The World’s First, High Performance & Environmentally Benign Power Generation Unit Driven by Waste Heat Silicon By-Product - Low cost and Mass Producible

If the device is applied to 30% of the cars in Japan, we can expect a 960,000kl oil substitution effect which is 1.5 times the assumed effect from solar energy generation of the year 2010.

This Press Release was first issued in Japanese on April 3, 2009.

A research team led by associate professor Tsutomu Iida (Tokyo University of Science - Faculty of Industrial Science and Technology – Materials Science and Technology) has developed a power generation unit driven by wasted heat composed of Magnesium silicide (Mg2Si), a filtered by-product of Si-LSI and solar cell cast wafer production.

This device, being the first in the world, has been successful in bulk-quantity synthesis, at the same time increasing the thermoelectric conversion rate. Approximately 2,500W/m² (per unit) of power generation and 3,000 hrs of continuous operation has been made possible, sufficiently fulfilling the criteria for commercial use.

By applying this device in industrial shaft furnaces and/or car engines, we can expect drastic reduction in fuel consumption and prevention of global warming. Implementation of this device has already been determined partially as an experiment for practical use and there are high expectations of application of this device in industrial furnaces nation-wide.

Mg2Si Power Generation Unit Driven by Waste Heat - Capability & Effect; This device has an effective temperature range from 200 degree to 600 degree; hence, there is high hope for implementation in industrial furnaces, cars, etc. When applied to gas-powered vehicles, 500~1,000W of electrical energy can be recycled, increasing the energy use efficiency.

If the device is applied to 30% of the cars in Japan, we can expect a 960,000kl oil substitution effect which is 1.5 times the assumed effect from solar energy generation of the year 2010. Also, if the device is implemented in industrial shaft furnaces which have an approximately 10% energy use efficiency, the efficiency will increase by 1.5 times and CO2 emission will be reduced by one-third. Iida’s research team is continuing research for further improvement in energy conversion and durability of the device.

Background of R&D and Success of Material Development;

Today, our main source of energy is fossil fuel. However the energy use efficiency has only gone up to 30% leaving 70% to be disposed as “wasted heat”. Efficiently reusing “wasted heat” and reducing fossil fuel consumption and CO2 emission, from the perspective of preventing global warming, has attracted attention from all around the world. The popularization of power generation from wasted heat has gone through many obstacles such as scarcity of material, cost, toxicity, etc. Iida’s research team has focused on the low cost and environmentally friendly silicon.

They have successfully managed to mass produce Magnesium silicide (Mg2Si), from the by-product of Si-LSI and solar cell cast wafer production, providing high-performance in power generation driven by wasted heat.

- Progress of Research -
Discovery of Magnesium silicide, material for Thermoelectric Conversion driven by Wasted Heat

Heretofore the compound of Lead and Tellurium (Pb-Te), have been known to be the material for thermoelectric conversion from wasted heat. However, Lead being hazardous and Tellurium being scarce, development of new material of low environmental burden was hoped for. Iida’s research team has been successful in being pioneers of mass producing Magnesium silicide from Silicon which is found abundantly on earth, holding the characteristic of being nonhazardous. Through this discovery of environmentally benign material, the realization of an environmentally benign technology of thermoelectric conversion through wasted heat was made possible.

Development of Magnesium silicide from Silicon by-product Silicon, being the main raw material for Magnesium silicide, is widely known to be a necessary ingredient for semiconductors throughout the electronic industry. However, in production of ultrapure silicon, much energy is consumed and more than half of the material comes out as Silicon sludge, usually being disposed of. This not only pollutes the environment, but raises the cost of production and also prevents further development of new materials and/or technology.

The research team has been successful in mass producing material for thermoelectric conversion through this waste product at a substantially low cost. Through this, thermoelectric conversion from wasted heat has become even more environmentally benign.

Profile - Tsutomu Iida
March, 1995: Meiji University Graduate School – completed PhD course
April, 1995: Japan Society for the Promotion of Science – Fellowship
July, 1995: Federal Republic of Germany – Volkswagen Foundation
April, 1997: Tokyo University of Science - Faculty of Industrial
Science and Technology – Materials Science and Technology
To Present
Major Field: Semiconductor Material Engineering
Field of Research: Semiconductor Energy Material (Thermoelectric Material / Solar Cell Material) ‘Environmentally Friendly’ Semiconductor Material

Research Content: Due to mass consumption of fossil fuel and also
for prevention of global warming, research and development of energy conversion materials are being conducted. Solar energy being the main source of reusable energy, development of solar cell material and thermoelectric conversion material is being conducted. Due to the fact that many elemental devices which are used for energy conversion tending to be toxic, development of environmentally benign semiconductor energy material continues to be conducted. Environmentally benign semiconductors are composed of semiconductor material which abundantly exists on earth and is highly ‘earth-friendly’.

Research Content:
1. Development of Thermoelectric Conversion Elemental Device through Magnesium silicide
2. Development of High Efficiency Solar Cells through Silicon Germanium
3. Photodecomposition and Hydrogen Composition of water through Semiconductor Photocatalyst


- Contact for this information -
Tokyo University of Science Technology Licensing Organization
Administrator: Niki
TEL: 03-5225-1089
e-mail:[email protected]