The crisis at the Fukushima No. 1 nuclear power plant has prompted the government to launch a seemingly radical rethink of Japan’s energy policy. On May 25, Prime Minister Naoto Kan announced that Japan will generate 20 percent of its electricity from renewable sources by the early 2020s, but without clearly saying that Japan will reduce its dependence on nuclear power and fossil fuels.
Currently, Japan imports nearly 80 percent of its energy supplies, and nuclear power accounts for 30 percent of the nation’s electricity generation. Renewable energy resources such as wind and solar account for only about 1 percent. When hydropower is added in, the total is about 9 percent.
The challenge of achieving the new target will be daunting, but a report released last month by the Intergovernmental Panel on Climate Change (IPCC) suggests that it is achievable. By mid-century, close to 80 percent of the world’s energy supply could be met by renewables if the right public policies are put into place, the report states.
The IPCC’s “Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN)” presents some encouraging findings about the state of renewable energies:
? Of the roughly 300 gigawatts of electricity generating capacity added worldwide from 2008-2009, nearly half came from renewable energy.
? The technical potential of renewable energy technologies exceeds global power demands by a significant amount, both globally and in most regions.
? More than 97 percent of the globally available renewable energy sources remains untapped, meaning that availability of renewable sources will not be a constraining factor.
Of the six key renewable energies reviewed in the report, bioenergy is the most popular, accounting for 10 percent of the current global energy supply, or 50 exajoules. Bioenergy technologies can generate electricity, fuels and heat from a variety of feedstocks.
While some bioenergies generate more greenhouse gas emissions than they save, the review notes that others, such as advanced conversion systems that convert wood waste into liquid fuel, can generate 80 to 90 percent reductions in emissions compared with fossil fuels. The review concludes that it could supply between 100 to 300 exajoules by 2050.
Solar energy contributes just a fraction of one percent of the global energy supply, but the SRREN notes it has the potential to become one of the major sources of energy supply by 2050 depending on continued innovation, supportive public policies and cost reduction.
In the most ambitious scenario, solar energy could account for as many as 130 exajoules per year, mostly through photovoltaic electricity generation.
Geothermal energy generates about 0.7 exajoule per year, but by 2050 it could supply roughly 5 percent of worldwide demand for heat and more than 3 percent of the demand for electricity. Hydropower produced 16 percent of the world’s energy supply as of 2008, making it the largest renewable energy source, and is expected to continue to grow, although its total share may decline.
Ocean energy technologies, which use the kinetic, thermal, chemical energies of seawater to produce electricity, are mostly at pilot project or demonstration phases, but could deliver up to 7 exajoules of power annually by 2050.
SSREN identifies wind energy as one of the most promising renewable technologies. Accounting for nearly 2 percent of the world’s power supply in 2009, wind energy capacity is growing rapidly in Asia, Europe and North America, and is expected to produce more than 20 percent of the global electricity supply by 2050.
While Mr. Kan did not go into details on how Japan would achieve the goal of producing 20 percent of its electricity from renewable energy resources by the early 2020s, he did state that the country would strive to reduce the cost of generating solar power to one-third of present levels by 2020, and to one-sixth by 2030. Solar power generation costs roughly ¥50 per kilowatt hour, compared with the ¥5 to ¥13 per kilowatt hour cost of nuclear and thermal power.
The prime minister set a goal of having solar panels placed on 10 million homes by 2030.
At least one astute businessman feels that solar power has great potential in Japan. Softbank Corp. President Masayoshi Son, who has called on the government to end its dependence on nuclear energy, announced at the end of May that his company is establishing a new subsidiary to build about a dozen large-scale solar-power plants on unused farmland in Japan, with construction starting this year.
Given Japan’s abundant waterways, woodlands, geothermal activity, energy experts also see hydropower, biomass and geothermal energy resources as capable of making substantial contributions to Japan’s future power portfolio.
But the presence of sufficient resources alone won’t guarantee results. To achieve its goal, the government needs to take several steps.
First, it must secure funds to promote the development of renewable energy sources.
Next, it must liberalize the power-distribution system to make it easier for people to buy electricity from small-scale power companies that use renewable energy sources.
And, finally, it must enact a bill that will obligate power companies to buy surplus electricity generated by renewable energy sources.