricity consumption may not be comparable to India, or COVID has some effect on this. This certainly is the first step towards a better future

France has been effectively off coal now, for a while.

Re: Britain has gone two months without burning coal to generate power

#53

Post by woodandsteel »

rowanG077 wrote: post #38
renegading wrote: post #35

Earlier quoted context omitted.

The carbon is captured when the tree grows and then released when the wood is burned. This is different from fossil fuels where it is underground.

How is that different? Fossil fuels were also captured many years ago. The only difference is the number of years.

The difference is ff's were captured over many millions of years, and natural forces controlled the total amount of co2 in the atmosphere.

What is happening today is the ff's captured co2 is being released a thousand times faster than it was captured, and that is overwhelming natural forces and causing co2 levels to skyrocket. Wood pellets are one of the ways to counter this.

I could be wrong, but my guess is that you already knew all this and were only pretending to be ill-informed because you are a member of the fossil fuels forever club. If I wrong, then please let us know your views on global climate change.

Re: Britain has gone two months without burning coal to generate power

#54

Post by VBprogrammer »

leonardaustin wrote: post #5

Hummm, not sure wood pellets are carbon neutral. I think the UK has just offshored its CO2 emissions to the US. Great video below explaining in more detail. https://youtu.be/6RP-jYDgiMg?t=100

Some back of the envelope maths, he said it takes an area 18 miles by 18 miles every year to produce 7% of the UKs electricity demand.

Pine trees are harvested around 30 years old (ignoring thinnings deliberately here). So to set up a 30 year rotation of 300 square miles you are looking at an area roughly the size of Wales.

That seems pretty unsustainable from a UK point of view but obviously there are less densely populated parts of the world where wood can be shipped from.

I'm not sure. Perhaps as a dispatchable source of power it makes sense.

Re: Britain has gone two months without burning coal to generate power

#55

Post by fred_is_fred »

VBprogrammer wrote: post #44
iguy wrote: post #30

This is a good discussion of the accounting of biofuels, with a guy called Tim Searchinger (there is a transcript if you don't want to listen): https://infoproc.blogspot.com/2019/11/manifold-podcast-23-ti... One takeaway is that you should think of farming trees as fuel as a competitor for land use. If it displaces growing food crops, then they will be grown elsewhere, possibly in newly cleared rainforest. Even if no…

That doesn't pass a smell test to me. Land which is used for forestry is usually not suitable for growing crops. Usually because it's on too great a slope and on poor quality soils.

This is especially true in the US where the article says they are sourcing from. US forest cover has been increasing for years as marginal farm land is reclaimed by trees - intentionally or otherwise - http://www.fao.org/3/x4995e/x4995e.htm

Re: Britain has gone two months without burning coal to generate power

#56

Post by dmurray »

zebrafish wrote: post #32
jonnypotty wrote: post #25

Burning wood pellets puts out co2. claiming zero carbon output for this means people could literally burn forests and claim they're being carbon neutral. It's scandalous. The only option would be forests that are managed and burnt for fuel. I'd be interested to know what area of forest you'd need to bring under this sort of management in order to produce say, enough power for a medium sized city. But ultimately this…

The pellets come from managed forests. Typically around 7 trees are planted for each harvested. The carbon emitted from the burning of the pellets is absorbed by the tree while it matures. These trees generally have ~10 year lifespans. If there were no productive use for the trees, the land would be taxed by the government anyways, the trees cut down permanently and the land would be used for ranching or farming.

> Typically around 7 trees are planted for each harvested

How does that work? Most trees die of disease or get eaten by animals? Or are you just saying that at this point in time, maybe in some specific country or region, planting vastly outweighs harvesting?

Re: Britain has gone two months without burning coal to generate power

#57

Post by [deleted] »

rapnie wrote: post #50
abhorrence wrote: post #2

The wood pellets are interesting —- if we were growing forests at the same rate as we consume them via the pellets, would it be close enough to a closed loop system?

I saw a documentary a while back related to the Netherlands, where they traced lots of these wood imports as coming from the US, mostly bought from private land owners cutting down pristine forest.

[deleted]

Re: Britain has gone two months without burning coal to generate power

#59

Post by polycaster »

vkou wrote: post #49
renegading wrote: post #35

Earlier quoted context omitted.

The carbon is captured when the tree grows and then released when the wood is burned. This is different from fossil fuels where it is underground.

1. 'Waste wood pellet' power plants are a con job. 2. There is not nearly enough wood waste from construction sites/etc to operate them. 3. They have to be supplemented with wood cut down from forests. 4. There aren't nearly enough forests in the UK to operate these plants sustainably. 5. So, the wood they burn comes from cutting down Canadian forests, trucking them down logging roads, loading them onto barges, and s…

> By the time you're done with all that, the carbon footprint of your wood pellet plant is greater than that of a coal plant.

Could be true. Are there numbers/sources backing this argument?

Re: Britain has gone two months without burning coal to generate power

#60

Post by torpfactory »

leonardaustin wrote: post #5

Hummm, not sure wood pellets are carbon neutral. I think the UK has just offshored its CO2 emissions to the US. Great video below explaining in more detail. https://youtu.be/6RP-jYDgiMg?t=100

Wood pellet burning is a temporary distraction and distortion caused by regulation that allows it to be counted as "renewable". I believe you can make a reasonable argument wood burning is carbon neutral. Unfortunately, land used for growing forests of fuel represents a terrible opportunity cost - you could grow food or let the forests absorb atmospheric carbon, provide animal habitat, re-wilding, etc.

However, there is no long-term future in which wood pellets are used for much other than limited residential space heating. Cutting down a forest, processing it into pellets and shipping them half way around the world isn't going to be the cheapest option for bulk power production.

Don't let the foolishness of wood-burning being counted as "renewable" distract you from the broader story of the quickly improving value proposition of solar, wind, and (soon, hopefully) battery storage.

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