Powering Japan’s future (Wind, Solar, Hydro, Tidal, Geothermal, Biomass)

The pros and cons of Japan’s renewable energy options

Last year, Japan produced close to one quadrillion watt-hours of electricity — that’s 1 followed by 15 zeros. The vast majority of that — which translates into one billion megawatt hours (MWh) — came from coal, natural gas and nuclear power plants operated by 10 utilities that, only a few months ago, seemed unshakably powerful.

News photo

Now, though, Japan’s energy future looks quite different.

Following multiple meltdowns at the Fukushima Daiichi nuclear power plant since the Great East Japan Earthquake and tsunami on March 11, its operator, Tokyo Electric Power Co. (Tepco), the country’s biggest utility, is facing financial disaster.

Public support for nuclear power has also plunged, and climate change continues to cast a shadow over the prospect of more coal-fired plants.

This May, with politicians, pundits and protesters calling for safer sources of power, Prime Minister Naoto Kan proposed a goal of generating 20 percent of electricity from renewable sources by the early 2020s (the figure is around 9 percent today, including big hydroelectric plants). The Diet is currently debating legislation that would push the country in that direction.

But can Japan, with its politically-connected nuclear industry, uneven renewable-energy subsidies, and problem-ridden electricity network change fast enough to reach that target?

The answer, its seems, has more to do with politics and economics than technology or resources.

For instance, Weisheng Zhou, an energy policy specialist at Ritsumeikan University in Kyoto, was unequivocal in saying: “It’s a question of political will. Are we going to do this or not?”

Sven Teske, a member of Greenpeace’s International Climate and Energy Unit in Amsterdam, put it this way: “The main obstacle in Japan until now has been a lack of long-term policy in favor of renewables and their infrastructure.”

This is not the first time Japan has faced a major shift in its electric-power industry. In 1973, the country generated 73 percent of its electricity by burning imported oil. Then the oil shock struck. Prices skyrocketed, power companies shifted to other energy sources and, by 2008, just 12 percent of electricity came from oil, according to government statistics. For the most part, nuclear, coal and natural gas plants filled the gap.

Nuclear power in particular has been heavily subsidized. In 2005, 64 percent of Japan’s energy research and development funding went to nuclear energy, according to International Energy Agency data; renewable energy, at 7.3 percent, got even less than fossil fuels. Last year, the nuclear industry received about ¥430 billion in government funds, of which about ¥110 billion went to communities near nuclear plants, according to the Citizens Nuclear Information Center, a Tokyo-based anti-nuclear organization.

Over time, bureaucrats, politicians and academics became entwined in a powerful pro-nuclear bloc dubbed the “nuclear village.” Many say this has hindered the development of alternatives.

“The nuclear industry has had a lot of political power, so we haven’t been able to get support for major wave- or tidal-power plants,” said Takayuki Nakamura, an ocean-power researcher at Ehime University in Shikoku, who added that he has even joined projects in South Korea to benefit from that country’s more generous research-subsidy system.

Before the Fukushima disaster, 54 nuclear reactors sited at 17 plants supplied about 30 percent of all the country’s electricity. With 14 new reactors planned, nuclear power plants were set to comprise more than half of total power capacity by 2030. (35 reactors are currently idle.)

Meanwhile, despite some early government support, power from solar, wind, geothermal, biomass and hydropower plants with a capacity of 10 MW or less languished at 3.4 percent of the total electricity supply in 2009, according to a report by the Japan Renewable Energy Policy Platform; adding in large hydropower plants brings the figure to about 9 percent, according to government figures.

By last year, Japan was ranked 11th on a Pew Environment Group list of the world’s top investors in renewable energy, well behind the top three of China, Germany and the United States.

Investment is lagging in part because the renewable-power industry faces problems in the domestic market.

In Japan, utilities like Tepco control both the production and distribution of electricity. Hence operators of wind- or solar-farms must sell their electricity to these renewable-energy middlemen. While utilities are required to purchase a small percentage of their electricity from renewable sources (last year about 1.3 percent) — and must pay a premium price of ¥42 per kWh for excess electricity from home photovoltaic panels — they have no incentive or obligation to replace any more of their conventional power with alternatives.

