Boffins tout solar efficiency boost

Re: Check the Graph in the Abstract...

"It seems to suggest an increases in efficiency of upto 2%."

Those appear to be the measured efficiency increase in a real cell - and that figure is also mentioned at the end of the article - the higher figure is referring to the theoretical peak efficiency. The group seem to be aware of the gap between the two, and know more work is needed, e.g. from the article..

Professor Schmidt said.

"We now have a benchmark for the performance of an upconverting solar cell. We need to improve this several times, but the pathway is now clear."

"Given the already appalling efficiency of such PV devices, that's not really much of an improvement."

I personally wouldn't say that a 20+ % total conversion rate is appalling, especially given the lack of required effort in creating the incoming flux - and the intial result from a cell giving a 10% relative boost is hardly to be sneezed at. PV devices are already more than efficient enough to be used for power production economically - the economics and logistics of storage are more of an issue.

Re: So....

"a theoretical boost, eh? I can't wait!"

The abstract seems to imply that the 1% efficiency increase is in a real device, and the data in the graph looks to be more experimental than theoretical. From the abstract

"We report an increase in light harvesting efficiency of a hydrogenated amorphous silicon (a-Si:H) thin-film solar cell due to a rear upconvertor based on sensitized triplet–triplet-annihilation in organic molecules. .... A peak efficiency enhancement of (1.0 ± 0.2)% at 720 nm is measured under irradiation equivalent to (48 ± 3) suns (AM1.5)."

Without access to the full paper it is not possible to prove this is real data however, perhaps someone who can get hold of it could clarify.

Bear in mind that

At the times when solar flux is plentiful, there's demand for aircon precisely during the times at which solar cells are most effective. This applies to gloomier latitudes as much as it applies to the Sahara.

I'll bet that daytime grid load exceeds nighttime, too, so solar is available at the point at which it is most useful... pretty stark comparison to wind power there.

Re: "One thing is loses when sending power over large distances"

Trickier to build HVDC links across the Med than it is to build them overland.

Re: Err, limiting factor.

It all depends on where you are. 1000W/m^2 is regarded as Standard Test Conditions, and is what the specified output of the solar cells will be reached under, but there have been a few occasions this month where my own installation has exceeded STC output, and that's in Scotland... Certainly if you were to use the same panels on the Isle of Wight, they'd produce significantly more given the same cloud coverage.

I've been trying to find a solar insolation map to tag onto this, but they all deal with average kWh/year, which I suppose makes sense. Ho-hum.