Back to page 3.

Most of the upgrades were done on the cheap, having learnt a few things over the last couple of years. 8 more 190 watt 24v 72 cell solar panels were picked up on eBay for about $80 per panel. This gives me 20 panels in total, 3800 watts. Panels pop up on ebay from time to time, these were from a solar panel installer who upgraded an existing system and had no need for the old panels. They are 3 years old, good condition. So the tip is you can buy panels cheap if you are willing to hunt around and pick them up. Check for hail damage, corrosion, cracks, etc. Panels have a life of 50 plus years, so 3 year old panels are like new.

I picked up another set of 8 golf cart batteries, same rating as my existing batteries, but 1 year older, for about $500. So now running two battery banks in parallel, giving more than double the battery capacity of the original battery bank. More than double? Yep, its a interesting effect of lead acid batteries, where 2 batteries in parallel give more the twice the Ah rating, if you don't increase the load. Its called the Peukert effect, see this Youtube video ( 3 part ) that explains it.

I also added a backup inverter. My main inverter, the Latronics 7kw, has been reliable, but I've always worried about it getting zapped by a lightning strike, leaving me without power for a week or so until it was fixed. So I built my own inverter using parts from eBay and a junked grid tie inverter. It was a interesting build, cost about $600 and there was a couple of days work involved including a 300km drive to pick up parts. I would rate it at 4kW, idle current is 0.5 amps ( similar to the Latronics ). The backup inverter means I no longer need to worry about shutting down the system during electric storms, if one inverter gets zapped I have a spare.

Lastly I added a on demand gas hot water heater. I use this if its been overcast for a couple of days, or the middle of winter where the solar hot water system struggles to keep warm. I no longer need to run the generator to top up the hot water tank. I have a couple of taps I need to turn to change over from the solar hot water to gas hot water and back. The gas hot water does use a lot of gas compared to the kitchen stove and oven, a 9 kg LPG tank lasts about 3 weeks when used for hot water, but it sure beats cold showers. One thing I did notice is the gas hot water system must have a built in electric heater to stop the pipes freezing in winter, it seams to draw about 80 watts on really cold nights.

The Sacrifices.

On the grid we've become accustomed to a very wasteful lifestyle. We "expect" to use as much power as we want, when we want. When someone thinks about moving off grid, usually they approach a business who can install the equipment, discuss their power habits, and walk away with a quote for $50,000 plus to install a system to meet their needs.

This gives the impression going off grid is expensive, but it doesn't' need to be. My initial system cost just under $12,000, all new equipment, but some parts supplied at cost price due to a few favors owed at the time. Add my labor and background in electronics and I saved a bundle in cash.

The main area I cut costs initially was the battery bank. It was small, but big enough for me, provided I made a few small sacrifices. To keep it simple, "after dark" also refers to heavy overcast rain days, though not as much of a problem now with the extra solar panels.

1. Restrict power tools after dark. Small jobs were OK, but I avoided using the welder, heat gun, metal lathe, etc at night.
2. Wash cloths during the day. My washer heats its own water, and electric heaters suck the amps.
3. Don't use the cloths dryer after dark. For obvious reasons. I have under cover cloths lines, so rarely need to use a cloths dryer anyway.
4. Don't run the air conditioner after dark. Not really a issue anymore with the upgrades, but nights are usually cool here anyway.
5. No electric heaters in winter. Night or day, unless its full sun.

That's it. Not a lot really. During daylight hours its a different matter, I have more power than I can use, so can run air conditioning, power tools, etc. Its the after dark stuff you got to watch. But night time loads like the computer, tv, lights, kitchen appliances, water pumps, etc, are all perfectly fine. I even use a electric blanket in winter, they only draw 50 watts.

Final thoughts.

There have been times when I wish I had grid power, like a cold sub zero night when all I want to do is turn on a electric room heater. But overall, I could not imagine living without the off grid system. I'm responsible for my own power requirements, its clean and renewable, I like that. Plus my power is much more reliable than the grid power, as my neighbours keep telling me, when their power goes out for no reason and they can see my house lights are still on.

Once installed, off grid power is very cheap, but its not free. The batteries do need replacing, every 6 to 15 years, depending on make and type. In my case, my original bank cost $1600. In the 3 years before the upgrade, I maybe spent $50 on distilled water, and I suspect the batteries are half way through their life. So my electricity bill for the last 3 years was about $850, around $285 a year.

If I were to move back into the suburbs, would I still go off grid? Mostly. I would still have the grid power connected, but also have the solar panels, battery bank, inverter, etc. The grid power would be reserved for short duration, high current loads, like workshop tools, while the inverter power would be used for lighting, house power points, air conditioning during the day, etc. This would reduce my cost of living and give a more reliable power supply compared to a totally grid fed house.

Some links

Rainbow Power Company