Del Valle Solar Installation


Whatcha’ Lookin’ At?

The Power of the Sun.

Rows of solar panels reflecting sunlight.

This is a 349-kilowatt solar electric power system at Zone 7’s Del Valle Water Treatment Plant in Livermore. The solar array spans approximately two acres and is designed to produce, on average, 643,600 kilowatt-hours (kWh) of energy annually. The system output is expected to degrade at a rate of 0.5% per year.

This represents approximately one‐third of the energy usage on-site and is expected to save Zone 7 more than $800,000 in energy costs over the 20‐year term of the agreement. These savings could be substantially higher if conventional power costs escalate more than the conservative projections.

Zone 7 will save more than $800k in energy costs over 20-years

Key Features:

  • The installation has 1,484 (235‐watt) solar panels mounted on Array Technology’s DuraTrack single‐axis tracking solar racking technology
  • These panels are able to track the path of the sun from dawn to dusk, providing increased efficiency and production over a system that uses fixed‐tilt racking
  • The Direct Current (DC) power produced by each solar panel flows into a Solaron Inverter where it’s converted to usable Alternating Current (AC) power
  • As a grid‐tied installation, the solar power interacts with Pacific Gas and Electric Co.’s utility distribution network. Among other things, this provides Zone 7 with PG&E energy credits when the power produced by the solar panels exceeds Zone 7’s immediate need and is sent into the PG&E system

An angled close-up of a large solar panel.

Solar Installation Funding

  1. The project was financed using a popular solar financing model called a Power Purchase Agreement (PPA)
  2. Under this PPA:
  • Borrego designed and built, and now maintains the solar power installation on Zone 7 property. Ownership has been transferred to CleanCapital, LLC.
  • In return for the right to use Zone 7 land, CleanCapital agrees to sell the clean energy the solar installation produces to Zone 7 at pre‐determined rates (currently 28% less per kWh than the PG&E retail rate) for 20 years. As a private entity, Borrego was able to take advantage of federal tax incentives

20-Year Agreement Expiration

After the initial 20-year term of the PPA, Zone 7 will have three options:

  1. Enter a new Power Purchase Agreement with CleanCapital (or owner)
  2. Purchase the system at the depreciated fair market value
  3. Have the system removed at CleanCapital’s expense

Zone 7 Customer Benefits

  • Zone 7 was able to add solar with zero capital investment
  • Results in an immediate and long‐term reduction in energy costs, saving $70,000 in the first year alone
  • An estimated $812,000 savings over the 20‐year term of the agreement is predicted
  • Saves water ratepayers money by reducing operating costs
  • No repair or maintenance required because these are covered by the system owner
  • Zone 7 will be able to better forecast energy costs for 20 years due to predictability of PPA solar cost
  • Zone 7 is buffered from volatile PG&E energy rate increases
  • Ability to deploy a renewable technology aligned with environmental stewardship. About one‐third of the conventional power at Del Valle will be replaced with renewable solar power

A solar panel engineer testing a solar panel with a voltage meter.

Environmental Benefits

  • Reduce Carbon Dioxide emission by 15,891,018 lbs.
    • This is equivalent to removing 64 passenger vehicles from the road
    • This is equivalent to planting 143 acres of trees
  • Reduce Nitrogen Oxide emission by 15,311 lbs.
  • Reduce Sulfur Oxide emission by 33,174 lbs.
  • It would require burning 23,547 barrels of oil to generate the same energy as this solar installation during its life.