Furthermore, the grid itself is built to handle centralized thermal and nuclear plants rather than distributed renewables (see accompanying article overleaf, “Distribution gridlock restricts renewables”).

Prime Minister Kan has proposed separating the existing power utilities into companies that produce electricity and ones that distribute it. But Norihiro Okumura, an economist with the Institute of Energy Economics, Japan, says a bigger problem — and one that legislators are currently trying to fix — is that renewable-power producers can’t get a high enough price for their electricity on the wholesale market, where they compete with cheap power from coal, natural gas and nuclear plants.

That’s partly because even though renewable-power costs are falling steadily, technology and production efficiency still need to be improved — and partly because conventional power pricing often conceals environmental and other costs.

According to estimates in a 2010 Agency for Natural Resources and Energy report, generating electricity from coal cost ¥5-¥6.5/kWh and from nuclear reactors, ¥4.8-¥6.2/kWh. Electricity from photovoltaic panels clocked in at ¥49/kWh and that from wind at ¥9-¥14/kWh.

The accuracy of those figures has been heavily criticized because they conceal subsidies and other costs (Ritsumeikan University economist Kenichi Oshima puts nuclear power’s true cost at over ¥12/kWh).

Everyone agrees, however, that renewables struggle in Japan’s current electricity market.

Okumura pointed out that the price balance will shift if ratepayers are forced to pay for the aftermath of the ongoing nuclear disaster and for improvements in nuclear safety. Up till now, the costs of cleaning up nuclear disasters, processing nuclear waste and combating global warming have been left out of both generating costs and electricity bills.

Legislation is currently being debated in the Diet to address some of these problems.

The proposed new law would require utilities to buy all electricity generated by renewable sources (except for solar power from residential roofs, of which utilities would only have to buy the portion not used at home). It would also introduce a feed-in tariff (FIT), requiring utilities to pay a premium price for electricity from solar, wind, geothermal, biomass, and small- and mid-scale hydro-electric plants. The premium would be passed on to utility customers. According to Ministry of Economy, Trade and Industry estimates, this would raise average home electricity bills by a scant ¥200 per month at most.

FITs are common throughout the world; a similar system recently helped Germany leap to the forefront of the solar market.

However, Spanish energy-policy expert and lawyer Javier Garcia-Lomas Gago warned that FITs must be carefully designed. In Spain, a government-funded FIT prompted a boom in the wind-power industry — followed by a crash when the government ran out of money to keep subsidizing it.

“A small policy flaw can create a huge problem in the market,” Gago said.

Japan’s FIT legislation faces opposition from politicians and industries concerned that the price of electricity will rise — and from those in the “nuclear village” who say nuclear reactors are cheap, clean, and reliable power sources. Many of those opponents, however, stand to lose influence and income if the market shifts toward renewables.

“They really are desperate to preserve their monopoly (on political power), no matter what the cost,” said Rikkyo University political economist Andrew DeWit, who has written extensively about Japan’s energy policy.

Nonetheless, in the long term both the economy and the environment may benefit from policies supporting renewable energy.

“Japan lacks fossil-fuel resources, but in 100 years (after we reach peak oil) the whole world will be in the same situation. If Japan really pushes for renewables now, it can lead down the road,” energy-policy expert Zhou said.

Wind

Current Status: Wind turbines provided 0.33 percent of Japan’s electricity in 2009, and by the end of last year, capacity was at 2,304 MW. Currently, all commercial turbines are on land, with most farms located in Hokkaido and the northern Tohoku region — which, along with Okinawa, have Japan’s strongest winds — and Kyushu. The largest wind farm to date has a capacity of 60 MW. Experimental offshore turbines have a total capacity of some 11 MW.

