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SAN FRANCISCO, (Xinhua) -- A
team from University of California, Berkeley, and Lawrence Berkeley National
Laboratory has used resource mapping tools and assessed the potential for large
solar and wind farms in 21 countries in southern and eastern Africa, concluding
that renewable energy has robust future in much of Africa.
The countries
studied, from Libya and Egypt in the north and along the eastern coast to South
Africa, include more than half of Africa’s population.
“The
surprising find is that the wind and solar resources in Africa are absolutely
gigantic, and something you could tap into for relatively low cost,” said senior
author Duncan Callaway, a UC Berkeley associate professor of energy and
resources and a faculty scientist at Berkeley Lab.
Duncan
Callaway added that “but we need to be thinking now about strategies for
fostering international collaboration to tap into the resource in a way that is
going to maximize its potential while minimizing its impact.”
With solar
and wind farms, and international sharing of power, most African nations could
lower the number of conventional power plants—fossil fuel and hydroelectric—they
need to build, thereby reducing their infrastructure costs by perhaps billions
of dollars.
The team set
out to understand where wind and solar generation plants might be built in the
future under a range of siting strategy scenarios, and how much renewable
generators might offset the need to build other forms of generation.
Based on the
team’s analysis, choosing wind sites to match the timing of wind generation with
electricity demand is less costly overall than choosing sites with the greatest
wind energy production.
Assuming
adequate transmission lines, strategies that take into account the timing of
wind generation result in a more even distribution of wind capacity across
countries than those that maximize energy production.
The
researchers say both energy trade and siting to match generation with demand
reduces the system costs of developing wind sites that are low impact, that is,
closer to existing transmission lines, closer to areas where electricity would
be consumed and in areas with preexisting human activity as opposed to pristine
areas.
“Together,
international energy trade and strategic siting can enable African countries to
pursue ‘no-regrets’ wind and solar potential that can compete with conventional
generation technologies like coal and hydropower,” said UC Berkeley graduate
student Grace Wu, who conducted the study with fellow graduate student Ranjit
Deshmukh.
Wu and
Deshmukh, the lead authors of a study published online in the journal
Proceedings of the National Academy of Sciences, gathered previously unavailable
information on the annual solar and wind resources in 21 countries in eastern
and southern Africa, and hourly estimates of wind speeds for nine countries
south of the Sahara Desert, and developed an energy resource mapping framework,
which they call Multi-criteria Analysis for Planning Renewable Energy, or MapRE,
to identify and characterize potential wind and solar projects.
They then
modeled various scenarios for siting wind power and examined additional system
costs from hydro and fossil fuels.
The team
concluded that even after excluding solar and wind farms from areas that are too
remote or too close to sensitive environmental or cultural sites, or what they
term “no-regret” sites, there is more than enough land in this part of Africa to
produce renewable power to meet the rising demand, if fossil fuel and/or
hydroelectric power are in the mix to even out the load.
Nevertheless,
choosing only the most productive sites for development, namely the windiest and
sunniest, would leave some countries with little low-cost local renewable energy
generation.
If, however,
countries can agree to share power and build the transmission lines to make that
happen, all countries could develop sites that are low-cost and accessible, and
have low environmental impact, while reducing the number of new hydro or fossil
fuel plants that need to be built.
“If you take
the strategy of siting all of these systems such that their total production
correlates well with electricity demand, then you save hundreds of millions to
billions of dollars per year versus the cost of electricity infrastructure
dominated by coal-fired plants or hydro,” Callaway was quoted as saying in a
news release. “You also get a more equitable distribution of generation sources
across these countries.” |
