Future technology could mitigate some of the challenges associated with electricity generation technologies going forward. For example, gas turbines integrated with battery backup enable contingency reserve without fuel burn, helping turbines to operate in ways they could not in the past.
The intermittent challenges of renewables could be mitigated by the development of affordable, large-scale energy storage. PJM Interconnection in California has proven that this is possible, albeit on a relatively small scale compared to the wider US electricity market. Other technologies such as demand-side response and smart meters are also changing the way energy is consumed.
Nevertheless, demand is expected to grow globally, and the EPRI model shows that a diverse energy mix will be needed.
There is no one golden energy-generation technology that can provide reliable and cost-effective electricity with as little environmental impact as possible. When considering an electricity generation portfolio, diversity of supply and maintaining a balance should be a priority.
The UK, for example, represents a diverse and balanced energy mix with 30% natural gas, 22% coal, 21% nuclear, and around 25% renewables, according to Energy UK. The rest comes from interconnectors in Europe.
Natural gas—with its faster start-up times and lower emissions—can help balance out the intermittent nature of renewables. However, in regions where natural gas isn't widely available, but there is an abundance of coal, coal-fired power plants may be a better option.
Depending on the area, coal will likely still be needed to ensure the reliability of baseload generation, even in a gas and renewables energy mix. If there is a need to balance out the negative environmental consequences of coal, fleets can add more wind and solar to the mix.
If capital investment is available and reducing emissions is a priority, then nuclear may be a better option than coal. It's also important to note that regional considerations, such as fuel availability, regulation, and air emissions targets, are important factors and can sway companies to invest in certain energy technologies over others.