News photo
Towers of power: This Electric Power Development Co. (J-Power) wind-power station in Koriyama, Fukushima Prefecture, taps into an immense national resource. KYODO PHOTO

Potential: Japan’s wind resources are immense. Taking geography and existing land use into account, the Environment Ministry estimates that Japan has the potential to develop up to 300,000 MW of onshore and 1.6 million MW of offshore wind power. Even low-end estimates put potential wind-power capacity at 131,000 MW. (Japan currently has 281,000 MW of power-generating capacity, but to meet demand with wind power more would be needed, since wind turbines produce electricity less steadily than coal or nuclear plants). The Japan Wind Energy Association aims to increase capacity about twentyfold by 2020.

How it works: Wind spins blades mounted on a tower, which in turn spin a generator. Turbines range from micro (Japanese researchers recently developed a paper model that mimics the aerodynamics of dragonfly wings and produces enough electricity to power an LED light) to small (home windmills can power an off-the-grid lifestyle) to giant (British firms are working on a 10 MW monster with a rotor diameter of 275 meters). They can stand alone or in armies of over 600, and can be sited on land, offshore or even — in a still-in-development design — fly 300 meters up in the sky, where the strongest winds are.

Analysis: Wind energy has taken the world by storm in the past few years. It’s not only abundantly available, but it blows at night when solar panels are idle and can be almost as cheap to produce as coal- or oil-fired power. At present, though, it provides less than 1 percent of Japan’s electricity.

“Japan has lots of mountains so turbines are difficult to install, and we get five to six typhoons a year. Also, the electricity grid is centralized, but wind is scattered,” said Yukio Suguro, president of the Japan Wind Energy Association.

Finding a home for noisy, unsightly towers can be hard, too. As for offshore wind farms, a major area of development in other countries, Suguro said typhoons, strong currents, and big waves pose problems in Japan.

The solution, according to him? Improve the grid and boost technological research.

“Wind is our biggest potential resource. What we need is greater public awareness of environmental problems and more government support, including R&D subsidies, a feed-in tariff, and a requirement that utilities buy all the wind power we can generate,” he said.

Sunlight

Current Status: In 2009, solar panels provided a mere 0.26 percent of Japan’s electricity. Most panels were on home rooftops, and in 2009 their total generating capacity was 2,821 MW, or 1 percent of the nationwide total (solar panels only work when the sun shines, which is why actual generation is so much lower than capacity). Japan exports about half the photovoltaic (PV) cells it produces.

News photo
Self-help: Solar panels on domestic roofs in Ota, Gunma Prefecture. KYODO PHOTO

Japan does not have any concentrated solar power (also called solar-thermal-electric) plants, but last year Mitsubishi Corp. became partial owner of four plants in Spain, marking Japan’s first major step into the market.

Potential: Even in cramped, mountainous Japan, sites exist for installing a staggering 8 million MW-worth of solar panels, with most occupying unused land rather than roofs, according to a 2009 study by the New Energy and Industrial Technology Development Organization.

In contrast, a 2010 study by the Environment Ministry — which defined potential sites differently (excluding in-use farmland and industrial facilities, for instance) — found that only 100,000 to 150,000 MW could at this point be feasibly developed. Nonetheless, that still equals about half of Japan’s current total power capacity.

How it works: There are two ways to turn sunlight directly into electricity: by using PV cells or concentrated solar-power plants.

Most PV cells today consist of layered crystalized silicon that generates a current when struck by sunlight, but researchers are developing cells that use new materials and processes to lower costs. Some, such as “thin film” panels made from cadmium telluride instead of silicon, are already commercially competitive; others, such as cells that mimic the photosynthesis processes plants use to convert sunlight to energy, are still in the research stage.

Concentrated solar-power plants use mirrors or lenses to direct sunlight at a liquid, heating it to 300 degrees C or more. The hot liquid produces steam to turn a turbine; the heat can also be transferred and stored in molten salt or other materials for later use.

Analysis: For decades, Japan was the world’s leader in solar technology and installation. Starting in the 1970s, the government’s “Sunshine Project” subsidized the industry, and by 2005 Japan was producing half of the world’s solar panels. That year, however, subsidies were eliminated, and Japan quickly slipped behind in both production and installation.

