I apologize in advance for the not so easy to see line in the image. I hope you can see the two lines well enough.
The thicker line at the top and who is wider shows Solar Radiation in Summer. This is a recording of an almost perfect day and close to the summer solstice. The sun rises around 6am and 6pm with a peak output of 1000 Watts per square meter!
The thinner line shows Solar Radiation in Winter. This is a recording of an almost perfect day and close to the winter winter equinox. It is a bit skewed because I think a hilltop blocks the sun early. But as you can see The less optimized position of the light sensor and the shorter days are clearly visible. The Solar Radiation climbs around 8am peaks at just over 400 Watts per square meter and has already dropped halfway by midday. And that's on a good day.
Recently the solar powered repeater station went offline because the batteries went flat. For almost a week there where clouds. We where lucky if there was between 200 and 300 Watts of solar radiation for more than an hour. Bur with solar panels only around 14% efficient this was not enough to put more energy in the batteries than the system would use. I did expect this to happen one day. You can only pay for so much redundancy with batteries. And batteries are very expensive. I am surprised it took more than a year for it to happen. But I guess my recent experiments with live streams from the cameras where a big drain on the batteries. Something more suitable for summer.
Would a wind generator have helped? Unfortunately this time, no. Together with the clouds there was an absence of wind. Only near the end of the last cloudy day the wind picked up but by that time my system had just charged enough to go back online.
I have plans for improvements which I will discuss in a future post.
George Timmermans, Research Toolmaker, Software Engineer and Tinkerer