No. 35: Using fallen leaves and dead branches for power generation (January 18, 2012)

Business trend

The Ministryof Land, Infrastructure, Transport and Tourism decided to install generation equipment in large-scale government-managed parks as an emergency power source in a time of disaster. It plans to start testing in one or two of the 17 government-managed parks across the country. The equipment to be installed generates by running a turbine using gases created by steaming fallen leaves and dead branches. It is designed to keep high generation efficiency even with unhomogeneous fuels. The ministry plans to put the technology into practical use in one year in alliance with private companies.

The electricity to be generated will be used for lighting inside the park normally and for rescue activities in case of power outage in a disaster. The ministry calculates that a government-managed park in Tokyo with an area of 1,650,000 square meters can supply enough amount fallen leaves and dead branches to generate about 10% of annual electricity demand. The ministry decision aims to decrease the amount of plant trash by using weeds and fallen leaves as fuel. About 2,000,000 tons of plant trash is produced annually in this country, most of which is incinerated while only a small amount is used for fertilizers.

No. 34: Using earth thermal for energy saving in a production plant (January 6, 2012)

Business trend

Japan is behind western countries in the application of earth thermal. Thanks to technological development, however, it has become possible to use earth thermal in a clean room that needs strict management of room temperature, and Fujitsu will start to use earth thermal for energy saving in one of its production plants shortly. In this plant, a total of 31 pipes are dug in down to 30 m below ground to collect earth thermal that is 15 degrees centigrade throughout the year. The plant will collect earth thermal efficiently using the heat pump technology. The collected earth thermal will also be used to warm air after dehumidification in summer.

The capital investment is 70 million yen, and the payback period is 14 years. The company plans to introduce the same system in other production plants. The system is estimated to reduce 50 kiloliters per year as compared with the existing air-conditioning equipment that uses city gas. In addition, about 120 tons of carbon dioxide emissions can be reduced, the company estimates. The application of earth thermal is growing popular steadily in Japan now, and it is expected to accelerate with the introduction in production plants.  

No. 33: Growing popularity of offshore wind farming in Asia (January 2, 2012)

Business trend

The offshore wind farming market is estimated to grow nearly three times in 2015 over the level in 2011. Since Denmark launched offshore wind farming in the 1990s, Europe has been taking the initiative in this business. Following Europe, Asian countries have grown serious about introducing offshore wind farming. Because wind farming creates lots of supporting industries, companies with advanced technology are asked to explore business opportunities.

J-PowerSystems and Sumitomo Corp. jointly got an order for the laid down of undersea power cable between an isolated island and the main island of Taiwan that stretches 350 km for 32 billion yen, beating JS Cable of Korea in the international tender. J-Power Systems will build the power cable in Japan, and Sumitomo Corp. will undertake the laid down and civil engineering work. A total of six cables, each of which is 15 cm in diameter, will be laid down. Offshore wind farming is expected to grow more popular as a renewable energy source in Japan, China, and Southeast Asian countries.

No. 32: Cosmo Oil participates in the offshore wing farming business (December 24, 2011)

CosmoOil plans to operate offshore wing farming plants, each of which is made up of more than 10 windmills, offshore of the Tohoku and other districts early 2020. Cosmo’s subsidiary EcoPower has already started the feasibility study offshore of Iwate Prefecture and offshore of Ibaraki Prefecture. The company plans to build plants in waters 15-20 meters deep about several kilometers away from the coast. It will conduct research on the wind on the waters and the geography of the seabed using a special ship starting in 2012. Each of the planned plants has an output ranging from 50,000 to 100,000 kW. The construction cost is estimated to exceed 10 billion yen per plant. EcoPower is the fourth largest operator of wind power generation, and it is currently operating about 130 land wind generation facilities.

Japan has lots of suitable areas for offshore wind farming because it has the sixth largest exclusive economic zone in the world. Some predict that offshore wind farming will have a generation capacity of about 13 million kW around 2030. That is, it will have two times higher capacity than the land wind generation, and the generation capacity of 13 million kW is equivalent to the generation capacity of 13 nuclear power plants. Japan will enforce the system that requires electric power companies to buy the whole amount of electricity generated by renewable energy at a fixed price in July 2012. J-Power and Ministry of Economy, Trade and Industry are planning to do the substantiative experiment of offshore wind farming after 2012.     

