Forecasting Solar Energy Costs Using Moores Law

Solar energy could get real cheap. Not a good time to own a coal plant. From this rough forecast it looks like fossil fired power generation is not going to be cost effective much longer. Wikipedia: Moore's law integrated circuit (density) doubles approximately every two years. Forbes, Oct 8, 2015, Wind And Solar Energy Technologies Eat Into Fossil Fuel Power's Business Plan by Mike Scott in UK and Germany cost is $106/MWh for coal. $122 for solar. Using Moore's Law I made a crude forecast for solar energy costs. Should we moth ball some fossil fuel plants?