Comment by undershirt
5 years ago
Is solar just a stopgap tech? Like, do they still require fossil fuel energy to create, not to mention maintain and rebuild? And I know we’re now strip mining the ocean for battery metals. I don’t yet sense the sustainability in this amid all this economic hand-waving of “it’s getting cheaper”. (forgive my tone, i have a hard time of making sense of the big picture of renewables, hoping to eventually see how it actually fits into a utopic idea of a “closed-loop economy”)
I’m reminded here a bit of Ted Chiang’s short story, Exhalation, where the people devise clever ways to try to put air back in the ground without using more than they’re sequestering. I hope our situation is better than that.
Virtually all energy on available on Earth is Solar-derived. Plants all use solar power, carbon sources are all ancient stores of solar power. There's enough solar energy for several of our civilizations (4-5 orders of magnitude more, by a napkin calculation). Roughly 1/50,000 of Earth's surface covered in solar panels would suffice.
> do they still require fossil fuel energy to create, not to mention maintain and rebuild
That's not really particularly relevant. What is crucial is that they produce more energy than they consume. This is an important figure, EROI (Energy Return on Energy invested), which should be >1
https://en.wikipedia.org/wiki/Energy_return_on_investment#Ph...
Photovoltaics generally have been well over 1. There are still sustainability challenges with the technology, but I think they're minor (relative to current alternatives and carbon technology).
I can't speak about wind (not my expertise), but for solar, the energy payback is about 1-year in operation for current installations, with a predicted 30-year lifespan. Compare this against estimates for the energy cost of bringing gasoline to market which can exceed 30%.
Almost 50% of residential energy usage is HVAC and Hot Water heaters.
I see no reason we couldn't use excess solar during the daytime to heat our hot water heaters, or cool/heat the house.
Modern Construction and Water Heaters have great insulation, and its possible to use the `cheap` electricity during peak solar to store as heating/cooling.
Heat pump technology has come an amazing way, as well!
Switching to an electric heat pump water heater from my natural gas water heater saves nearly as many emissions per year as stopping 12,000 vehicle miles. And it saves money, though it front loads the cost a tiny bit.
We could have a massive economic boom just by retrofitting existing buildings with more efficient and modern technologies.
I'm not sure about the resource costs of solar in particular but the question is a very salient one. Vaclav Smil has a great piece on this. "What I see when I see a wind turbine"
"the quest for renewable electricity generation. And yet, although they exploit the wind, which is as free and as green as energy can be, the machines themselves are pure embodiments of fossil fuels. • Large trucks bring steel and other raw materials to the site, earth-moving equipment beats a path to otherwise inaccessible high ground, large cranes erect the structures, and all these machines burn diesel fuel. So do the freight trains and cargo ships that convey the materials needed for the production of cement, steel, and plastics. For a 5-megawatt turbine, the steel alone averages 150 metric tons for the reinforced concrete foundations, 250 metric tons for the rotor hubs and nacelles (which house the gearbox and generator), and 500 metric tons for the towers.[...] For a long time to come—until all energies used to produce wind turbines and photovoltaic cells come from renewable energy sources—modern civilization will remain fundamentally dependent on fossil fuels."
http://vaclavsmil.com/wp-content/uploads/15.WINDTURBINE.pdf
Well we should ask this for every energy technology and fortunately people have done this. The term for this is energy return on investment (EROI) where solar has between 8.7 and 34 and wind between 10 and 20 (although other literature says 20 to 50). A value 1 means you get as much energy as you invested. So for solar that means you get your energy used for production back in 1 to 4 years.
Source: https://en.m.wikipedia.org/wiki/Energy_return_on_investment
And the EROEI has been increasing, since one aspect of driving these technologies down their experience curves is reduction in inputs, including energy, needed to make them.
That’s just asking for a chicken and egg problem.
You can’t get fully renewable energy production until you can use EV trucks to deliver the windmills, and you can’t get clean EVs until you have windmills to power them. Sure, we currently burn some diesel to setup these windmills, but the alternative is to burn coal. Don’t let the perfect become the enemy of the good.
Also, who’s the ominous “they” above? Energy companies don’t setup power production out of spite; they setup energy production so we can have AC and TVs. We’re the consumers of all of that electricity, directly or indirectly.
Sounds like a bullshit purity test.
Yeah :) . They can't see those machines using electricity instead of diesels, they can't see steel making without atmospheric pollution, and same goes for cement.
I guess some people have hard times adjusting to some novelties. Their arguments don't stand, and they don't see that.
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No, the author is just saying we're still a long ways away from the true final goal of using no fossil fuels.
It's not a bullshit purity test at all. It highlights the extremely neglected costs in raw material and non-electrifiable infrastructure that is required to produce materials that are nominally 'green'. In some cases it's questionable if some green technologies actually are a net positive at all.
