Solar is cheapest in a similar way that fish is the cheapest food on an island.
If you only look at the days when catches are high then it is the cheapest method to produce food. If fish are your primary source of food, and every day you don't get enough you will have to eat expensive imported food, you food cost over the year can be quite high for a primary fishing nation. The fish will still be cheapest, but as a strategy it is somewhat expensive or carry a high risk of starvation.
Nations will build as much solar/wind as there is peak demand, because it is the cheapest energy when it produce. Nation will also build coal, oil and gas power plants in order to be there when those solar and wind aren't producing. Economically that is the cheapest way to produce a stable energy grid. Environmentally it is far from the best. Falling solar and wind prices reinforces this model.
If you only look at the days when catches are high then it is the cheapest method to produce food. If fish are your primary source of food, and every day you don't get enough you will have to eat expensive imported food, you food cost over the year can be quite high for a primary fishing nation. The fish will still be cheapest, but as a strategy it is somewhat expensive or carry a high risk of starvation.
Nations will build as much solar/wind as there is peak demand, because it is the cheapest energy when it produce. Nation will also build coal, oil and gas power plants in order to be there when those solar and wind aren't producing. Economically that is the cheapest way to produce a stable energy grid. Environmentally it is far from the best. Falling solar and wind prices reinforces this model.