Thin-film Solar

So this is very cool.

http://www.wired.com/wiredscience/2009/09/nanosolar/

It's not enough to make solar a replacement for base generation, but it should definitely help with peak summer production in warm U.S. cities.

Some additional realities:
- According to NREL, Nanosolar has the most efficient printed solar cell--at 16.4 perecent.
- No mention of small scale production. They seem to be focusing on metro scale and up.
- They're currently only producing 1MW worth of cells/month. But they say it'll be easier to go from 1MW to 100MW than it was to go from zero to one. Even so, it'll probably be a while until we see real economies of scale.

Wind Dependability

Randall Parker at Futurepundit does some heavy lifting on the North American Reliability Corporation (NERC) 2009 Summer Reliability Assessment:

...on page 52 of the PDF file I espy mention how in the US Midwest in one one grid region at peak demand time (hot summer afternoon) the worst case they've seen with wind generation was only 2% of nameplate capacity. That's pretty bad.

That's just one region, and it's probably a worst-case scenario, but...ouch.

(h/t Instapundit)

Solar Power from Orbit

So beamed solar power has been discussed for a while, but it's never been more than science fiction. It still hasn't happened, but according to MSNBC.com it's looking...imminent.

Sounds like a great technology to me, but with some caveats. The collectors would be very high efficiency (no atmosphere to deal with), but the capital expense must be enormous. Especially since they'd need to be deployed higher than most satellites (I would guess near or higher than geosynchronous, which is ~38000km), otherwise they'd suffer the same nighttime occlusion that plagues earthbound solar collectors.

Oh, and while collection would enjoy high efficiency, transmission would still have to deal with atmospheric effects. Also, transmitting megawatts through the atmosphere is bound to have side effects (I would think the heat bloom would be substantial), but maybe they've got a solution for that.

Edit: Meant to quote this...

Unlike ground-based solar arrays, space satellites could generate power 24 hours a day, unaffected by cloudy weather or Earth's day-night cycle. The capacity factor for a ground-based solar is typically less than 25 percent. In contrast, the capacity factor for a power-generating satellite is expected to be 97 percent, Marshall said.

That's the issue that virtually all solar power promoters elide. They focus on max power production, and ignore the average, not realizing that the nature of solar power and Earth's curvature require you to provision two to three times as much solar generation as you would coal- or gas-based.

When you consider the number of collectors you have to build, as well as the number of power lines, solar looks a lot less environmentally attractive. The space-based solution goes a long way to neutralizing that issue.

(And yes, I realize the article says solar's capacity factor is less than 25 percent, suggesting you'd have to build four to five times as much solar capacity. That would be true if power consumption were uniformly distributed over the 24 hours in a day. But power consumption falls significantly at night, meaning nighttime areas wouldn't be drawing as much, requiring less power capacity.)

Finally Someone's Serious About Solar

Solar power has a major drawback: it only works part of the day. In most locations, energy production drops significantly after a few hours, and vanishes entirely at night. This means solar can only be used during the day, and therefore cannot be used for primary base generation. There are two strategies for overcoming this problem: store excess energy for use during off-peak hours, or transmit excess energy from areas in peak hours to areas in non-peak hours. Neither strategy has been very feasible--batteries are inefficient, and global(!) transmission lines are prohibitively expensive.

So this is cool: Store solar heat in molten salt. It's not a slam dunk solution, but it's definitely better than anything else anyone's come up with.

(h/t JustOneMinute)

The Headlong Rush to Solar

The NY Times reports California is planning two large solar plants:

The plants will cover 12.5 square miles of central California with solar panels, and in the middle of a sunny day will generate about 800 megawatts of power, roughly equal to the size of a large coal-burning power plant or a small nuclear plant.

Sounds great. Except there's a catch.

Though the California installations will generate 800 megawatts at times when the sun is shining brightly, they will operate for fewer hours of the year than a coal or nuclear plant would and so will produce a third or less as much total electricity.

"Or less." Oh, and there's another catch as well.

Neither approaches the economy of fossil-fuel burning plants, said Ms. Zerwer, the spokeswoman for Pacific Gas & Electric. But they will be competitive with wind power and with power from solar thermal plants, which are equipped with mirrors that use the sun’s heat to boil water into steam. And prices will fall, she predicted.

It's great that California is willing to experiment with large-scale solar deployment. This project can only help to improve solar as an alternative to fossil fuels. But the article clearly points up the number one biggest problem with solar (and wind): by it's nature, it can never replace traditional power plants on a one-for-one basis. Which means even after you've developed hyper-efficient batteries, or hyper-efficient transmission, you're still building solar plants that are less cost-efficient than hydrocarbon or nuclear plants that can run 24/7.

Missing from the story is any mention of the life expectancy of the solar cells. Also no mention of transmission costs from what must be a fairly rural site.
(h/t Jonathan Adler at VC)