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> As long as the wood doesn't end up rotting or being burned, the carbon is not released. So this is only carbon negative if the trees are net-new and we recyc
by mulmen 3y ago
> As long as the wood doesn't end up rotting or being burned, the carbon is not released.
So this is only carbon negative if the trees are net-new and we recycle or sequester the wood at the end of the service life.
I’m skeptical of trees as an effective carbon sink for the purpose of slowing global warming until we have a way to sequester the carbon on geological time scales.
This is a great technology and if wood has a smaller footprint than existing material it is a win. I see how wood could be carbon neutral. I’m less certain about it being net-negative.
- berkes 3y agoIf there were no humans to cut forests down, they'd be renewing themselves too. Trees die, fall and rot. Releasing a part of their captured carbon back, and releasing some methane (a worse greenhouse gas than carbon-dioxide). Now that there are humans to cut them down, it makes no difference in re-release of carbon, as long as we replenish the forests in the same rate as we cut them down. Which we don't, but we could. Point being, on the grand scale of things, using (not burning) wood is fine as long as it is renewed. Letting it rot or burning it after use, is fine too. It's what the world would do without humans anyway, without that causing a run-off greenhouse effect. Obviously, processing wood costs energy (footprint), but from what I know when I studied this stuff (early 2000s) steel and concrete are way, way (way!) worse in this, so on that scale too, wood is preferable. It really is magic stuff.
- mulmen 3y agoI agree. But you are describing a carbon neutral system. The article claims wooden wind turbines are carbon negative. This is only true on a short time scale. Once all wind turbines are wood and the first generation reaches EOL they become carbon neutral.
- berkes 3y agoMaybe they are "carbon negative" in the same way as many datacenters or international flights are "carbon neutral": by buying it off: e.g. planting more trees than they cut? But I guess you are right and they're just doing short-term bookkeeping here.
- mulmen 3y agoYeah it's a great technology and we should absolutely pursue it but I think they are overstating the benefits a bit.
- bluGill 3y agoThey can still be carbon negative if at EOL we don't release the carbon. Turn it into charcoal is an obvious idea, but other options may exist.
- mulmen 3y agoThe charcoal is only carbon negative if we also bury it. Those “other options” all fall under “sequestration“.
- Angostura 3y agoLet's assume that the wind turbine operates and generates power for a few decades, and is them chipped and burned in a biofuel power generation plant - it would be carbon negative.
- mulmen 3y agoWhere does the exhaust from the biofuel plant go? If it doesn't go into a hole in the ground then the system is neutral, not negative. Carbon negative means there's less carbon in the atmosphere at the end of the lifecycle. It seems to me that requires long-term sequestration.
- bluGill 3y agoHow do we burn them? Heat them in a low O2 enhironment would result in enough hydrogen released to renerate power and fuel the reaction while leaving carbon to behind. Not very efficent but it is known to work.
- Angostura 3y agoThe exhaust goes into the atmosphere. Overall then, assuming low carbon manufacture, the turbine is roughly carbon neutral. But then you factor in the decades of zero carbon operation. Assuming that some small proportion of that capacity is used to power carbon scrubbers/sequestration and you can fairly easily get to carbon negative
- mulmen 3y agoHow is a positive number minus zero negative? The carbon scrubber itself can be carbon negative if the carbon is sequestered but that’s true even if the power supplied to it emits carbon. The power source doesn’t get to take credit. That only complicates the math and leads to double counting. I still don’t see how the wind turbine itself is carbon neutral. And even if I did nothing about being made of wood makes a wind turbine more suitable for powering a carbon scrubber. These terms have meaning and overstating the capability undermines credibility.