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Artificial Leaf Could Provide Cheap Energy
sciencehabit was one of several readers to tip news of a sunlight-harvesting artificial leaf, writing:
"Nearly all the energy we use on this planet starts out as sunlight that plants use to knit chemical bonds. Now, for the first time, researchers at the Massachusetts Institute of Technology have created a potentially cheap, practical artificial leaf that does much the same thing—providing a vast source of energy that's easy to tap. The new device is a silicon wafer about the shape and size of a playing card coated on either side with two different catalysts. The silicon absorbs sunlight and passes that energy to the catalysts to split water into molecules of hydrogen and oxygen. Hydrogen is a fuel that can be either burned or used in a fuel cell to create electricity, reforming water in either case. This means that in theory, anyone with access to water can use it to create a cheap, clean, and available source of fuel."
Well, at the point solar power runs out, we'd have to find a new planet anyway. It would provide energy for billions of years rather than hundreds. For all intents and purposes, solar, wind, and biofuels never run out.
Also, all forms of energy generation require human workers. Who do you think digs up the coal, oil, and uranium? Who do you think runs the oil refineries, nuclear power plants, and coal plants? Do you have any evidence that we'd need more workers per unit of solar power than for other forms of power?
What a fool believes, he sees, no wise man has the power to reason away.
Normal solar panels have albedo of 0.35, which is close to average of earth 0.30. We'd be far better off thermally using that than burning fossil fuel or fissioning atoms. However, comparing the energy input of the sun to what man generates, the fraction is so very tiny that the global direct thermal effects (not greenhouse gases which is another discussion) of our power generation in essentially zero.
Well, at the point solar power runs out, we'd have to find a new planet anyway.
I was more concerned about the materials which go into panel production.
Also, all forms of energy generation require human workers. Who do you think digs up the coal, oil, and uranium?
The same types of people who dig up the materials needed to make your panels?
You'd need more resources (ergo, more people working) to build the damn panels in the first place, and THEN you'd need to hire tens of thousands of workers to service the panels. There's a reason why solar power is currently THE most expensive source of energy on the market, and is between 2 and 3 times more expensive over the lifespan of the panels when compared to nuclear (and 4-6 times more expensive than oil/coal).
Do you have any evidence that we'd need more workers per unit of solar power than for other forms of power?
You know, I had a really long comment written up, with figures showing you'd need upwards of 10,000,000 man hours to do a single cleaning, and extrapolating that to X number of full time workers and comparing it to number of workers needed to run a nuclear power plant .... but then I went and checked and it turns out solar panels don't need to be cleaned all that often. So, suffice it to say, I don't have any solid figures, and I don't think anyone else does at this point. We'd have to figure out a mean rate of failure, which would be different for different panel types, AND we'd have to figure out how often they need cleaning, which would be different for each area. You'd also have to worry about unexpected things, like tornadoes and other extreme weather (which don't generally affect nuclear power plants), and you'd have to worry about man-made problems, like Billy Bob and his cousin Cletus figuring out that there's millions of free panels sitting there for the taking. I'd say that it's fairly obvious that they would, at the very least, require a similar number of personnel as other forms of power generation, but I suspect the number would be far higher.
You should consider:
1) The energy harvested by solar would hit the earth anyway, and thanks to laws of thermodynamics, we can't get 'more' from it than would already arrive.
2) The energy harvested using fossil fuels hit earth millions of years ago and was stored in chemical bonds that we break with combustion. If we otherwise did not choose to release this energy via combustion, it would stay in chemical form.
There is a difference. There is also no excess blanket of CO2 being produced, where carbon that has been absent from the atmosphere for millions of years is now reintroduced, and as it is a heat storing gas, it aides in global warming.
There is a difference.