Grid storage has historically been cost prohibitive. However several big energy players are working with the auto industry to re-purpose
used batteries from EV's and hybrids which is driving the cost of grid storage down making it more economically feasible.
You are correct that nuclear is the way to go based on existing technology but the NIMBY attitude is so strong getting them built anywhere is a monumental task and even if they get built face continuous resistance and scrutiny on a much larger scale than solar or wind.
If this product can produce a fraction of the claims it makes
it will still be seen as a win for MoDOT.