So far the calculations are correct (despite unfortunate unit errors ...)titiyador wrote:Well, I have just made a "summary" calculation, not being a specialist or a physicist:
One pump: 15 W * 2 (two pumps): 30 Wh. Let's say they will work 12 hours / day (but hey I still have to find a 12 V programmer, which is quite expensive from what I could see), or 360 w / d of consumption. It would therefore already be necessary to produce 360 W / day just for the pumps. In the worst case, what I could do would be to connect a panel directly to the pumps which would start up as soon as the sun came up (via a 10 A regulator). So no need for a programmer. A 50 Wp panel is required.
For the heating bulb, let's say 100 W at the rate of 12 hours of daily operation (I remind that it will be installed in the greenhouse and that the temperature rises quickly enough as soon as there is a radius, not to mention the solar air heater that I made last year with soda cans and which, thanks to a fan, provides a lot of additional degrees) which would give 100 * 12 = 1200 W / day.
There on the other hand, I think that you are too optimistic.titiyador wrote:Thus the month of March (period of resumption of breeding) in Lille gives 121.1 hours of sunshine, or 3.9 hours / day on average (source: http://www.meteofrance.com/climat/franc ... 1/normales )
Thus for 4 peak power panels of 100 W each, this would give 4 * 100 * 3.9 = 1560 w / day. But the average sunshine does not take into account that the panels produce, certainly less, but still produce in cloudy or even rainy weather (these are panels with monocrystalline cells). So we have at least 1560 w / day on average.
Would that apparently be enough to power the bulb as expected if we exclude the pumps, or am I completely off the plate?
First of all, the 121,1 hours of sunshine are not necessarily at noon, when the sun is well in front of the signs.
I think you have to divide the production by a factor of 2 because of the angle of incidence.
Then (and this is even more annoying), as the elephant points out, we cannot size this kind of installation on a monthly average: despite 121,1 hours over the month, you can very well have more than 10 days consecutive without sun.
In this case, either you have a backup solution (independent heating, generator, extension cord, ...) or you have to design a very large storage (therefore very expensive) especially as on days without sun, the greenhouse heats little and the bobbin panel does not produce either, so power consumption will be greatest on the days when the panels produce the least.
For a consumption of 1200Wh / day, for 10 days, a storage of 12kWh is needed ... i.e. a battery of more than 1000Ah in 12V.
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