Page 252 - Solar Power in Building Design The Engineer's Complete Design Resource

222 CALIFORNIA SOLAR INITIATIVE PROGRAM

All equipment such as PV modules, inverters, and meters sold by equipment sellers
must be UL approved and certified by the California Energy Commission. All equip-
ment provided must be new and have been tested for at least a period of 1 year. Use
of refurbished equipment is not permitted. Note that experimental, field demonstrated,
or proof-of-concept operation type equipment and material are not approved and do
not qualify for a rebate incentive. All equipment used therefore must have UL certifi-
cation and performance specifications that would allow program administrators to
evaluate equipment performance.
According to CEC certification criteria, all grid-connected PV systems must carry
a 10-year warranty and meet the following certification requirements:

■ All PV modules must be certified to UL 1703 standards.
■ All grid-connected solar watt-hour meters for systems under 10 kW must have an
accuracy of ±5 percent. Watt-hour meters for systems over 10 kW must have a
measurement accuracy of ±2 percent.
■ All inverters must be certified to UL 1741 standards.

PV System Sizing Requirement

Note that the primary objective of solar power cogeneration is to produce a certain
amount of electricity to offset a certain portion of the electrical demand load.
Therefore power production of PV systems is set in a manner as not to exceed the
actual energy consumption during the previous 12 months. The formula applied for
establishing the maximum system capacity is:

Maximum system power output (kW)
12 months of previous energy used (kWh)
=
(0.18 × 8760 h/yr)

The factor of 0.18 × 8760 = 1577 h/yr can be translated into an average of 4.32 h/day
of solar power production, which essentially includes system performance and derating
indexes applied in CEC photovoltaic system energy output calculations.
The maximum PV system size under the present CSI incentive program is limited
to 1000 kW or 1 MW; however, if the preceding calculation limits permit, customers
are allowed to install grid-connected systems of up to 5 MW, for which only 1 MW
will be considered for receiving the incentive.
For new construction where the project has no history of previous energy con-
sumption, an applicant must substantiate system power demand requirements by engi-
neering system demand load calculations that will include present and future load
growth projections. All calculations must be substantiated by corresponding equip-
ment specifications, panel schedules, single-line diagrams, and building energy simu-
lation programs such as eQUEST, EnergyPro, or DOE-2.