rogerblack has a good point but can it work 31 October 2011 at 1:05PM in Green & ethical MoneySaving 3 replies 672 views

energysavingexp

I made a post last week joking about lighting up my solar panels at night so they would generate 24/7

rogerblack has a good point

will this work?

using low energy bulbs powered from the grid at E7 rates say 7p per kwh.
if the panels produce leccy you get paid 43.3p per kwh + 1.5p export
44.8p in total
so my question is can you make money 44.8p vs 7p ?

Yut_Man

If you get 15% efficiency from the panels. 43.3p * 15/100 would give you 6.45p. so at 7p per unit you would still loose money. Nice idea. like to see a house trying this idea. better than xmas lights.

Cardew

Why bother with lights?

Connect your mains electricity(via a rectifier) to the inverter and you can ‘generate’ electricity all night. 10p/kWh input and a 43.3p/kWh output:T

Still a serious fraud, as some people in Spain discovered!:mad:

I bet the Utility companies computer wouldn’t flag up that you were ‘generating’ 4,000kWh pa from a 1kWp PV system.


You can get double that output from a B&Q Windsave turbine – mounted in the attic(so it doesn’t chop up birds)!

rogerblack

Yut_Man wrote: »

If you get 15% efficiency from the panels. 43.3p * 15/100 would give you 6.45p. so at 7p per unit you would still loose money. Nice idea. like to see a house trying this idea. better than xmas lights.

It's in principle slightly better than this, the panels get around 33% or so on deep red light.
But the best, most efficient lights are about 50% efficient, taking you back to about the figure you mention.

Using ordinary linear fluorescent tubes would get you more like 3% total output, so not close.

At 5p/kWh - the cheapest I can find electricity on night-rate, it would slightly pay back, neglecting the totally implausible cost of the lights. (lots more than the panels)