Sunday, January 17, 2010

Moving and Static Photovoltaic Systems.

By static I mean solar panels mounted on your roof, facing south and angled at 20 degrees. They don't move. Controller, battery bank or grid tie, inverter, your load...your demand. If you know how much electricity you want it's fairly easy to calculate the photovoltaic equipment you will need. There is so much information out there.

Pretty much maintenance free. Electricity generation on your roof top. Simple and 1/2 the cost of what it was. Now solar equipment is inexpensive and oil is cheap/life is cheap. Everyone is a bit scared of cloudy days.

This kind of system is replacing or enhancing your connection to the grid.

With the sun, taking advantage when the sun is shinning we track the sun manually as we work. Our main system is 416 watts of panels tracking the sun from a manual tracker that stands 20' high beside our cabin.

Tracking systems can be manual or automated, single or double axis and mounted on a pole or track. Some trackers use movable mirrors and concentrators rather than moving the panels themselves.

(picture to the left is of our
panels and our dish to the internet).

We built a tracker with two axis and for years diligently tracked the sun at tilt and angle. We recently put a steel roof on our place and now track the sun only by turning the tracking pole leading the sun from the time it comes up until it goes down. The steel roof reflecting sun light on the panels eliminated the need to tilt.
The practice of tracking has increased our energy production by 45 %.


Tracking the sun sounds like a chore but is far from it. We work and live in the same location and the tracker is located on the way to our shop. We have become in tune with the sun, always aware of where it is in the sky and adjusting the panels leading the sun by an hour or two on either side. In a 15 hour high demand day we adjust the angle 4 or 5 times. A high demand day maybe a couple of loads of laundry, working with a tablesaw for the day, four hours working on the computer, a couple of lights for the evening and watching a dvd. Since we do all the heavy demand work during sun up our batteries still around 65% in the morning. Most days the batteries are hovering between 80 to 100%.

The pole swivels for angle, as the sun moves across the sky, on its base of 1/2" plate steel set in the ground with concrete. This mechanism, as shown below, is a "T" of larger diameter pipe slipped over the pole end and welded in place. Sliding a smaller diameter pipe through the top of the "T" accommodates tilt.




Click on pictures for larger images


We drilled a couple of holes through one side of the larger pipe at the ends, welded nuts over the holes and then screwed bolts snugging against the smaller pipe within to control the tilt.
We use to tie a rope to the top and bottom of the panels to adjust tilt and a cross on the pole to move with the sun across the sky.

If you snug up to the smaller inside pipe with the bolts you'll have complete control of the tilt with the ropes. It is very simple and effective.
By using standard bolts, there is very little wear. For the 10 years we've operated this tracker the bolts have worn off paint. We figure in about 100 years somebody will have to shift the assembly over a 1/2".

This method of tracking the sun may not be for everyone. There are many solar trackers on the market.
Using recycled scrap pipe our photo-voltaic panel tracker cost us $45 and a days work, installed.

We started living here in 1997 with no electricity and slowly built our system as we needed it.

A second action we perform happens on winter days. On a perfect solar energy filled winter day there are only 6  1/2 hours of sun here. After a couple of dark days in December our batteries are hovering around 20%. First thing when the sun begins to peak over the horizon we'll charge the battery bank for 20 minutes with our  S-10's 2.8L engine. We installed a 200 amp altenator. While the engine is on we'll pump water, charge batteries for the drill, computer etc... Our batteries are discharged to low levels in the winter. There is resistance that develops in the batteries from discharging, preventing them from accepting a charge. The low amperage the panels produce in the morning is not sufficient to wear through the resistance in time for a good charge during the short days. The higher amp and voltage charge from our charging system is sufficient, breaking through the batteries' resistance and allowing the panels to do their job. During really challenging no sun periods we'll disconnect half the battery bank (undoing a wing nut connection), charge half the bank to 60% then reconnect. A sunny winter we may burn $40 of gas. A dark winter we may burn $200. We are in a good spot on the planet as far as exposure to sun light. On average we are burning 70 - 80 litres of fossil fuel per year for our fix of electricity.
This method of energy maintenance has increased our battery charge up to 70% on the darkest days of winter.
This all sounds like a lot of effort but it is not. With a bit of modification it could be simplified further to just flicking a switch. It is a fit that will become standard.

From March until mid October we have more power than we need.
Supposing that the whole point to this endeavor is to find the point at which we find what we need as opposed to what we want.


For more information on our sun power system and our back up power system please visit,
Solar Power, Engines and Alternators.



Enjoy the sun.

Aki and Scott



1 comment:

  1. Thank you for sharing this information. I have a shop of my own, and would like to convert it to solar. The advice is most appreciated. Good luck - and what beautiful stock you have created!

    ReplyDelete