On the 11th February 2012 we ran a one day PV workshop at Irish Seed Savers in Scarriff, Co Clare. The hands-on workshop project was the installation of a photovoltaic 50w panel to charge a 12volt battery. This small 12volt system was to supply lighting for Seed Saver’s Cob House which had no electrical power. It was decided to use the system to supply electrical power to two low 4.5w 12volt LED light bulbs.
The workshop participants were eager to get involved and divided into two groups, one working inside to get started on the wiring for the lighting and the others went outside and were soon planning how to best hold the photovoltaic panel in position so that it would get plenty of daylight.
A battery box had been built to hold the battery and protect it from the elements. Soon we were on the way to constructing a frame which attached to the battery box and would hold the pv panel securely. Even better, the frame is adjustable so the angle of the pv panel can be changed to suit the seasons. It is advantageous, if possible, to have the panel angled upward for summer sun and angled lower to catch the winter sun.
Inside the Cob House the wiring was being put in place to allow for two lights, one at either end of the living space. The lights chosen were a pair of 12 volt LED lights. LED stands for Light Emitting Diode. These little light producers are really semiconductor junctions—diodes. The LED is designed so that the energy lost across its diode junction radiates as visible light. When it comes down to making light from electricity, the LED is three to seven times more efficient than fluorescent and incandescent lighting technologies. LEDs make more light using less power.
The charge controller and a fuse box were affixed to the wall and ready to take the cables from the pv panel, the battery and the lights. A cable was run through a hole drilled in the window frame and attached to the pv panel outside. The panel was wired up to the battery. All the cables were securely wired into the relevant parts of the the charge controller and disconnect switches.
When all was connected the light switch was pulled and we were all delighted to see the light come on.
Everyone had worked together and had taken turns to do the various parts of the installation. There were also times during the day when the different phases of the installation were being explained and then everyone stopped what they were doing to listen and ask questions, going back to their own particular job afterwards.
A group of strangers had started the day not being quite sure what to expect and by the end of the day the strangeness was gone, a chatty bunch of people had come together successfully to work on installing a fully functioning power system to supply lighting for the Cob House – with a little help from Jimmy and Miriam of Eirbyte Renewable Energy.