Complex sentence: Photovoltaic prices have fallen from $76.67/Watt in 1977 to an estimated $0.36/Watt in 2014, for crystalline silicon solar cells, however, cost per watt is a poor way to compare actual life-cycle costs of energy sources, as explained above.
Split into simpler sentences: Photovoltaic prices have fallen from $76.67 per watt in 1977 to an estimated $0.36 per watt in 2014, for crystalline silicon solar cells. However, cost per watt is a poor way to compare actual life-cycle costs of energy sources, as explained above.