“Because the wind blows during stormy conditions when the sun does not shine and the sun often shines on calm days with little wind, combining wind and solar can go a long way toward meeting demand, especially when geothermal provides a steady base and hydroelectric can be called on to fill in the gaps.” – Mark Z. Jacobson and Mark A Delucchi, Scientific American, November 2009.There’s no doubt that renewable energy has enjoyed great support from a wide range of groups, ranging from homeowners to businesses to schools and governments. Many are taking advantage of development and tax incentives along with the remarkable drop in cost of photovoltaic (PV) solar.
For example, the International Energy Agency (IEA) reports that in 2014, $112B of subsidies were available for renewable energy globally. Although it was recently reported by BP that only 2.5% of the world’s electricity is from renewables, the trend indicates that it’s feasible that in the future, renewables will be able to meet a good portion of electricity demand.
Ah…but with all new technologies, circumstances arise that are unforeseen and renewables are no exception. Examples include growth of solar in China to a point that the country now has significant overcapacity and wind development in Texas, which has resulted in utilities having to give away power because of excess generation.
Another is the price of electricity has steadily decreased, which has made it hard for traditional base load assets to keep operating profitably. Many see this as a positive development, but without a viable alternative to make up for intermittency, this can lead to overall grid instability, something counter to the goal of utilities to provide both affordable and reliable power.
In the longer term, utility scale batteries are the missing link, like the ones being installed by AES in Southern California. However, until they come down the cost curve, other measures are needed. Changes to the pricing structures developed in the 1990s and early 2000s that assumed coal plants are base loaded are a start. Another change should be providing capacity payments in more markets to support both fossil and nuclear plants.
The changing energy mix is complex with many moving parts. As new technologies make their way to the mainstream that address supply intermittency, things will steadily improve. Until then, tried and true nuclear and coal plants need to remain in the generation mix to ensure that power remains both inexpensive and reliable.
From Jim: You can connect and interact with other electrical power generation experts in the Power group in the Emerson Exchange 365 community.