from $76/watt in 1977 to $0.36/watt in 2014 from $76/watt in 1977 to $0.36/watt in 2014 from $76/watt in 1977 to $0.36/watt in 2014 from $76/watt in 1977 to $0.36/watt in 2014 100% renewable energy 48 cents per watt