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Solar Power Project Part 4 Mains electricity from the sun

Published on Friday 12 December 2008
Categories: Solar Power |

The solar panel has has a pair of 60 amp wires which run from the apex of the roof to a first floor cupboard where the battery, charge converter / controller, inverter and relay switch box is situated.

The picture below shows the large red 60amp wires on the left which come from the panel to a pair of high current connection blocks and then into the charge controller which is a 45 Amp PWM Solar Controller from http://www.solarproductsuk.eu (no longer trading) at a cost of £69.

The 45 Amp controller will give ample room to upgrade to further panels in the future.

Charge Converter and Controller

solar charge controller

The charge converter is connected to a 75 Amp leisure battery which was obtained from a local car spares shop.

The converter is connected to a Sine Wave mains power inverter which produces up to 275 watts from a 12 volt supply. The unit I purchased was a Studer AJ Inverter from http://www.brightgreenenergy.co.uk at a cost of £194.

This was connected to a DPDT mains operated relay which was fitted onto a DIN rail in a small mains consumer box, these parts were obtained from http://www.rapidonline.com/ at a cost of £20

The relay allows the supply to be switched between solar via the inverter and the mains electricity supply.

Inverter wall mounted and relay box before relay and cover fitted

Mains inverter and relay box being fitted

Once the inverter had been tested on a 100w load, the relay was fitted and the cover secured in place.

Charge controller, mains inverter and relay box.

Solar lighting system with inverter

The current consumption of the inverter with 5 x 21w compact fluorescent bulbs running was around 9.5 amps.

The inverter is currently only connected to the upstairs lighting circuit which supplies 7 bulbs, all 21w or 10w compact fluorescent's on the first and second floors but it is very rare for all of these to be on at the same time.

The single panel on a clear and sunny day is charging at a rate of approx 3 amps (36w) into the battery.

When finances allow, we will build an additional 3 panels using similar construction methods apart from making the bases from a single 20mm thick sheet of material with the solar panel areas milled with a CNC mill. These three panels should supply an additional 9 amps (108w) of charging capacity which will hopefully supply enough power to run all the lighting circuits in the house and also supply low voltage power for led lighting for bedside lights and small appliance charging.



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