$800,000 in energy savings over the life of the system
Zone 7 Water Agency Solar Tracker
Zone 7 is committed to providing a reliable supply of high quality water and an effective flood control system to the Livermore-Amador Valley. By going solar, Zone 7 is able to remain fiscally responsible and environmentally sensitive as they supply treated drinking water to retailers serving more than 200,000 people in Pleasanton, Livermore, Dublin and, through special agreement with the Dublin San Ramon Services District, to the Dougherty Valley area. They also supply agricultural water to 3,500 acres, primarily South Livermore Valley vineyards, and provide flood protection to all 425 square miles of eastern Alameda County.
Zone 7’s solar power installation is a single axis ground mounted tracker. That means the solar panels tilted at 45° facing east meeting the rising sun in the morning, and with the use of a system drive motor for every 20 rows max, the array will track the sun’s trajectory over the course of the day until they’re at 45° facing west when the sun sets. Zone 7 chose a tracking solar solution in order to maximize its energy production on the available 34,454 square feet of land adjacent to their Del Valle Water Treatment Plant. As a grid-tied installation, the Zone 7 solar power installation interacts with Pacific Gas and Electric Co.’s utility distribution network. Among other things, this provides Zone 7 with energy credits from PG&E when power produced by the solar panels exceeds Zone 7’s immediate need and is sent into PG&E’s system.
The Zone 7 solar energy system has been financed using Borrego Solar’s integrated power purchase agreement (PPA). Under the PPA, Zone 7 agreed to lease its land to Borrego Solar, which covered the costs to design and build the solar power installation, and will cover any future maintenance and repair expenses. In return for the exclusive right to use the host’s land, Borrego Solar (which qualified for solar rebates and federal tax credits) agreed to sell the clean energy the solar installation produces to Zone 7 at pre-determined below-the-grid rates (currently 28% less per kWh) for 20 years. Zone 7 is spending no money to go solar, and they will save $50,000 in year one, and over $800,000 at the end of the PPA contract. If the utility rates increase over the next 20 years, Zone 7’s energy savings will increase as well, since their PPA rate is set in advance with a predetermined escalator.