Trajectory of renewable energy policies depends on “price gap”: Learning from photovoltaic energy policies lead to “grid parity”

Renewable energies cloud reduces the GHG emissions. However, renewable energies have “price gap” of electricity between renewable energy and grid power. Thus, government policies are important to lead to “grid parity.” The renewable energy policies in Japan and Europe were analyzed. As the results, I found that the policies depend on the “price gap” between renewable energy and grid power. I propose “price gap” dependence model of the renewable energy policies. In the case of large “price gap”, the R&D support policy is most important to reduce the electricity price from the renewable energy and reduce the “price gap” as Japanese “Sunshine Project.” In the next step of middle “price gap”, “subsidy policy” and “net metering” are effective policies to enhance the renewable energy as the case of Japanese government and NEF. After the “price gap” ratio reduces to two or three, the Feed-in tariff (FiT) policy is most effective to lead to the “grid parity” as European and Japanese FiT. However, the “hard landing” FiT policy led PV market to shrink and exhaust in Europe. Thus, the important point of FiT policy is “soft landing” which smoothly leads to “grid parity” keeping the sustainable society, PV market and industry.