Dual–voltage Micro-electricity Grids

AbstractMost developing countries are facing energy shortage and this impacts the social and economic development. Reliable electrical networks are absolutely necessary for energy supply. Unfortunately, the energy access has become a major problem in developing countries. When electricity is available, in large cities for instance, the grid is not reliable. Additionally, power cuts, power interruptions and electricity rationing are frequent, causing social tensions. This work focuses on a solution for lighting during electricity rationing. The use of a dual-voltage LED lamp can be an alternative solution to expensive kerosene and candles. A dual-voltage LED lamp can give the same light output at 240 VAC, 20 VAC or 24 VDC. Here is proposed a design of a small electrical grid encompassing dual voltage lamps and energy storage. This solution can be implemented in single family homes and in renewable energy mini-grids, and as well as in whole cities. Successful trials have been carried out at the Open University and in Cambridge, UK and results are presented in this paper

New approach to waste-heat energy harvesting: pyroelectric energy conversion

Harvesting waste heat for useful purposes is an essential component of improving the efficiency of primary energy utilization. Today, approaches such as pyroelectric energy conversion are receiving renewed interest for their ability to turn wasted energy back into useful energy. From this perspective, the need for these approaches, the basic mechanisms and processes underlying their operation, and the material and device requirements behind pyroelectric energy conversion are reviewed, and the potential for advances in this area is also discussed