SAN FRANCISCO, April 9 (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."
