In parallel with short-term electricity supply issues, the DPJ administration began to review the country’s mid- to long-term energy policies in May 2011. They focused on how to deal with the nuclear power industry and began investigating the potential of alternative, renewable energy sources such as wind and solar, even though those power sources were not used widely in Japan at that point. Further, combined cycle power plants and highly efficient gas turbines are among other technologies that play a role in the energy mix. During its many decades in power, the Liberal Democratic Party (LDP) had been a consistent proponent of nuclear energy. When the LDP fell from power in 2009, the DPJ, riding a wave of public popularity, gained the leverage to make major changes in national policies.