Thursday, August 13, 2009

Solar power 1

This is an english translation of an article that was posted originally on the polish version of this blog on june 22nd.

With a bit of help from my father-in-law I managed to work on my solar power system couple days ago. Today I finally managed to write a post about it with some photos and schemes. I want to describe the current status of the solar power system, and to write a bit about the future of the system.

According to our plans, we're going on the first part of our summer holiday on july 6th, the next monday. I don't have much time to finish the work with supplying all the electrical devices with electricity from the solar panels.

From Volkswagen Transporter T3
The first thing I did was to put two gel batteries in one of the cupboards of the camper. I wanted to fit them under the driver's seat, but there's no enough space there. I connected the batteries (parallely) to the solar charge controller, unfortunatelly using cable with cross-section much smaller than suggested by the controller's manual. The controller can be seen on the right hand side of the photo -- it's the black plastic thing hanging on the white wire.

On the second solar panel my father in law soldered two connectors -- male and female, one will be used to supply power to the charge controller and the second to connect the two panels together (parallely).

Here you can see the cable from the panel connected to the one from charge controller.

The solar panels aren't attached to the roof yet. In order to use them, I'll have to manually put them in sunny place...

...and connect together. This was the best I could do. Until they're permanently fixed to the roof, I won't connect them permanently to the charge controller.

To be honest, I have two independent solar power systems. Two sets of batteries, two charge controllers, two sets of solar panels. The scheme of all this looks the following:

On the left hand side of the drawing you can see the new solar power system: two solar panels, 40 W each, and two gel batteries, 38 Ah capacity each. On the right hand side, the old solar power system, the old solar panel (10 W), old charge controller and old battery. At the moment, all the appliances (shown as an icon of electrical bulb) are connected to the old battery, using quadruple cigarette lighter socket.

"reg.ład." is a short for regulator ładowania -- solar charge controller.

I want to add a couple of extra parts to the system and make it look the following:

The most important part of this system is the set of two gel batteries, charged with the two solar panels. To this solar charge controller I will connect all the camping appliances: radio, lights, fridge, water pump. The older part of the system will work as emergency energy source, will be connected manually to the rest of the system.

Directly to the batteries I will also connect:
  • inverter, shown as 12-230, that will supply 230V AC power to my laptop computer and TV tuner,

  • gel battery charger, shown as 230-12, that will charge the batteries whenever I will have the 230V power supplied to the camper from external source,

  • additional battery charge controller, SLA40, that will start charging the gel batteries when the alternator makes enough electricity.

Most of the appliances must be connected via charge controller, that will disconnect them when the voltage in the battery drops below safe level. The inverter has this security measure built-in, so it might be connected to the batteries directly.

I already have the inverter, the 230V charger and new wire to connect it all (4mm² cross-section area - 12 gauge!).