Naked Science Forum

Non Life Sciences => Technology => Topic started by: turnipsock on 22/03/2008 00:16:37

Title: Solar Panels
Post by: turnipsock on 22/03/2008 00:16:37

I noticed, a couple of days ago, some new road have grown on the verge in our village. They have have solar panels and ever since they appeared it has been bloody freezing. How much of the suns energy do these things soak up?

Does anybody know if there is any extrernal wiring to the solar powered signs? If not would they be a target for theives?

How easy would it be to remove the solar panels from the signs and connect them to a UPS, for instance?

Title: Solar Panels
Post by: DoctorBeaver on 23/03/2008 08:34:18

We've got a lot of those round here. Most of them flash speed warnings at you. 1 in particular flashes "30mph - SLOW DOWN" at you if your speed is in excess of 20mph!

Title: Solar Panels
Post by: lyner on 24/03/2008 17:42:11

I imagine that they are 'potted' in resin or something to render them weatherproof. You would probably need to nick the whole thing and then spend hours at home, separating the panel from the electronics.
As for the power output, you start with 1kW per metre sq from the Sun, then, if you used the most recent cell type, you could get up to 40% of the received sunlight. (Real cells will not be better than half of that). You need to allow for the fact that the Sun will be off axis most of the time and it won't work at night (durr).

Title: Solar Panels
Post by: Pumblechook on 24/03/2008 18:16:26

Americans seem to measure efficiency in a different way and end up wiith higher figures than European or Japanese companies for the same technology.

Average output is quite low actually... only 10 - 20 Watts per sq m..over a full year.    Clearly no ouput at night and low output with dull skies and for the most of the day when the Sun is not square-on to the panel.

Capacity factor is poor... of the order of 10%..  Ratio of average to peak output.