Engineers and researchers at Yale worked to develop a new technology that uses low-temperature waste heat into power.

Industrial plants and power plants produce heat-waste that could not be used in the cogeneration because of its relatively low temperature. Yale researchers developed a method that taps into the world's most unused resource -low-temperature heat waste.

The waste heat levels recoverable in the United States alone is estimated to be high enough to power tens of millions of household. There are existing technology that uses high-temperature waste heat into power. This is called Combined Heat and Power (CHP). This technology has been used to convert heat in produced the manufacturing and power plants to produce steam that turns the turbines and provide electricity. This technology contributes 12 per cent of the total electricity in the U.S. in 2006, Inside Energy reported.

This new method developed in Yale uses low heat and are fully operational even with fluctuations in the heat source, unlike the CHP technology.

The researchers at the Department of Chemical and Environmental Engineering developed a so-called "nannobubble membrane". This membrane has pores that traps tiny air bubbles when immersed in water. When one side of the membrane is heated, the water evaporates and travels across the air gap. On the opposite side of the membrane, the water condenses. The water is driven by temperature to flow. The flow is then directed to a generator turbine, thus, electricity is produced, Yale News reported.

The team of researchers built a system on a very small-scale to demonstrate this technology. The y have shown that the system functions even when the temperature drops to 20 degree Celsius. This 'nannobubble' technology is feasible even on low heat sources in industrial plants. Their findings were published in the journal Nature Energy on June 27.

The members of this team include Menachem Elimelech and Anthony Straub. Elimelech is a Professor of Chemical and Environmental Engineering at Yale while Straub is a doctoral student. There are also doctoral graduates of Yale who participated in the project. One of them is Ngai Yin Yip, currently working as assistant professor in Columbia University. Shihong Lin and Jongho Lee, which are also postdocs at Yale, are also part of the team.