It may be on its way back up. Installation subsidies were restored in 2009, along with a feed-in tariff requiring utilities to pay a premium for excess solar power from homes and businesses. Since the Fukushima nuclear disaster, solar has featured heavily in Prime Minister Kan’s calls for a new energy plan.

The private sector is getting involved too. SoftBank President Masayoshi Son has proposed a project to massively expand solar power by installing panels on unused agricultural land; so far 36 prefectures have joined the initiative. Political economist Andrew DeWit sees this as Japan’s best hope for a real energy revolution — if the efforts can overcome the government’s long-time bias toward nuclear power.

“You see a younger, IT-centered new Japan rising up in the crisis, but hitting the bottleneck of vested power interests ensconced in Nagatacho (the central Tokyo district where the Diet is located),” said DeWit, a professor at Rikkyo University.

Meanwhile, electricity from PV cells remains the most expensive power on the market.

“We need to cut costs and improve the efficiency of the cells, the systems and the factories, ” said the Japan Photovoltaic Energy Association’s Masaaki Kameda, whose organization aims to expand solar to make up 10 percent of Japan’s entire electricity capacity by 2030.

Biomass

Current Status: After hydroelectric plants, biomass is Japan’s renewable electricity powerhouse.

News photo
Waste not … : A biomass power plant. KAWASAKI BIOMASS ELECTRIC POWER CO., LTD.

The country has 190 generators at municipal waste incinerators, 70 other biomass power plants, and 14 that burn both coal and biomass. In 2009, they together generated 1 percent of the country’s total electricity and nearly a third of its electricity from renewable sources. More than half of that came from processing industrial waste, 40 percent from municipal waste, and 4 percent from “woody biomass” like trees and brush.

A 33 MW biomass power plant — which yields enough electricity to power 40,000 homes and is the largest of its kind in Japan — began operating in Kawasaki this February. It burns construction waste and other woody residue.

Potential: Generators have yet to be installed at 90 percent of Japan’s municipal waste incinerators. While the country lacks space for growing specialty biopower crops, 14 million tons of crop residue go unused each year. Millions of hectares of unthinned plantation forests offer another potential fuel source, since small trees must be removed for forest health but have little value as building materials.

How it works: Biopower is generated by burning, gasifying, or fermenting organic matter ranging from trees to garbage. Burning biomass (or mixing it with coal and then burning it) to produce steam and turn a turbine is the most common method used in Japan. By heating biomass under pressure, it can also be turned into gas to use in gas or steam turbines, often after a refining process.

Finally, in a process called anaerobic (oxygen-less) digestion, micro-organisms are used to break down manure, garbage or sewage, producing methane that can be burned in generators. Some large livestock farms use on-site anaerobic digesters to turn the huge amount of manure from their animals into a valuable electricity sou rce (critics point out that the residue can still contaminate the environment). Methane is also produced naturally by decomposition in landfills, and has been used to fuel power plants in the United States since the 1950s.

Analysis: Until recently, burning biomass was widely seen as being more sustainable than burning coal or oil. A number of recent studies, however, have questioned that assumption.

Biopower is considered renewable because the trees, cornstalks or other organic materials that are burned (or gasified) eventually grow back and can be harvested again for fuel. Similarly, while biomass emits carbon dioxide when burned, it is reabsorbed when plants grow back (the same cycle applies to coal and gas, but takes millions of years). The cycle’s sustainability, though, requires careful calculations regarding timing and land use.

A 2010 study by the U.S.-based Manomet Center for Conservation Sciences concluded that while burning trees rather than coal in electric-power plants could reduce greenhouse gasses in the long term, carbon dioxide emissions would exceed absorption for the first 30 years of forest re-growth (industry groups criticized the report because it did not consider the use of sawmill debris and other waste).

This February, a report from Japan’s Internal Affairs and Communications Ministry found that of 132 government-funded biomass projects, only 2 percent had calculated their greenhouse-gas impact. When the ministry did its own calculations, it found that 20 percent had no positive impact at all (the report was not limited to electricity projects).

Another obstacle to biopower is that while sun and wind arrive free of cost, organic materials must be transported to power plants for use. Drying materials before transport and building small local power plants both help, but costs can still exceed returns from electricity sales.

