To say there has been a big push for renewable energy in the last 10 years would be an understatement. For various reasons outside the scope of this blog post, many would suggest the rapid closure of all coal-fired power plants. Thus filling the resulting generation gap with renewable energy. Others argue that a slower and more systematic approach to a shift from coal to renewable energy is needed. A solution that appeases both sides of the argument would be building Hybrid Power Plants.
A Hybrid Power Plant combines renewable energy (solar, wind) with thermal energy (coal, natural gas, nuclear). Why is this better? Renewables are great when the sun is shining or the wind is blowing. However, lack the output needed when these conditions do not occur. For instance, at night or on calm days. When production from renewables does not meet electrical system demand, thermal sources are used to make up the difference. It should be noted that another solution for those times is to use an energy storage solution such as batteries or a pumped storage plant; however, the installation of renewables is far outpacing the energy storage they require, forcing the increasing necessity of thermal energy generation.
Some examples of hybrid power plants include(2):
In order for this to be successful, some foresight is needed. It is estimated that the US will shut down 25% of the remaining coal plants in the US by 2029. If we get it wrong, shutting down those plants could result in an energy shortage, as some have forecasted – we cannot just turn them back on. Once a coal plant is retired, it is generally torn down or converted to fire on alternative fuel. Since the US has not built a new coal plant since 2013, once the coal plants are retired, they rarely come back.
Like all problems faced by the country, the environment, and society rarely does one solution fix the problem. Hybrid power plants use multiple solutions to fix the problem of climate change and the growing need for power in the US.