Just a remind... renewable energy and green energy are two very different things. Charcoal and wood are renewable energy sources but are not green energy sources.

@freemo you just need to plant more trees than you take. it's like bittorrent :)

@bonifartius That doesnt make the act of burning them any less green though. just means in addition to the harm you did some seperate thing that did some good.

Its like saying gasoline is green cause I planted a tree when i was a kid.

@freemo why is burning wood non green?

is chemical energy non green?

@bonifartius Energy which is burned to release CO2 and other pollutants and green house gases isnt considered green.

Of course some small CO2 is usually still considered green over a life time (like solar panel production) but are 0-emmision for producing power... But this is insignificant. For example an acre of solar panels will save about 140 **tons** of co2 a year compared to the same amount of energy from coal.

@freemo i thought we were arguing wood! :)

i'd argue that wood is just stored energy from the sun. so are fossil fuels but the problem (if it is a problem) are the time scales and using energy of millions of years in a few decades. that wouldn't happen with wood. you will never create more co2 than stored. if you strive for growing more than used, you will store carbon.

solar and wind energy aren't easily storeable for prolonged times except maybe as potential energy. biomass fixes this problem for free. doesn't have to be wood of course, there are some grasses which are very good at this and work even where other things wouldn't grow as well.

i think it's not wise to not consider the "original" way of using the suns energy. it won't fix every problem but neither do solar panels or wind turbines.

there even are some more exotic but low tech ideas of using photosynthesis to capture co2, like using fast growing brushwork to make wood coal which in turn is used to improve soil by making terra preta. most farmers regularly remove brushwork anyway.

i think the orthodoxy of the green movement considering the accepted solutions might ultimately lead to it's demise.

@bonifartius

> i thought we were arguing wood! :)

We are, but often talking about other examples help us to understand the specific case of wood.

> i'd argue that wood is just stored energy from the sun. so are fossil fuels but the problem (if it is a problem) are the time scales and using energy of millions of years in a few decades. that wouldn't happen with wood. you will never create more co2 than stored. if you strive for growing more than used, you will store carbon.

The stored energy from the sun is irrelevant.. as I said chemically releasing energy from the sun is **not** what makes wood problematic. The fact that it releases tons of pollutants like CO2 to do it is.

CO2 may just be captured from the air, sure... but before trees the air couldnt sustain life and would be toxic to humans... trees came along and captured all that CO2 so it was no longer toxic... once the air wasnt toxic non-plant life could evolve...

Now your suggesting "hey its perfectly fine all that toxic stuff existed before animal life so who cares if it gets back out"... except it getting it back out reverts us to a pre-life condition and kills all life ont he planet.... so yea.

@freemo
maybe i should have seperated those better:

with fossil energy you release the carbon of millions of years, i can follow you that there might be a problem there.

with wood - mind that i argued for planting more than used - it's decades, with shrubbery and grass its years or single seasons. carbon is captured and released as CO2 in these time spans with those. other pollutants like CO can very likely disregarded with a well controlled oxidation. particles might be a problem, but that's a solved problem iirc.

i just really don't see the difference between energy captured by solar panels or wind power (which is sun energy as well) and energy captured by photosynthesis given it's happening in our epoch and not millions of years ago like with coal or oil.

the only thing different is that you can store dry plant material for a long time while solar and wind power has to be consumed instantly because we can't store it well.

@bonifartius

> with fossil energy you release the carbon of millions of years, i can follow you that there might be a problem there.
>
> with wood - mind that i argued for planting more than used - it's decades, with shrubbery and grass its years or single seasons. carbon is captured and released as CO2 in these time spans with those. other pollutants like CO can very likely disregarded with a well controlled oxidation. particles might be a problem, but that's a solved problem iirc.

Why does it matter if its decades or millions of years... burning fossil fuel vs plant material release the same set of pollutants more or less, so burning one or the other in and of itself is no more or less harmful.

What your pointing out, rightfully so, is that i can plant a tree and capture carbon dioxide first, having a positive impact, and then burning some portion of that having a negative impact. The idea being that the positive is bigger than the negative.

But that has absolutely nothing to do with what you burn... If fossil fuels release lets say 1 ton of CO2, then why not plant enough trees to capture 1 ton of CO2 then instead of chopping them down for fuel you chop them down and bury it in a deep pit somewhere... Now you did the same thing, you captured as much CO2 as you were going to release. You just choose a different source to release it from... it is all the same.

But just because you can capture the CO2 first before releasing it, doesnt make it any more green... I can capture CO2 countless ways to offset my waste, it doesnt really matter, nor does it change it.

> i just really don't see the difference between energy captured by solar panels or wind power (which is sun energy as well) and energy captured by photosynthesis given it's happening in our epoch and not millions of years ago like with coal or oil.

