At 11am this morning, we had our delivery of our new solar panels, all seventeen of them. They came flat on a large pallet, strapped down good and tight. Each panel measures 2metres by 1metre and they are capable to generate about 400watts on a good sunny day.
Solar-Panels-have-arrived
We inspected each one in turn for damage and electrically tested them and all works. For the last one, we left it outside in the sunshine and found several high powered resistors to measure what power we can get. The first resistor was a 22ohm and using two test meters, one to measure the current and the second one to measure the voltage, we were getting 38Volts and about 1.7Amps in bright sunshine. This works out at around 50watts, which is not very high at all. So, we switched over to our other resistor, 3.2ohm instead and rated at 100watts and watched the meters. Suddenly we were getting 33Volts and 4Amps which is over 120Watts which is much better. Then, Stephen told me to get my shadow off the corner of the panel and suddenly we got 35Volts and 9.2Amps which works out at well over 300Watts. That is much much better. In fact, we were so engrossed in the changing numbers as the Sun came and went in the hazy sky that we didn’t realise that our poor resistor was melting and boiling!!
A-solar-panel
Testing-a-solar-panel
It is very interesting to realise that even a small shadow on the solar panel causes such a change to the performance and we have learnt first hand that you must avoid shadows as much as possible.
We are now waiting for the metalwork to be delivered that will allow us to bolt the panels up on our roof. We are planning to put up seven panels up on the P roof, this faces slightly East of South (looks over our Patio) and a further ten panels up on the M roof which faces West of South (looks over the swimming lane) and each area will be “strung” together in series and the two sets of cables routed all the way back to our invertor “magic” box in the Utility Room. We will need to break into the Skylight to get the cables through but we will be careful and make sure it is all weather sealed and everything.