We cannot afford to delay the transition to renewable energy sources. There is much debate over how to do this. However, increasing research and real-world evidence show that it is a feasible and practical option.
A new study by an international team of researchers should help to settle the matter.
This study shows that most of the electricity needs in industrialized countries can be met using a combination of solar and wind power sources. However, it is important to make extra effort to install energy storage facilities for periods of intermittent production.
The researchers examined the energy consumption of 42 countries over 39 years (1980 to 2018) and were able to calculate how an increase in solar energy power could meet the needs of nations from Afghanistan through Zimbabwe.
Steven Davis, University of California, Irvine (UCI) says that wind and solar could meet more then 80 percent of the demand in many locations without excessive storage or excess generation capacity. This is the critical point.
"But, depending on where you live, there might be multiple days throughout the year when some demand may need to be met with energy storage and other nonfossil fuel energy sources in a future that is zero-carbon.
The study shows that renewable energy systems can meet the needs for the countries studied even without having any energy storage. Wind power is leading the charge. You can add 12 hours of energy storage to the equation and it will increase to 83-94% of the time with solar becoming the dominant energy source.
This assumes that countries are committed to producing enough solar and wind energy to meet their needs. The focus of this study is on the reliability and dependability of renewables, rather than how much power they can produce.
As with sunlight and wind, electricity needs of people change over time. Because they could rely on sunlight for a larger portion of the year, modeling showed that switching to sustainable power would be easier for countries at lower latitudes.
According to researchers, smaller countries located at higher latitudes (e.g. Germany) would be more likely to turn to their backup energy sources more frequently. These issues could be minimized by long-term storage or pooling sources (e.g. solar from Spain and wind coming from Denmark).
"Historic data shows that countries farther away from the Equator can sometimes experience periods of 'dark don'ts' when there is limited solar and wind power availability," said Dan Tong, Earth system scientist at Tsinghua University.
"A recent German occurrence of this phenomenon lasted two weeks. Germans had to resort to dispatchable generator, which is often provided by fossil fuel-burning power plants."
To give an example, in the United States, wind and solar could account approximately 85 percent of total electricity consumption. This number could be increased by adding storage methods such as batteries to increase capacity and connecting to other countries in North America.
The researchers state that each country will have to approach it differently depending on its resources and location. These assumptions include perfect electricity transmission and no wasted energy. Annual generation must also be equal to annual demand.
These models provide a framework for how we can achieve a sustainable, zero-emissions energy system around the world.
Davis states that there are definite geophysical limitations on the ability to generate net-zero carbon electricity around the globe.
It comes down to the distinction between the possible and impossible. Although it will be difficult to eliminate all fossil fuels from our power plant mix, we can make that happen if technology, economics, and socio-political will align.
Nature Communications published the research.