Living Off-grid: Solar lighting [2018]

[Still updating details of this post, quite a lot I had written down and lost]

In 2018 we spent the holidays in the village at our family home along the Maggi Highway, Makana Dobu. A lot has changed back home and although much of the land still looks the same there are a few homes up now and the community is growing bigger each year.

A few of the homes now have solar lighting but the usual setup a single 20W panel, one or two lights and a 12V battery. Just recently we had power poles erected and electricity brought in through a New Zealand government funded (have to confirm this) project. Before this project this was the off-grid setup we had at home.

Our house had the following equipment:

• 65 Amp battery - 12 volt

• 100W Solar Panel
• 50W Solar Panel
• Lights:
• 2W x2
• 8W x4
• 10W spotlights x2 

 

 

• Charge controller x1 rating 10Amps
• max panel 100W panel
• for >100W panel you need at least 15-20 Amps rating controllers.

 

The final setup on paper...

This was a draft on paper of how things were setup in the house.

Calculations:

• 65 Amps / Hour    X    12V    = 780 Watts/Hour

Everything depends on the load of appliances connected and used in an hour or so.

Formula

100W solar panel divided by 18 volts = 5.56 Amps

(18 V, Nominal output / max output if sun is strong)

5.56 Amps x no. of sun hours.

E.g. 5.56 A x 8 hours of sun = approx. 40 W total power.

Therefore, it depends on the sun (the hours of sunlight you get).

100W is able to give you 40amps in 8 hours of direct sunlight.

 

Figure 2. Uncle John wiring the charge controller

 

Figure 3. The charge controller

 

Figure 4. The power inverter which I used later to power up my laptop.

 

Figure 4-b. Important details about the inverter that you need to take note of when using one.

 

Figure 4-c.

Two charge-controllers, one additional controller for the fans.

The 10W spotlight for the front

2 Watt lights for the living room.