Geothermal

Current Status: Eighteen geothermal plants generated just 0.24 percent of Japan’s electricity in 2009. Japan has the eighth-highest installed geothermal capacity in the world, with a capacity of 535 MW, and it is the top producer of geothermal turbines.

News photo
Hot property: A geothermal power plant in Onikoube, Miyagi Prefecture. KYODO PHOTO

Potential: Hot-spring-rich Japan, located on the volcanically active Pacific “Ring of Fire,” has 33,600 MW of potential geothermal resources, according to an Environment Ministry study. However, most hotspots are in national parks, where regulations rule out development. Even so, the study estimates that 9,800 MW could be developed, and the ministry recently announced it may loosen restrictions to open up more sites.

Considering economic considerations and the 10-year time lag to build a new plant, however, Isao Matsunaga, president of the Geothermal Research Society of Japan, said that just 500 MW could realistically be running by 2020. That’s the equivalent of half the capacity of one nuclear reactor.

How it works: Naturally occurring radioactive materials continuously produce heat beneath the Earth’s surface. Water that filters into permeable rocks is turned to steam or is superheated by this energy (think hot springs), and can be used to spin a turbine.

To build a geothermal plant, a hole is drilled and a pipe inserted up to 3 km below the surface at a promising site. Where the underground rocks are very hot, steam rises through the pipe, turns a turbine, and is then returned to the Earth via another pipe (most Japanese plants use this system). Where hot water rather than steam is available, steam can be produced by reducing the water pressure. Still cooler water can be used to heat another liquid with a lower boiling point (such as butane), which produces steam. Newer technology called Enhanced Geothermal Systems could eventually tap the vast amount of heat in less-permeable hot rocks deeper below the Earth’s surface.

Analysis: Geothermal plants provide greenhouse-gas-free electricity around the clock, rain or shine — and Japan has both geothermal resources and the technology to develop them. Yet a new plant hasn’t been built since 2006’s geothermal add-on to Kyushu’s existing Hachobaru Power Station.

One reason is the high (and highly variable) cost of exploration and plant construction. While geothermal electricity becomes competitive with conventional electricity once construction costs are paid off, it can initially be two to three times more expensive to produce, according to the Geothermal Research Society’s Matsunaga. The Japanese government heavily supported plant construction following the 1973 oil shock. However, support tapered off in the ’90s, electricity prices fell, and construction ground to a halt.

Some communities oppose geothermal power plants because they fear they will destroy local hot springs. Matsunaga says that’s never happened in Japan, because hot water is pumped back underground after use. But he admits that long-term environmental effects can’t be predicted.

Freshwater

Current Status: Hydroelectric plants generated 8.1 percent of Japan’s electricity in 2009, or 76.9 million MWh. Small-scale plants (usually defined as having a capacity of less than 10 MW) made up about 6.6 percent of total hydroelectric capacity.

News photo
On stream: Small-scale hydropower up and running in Arashiyama, Kyoto. KYODO PHOTO

Potential: Up to now, large-scale hydropower has been the mainstay of renewable energy in Japan, so most sites suitable for large dams have already been developed. Nevertheless, if Japan used all its remaining economically and technologically exploitable dam sites — and made better use of existing dams and agricultural waterways — it could boost its yearly hydroelectric generation by about 40 percent. Japan’s major utility companies currently plan to increase hydroelectric generating capacity by about 3 percent in the next eight years.

How it works: Electricity can be generated wherever water runs from a higher to a lower elevation, creating what’s called a “head.” (Japan, with its abundant rainfall and many mountainous areas, has plenty of these.) The falling water pushes the blades of a turbine, which in turn spins a generator. More water falling further means more power, but researchers are developing turbines that work even with a very low flow and elevation gap.

Analysis: From here on, Japan will likely be building medium-, small- and micro-size hydroelectric plants, rather than the huge dams that caused so much controversy in the past. Making the transition is mainly a question of logistics, experts say.

