Solar powered loft
Case study:
Dramatically rising energy costs burdening people with extra expenditure and also to the planets detrimental well-being.
Solution:
Erection of two 20 watt solar panels on the roof space which are the size of two adjacent A4 pieces of paper. The solar panels are wired in parallel to give 40 watts at 12 volts in optimum conditions. The next item down the line is a self built regulation system limiting the voltage to 14.4 volts maximum as it was noticed in optimum conditions that the output voltage was too much for the battery system and was an explosion risk. The next part of the solar system then feeds a charge controller. This device stops feeding the power to the battery’s when they are fully charged to again protect the batteries. The battery bank is two 110 Ah leisure battery’s, which where selected because they are better for deep discharge as apposed to the average car battery.
Attached to the battery bank is an 12 volt to 230 volt inverter which provides the mains electric from the battery bank. One consideration of utilising an inverter is the power loss as nothing is 100% efficient. Hence I would suggest runing as much as possible directly from the battery bank (via a fuse or trip system).
Costs:
The solar panels are expensive, however once they are up and running you will recover your costs in approximate 6 years. The solar panel I have used cost just short of £100 each as I selected ones that work on daylight as well as sunshine (one to look out for). The battery’s cost £45 each, however they have recently increased in price. The parts for the regulator cost about £5 and the charge controller cost £15. The inverter is rated at 400 watts and cost £50 . In addition it is necessary to calculate the total expected load on the battery bank system to ensure the amperage is adequite. finally the only other requirments are suitable cabling. 12V distribution box and battery clamps. the total cost of the prototype system in my loft came to £475.
As energy costs keep rising at the current rate then the pay back time correspondingly reduces.
