That's a good point. It's similar to the situation with coal.
  Coal = 39% Natural gas = 27% Nuclear = 19% Hydropower = 6% Other
  renewables = 7% Biomass = 1.7% Geothermal = 0.4% Solar = 0.4%
  Wind = 4.4% Petroleum = 1% Other gases < 1% Coal is King. It's
  #1. Nuclear produces 19%. We can talk about replacing them
  but... with what? If you can't build newer facilities that are
  safer and more efficient, you're stuck with the old ones
  crumbling and just look at the low numbers for the renewables? I
  think we need better 'stop-gap" measures because renewables
  aren't there yet. Haven't been there. Aren't there, yet
  preventing upgraded facilities of proven technologies because of
  public opinion makes it hard. Any transitioning to cleaner
  energies needs long spans of time. Replace some old nuclear
  plants with new efficient ones designed to last 50 years. Give
  50 years for the other technologies to catch up and do better.
  Give 50 years for more efficient batteries to be developed.