Making my home free from the grid

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Martin Chape has made an independent power supply for his lights and home office. Next it will be the whole home as he tries to escape his electricity retailer.

As a semi-retired engineer I have always dabbled in technical projects and probably always will. This latest project came about when my electricity retailer Synergy cut the rate paid per kilowatt-hour of electricity sent to the grid to 7c per kWh, to coincide with the introduction of the West Australian government’s feed-in tariff in 2010.

The thought that, after my solar feed-in tariff ended in ten years, my system would become merely a cheap generator supplying all the local air conditioners at a profit to my power company annoyed me. Especially as I would have to fund any maintenance to the solar PV system from my pension.

So I decided not to invest further in additional grid-connect panels but rather, to put my dollars into making my home office totally independent of the grid. I built an off-grid solar power system with 12 volt battery storage, supplying a 240 volt inverter at the lowest cost possible.

Online shopping for parts
I sourced a pair of new 6 volt deep cycle lead-acid batteries from a local retailer. The brand was Interstate Batteries model GC2-HD-UTL, with a capacity of 216 amp-hours each. I purchased a 200 watt, 12 volt monocrystalline solar panel for $500 from eBay store LHP Power, which came with a 25-year warranty, and found a low cost 10 amp solar controller from a Chinese eBay supplier.

The solar controller has three sets of connectors, one for the PV panel, one for the load, and the third for the battery bank. The solar controller prevents overcharging the batteries, unwanted discharge of the batteries through the PV system at night, and disconnects the load to prevent battery damage if it becomes run down.

After purchasing a couple of low cost 800 watt 12-240 volt inverters from another Chinese eBay store I was ready to roll with my first system.

Read the full article in ReNew 119.