Rice University researchers propose a way to boost solar efficiency

Post by Brakenshire » Sat, Aug 10, 2019, 2:14 PM UTC

ThomPete wrote: post #109

Brakenshire wrote: post #59

Earlier quoted context omitted.

These are arbitrary metrics, why does energy density matter for anywhere which has the space? Even in Northern latitudes and high density countries you can generate a lot of electricity with a nominal amount of land. All the more if they can be fitted on rooftops. For sunny places near deserts it can absolutely provide a big percentage, even a dominant percentage of power. The main issue is matching demand to supply,…

Energy density isn't arbitrary. It normally means something can be used in compact form (batteries, oil, gasoline, coal, uranium) and deliver energy at will. Look at the capacity factor of wind and solar, add to that the huge areas they need and the fact that they are intermittent and you start to get a glimpse of the problem. This is neither economically nor technically feasible. You can't generate as much as you th…

Post by Retric » Sun, Aug 11, 2019, 12:08 AM UTC

skosch wrote: post #114

tim333 wrote: post #101

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>This heats up the nanotubes, which then emit visible photons I'm a bit skeptical that that would work. Otherwise you could build a perpetual motion machine by having the nanotubes in a hot room and running your perpetual motor off a solar cell powered by the light. My guess is when the article says emit light they mean emit infra red light / radiation rather than visible. The article doesn't really make sense to me…

The article doesn't provide very much detail, but it's absolutely possible to absorb multiple low-energy photons and emit fewer higher-energy ones, see e.g. https://en.wikipedia.org/wiki/Second-harmonic_generation – and apparently carbon nanotubes can do this as well.

Post by jfrankamp » Mon, Aug 12, 2019, 5:52 PM UTC

coldtea wrote: post #95

jfrankamp wrote: post #78

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Why is it not feasible? I run 32 panels on my roof, in the pacific northwest which is known for its rain, it covers 100% of my residential and electric car usage when considered on an annual basis. If roofs required solar panels we would have a large part of power generation done at a much lower intallation cost and could focus on large scale energy storage projects instead. My payoff period is 11-12 years, system is…

> I run 32 panels on my roof, in the pacific northwest which is known for its rain Aren't you still connected to the traditional grid anyway?

Post by jfrankamp » Thu, Aug 22, 2019, 5:05 PM UTC

ThomPete wrote: post #126

jfrankamp wrote: post #125

Earlier quoted context omitted.

That's right. All my neighbors use the excess solar power during the summer, and during the winter I use more grid power than I create. I get credits in the summer and use them up during the winter. A giant leap in solar efficiency doesn't solve the storage problem, and the storage problem doesn't need a magic physics solution, just large scale heads down engineering. My point is: solar is efficient enough now, and a…

It does need a magical physics solution unless you are fine with keep using coal, oil, gas and nuclear as backup. When you factor in the infrastructure to support you when you don't have power yourself then it suddenly looks less economically sound. That's the point.