According to a recent joint University of Delaware and Delaware Technical Community College study, a well-designed combination of wind energy, solar energy, and storage in batteries and fuel cells would be a cost effective way of meeting electricity demands.
One of the main critiques of solar and wind energy is that these are intermittent sources of energy, generating electricity only when the wind is blowing or the sun is shining, respectively. This would thus create potential problems for utilities and grid operators who must keep the supply and demand for electricity in balance to meet the demands of the population.
However, a combined wind and solar plant may be the answer to this problem. Combining the the two resources in a single plant allows for a more efficient use of transmission lines and a more cost-effective way of generating electricity.
The authors of the study developed a computer model to consider all of the combinations – 28 billion to be exact – of renewable energy sources and storage mechanisms. The combinations were simultaneously tested over four years of historical hourly weather data and electricity demands from 13 states, which represents one-fifth of the country’s total electric grid.
Due to the fact that wind speeds and sun exposure vary with weather, location, and season, there had to be ways to improve reliability of these systems. Reliability in the model was achieved by expanding the geographic area of renewable generation, using diverse sources, employing storage systems, and burning fossil fuels as a backup – usually for the last few percent of the electricity needs when neither renewable or stored energy was available.
The study, published in the Journal of Power Sources, used estimates of solar, wind, and general technology costs in 2030, leaving out government subsidies – since they are unsure – to project the cost of renewables in 2030. The projected costs are about half of the current wind and solar costs, while maintenance costs would stay the same.
The authors then compared this cost to the costs of fossil fuel use, which includes both the estimated fuel cost and the known negative externalities, including human health hazards caused by air pollution, and found that the combined solar and wind plants would be more cost effective than using fossil fuels.
This project isn’t the first to realize that a combination of wind power, solar power, and storage could be a cost-effective solution to meeting high energy demands. For example, California also made this realization earlier this year.
Thanks to the combined legislation, policies, and citizen motivation, California became the top solar state in the country and San Diego solar panel installation has outreached any other city within the state. However, they still had to deal with the problem of solar power not being able to generate electricity all of the time. So in November 2012, California created its first wind and solar plant in the Tehachapi-Mojave region of Southern California.
The wind in California blows strongest at night while the sun is strongest during the day. The power generated in this project will supply San Diego solar initiatives with renewable energy to use in residential areas and businesses.
The Tehachapi-Mojave is just one example to support the findings of the joint UD and DTCC study. By 2030, when fossil fuels are expected to increase in price and decrease in amount stored in the world, renewable sources will need to come into play in order to meet energy demands. It is important to design and implement the projects so that when the country needs the power, it will be readily available.
Article by Jeana Brookes.