Page 150 - Alternative Energy Systems in Building Design

126 SOLAR POWER SYSTEM PHYSICS AND TECHNOLOGIES

the small commercial rebate to 30 kW per user per meter, whereas the Los Angeles
Department of Water and Power caps it at a maximum of 300 kW per user per meter,
and Southern California Gas and Southern California Edison limit the cap to 1000 kW
per user address or meter per year. It is suggested that solar power design engineers,
before commencing their designs, should familiarize themselves with the specific
requirements of energy service providers.
Additional documents that must be provided with the rebate application form are as
follows:

■ Electrical power system single line diagrams that show solar power PV arrays, dc
combiner boxes, inverters, ac combiner boxes, conduit sizes, feeder cable sizes and
associated voltage drops, solar power fused service disconnect switch, solar power
meter, and the main service switchgear solar disconnect circuit breaker
■ Total building or project electrical demand load calculations (TBDL)
■ Calculated percentage ratio of the total eligible rebate watts: (TERW/TBDL) × 100
(This figure is required to confirm that the overall capacity of the solar power
cogeneration system does not exceed 125 percent of the total project or building
electrical demand load.)

In order to protect the client and avoid design error and omission liabilities, it is sug-
gested that all documents and calculations be prepared by an experienced, qualified,
and registered electrical engineer.

Solar Power System Deployment

Previous sections covered the basic concepts of solar power system design, reviewed
various system configurations, and outlined all major system equipment and materials
required to implement a solar power design. This section discusses a number of solar
power installations that have been implemented throughout the United States and
abroad. The broad range of projects reviewed includes very small stand-alone pumping
stations, residential installations, solar farm installations, large pumping stations, and
a few significant commercial and institutional projects. Prior to reviewing these solar
power projects, design engineers must keep in mind that each solar power system
design presents unique challenges, requiring special integration and implementation,
that may not have been encountered before and may recur in future designs.

DESIGNING RESIDENTIAL SOLAR POWER

A typical residential solar power system configuration consists of solar PV panels, a
collector fuse box, a dc disconnect switch, some lightning-protection devices, a charge
controller for a battery (if required), an appropriately sized inverter, the required number
of PV system support structures, and miscellaneous components such as electrical con-
duits or wires and grounding hardware. Additional expenses associated with the solar
power system will include installation labor and associated electrical installation permits.