There is a strong 'abundance' bias implicit in articles by people like Ramez Naam, who push so strongly for green energy production because they don't want to consider the very obvious alternative, dematerialisation and reduction of energy consumption. People like Naam still categorically hang onto a growth narrative so they tend to neglect the downsides of the solutions they provide.
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> the machines themselves are pure embodiments of fossil fuels. • Large trucks bring steel and other raw materials to the site, earth-moving equipment beats a path to otherwise inaccessible high ground, large cranes erect the structures, and all these machines burn diesel fuel. So do the freight trains and cargo ships that convey the materials needed for the production of cement, steel, and plastics. For a 5-megawatt turbine, the steel alone averages 150 metric tons for the reinforced concrete foundations, 250 metric tons for the rotor hubs and nacelles (which house the gearbox and generator), and 500 metric tons for the towers.
This is FUD. The mass of construction materials pads the quote but is not a useful measure of environmental impact.
Vaclav Smil is looking at this all wrong. There are three phases here
1) power is produced by plants that take fossil fuels to build and fossil fuels to run
2) power is produce by plants that take fossil fuels to build and no fossil fuels to run
3) power is produced by plants that were built using renewable energy and run off of it too.
Most of the people who focus on phase 2 basically want us to stay on fossil fuels forever, but they don't want to come out and say it.
> Most of the people who focus on phase 2 basically want us to stay on fossil fuels forever, but they don't want to come out and say it.
How do you know this? Serious question.
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This seems a little silly - of course to develop future technologies we need to use existing technologies.
Imagine debating using an abacus to develop a computer - "ah but we must remain pure to the hopes, dreams and philosophies of what the computer aspires to be." Yeah, ok. I'll be over here funding wind turbine companies, you can debate the merits of the methodology and strategies of funding green tech with petroleum-based products yourself. Sounds a little boring to me.
I don't understand your comparison at all. Given that the primary problem that a wind turbine seeks to solve is environmental, the environmental costs in making the turbine have to be considered.
There's no relationship to computers here, it's not a question of philosophical purity, but of correct evaluation of the costs and benefits of a technology.
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So are you saying that we should abandon renewables, and stick with fossil fuels until a truly green energy technology is invented, sometime in the future?
And if that is not what you are saying, then what exactly do you think we should be doing today?
Cut down on the energy we expend, minimize the amounts of materials we use, focus on technology that consumes less energy rather than just attempting to make more of it in marginally less dirty fashion and so on.
Instead of promoting electrical cars which consume vast amounts of materials and still run on a dirty energy mix cut down on the car reliance altogether, for a trivial example.
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In the big picture, you could say that fossil fuels are a stopgap technology (with complex manufacturing and lots of parts needing maintenance) until engineers invent(ed) better/cheaper batteries. But the way I prefer to see it is that solar is helping the transition to 100% renewable energy.
Another way to see it is that we already have an electric grid, so we are just finding ways to provide electric power cheaper--then the "efficient market" will figure things out. Also, electricity is used directly in manufacturing, for example smelting aluminum, and that is often done with renewable electricity (hydro in the US Pacific Northwest, geothermal in Iceland). Trains in many parts of the world run on electric power, and of course you can charge EVs with solar power or other renewable energy. And I'm sure some ICE cars are manufactured with electric-powered tools that run on solar energy during the day.
PS: if you know your tone is off, why not ask in a different tone?
Solar panels can’t use all that much energy and raw materials if the final unsubsidized price is under 2c/kWh.
If the manufacturing facility that makes the panels is itself powered by solar, then the true cost is mostly the materials and what it takes to source them.
As for batteries, not every dollar application needs metal or chemical batteries. There are other options as low tech as pumping water uphill, heating water, compressing air, etc.
with enough infrastructure, particularly batteries and interconnected smart grids, you could average out solar power generation across the globe and fuel the whole world on solar many times over.
10% of our energy needs come from 440 nuclear power plants worldwide. for comparison, the sun is a nuclear plant 1.3 million times the size of the earth. all life on earth basically runs on solar energy (or a derivative of it).
Yes. Nuclear energy proponents sometime seem to forget that solar energy is effectively thermonuclear energy from a big free source reactor - the question isn't in having that reactor, or running it, the question is just in catching energy it radiates. Solar guys become increasingly good at that - together with wind guys, who employ that energy after another free conversion into moving air.
Until there exists 100% clean options for the entire pipeline of resource extraction, transport, assembly, distribution, etc., there will still be fossil fuel involvement in 'clean energy generation'. Can't really make clean energy cleanly unless we have clean energy to make it in the first place.
Resource extraction / recycling is a whole other issue of course.
We have that technology for decades - for example, Tu-155 flew on hydrogen in 1988 - and we gradually replace existing usage with more and more clean options. Don't worry - we won't turn off pollutions overnight, but will gradually drive them to zero. And then to net negative values, restoring some losses in the environment.