Mark Snyder Electric was contracted to install 90 kW tracking solar power system at Alpine Elementary School at Alpine, CA. It is the largest passive tracking solar installation in the world and generates 126 kW annual average due to the greater efficiency that trackers give you. SDG&E used the project in a brochure illustrating solar projects for the future.
In late 2004, I was referred to a project developer by Zomeworks Corporation, makers of solar trackers and other solar products that I distribute. The project developer was working with the Alpine School District to provide solar power. I visited the property and met the Alpine School District business manager Rob Turner. The proposed solar array location was very rocky, full of tall brush, and had a 10-15 degree slope. Due to the rocky soil I had to devise a plan with three alternative lay outs of the system due to shading issues.
I had to assign GPS locations for each tracker and we optimized each location in three planes to optimize their power production. I provided a cost and the school had a fixed cost per watt. The price was very low and was for a fixed array not tracking.
I had calculated that the tracking system would zero out the school’s electric bill and the fixed system would fall 40% short. I was committed to do the job with trackers I really wanted to see the School be net zero. I signed a contract. We ran into a lot of rock and had to break them up, use alternative layouts, and dowel footings to the rock. You name it, we had to deal with it.
Vandals tried to break into our storage containers on school property three times. I had to put up cameras and motion lights to foil them.
I had worked with the Department of the Navy from 1998-2000 when I was working for the Clinton Administration under the White House Y2K Czar John Koskinen. I was granted the use of the Navy GPS positioning satellite to optimize our tracking solar PV system very precisely.
Our goal was to have the trackers work from 9AM to 5PM with no shadows on the darkest day of the year. We achieved this goal and we were able to complete the job successfully on budget.
I donated my time and made a small profit on my crews and the material. I knew the tracking system had to be installed. When I initially met with SDG&E reps they said that the system would produce at best a 25% increase over standard pole or ground mount. They laughed at me when I said that we were routinely getting 40-50% more power daily when the tilt was changed seasonally our Alpine Elementary School Tracking Solar PV system was super optimized. Without changing the tilt seasonally maintaining it at latitude it is producing 40% more power overall and 65% more during peak in the summer. See SDG&E graph of production.
The Alpine Elementary School Tracking Solar PV System has exceeded expectations and has consistently produced 100% of the power for the Alpine Elementary School. The Alpine Unified School District has been very aggressive about energy efficiency and reducing their power use. The Zomeworks passive tracking solar PV system at Alpine Elementary School can actually be optimized by an additional 15-20% beyond its current level. The first optimization requires seasonally adjusting the second axis. This requires about 1.5 days of labor for each season. The extra power is well worth the trouble.
Mark Snyder Electric has developed another innovation that produces an additional 7-10% annually. This is a thermal device that requires about 35 watts of power each day at each tracker before sun up to move the tracker to face east before sun up picking up more sun hours daily.
Mark Snyder Electric installed spare conduits at Alpine Elementary School in case extra power was ever needed the wake up could be installed, squeezing all the power possible out of the array.
It makes the equation less attractive when we are not offsetting 15-25 cent or higher kilowatt hour rates. Our strategy is always to super optimize the PV power system and produce a little extra power to provide a comfortable cushion of power credits.
The Zomeworks passive tracker has a number of advantages over dual axis trackers. Simplicity of design, fewer moving parts, low maintenance cost, very long life. My oldest Zomeworks tracking system is close to 35 years old and still working. No actuators to fail. No electronics. Simplicity of design and the ability to super optimize is hard to beat. Alpine is a high lightning risk area we installed a wetted grond system that has kept the system safe from lightning. The fire house has been hit next door and property across the street.
The Alpine Elementary School solar enclosure is fenced in. Goats keep the brush down and a wireless security system keeps the modules safe along with some pretty mean horns on the Billy goats.
The world’s largest solar PV passive tracker array is a daily reminder of how cooperation with the forces of nature can provide all the power we need for our schools and our homes: a dream becomes a reality.
Please let us know if you are interested in having a zero electric bill.