“The technological problems of small-scale hydropower have been almost entirely resolved,” said Toru Nakanishi, a researcher with the New Energy Foundation’s Hydroelectric Power Development Center, an industry-backed research organization. But even though small-scale hydropower equipment has been around for decades, initial investment costs remain high, and bureaucratic restrictions on the use of waterways make rapid expansion difficult, Nakanishi said.

Some of the most interesting examples of small-scale hydropower use existing water infrastructure, from municipal water lines and sewer systems to agricultural canals. For instance, in 2009 the Joetsu Water Supply Authority in Niigata Prefecture installed a 0.08 MW-capacity turbine at a water-purification plant. The plant now supplies 20 percent of its own electricity. Installations like these are easy on the environment because they don’t involve any new river engineering.

In a 2009 survey by the European Small Hydropower Association, however, environmental groups pointed out that other kinds of small-scale hydroelectric plants can harm aquatic ecosystems, and argued that energy output is low compared to environmental damage.

The Ocean

Current Status: No commercial power plant using the energy from currents, tides or waves has yet been built in Japan, although large tidal-power plants do exist in other countries. Experimental wave-power generators have been set up in Yamagata, Mie, Hokkaido and locations in several other prefectures.

Potential: Even though Japan is surrounded by water, there are just a handful of sites with tides fast and wide enough to generate electricity. According to Ehime University ocean-power researcher Takayuki Nakamura, tides in the Seto Inland Sea (between Honshu, Kyushu, and Shikoku) and Kyushu’s Ariake Sea could generate about 3,000 MW — equivalent to the capacity of three nuclear reactors.

Technology to exploit energy in waves is further from commercialization, but the ultimate potential is greater. Scientists have estimated that waves off the eastern coast of Japan and in the Sea of Japan to the west could generate more than 40,000 MW. The powerful Kuroshio Current — which flows from off Taiwan and then along Japan’s eastern coast from Kyushu to Tokyo — could also eventually generate significant power, Nakamura said.

How it works: Researchers have experimented with many different ways of harnessing energy from waves. Some use the bobbing motion to power a pump, while others funnel water through chambers with turbines in them or force it up a channel to an elevated onshore reservoir, which then releases water back down through turbines.

Tidal generators can look like turnstiles, underwater windmills, or dams with turbines in them surrounding tidal flats. However, only certain locations have tidal ranges between high water and low water that are wide enough, or tides fast enough, to generate electricity.

Ocean current power systems — some of which resemble underwater windmills anchored to the ocean floor — are at a very early stage of development.

A fourth technology, called ocean thermal-energy conversion, uses warm surface water to produce steam, either by lowering the pressure of the water or by using it to heat another liquid with a lower boiling point, such as ammonia. The steam spins a turbine and is then cooled using water from deep below the surface.

Analysis: Ocean power has received comparatively little support or attention in Japan, and researchers still need to figure out how to make underwater turbines storm resistant and affordable.

“Not to mince words, we’re losing out to Europe and the United States,” Ehime University’s Takayuki Nakamura said. With some technologies about five years from commercialization, researchers are lobbying to have ocean power included in the support system for new energy.

Ocean-power proponents must also negotiate with fishermen’s unions, who hold usage rights over coastal areas and are generally afraid that clusters of underwater turbines could harm fish.

Currently, Nakamura is working on a system that could be installed on the seaward side of the concrete breakwaters that line most of Japan’s coastline and are meant to absorb the potentially destructive energy in waves. The turbine in this system would turn that energy into electricity while avoiding any new damage to marine habitats.

Distribution gridlock restricts renewables

Dial the clock forward a decade or so, and Japan will be getting a lot more of its electricity from renewable resources and a lot less from nuclear power and fossil fuels — that is, if you go by recent government announcements proclaiming 2011 an energy watershed.

But Yasuhiro Hayashi, one of Japan’s top experts on power grids, says the current network can only handle a fraction of the solar- and wind-power that government goals call for.

Before the ongoing Fukushima nuclear disaster started in March, Japan’s energy plan called for boosting solar-power generating capacity 10 times by 2020, to about 28,000 megawatts (MW), or 10 percent of the current total electricity-generating capacity.

