Parking Lot or Power Plant?
by Alison Pernell
Close to half of the urban landscape in the United States is dedicated
to automobiles ® about 20% reserved for parking alone. With land
becoming an increasingly scarce resource, attention has turned toward
making parking lots more productive urban features, serving multiple
functions rather than only providing space for cars that sit idle
95% of the time.
Parking lots provide an unparalleled opportunity for generating
clean, renewable energy through installation of photovoltaics (PV).
PV carports provide highly desirable shade for parked cars and can
help improve air quality by reducing parking lot temperatures, thereby
reducing hydrocarbon emissions from gasoline that evaporates from
leaky fuel tanks and worn hoses.
The abundance of large parking lots can be considered a resource,
as these sites are particularly well suited for large-scale PV installations
that support goals of municipal energy independence.
In an October 2000 study for the LGC, the National Renewable Energy
Laboratory reported that buildings owned by California local governments
have the capacity to generate nearly 200 MW of solar electricity.
However, the capacity for parking-lot installations is greater still.
For many “asphalt rich” communities, identifying a parking
lot with good solar potential can be easier than identifying a properly-oriented
roof with unobstructed solar access and the structural integrity
to support solar panels. This kind of “mixed-use” parking
provides the additional benefits of shade, public education, energy
reliability, and better air quality.
The mounting support structure itself can cost one to two dollars
per watt, according to Marianne Walpert of Schott Applied Power.
The additional cost of the PV system can be offset, however, by
charging for sought-after covered parking spaces, using public-private
partnerships that maximize incentives, and wrapping the installed
system cost into long-term financing.
 Sacramento
The largest parking lot solar system in the world is located
at Cal Expo, in Sacramento. The 540-kilowatt system produces enough
energy to power about 180 homes. The solar arrays, mounted on solar-tracking
devices, provide shaded parking for 1,000 cars and serve as a stunning
display of parking lot PV potential. The energy produced by the
arrays is fed into Sacramento Municipal Utility District’s
(SMUD) grid, for distribution to its Greenergy customers.
In partnership with SMUD, Arden Fair Mall recently announced plans
to build the largest commercial solar project in Sacramento County.
The two-part project includes installation of pliable solar panels
that will be installed on the mall’s roof by rolling them on
like traditional roofing material. A separate installation will
include a 66-space PV carport with improved appearance, making it
suitable for a retail environment. The shaded parking structure
will be used for valet parking – free to the utility district’s
Greenergy customers. The 30 kW carport will be highly visible along
busy Arden Way, and demonstrates the leadership role the mall has
taken with solar energy.
Through a creative partnership, the mall will pay for the support
structure and SMUD will install the solar panels and retain the
electricity. The mall benefits by greening its image and supplying
valet parking to customers. Arden Fair will own and use the 37 kW
rooftop installation to diversify its power supply.
Riverside
The Riverside Utilities Operations Center is providing shade for
152 parking spaces with a new solar carport. The 113-kW PV array
generates clean, renewable energy that helps reduce afternoon peaking
demand and reduces the City’s dependence on outside electricity
sources.
The carport’s graceful cantilever design provides maximum
unobstructed space for vehicles and a unique, aesthetically pleasing
look.
The grid-tied application was completed in October 2001 under contract
with Schott Applied Power Corporation. Riverside Electric Utility
is also pursuing other opportunities for large-scale PV installation.
Fairfield
Completed in July 2001, the Fairfield Transportation Center
integrates sustainable building principles, optimized building orientations,
durable building materials, daylighting, super-insulation, and electric
vehicle solar charging ports. A 2.6 kW PV array is included as an
architectural element to make a public statement that there are
sustainable alternatives to the internal combustion engine. The
PV system powers four electric vehicle charging ports and sends
excess power back to the grid.
Fairfield plans to leverage state incentives to implement the second
phase of the project – PV shade structures for 175 parking
spaces immediately adjacent to the new transportation center. The
City also has ambitious plans to install a PV parking structure
designed to shade over 500 parking spaces off Red Top Road, at the
intersection of Interstate 80 and 680.
State government goes solar
California is taking a lead in incorporating PV into government
facilities. The Capitol Area East End complex – California’s
largest and greenest state facility to date – includes Building
Integrated Photovoltaic (BIPV) and a PV carport. The five-city-block
project incorporates 28 kW of thin film PV technology into vertical
screens that hide rooftop equipment. The 21 kW PV carport shades
the top level of the 750-space parking structure.
The East End complex is the first state facility to incorporate
sustainable elements, as ordered under Governor Davis’ Executive
Order D-16-00 that sets forth a goal of sustainable building practices.
The complex is featured in Building Better Buildings: A Blueprint
for Sustainable State Facilities as a “leadership building”
that serves as a prototype for state agencies.
Other features of the 1.5 million-square-foot complex include recycled
and reused building materials, water-efficient technologies and
daylighting. Designed to exceed 1998 Title 24 standards by 30%,
the project will result in approximately $400,000 annual energy
savings.
Recent legislation supports renewable energy on state facilities
and parking lots. Senate Bill 82 (Murray), signed into law in October
2001, requires installment of PV on all state buildings and parking
facilities no later than January 1, 2007, where feasible. It also
requires PV to be installed, where feasible, as part of the construction
of all state buildings and parking facilities commenced after December
31, 2002.
In pending legislation, Senate Bill 532 (Sher) would create the
California Renewables Portfolio Standard to increase the amount
of renewable energy in the state’s energy portfolio from 10%
to 20% by the year 2010.
| Back | Next
|
|
