A desirable energy mix is one that can supply reliable, clean energy and meet growing demand. Because each region in the world has unique resources, environments, and demands, each will have a unique optimal energy mix.
A region with a high population density and large industrial base will require dependable (dispatchable) energy sources, like those obtained from fossil fuels. A region with a low population density and limited industry, and with plentiful wind and solar, may benefit more from renewable technologies. There is no single energy source or mix that will be “the best” everywhere; the best energy mix for a given region is determined by the demand, resources, and the environment of that region, as well a public perception. Public perception is particularly important. For example, covering beautiful countryside with wind and solar is desirable for some, but untenable for others.
Even though there is no universal “best” energy mix, all regions benefit from having a diverse mix. A diverse energy mix capitalizes on the strengths of each of its contributing technologies and provides grid reliability and security. An analogy of this is a diverse investment portfolio. Investors often want a diverse portfolio: some stocks will be low-risk, modest gain, and these can be counted on to keep the portfolio value relatively steady during times of uncertainty. Other stocks will be high-risk, high gain, which have the potential for significant gain, but they may loose value or not be liquid when needed. A diverse energy mix of the future would be similar. Low- or negative-emissions fossil-fuel plants would supply a reliable, clean base-load, and renewables would provide emission-free energy, but with intermittency issues that must be managed. Supplying an electrical grid from multiple sources also increases the likelihood that adequate fuel supply will always be available, decreases the effects of malicious attacks on any one source of energy, and provides more options for restarting a grid after a blackout.
Technological diversity is especially important as we seek to decarbonize and expand worldwide electricity generation to protect our climate while meeting a growing demand. Developing a wide array of low- or negative-carbon technologies (clean fossil, wind, nuclear, solar, biofuels, etc.) increases the likelihood of breakthrough discoveries as we advance on our journey to sustainability. Technological diversity also allows us to develop a multitude of plans for a sustainable future, giving us the chance to choose the cheapest and most efficient route to carbon neutrality, and providing us technological flexibility in case of changes to our energy needs in the future.
To create an optimal energy mix for any given region, we must be willing to consider every energy technology available to us, and evaluate what benefits and drawbacks they bring to the energy supply. We must implement our technologies in ways that allow for the most efficient generation of clean and reliable energy, while having the least impact on our environment.