The difference is huge. and it comes down to efficiency... trees are 6% efficient at turning sunlight into stored energy.Solar panels are 15%-29% efficient depending on how cutting-edge you go with the tech. Thats at least 3x more effecient.

That efficiency means you get more power per unit land (significantly so). And since you arent constantly cutting down trees and disrupting animals and insects and their home, and the panels are usually placed in already developed areas (leaving our forrests untouched)... that leaves for a significantly superior situation that using trees, especially considering the forrests keep doing their thing along side the panels.

@freemo
> But just because you can capture the CO2 first before releasing it, doesnt make it any more green… I can capture CO2 countless ways to offset my waste, it doesnt really matter, nor does it change it.

it is if the argument for "green energy" is based on the _current amount_ of CO2 in the atmosphere. which it is, that's why people put things like "born @123ppm" into their profiles here.

burning plant matter isn't changing this amount if you do make sure to grow as much as you take.

> The difference is huge. and it comes down to efficiency… trees are 6% efficient at turning sunlight into stored energy.Solar panels are 15%-29% efficient depending on how cutting-edge you go with the tech. Thats at least 3x more effecient.

will the efficiency be as well if the energy is to be stored? we might have more than enough sun here in germany in one half of the year but we can't store it. same with wind energy.

maybe i should add some perspective: i'm not arguing that wind and solar energy are "generally bad" but they are currently sold as panacea here in germany. _everything_ is plastered with wind and solar energy right now. they defacto removed the distance regulation for wind turbines. i think it was 2km, now it's some hundred meters for the giant ones larger than 200m. solar energy isn't as crazy, i can't argue with panels where they let sheep graze underneath.

all while the "greens" try to kill off any use of wood for heating, no matter how sensible it is: i don't have a link, but there was a story about a sawmill or something like that which burns their leftover wood scraps for heating (with a modern fully automatic device!) and they should replace it with a heat pump. it's absolute madness here right now.

@bonifartius

> it is if the argument for “green energy” is based on the current amount of CO2 in the atmosphere. which it is, that’s why people put things like “born @123ppm” into their profiles here.

Indeed that is what matters for the consumer and our impact on the environment.

> burning plant matter isn’t changing this amount if you do make sure to grow as much as you take.

It absolutely is though... If i burn wood that was obtained by cutting down existing wild trees and not replacing it, then yes I made a **huge** change.

As I said you can do something arbitrary like plant trees in equal number or run a solar panel with a CO2 scrubber to offset the CO2 and have the whole operaton be carbon neutral... but that is not the same as saying that wood is, itself, carbon neutral, it isnt.

As I said before, wood isnt special, you can do ANYTHING to offset carbon, trees, a co2 scrubber, anything, and you will sell a carbon neutral product.

You can literally plant trees and sell gasoline and the gasoline is carbon neutral because its offset by the plants you planted. That doesnt make the same as saying "burning gasoline is always carbon neutral" No gasoline, like trees, is never carbon neutral to burn, it may be part of a carbon neutral supply chain however.

> will the efficiency be as well if the energy is to be stored? we might have more than enough sun here in germany in one half of the year but we can’t store it. same with wind energy.

The effeciency is even higher if you consider storage. Those numbers is just for what percentage of the light is turned to energy vs heat, the storage part is a seperate part of the equation... and going from sun to sugar to electricity has extra steps and is even less effecient then going from electricity to battery to electricity.

> maybe i should add some perspective: i’m not arguing that wind and solar energy are “generally bad” but they are currently sold as panacea here in germany. everything is plastered with wind and solar energy right now. they defacto removed the distance regulation for wind turbines. i think it was 2km, now it’s some hundred meters for the giant ones larger than 200m. solar energy isn’t as crazy, i can’t argue with panels where they let sheep graze underneath.

I certainly have no objection to any issues you have with location of wind turbines and how it might be placed in unwanted locations... thats an issue that is tangental in my eyes... But it very much is a very significant improvement for the environment over lighting stuff on fire, in terms of being carbon neutral (as covered burning plants arent), effecient, and overall far less polluting.

> all while the “greens” try to kill off any use of wood for heating, no matter how sensible it is: i don’t have a link, but there was a story about a sawmill or something like that which burns their leftover wood scraps for heating (with a modern fully automatic device!) and they should replace it with a heat pump. it’s absolute madness here right now.

Burning wood is never sensible compared to other sources... take this example, the act of burning that wood as we covered would release a ton of CO2 and ultimately cause harm as compared to the alternative, burrying it in a ditch somewhere and letting the CO2 remain. If you try to burn it to get energy out of it you just put a ton of CO2 in the air and loose the vast majority of the energy to heat pumped into the air rather than as electricity. You are better off burying the wood and sticking up a solar panel to get that energy in a way that does less harm and actually reduces CO2.