Solar Electricity


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  I took advantage of the government grant scheme, to have a 1.8 kWp grid connected PV system installed. This was done on 2nd March 2004. Pictures and performance data are available here.

Having had the system in for a few months, I thought about making the system totally independent, the pump and controller were running off the grid mains electric, even though this was being bought from a 100% renewables source. - Good Energy. I wanted to experiment with PV and be able to monitor what was going on. So the following components were purchased and added to the system.

  A solarex 75Wp PV panel , 130 Amp-hour deep cycle battery , a 6amp battery charge controller, and a 300W ASP Domino true sine wave inverter to convert the 12V DC from the battery into 240V AC for the pump and controller. The charge controller and inverter were of a higher rating than necessary at present to allow for expansion of the system in the future. I have since expanded the battery bank to 320 Amp-hour capacity and added a BP 75 watt PV panel.

  I have also installed Very low power 12 volt White LED lighting in the hallway, landing & living room of the house which run from the batteries. The hallway light is a wide angle LED bulb using only 5 watts but gives out about 50 watts equivalent of light, easily lighting up the whole hallway. The landing light takes less than 1 watt and can be left on all night when we have people staying.
picture of 5 watt wide angle LED bulb

To enable me to monitor how the system was performing I attached an ‘emeter’ battery monitor and shunt to the battery and this is connected to my computer via an RS232 interface. It has given me a lot of data on the system performance. See data page for more details.

    The emeter gives details of battery voltage, amps in / out of battery, Amp-hours showing amount of energy taken from battery and time - estimated time in hours that battery will sustain a load. As well as storing history about usage.