We're surrounded by life forms that turn water, CO2 and sunlight into energy. I figure there must be some way to harness this process.
I wonder how much power a large tree takes in from its leaves. If we could interface with its root system, perhaps we could extract newly created starch, and either store it or burn it off.
Image a huge concrete power plant with large trees growing out of it.
No, that's not likely to happen. Photosynthesis is pretty inefficient, typical plants have a radiant energy to chemical energy conversion efficiency between 0.1% and 2%. Most commercially available solar panels have more than 10 times this efficiency.[1]
Sure, but I bet your solar panels don't manufacture and maintain themselves.
To the GP's point, the total cost of ownership of a plant that makes gasoline-level fuel is going to be more about water and land than anything else.
But the efficiency of solar panels, considering their subsidies, the rare minerals used in their manufacture, their delivery and their maintenance... I'm confident it's a lot less than e.g. coal, even accounting for pollution costs, because if it really were cheaper all-around we'd be using it everywhere!
If you look at trajectory, coal is in decline and solar panels are being installed at a great clip. The decline in coal is mostly due to natural gas, but in the US, generation from solar tripled between 2013 and 2015.
Well, for any kind of industrial operation you'll want to plant the trees.. then there is the 10-20 year growth period that's kind of a problem for planning flexibility.. and then you need to chop them down and move them to the power plant which is a non-trivial and costly logistical constraint.
All the while the solar cell sits there and produces energy without any intervention. That's a big difference.. Also, wood does not scale well, there is just so much space for forests.
Solar cells don't just sit there without intervention, and have larger up-front capital and labour costs than planting an orchard, or more appropriately, fuelwood or timber forests. And have a lifespan of 20-25 years.
I dont know how much they differ but planting trees has lots of cost. I estimate the cost of planting is something like $3 per surviving tree. (Cause you usually over plant assuming many will die).
For some forestry applications, seeding is done from the air.
Note that if you're growing wood for fuel, you're not worried about grafting stock, or the net health (much), or overcrowding (you can thin later if necessary), etc.
Planting orchards is, as it happens, pretty expensive. But that's also a pretty high-end case, and the expected life is generally 20-50+ years. Upwards of 300 in cases (olives, grapes, and citrus).
Yes. But on the other hand, oil is extremely convenient for storage and transporting. Perhaps we can achieve a more efficient way of converting atmospheric CO2 to oil than photosynthesis. (And while there, complex oil instead of simple sugars)
1. Plant tree
2. Wait 20 years
3. Chop tree
4. Burn tree in steam engine and generate electricity.
However, that's a long time for a relatively small amount of energy (not even counting logistics losses here). Most trees are just not very efficient at converting solar energy/CO2 into fuel (wood). There are better results being looked in with algae that might result in fuel some time, but it's still in research.
Isn't what you're describing called biodiesel? Palm oil, rapeseed oil, etc.
The problem is that however much humans need electrical energy, they need food a hell of a lot more. Electrical energy has to come from the land we're not feeding ourselves from, i.e. deserts, grasslands, rooftops.
I believe we have plenty of food. We could put panels in our backyards, but solar panels are rather expensive, and it's usually more convenient paying a power company and forgetting about the matter than setting up our own mini power plants.
It's actually a major approach under the name biomass. Despite releasing carbon when wood is burned, the tree has taken in significant CO2 over the course of its life. In addition, decomposing wood byproducts are going to release carbon anyway as they decompose, I believe. Places with excess wood byproduct can generate power onsite.
It's not going to replace other power sources, but it is commonly done.
We're surrounded by life forms that turn water, CO2 and sunlight into energy. I figure there must be some way to harness this process.
I wonder how much power a large tree takes in from its leaves. If we could interface with its root system, perhaps we could extract newly created starch, and either store it or burn it off.
Image a huge concrete power plant with large trees growing out of it.