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Comment by rm_-rf_slash | Hacker News Reader

I used to think this way until I started dating a geologist. She brought down my optimism when she detailed the ways that the environment is ravaged to extract the materials necessary to create solar panels, wind turbines, and so on. Rare earths are great for handling high heat, but their resistance to reaction also means it takes a LOT of nasty chemicals to purify the ore. Not that we should keep on burning fossil fuels, but we shouldn't kid ourselves into thinking that renewables are a one-way street to environmental prosperity.

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Not all PV panels, wind turbines or EV car designs use rare earths e.g. Tesla doesn't use any in their motors.

Also, lots of other things that aren't good for the environment use rare earths. Kind of weird and illogical that people only care about it when you're trying to do good.

People are terrible when dealing with large scale diffuse issues. Coal might be 30 times as bad as solar, but that's not zero and most of coal’s harm is spread over a large area.

In 2003, China had 4,143 coal related accidents that killed 6,434 people. But, installing rooftop solar also kills some people so it must be the great evil.

PS: A report by the World Bank in cooperation with the Chinese government found that about 750,000 people die prematurely in China each year from air pollution. https://en.wikipedia.org/wiki/Coal_in_China#Accidents_and_de...

I would rather have 0.1% of the Earth be made toxic enough to kill me in 600 seconds than have 100% of the Earth be made toxic enough to kill me in 600 months.

The pollution from solar cell manufacture is mostly near the mines and chemical processors, and the effects are mitigated if you don't go near there or live downstream. Pollution from coal burning affects everyone who lives downwind of any furnace, and those are located near the users to cut down on transmission losses.

Natural sources of pollution, like volcanoes, are not much of a concern, because most of the biosphere chooses not to live near them. So an artificial zone made more inhospitable than the surface of Venus, confined somehow, and situated far from civilization, is a bit less of a concern than the air quality index of Beijing.

Would it help if the raw materials were mined from asteroids, the finished product manufactured in space, and then dropped to the surface by nontoxic ablative shields and parachutes? If the answer is yes, being able to confine the pollution to specific areas on Earth is almost as good. (But the confinement is the hard part.)

Are you sure about Tesla? What material do they use for the permanent magnets in their motors? I know the motor has to contain permanent magnets since Tesla cards have regenerative braking.

http://my.teslamotors.com/roadster/technology/motor

No magnets, induction motors.

You need a magnet for regenerative braking, not a permanent magnet. An induction motor cannot regenerate without a source of electricity, but you can get a lot more out than you put in to generate the magnetic field.

The thing is, exactly the same is true of all the other methods of power generation and mineral extraction. You have to at least compare the size and nastiness of the tailings piles. Not to mention CO2 produces carbonic acid when dissolved in oceans; the least "nasty" acid, but still enough to very very slightly change the pH and damage a lot of ocean life.

A one-time dirty process for a future steady source of clean energy. Isn't it still much better than continually burning fossil fuels? And if we're counting extraction costs, don't discount the extraction cost to get fossil fuel and build fossil fuel processors (car engines, power plants, etc).

> A one-time dirty process

If only it was. Neither solar panels nor wind turbines last for a very long time, and the recycling processes don't exist on an efficient or clean scale for either yet.

Most panels have a rated life of 25 years and deteriorate slowly. That provides plenty of time for the recycling to be built. It's also comparable to the design lifetime of most types of non-renewable power plant.

I'm not qualified to answer either way.

But my grandfather worked at a coal fired plant. I've been to the strip mine. I've seen the trains that run continuously to truck it in.

From a layman's perspective it seems like an incredibly efficient process. Is there any chemical refinement going on at all? All that I saw looked mechanical (but I was very young).

I would guess that it would take many years of Solar before it broke even, in an environmental impact sense, with "cleaner" coal.

I think ultimately solar probably wins. But the initial cost seems like it must be orders of magnitude higher.

That said, I'd get solar if I could. Just not my highest home-improvement priority and I'd have to do something about the trees shading the south side of my roof. I like my trees. :-(

OTOH it would be nice if there were a high power (~2KV), affordable (<$2,000?), silent wind turbine solution to supplement our grid power.

There isn't chemical refinement in the same way as there is with oil. But there are mine tailings, ash, a surprising amount of radioactive thorium in the ash(1), sulphur (usually neutralised by trucking in limestone and out gypsum (2)), and of course vast quantities of carbon dioxide. "Clean" coal does not and cannot really address the CO2 even if it has been cleaned up in the other ways.

There are various estimates of the breakeven time, but even the most conservative ones put it under ten years.

You don't have to get your own solar if it's not convenient, that's what the grid is for.

1: http://www.scientificamerican.com/article/coal-ash-is-more-r...

2: https://en.wikipedia.org/wiki/Flue-gas_desulfurization

Deciduous trees on the south side of your house are great for energy efficiency. The shade reduces summer cooling costs, and then the leaves drop so you get solar heat in the winter. You should definitely think about it carefully before cutting them down to install solar panels.

Unless you live in the southern hemisphere, in which case you want to plant them on the north side of your house. On a somewhat related note, rooftop solar panels have also been shown to have good insulation benefits[1]. [1] http://www.sciencedirect.com/science/article/pii/S0038092X11...

True, you want the trees and panels on whichever side of the house is sunniest.

Since the GP was talking about "trees shading the south side of my roof" I'm guessing that he's in the northern hemisphere. Or maybe he's just really bad at siting solar panels, but I was giving him the benefit of the doubt. :)

Anything we do we have to undo, and undo always costs more. It's not a perfect solution (nothing ever is), but we really ought to be bridging the gap with nuclear.

You're right, we will have to bite the bullet to have enough renewable capacity in the future. All I'm arguing is that we know both the risks of action and inaction. It's hard to get a sense of environmental damage from inside a comfortable air-conditioned building.

It's funny how the current debate regarding sustainable energy is always about production, not consumption. Somehow consumption is always taken as a given, about which nothing can be done.

It's obvious modern societies are wasteful - energy, food, water, transportation - but everybody is talking about how to increase production efficiency, no one is talking about how to decrease over-consumption.

This is partly because modern societies are struggling to figure out how to enjoy prosperity without growth[1] (some would depressingly argue that prosperity is the growth of consumption).

[1] A big topic for sustainable development: https://scholar.google.co.uk/scholar?q=prosperity+without+gr...

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