Prime Minister Naoto Kan upped the goal at this May’s G-8 summit by calling for solar panels on 10 million Japanese roofs, and for 20 percent of electricity to come from renewable sources by the early 2020s.

According to Hayashi, however, the grid can currently handle 10,000 MW of solar and wind power- a capacity roughly equivalent to the maximum output of 10 nuclear reactors.

“The existing goal was already quite challenging. To meet the new goal, we’re really going to have to push hard,” said Hayashi, a professor at Waseda University’s Research Institute for Advanced Network Technology. “The current grid wasn’t built for renewable energy.”

A central technical problem stems from the fact that solar and wind power depend on the weather — and the weather changes a lot. The outputs of geothermal and biomass plants are more predictable.

“Electricity from solar and wind sources is wild. The amount generated fluctuates greatly,” he said. When that unpredictable energy flows into the conventional grid in large amounts, controlling the quality of electricity becomes difficult.

That’s because, in order to keep a stable voltage and frequency flowing from sockets and other home outlets, power companies must continuously adjust electricity supply to meet demand. If not enough electricity is supplied in relation to the quantity consumed, frequency falls below standard levels (for instance, from 50 hertz [Hz] to 48 Hz), which can cause electrical devices to stop working. In practice, a utility would opt for a blackout rather than allow this to happen.

In Japan, fluctuations on the demand side are extreme. “Everyone turns on their rice-cooker around the same time in the morning, goes to work and school around the same time, and watches television at night around the same time. That makes for big peaks and valleys in power use,” Hayashi said.

Meanwhile, on the supply side, Japan’s ability to adjust is limited. About a quarter of electricity comes from nuclear reactors, whose output level is fixed. And unlike European countries, which are connected in a mesh-like electricity grid that operates on a unified frequency, Japan’s looks more like a fishbone: in each region a single power company controls both production and distribution, with limited links between regions and none to other countries.

In addition, when Japan first began to build its electric network, Osaka used a U.S.-made generator while Tokyo used a German-made model. The result — which remains unchanged — was that as power lines were extended out from Osaka, western Japan came to use its 60-hertz system, while eastern Japan followed Tokyo’s 50-hertz lead. However, the two frequencies are incompatible without conversion — and only three converters exist.

Japanese power companies are thus less able than their European counterparts to adjust supply by sending or receiving electricity to or from other areas. Instead, they tweak it by burning more or less coal or oil. Add in large amounts of variable power from solar- and wind-farms, and matching supply to demand becomes difficult.

Within service areas, however, Japan already has an advanced “smart grid,” an automated system that helps balance supply and demand and improve network efficiency. Even so, to handle lots of solar and wind power, Hayashi said the grid needs to be even smarter.

For instance, so-called smart meters can be installed in homes and businesses to show consumers how much electricity they are using compared to how much the network is generating, so they can adjust their usage in response. (Japan has yet to introduce this technology on a broad scale.)

Software added to wind turbines can allow them to change the angle of their blades to reduce or increase generation. Storage systems including batteries, electric cars and appliances that convert electricity into hot water can absorb excess electricity and release it when needed. Finally, improving connections within and between power regions will be key for improving flexibility.

All this takes money, time, and the political will to break up the power companies’ strangleholds over regional networks — a move Prime Minister Kan has called for recently.

Hayashi said the government is helping to shoulder the financial burden. He is part of a three-year, ¥2.1 billion government-funded project to improve the ability of Japan’s grid to handle power from new energy sources. The project brings together researchers from the University of Tokyo, Waseda University and the Tokyo Institute of Technology; manufacturers including Toshiba, Mitsubishi and Hitachi; and nine major power companies (all except Okinawa’s). The Ministry of Economy, Trade, and Industry is also funding four regional grid-improvement pilot projects.

But whether that will be enough to create a grid that can meet Prime Minister Kan’s ambitious new renewable energy goal remains to be seen.

The Japan Times

http://search.japantimes.co.jp/cgi-bin/fl20110724x1.html

Advertisements
This entry was posted in Renewable Energy and tagged , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s