Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

How Cheap Can Solar Get?

rameznaam.com

Post reply on HN
Print view View original

131–138 of 138 posts

Re: How Cheap Can Solar Get?

#131

Post by avnfish »

ciconia wrote: post #129
rm_-rf_slash wrote: post #78

Earlier quoted context omitted.

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 f…

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...

Re: How Cheap Can Solar Get?

#132

Post by brrt »

542458 wrote: post #86
brrt wrote: post #58

Earlier quoted context omitted.

This is calculated in energy return on energy invested (EROI). Solar is doing.. ok in that regard: http://rameznaam.com/2015/06/04/whats-the-eroi-of-solar/ The comparable number for fossil fuels (in this case, oil) is 'well to tank efficiency', which amounts to about 25% for oil, if i recall correctly. So 1/4th of energy contained in oil is already spent to bring it to market. Notably, wind energy has a far more favo…

Wow. I suppose it should have been obvious, but it's still interesting to see nuclear's numbers so high, considering the enormous material requirements for reactors. Only makes me more sad that the world seems to be closing down nuclear rather than opening it up.

A large problem with current generation nuclear is that the easily obtainable uranium isotopes are in the process of running out (in no small part due to artificial limitations on e.g. reprocessing of fuel). We'll probably continue to have enough for some time to come, but a large-scale switch to nuclear energy is actually quite unlikely at this stage.

I don't mean to say that this is the primary reason for nuclear's demise - it isn't - but it is a real hurdle against increasing deployments.

Of course, there are very exciting new developments in nuclear technology that solve this - breeding, reprocessing, etc - but they are all (still) at an experimental stage. That's the catch-22 of nuclear: there's an existing, mature industry, which uses it's fuel unsustainably, and there are developments to sustainably use nuclear power, which is quite far from being an industry.

Re: How Cheap Can Solar Get?

#133

Post by aidenn0 »

castratikron wrote: post #122
ZeroGravitas wrote: post #94

Earlier quoted context omitted.

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.

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.

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.

Re: How Cheap Can Solar Get?

#134

Post by walshemj »

ZeroGravitas wrote: post #130
walshemj wrote: post #77

Earlier quoted context omitted.

Even in the UK with a massive government tax break our set of panels will take 8 or so years to break even - and we have an almost perfect south facing roof. Makes sense if you own the property and have the spare cash to take the free money (8% yield tax free) - though the UK government is reducing the subsidy

For the north american audience, it's worth pointing out that the UK is as northerly as Canada, so its not ideal for solar, though it does have a part to play I think.

We Are not to bad (50 miles north of London) and we do have a perfect south facing roof

Re: How Cheap Can Solar Get?

#135

Post by DennisP »

mikeash wrote: post #101
joshuapants wrote: post #48

Earlier quoted context omitted.

> 2. "Rare earths" are not so rare. Their prices have tumbled substantially as new mines have opened up and substitutes have been found. Yes, but mining them is an environmental disaster.

Can you quantify that? I'm seeing comments in this thread saying, over and over again, that manufacturing these things is an environmental disaster. But without numbers, the statement is meaningless. We are currently poisoning pretty much the entire planet for our energy needs. If we cut that down to, say, poisoning an area the size of Texas for our energy needs, that would be a massive win.

Solar is definitely far better than fossil. It's just not entirely clear that it's better than nuclear, especially with the advanced reactors that get a hundred times as much energy from the same fuel, and produce only a small amount of short-lived waste.

Re: How Cheap Can Solar Get?

#136

Post by [deleted] »

castratikron wrote: post #122
ZeroGravitas wrote: post #94

Earlier quoted context omitted.

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.

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.

[deleted]

Re: How Cheap Can Solar Get?

#137

Post by Grantarvey »

RamezNaam wrote: post #7

Hi. I'm the author of this blog post. Happy to answer questions people have, as time allows, on Wednesday. Upcoming posts will look at the future of wind power, the future of energy storage, and what the missing pieces are. If you don't want to wait, you can read my thoughts on energy storage here: http://rameznaam.com/2015/04/14/energy-storage-about-to-get-...

Thanks Ramez! Cool of you to come on here.

Re: How Cheap Can Solar Get?

#138

Post by tired_man »

hwstar wrote: post #115
tired_man wrote: post #109

Earlier quoted context omitted.

That's San Diego Graft and Extortion you're talking about, right? This movement is going to put the skids under the home solar company's pitch that you'll be able to feed electricity back and sell it to the power companies.

Yep, that's the entity I'm talking about. Unless the utilities decide to become more competitive, the only way to win in the long term is NOT to feed the energy you make back into the grid.

I never understood any of the crazy crap they came up with.
Post reply on HN