Page 140 - Sustainable Cities and Communities Design Handbook

Renewable Energies Technology and Smart Grid in China Chapter j 6 117

We need an interstate power transmission superhighway for the electric
power system. Immense solar power farms in the US deserts are facing the
transmission challenge for moving through the power grid to the consumers.
Congestion of the grid can create significant limitations that can reduce the
potential advantage of large renewable power generation to pump power into
the electric grid.
What limits the renewable energies (as a commercial bottleneck) is the
outdated power transmission grid as mentioned in the last section. For
example, the current system cannot accommodate the present and future needs
of delivering hundreds of megawatts of wind power to users. In one scenario,
the rebuilding of a total of 200,000 miles of power transmission may provoke
fights among 500 divided owners and numerous property owners. In another
scenario, the large power generation usually requires extra storage system. For
today’s market, there is no commercially advantageous solution yet. Active
development in the storage system area is underway.
The layout of the current power grid should be eventually accessible to a
flexible change of total power (e.g., gigawatts) for power interconnection and
transmission lines. The current transmission lines cannot increase their
transmission capability by hundreds of megawatts needed to meet the chal-
lenges. Power pumping shows up as challenges at times even over a distance of
a few hundred miles. The commercial pain is the severe congestion today for
long-distance power transmission.
We have to achieve clean tech or renewable energy vision. The Kyoto
Protocol has set a target that the world needs to reduce greenhouse gas
emissions by more than 25% by 2020, and by more than 80% by 2050 (Current
Goal). One of the solutions comes from an advanced energy technology, i.e., a
wind power generation that it is very cost effective for today’s commercial use.
Wind turbine manufacturing is cleaner than the volume production of solar
PV cells. Today the United States utilizes barely 1% of the power produced by
wind energy. Its goal is to achieve 20% from wind power by the year 2030
(DOE news, 2008). Wind power turbines of the Maple Ridge Wind Farm near
Lowville, NY, are capable of producing a total maximum of 320 MW. It has
been shutting down at times due to the limitations on pumping capacity of the
electric power system. The wind farms too are having power transmission
challenges. One cannot easily pump a large amount of power to the grid due to
various reasons that we will discuss later. In order for users to utilize the full
potential of wind power or other environment-friendly energy, it is imperative
for the nation to significantly improve or to rebuild a system of populated and
optimized transmission lines.
The wind power is a type of solar-induced energy. Wind is always present
on our planet due to uneven heating of its surface by the Sun and due to the so-
called Coriolis effect, which relates to the wind being dragged by the constant
rotation of Earth on its axis.