No. 31: Ongoing development of the organic solar battery (December 21, 2011)

The development of organic solar batteries is accelerating. The technology of organic solar battery is to cover the walls and curved surfaces of a building and the roof, doors, and body of a vehicle. Although a large flat space is needed to install a solar battery, an organic solar battery is free from restrictions on installation space because it is a film. Mitsubishi Chemical takes the lead in the development of organic solar battery. It organized the generation layer using an organic material that emits electrons and fullerene that is the representative material of nanotechnology. The company already achieved the generation efficiency of 10% that is the highest rate achieved by an organic solar battery so far. It plans to launch film organic solar batteries and market them to automakers and building material producers in 2012.

Because the finished product is a film, it hardly weighs besides being flexible. It is less than one millimeter thick and almost free from any restrictions on installation space. Accordingly, it is realistic to build a vehicle covered entirely with the film organic solar battery. The company is conducting market research on the product that integrates a wall material and an organic solar battery based on amorphous silicon with a view to installing it on building walls and rolling it on the iron pole of the base station of mobile phones. While amorphous silicon-based products spread, crystalline silicone will spread to be used for the large-scale photovoltaic power plant called mega solar.

SumitomoChemical is also developing organic solar batteries using not fullerene but polymer materials. Thanks to the efforts of these companies, a new business domain of photovoltaic generation is being established.  

No. 30: On small storage equipment (December 15, 2011)

Families equipped with a solar battery were able to use power in the daytime and give their neighbors an opportunity to take a bath in the disaster-stricken areas during the Fukushima disaster. As this story shows, generation equipment and storage equipment allow households to use the minimum amount of electricity necessary for daily life even though power supply from an electric power company is shut down. In this sense, household storage equipment and movable storage equipment will grow more important for the construction of a future energy system. In addition, operating such a distributed energy system as fuel battery that generates electricity from hydrogen requires storage equipment to allow for self-sustained operation of the system.

The current four major secondary chargeable batteries are lead battery, sodium sulfur battery, lithium-ion battery, and lithium air battery. The theoretical energy density is 165 kW, 786 kW, 583 kW, and 11,700 kW, respectively. Lithium-ion batteries are most popular at present, but excess voltage and low voltage greatly affect them. After the Fukushima disaster, household storage systems using a lithium-ion battery were commercialized by consumer electronics makers. They are mostly sold for 400,000-500,000 yen per kW. A household storage system is supposed to be put on the market for a little higher 100,000 yen per kW in 2012. Because a standard family with three members consumes about electricity of 3 kW per day, the price range a little higher than 100,000 yen is supposed to make a storage system spread wider.

No. 29: On storage equipment (December 14, 2011)

Storage equipment is vital to level off the supply-demand gap of power between the daytime and nighttime, given the fact that renewable energy susceptible to weather and geographically-distributed power generation are expected to spread in the future. At present, sodium sulfur storage battery is commercialized. It employs metal sodium for anode, sulfur for cathode, and ceramics called beta alumina for electrolyte. It charges and discharges at 300-350 degrees centigrade, and it has a life of about 15 years. It has an energy density of about 100 watts per kilogram comparable to that of a lithium-ion battery. It enjoys high expectations as a stationery large-scale storage at present. Currently, only NGK Insulators produces and markets this kind of storage battery. It has an annual production capacity of 150,000 kW on an output basis.

The sodium nickel chloride storage battery that uses beta alumina for electrolyte like the sodium sulfur storage battery is also a high-capacity storage battery that operates at a high temperature. It is expected to be widely used in the future for delivery trucks and taxies that have to bear continuous load. In addition, another storage technology is available for surplus power from large plants that generates power using renewable energy, such as large-scale photovoltaic power plant called mega solar power plant. It electrolyzes water using surplus power, and produces and stores hydrogen. The stored hydrogen is converted to energy with the help of a fuel cell as necessary. However, lots of technological issues, such as increasing the efficiency of electrolysis of water and securing safety production and storage of hydrogen, are need to be settled to spread this technology.