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How cheap does solar power need to get before it takes over the world?

vox.com

41–50 of 110 posts

Re: How cheap does solar power need to get before it takes over the world?

#41
post #40

>> 25 cents per watt by 2050 — down from around $3 per watt today Can I trust a report that does not even have the units right?! Price should be proportional to energy (i.e., Joules or Watt-seconds) not power (Watts).

Both are relevant. The government and companies probably build capacity in watts (power), but consumers purchase actual joules (energy).

Re: How cheap does solar power need to get before it takes over the world?

#42
post #40

>> 25 cents per watt by 2050 — down from around $3 per watt today Can I trust a report that does not even have the units right?! Price should be proportional to energy (i.e., Joules or Watt-seconds) not power (Watts).

Huh? What's wrong with measuring in price/watt? Price/watt is actually the standard for comparing electricity generation due to not having to create arbitrary units of time to compare with

Re: How cheap does solar power need to get before it takes over the world?

#43

I think the issue is that OK, say we managed to get to 100% electricity being solar when the sun is shining. You'd still have the time the sun is not shining, which would likely be more expensive than before (a gas powered plant would only be running half the time - effectively doubling its capital/construction cost per kWh). So you'd definitely have an improvement on some levels but I'm not sure that would really he…

Short summary: The issue is not the cost of solar but the cost of storage.

Re: How cheap does solar power need to get before it takes over the world?

#44
post #21

Storage is the /only/ way for solar to provide baseload power. Pumped water storage is vastly cheaper than batteries, and a better example of grid scale storage today. I should add that battery prices are coming down as volume increases (manufacturing learning curve), but not as fast as photovoltaic cells. Elon Musk's goal with tesla is to boost battery production volume significantly to reduce the cost of batteries.…

Pumped water storage is awesome where you have the geography to support it. Alas, that's not everywhere.

Furthermore, mountains, canyons, and valleys are beautiful and valuable as they are.

Re: How cheap does solar power need to get before it takes over the world?

#45
A significant impediment is handling peak usage power. Maybe solar can provide most of our energy needs, but for those times where peak power is needed, it's probably more sensible to take a more balanced/mixed approach.

*edit looks like the article has a convenient link to another article talking about this exact problem:

http://www.vox.com/2016/2/12/10970858/flattening-duck-curve-...

Re: How cheap does solar power need to get before it takes over the world?

#46

Earlier quoted context omitted.

If the whole world could get their s * together, we can perhaps have a worldwide grid.

Electricity transmission is constrained by line loss, which is proportionate to amperage. To minimize it, voltage is raised to as much as over a million volts, keeping amperage down. This makes for very serious cross-country transmission lines, and electric companies still lose a quarter of the generated power to it. In my opinion, the two great strengths of solar are cleaner power and localizing power generating wit…

Proportional to the square of current (amperage). Or alternatively, inversely proportional to the square of voltage.

Re: How cheap does solar power need to get before it takes over the world?

#47
People are comparing the wrong things when it comes to solar, and that leads to solar not showing how expensive it truly is.

For one, there is nowhere where solar is the baseload power, because it can't be, so it gets a bit of a "free rider" advantage. For another, solar plants depreciate like any other, but those costs aren't really factored in to a lot of solar power costs yet.

We'd need to build out a significant amount of energy storage capacity and change a lot of the grid as well in order to fully adopt solar as a baseload power source. And that would increase its cost by non-trivial factors. Would it still be worthwhile? Maybe?

Re: How cheap does solar power need to get before it takes over the world?

#48

I think the issue is that OK, say we managed to get to 100% electricity being solar when the sun is shining. You'd still have the time the sun is not shining, which would likely be more expensive than before (a gas powered plant would only be running half the time - effectively doubling its capital/construction cost per kWh). So you'd definitely have an improvement on some levels but I'm not sure that would really he…

Everyone seems a bit obsessed by batteries as a storage method, when we have more traditional methods: - Pumped-storage hydroelectricity - https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... . Sure it's not suitable everywhere. - There's always Molten Salt as well - http://www.solarreserve.com/en/technology/molten-salt-energy... . Also, solar isn't the be all and end all of renewable energy generation. Wi…

Similar to pumped water storage I wonder if we could do a household version with weight. Something like the gravity light (gravitylight.org) but on larger scale. I wonder if we could see a resurgence of chimneys on houses except now instead of letting smoke out they contain a XY ton weights that gets pushed up by excess solar capacity during the day, and then drops by evening powering the house.

I have no idea if that's realistic. Does someone know what the weight/distance to power output would be limited at...

Re: How cheap does solar power need to get before it takes over the world?

#49
post #40

>> 25 cents per watt by 2050 — down from around $3 per watt today Can I trust a report that does not even have the units right?! Price should be proportional to energy (i.e., Joules or Watt-seconds) not power (Watts).

No, it shouldn't be Ws. It's the ratio of the manufacturing cost per rated power of PV-modules.

Re: How cheap does solar power need to get before it takes over the world?

#50

There's an economics caveat to interpreting solar prices, which I think may have put a lot of people on the wrong track. Suppose solar panels were priced such that, after accounting for installation costs and subsidies and everything else, solar was much cheaper than grid power and paid off quickly. Then pretty much everyone would want one, and the manufacturer would have a huge backorder. So the manufacturers wouldn…

If you can create a solar panel that pays off too quickly you could be better off selling the energy than selling the panels. You only need to start selling to the public when your competitors release enough solar panels to lower the grid price or you need cash. This is somewhat analogous to the situation with the manufacturers of hardware bitcoin miners.
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