agenda city of watsonville city council/redevelopment agency meeting

Table 7.1 - Solar Projects
KWH generated DC KWH
City Hall 148,848 106.425
Municipal Services Center 177,372 128.945
Materials Recovery Facility 49,539 36.08
Water Resources Center 170,130 122.59
total 545,889 394.04
Projected annual savings in kg of CO 2 610,667
The City is incorporating the use of renewable solar electricity into its Corralitos water supply project
designs. This new Corralitos Creek Water Supply and Fisheries Enhancement Project will host solar
panels providing approximately 65% of the electricity needed to operate, estimated at 620,000 kilowatthours
(kWh). The solar electricity will be used entirely on-site. The new facility, by design, offsets
groundwater pumping with use of a surface water membrane filtration plant, reducing power needs by
40%. This efficiency improvement is an important design step for solar electricity. First, the project
reduces total energy use and then replaces a portion of the future energy usage with renewable energy.
The City will procure solar electricity by entering into a Power Purchase Agreement (PPA). A PPA with a
third-party provider is preferable to direct purchase and ownership of the solar photovoltaic (PV) system
because it does not require a large capital outlay. A PPA does, however, give the City the option of
ownership through buyout at the end of the contract period. A PPA further mitigates ownership risk to
the City by eliminating performance degradation risks, design and construction contingencies, and
ongoing maintenance.
Overview of Power Purchase Agreement
The selected PPA contractor will provide all capital (photovoltaic equipment, installation) and O&M
related activities (power monitoring and equipment maintenance), while the City will provide the
necessary land and roof access at the treatment plant site. The parties will negotiate a price at which the
City would purchase the power back from the solar operator. The City plans to cover the existing
filter/sedimentation basin and the new membrane building with a solar photovoltaic system. The
combined 37,700 square feet will provide enough space to support a photovoltaic system of
approximately 322 kW producing approximately 400,000 kWhs, as described below. Future expansion of
the photovoltaic system is planned as the plant increases in capacity.
A typical PPA lasts for 10 to 20 years. The City can either renew the PPA or “buy out” the remaining
value of the system, thereby taking ownership of the equipment and ending the contract arrangement
with the provider. The PPA provider will install the PV system with no capital cost to the City. The
provider will coordinate financing for the project and will design, construct, operate and maintain the
system for the duration of the agreement. The energy from the project will be sold to the City at a fixed
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