Interesting that the second graph you're referencing is not energy price - it's LCOE, or levelized cost of energy. It's an more of an estimation of profitability that very strongly depends on discount rate which is chosen more or less arbitrarily. Lazard for example chooses it at around 10% which basically means each year the energy from given facility is 10% worth less - which makes no sense for an power plant that can work for 50 years... but makes sense for investors.