Excessive utilization of non-renewable sources results in emission of greenhouse gases. Moreover, limited availability of non-renewable sources has posed a serious issue of prudently managing them. Having said that, the optimum utilization of renewable sources is the need of the hour. This would offer clean power and save non-renewable sources for future generations. Identifying the need to utilized renewable sources in abundance, a lot of cities and states in the U.S. have proposed or passed a bill to generate electricity through solar and wind energy in the next few decades. Though it feels like a sensible thing to do considering the limited availability of non-renewable source, researchers think otherwise. It appears that relying entirely upon renewable sources and rejecting all the sources that produce greenhouse gases would turn out to be expensive and difficult.
In a recently published research in The Journal of Energy & Environmental Science, researchers outlined that solar and wind energy could fulfill 80 percent of the annual electricity requirements of the U.S. They also stated that enormous investments for storage and transmission of energy during blackout days are needed. On the other hand, if the entire reliance is to be practiced, massive investments for building additional solar and wind farms are required. Moreover, investments would go up if more storage and transmission plants are built. This will be very expensive as per the current costs.
Along with increase in investments to build power plants, there is a basic problem. The wind does not always blow, and the sun does not always shine. So, total reliance on these sources would scale up the costs to create backup for storing excess energy during sunny and windy days. In addition, massive storage systems are required to store energy for days or weeks. Building storage systems will not alone solve the problem. Building huge transmission routes are also necessary if backup in one state is not enough and other state needs to transmit the stored energy.
Taking the cost required into consideration, storage systems and transmission lines are incredibly pricey. Batteries to be used in storage systems are very expensive. Moreover, pumped hydroelectric can be used only at specific geographical locations as set of reservoirs are required at different heights. Transmission routes are expensive to build and will take years to get approval. To fulfill 80 percent demand of electricity with wind and solar energy in the U.S., a nationwide high-speed transmission system is required along with electricity storage of 12 hours. This will cost more than $2.5 trillion.
The research also found that fulfilling electricity needs with 99.97 percent reliance on renewable sources requires building storage systems with storage of 12 hours along with twice the amount of generation of renewable energy. Nathan Lewis, a chemist at the California Institute of Technology and co-author of the study, said in an e-mail, “Policy makers would be well advised to consider the data and trade-offs that result from this type of data analysis before adopting policies or mandates for a 100% wind/solar grid.”
The argument over the entire reliance on renewable energy heats up as Mark Jacobson from Stanford University stated that countries can make transition to renewable energy affordably. Different opinions have been expressed on the utilization of renewable energy, but only time will tell how renewable energy will serve the energy needs of the world.