In a paper published recently in Nature Communications, the authors, including experts from China's Tsinghua University, said that most of the current electricity demand in advanced, industrialized nations can be met by some combination of wind and solar power. "Wind and solar could meet more than 80 percent of demand in many places without crazy amounts of storage or additional generating ability, which is the critical point（临界点）, "said co-author Steve Davis, UCI professor of Earth system science, "if we want to have a zero-carbon emission（排放）future without using fossil energy resources".
The team analyzed 39 years' worth of hourly energy demand data from 42 major countries to evaluate the adequacy of wind and solar power resources to serve their needs. They found that a full shift to sustainable power resources can be easier for lower-latitude（低纬度的）countries, which can rely on solar power availability throughout the year. The researchers highlighted Germany as an example of a relatively smaller country, in terms of land mass, at higher latitude which will make it more challenging to meet its electricity needs with wind and solar resources.
"Historic data show that countries which are farther from the equator（赤道）can occasionally experience periods during which there is very limited solar and wind power availability, "said lead author Dan Tong, assistant professor of Earth system science at Tsinghua University. "One recent occurrence of this phenomenon in Germany lasted for two weeks, forcing Germans to turn to dispatchable（可调度的）generation, which in many cases is provided by fossil fuel-burning plants. Among the approaches the researchers suggested to alleviate this problem are building up generating capacity, developing long-term storage capabilities and pooling resources of multiple nations on a continental land mass to make the burden lighter to a certain country.
"Europe provides a good example to help people produce net-zero carbon electricity, "said Tong. "A lot of consistency and reliability could be provided by a system that includes solar resources from Spain, Italy and Greece with plentiful wind available in the Netherlands, Denmark and the Baltic region.
