There are a couple things to consider here: Energy required, quality of that energy, replacement rate, and consistency.
First off, those energy scenarios mentioned here (Unrealistic and crippling energy scenarios), show that through using purely renewables, we will have to also reduce our energy consumption to meet Greenpeace’s 2050 77% renewable goal. This calls into question the amount of energy that can be produced. It’s like taking your phone battery and reducing its charge time. If we are able to harness this limitless energy, but have to restrict or reduce people’s available energy, it doesn’t seem like a good plan.
Quality in this sense is energy for industrial applications. They use a lot of heat energy and need it year round and 100% reliable. Otherwise they can’t make soda bottles, cellphones, cars, and the list goes on. Solar will heat salt to then heat water to turn a turbine for longer reaching power generation, but the logistics of transporting molten salt from isolated regions that are ideal for solar is just not practical at all.
Replacing renewable sources will be an issue. Solar and wind lose about 50% efficiency after around 25 years. This means that they need to be replaced twice to match current lifetimes of a nuclear plant. So, it’s more than a matter of building new renewable plants to power things. After a point, they’ll be replacing instead of creating, and then disposal of solar panels is an issue (click here to see the issues with that).
One of the biggest things people talk about is the consistency of renewables. Wind doesn’t work without wind; it fluctuates with it as well. Solar doesn’t operate for the majority of the 24-hour day, and has to be constantly cleaned to maintain efficiency, like trying to watch a movie through a clean window versus one with hand prints all over it. Combining the two helps make this less of an issue. But what about a cloudy day with no wind?
We like wind and solar; they have their place in the fight against fossil fuels. But bringing in Gen IV nuclear mitigates all of the points mentioned. The amount of energy that can be produced by nuclear doesn’t restrict any day-to-day activities. Their ability to be placed anywhere makes their heat energy (thermal energy) easily accessible. Nuclear is built to last; they’ll update or replace parts on a rotating basis as needed making them last as long as their needed. And they can run 24/7 at the same output, rain or shine, just like the post office.
So, coupled with nuclear, they can keep growing and be the main source of power in places and supplement in others. At least until they run out of silver and tellurium, which we talk about here.
Partanen, Rauli, and Janne M. Korhonen. “Is “Wishing for the Best” Really the Only Plan?” Climate Gamble: Is Anti-nuclear Activism Endangering Our Future? Finland: Rauli Partanen & Janne A. Korhonen, 2015. N. pag. Print.