Page 120 - Sustainable Cities and Communities Design Handbook

Renewable Energy: Scaling Deployment in the United States Chapter j 5 97

ADVANCED RENEWABLES DEPLOYMENT
Through the experience of deployment and the engineering breakthroughs of
the laboratory, renewable energy technologies have over the last decades
steadily improved in terms of performance (efficiencies, capacity factors) and
economics (capital costs). These iterative advances have brought renewable
energy technologies ever closer to shedding the long-held perception that they
are “alternative” energy sources.
Moving forward, in addition to the regular technological advance of
renewable energy devices, there are several measures and developments that
can further enhance the utility of renewable energy systems. Broadly, these
categories include building integration, vehicle integration, and hybrid
systems.

Renewables and Buildings
One of the fastest-growing segments of the solar industry is that of building-
integrated photovoltaics (BIPV). BIPV designs seek to replace and enhance
certain elements of a building, such as the roof, window overhangs, or walls,
with solar panels. This reduces both the materials cost of building construction
and the installation cost of the PV panels, and ensures that the PV panels will
be optimally situated on the finished structure. Passive solar building design
can also take advantage of solar energy, using windows and interior surfaces to
regulate indoor air temperatures.
Building-integrated wind designs have also been proposed and implemented,
but such arrangements have so far featured substandard turbine performance and
unappealing impacts on building inhabitants.

Vehicle-to-Grid Systems

Plug-in hybrid vehicles (PHEVs), which feature both internal combustion
engines and electric motors, have the potential not only to reduce the con-
sumption of petroleum products but also to facilitate greater penetration of
renewable power sources. The electric battery in PHEVs can both be
charged by and discharged into the electric grid, turning the car into a
mobile, distributed electricity storage device. This storage capability is
thought to be of particular benefit to wind turbines, the power output of
which is generally greatest at night when the demand for electricity is the
lowest. PHEVs would allow for higher penetrations of wind power than
might otherwise be economically viable, storing excess generation at night
and dispatching that electricity to meet greater loads during the day. An
intermediate step in the vehicle-to-grid system might be a vehicle-to-home
approach, wherein electricity is delivered to a household through a direct
connection with a PHEV.