WOW! —– SUN-TRACKING DEVICE

A team of three MIT students have designed a system that will allow solar power panels to track the sun without motors or control systems.The student team, called Heliotrope, won top honors and a check for $10,000 in the finals of a competition aimed at developing innovative energy technologies.

They designed the system to imitate the way plants track the sun across the sky, by using the difference in temperature between shaded and sunny areas to change the properties of the material supporting solar photovoltaic cells. The system, once built, is completely passive, requiring no power source or electronics to control the movement. Solar cells that track the angle of the sun can be 38 percent more efficient at generating power than those that are mounted in a fixed position.

The team explored several different variations of the proposed system, using various materials including polymers and bimetallic strips. The system that shows the most promise, they said, mounts solar panels at the top of a curved arch made of a pair of metals such as aluminum and steel, which should be durable enough to withstand the elements with little or no maintenance.

The team demonstrated a scale model of the arch by shining a spotlight to warm up one side and cause the arch to bend, tilting the solar panel toward the light. They explained that the prototypes are cheaper than existing systems for tracking the sun and could be built from materials that are readily available in developing nations.

BIG WOW! —- SOLAR ENERGY STORAGE

MIT researchers have hit upon a simple, inexpensive, highly efficient process for storing solar energy. Until now, solar power has been a daytime-only energy source, because storing extra solar energy for later use is prohibitively expensive and grossly inefficient.

Inspired by the photosynthesis performed by plants, the researchers developed an unprecedented process that will allow the sun’s energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.

The new technique takes advantage of a cobalt catalyst’s ability to create oxygen gas when combined with water and an electric current. The solar panels provide the electric current, and the energy from that current is stored in the form of the hydrogen and oxygen, rather than in a capacitor.

More engineering work needs to be done to integrate the new scientific discovery into existing photovoltaic systems, but they are very confident that such systems will become a reality. In fact, the MIT researchers hope that within 10 years, homeowners will be able to power their homes in daylight through photovoltaic cells, while using excess solar energy to produce hydrogen and oxygen to power their own household fuel cell. Electricity-by-wire from a central source could be a thing of the past.

A Professor at Imperial College London said, “This is a major discovery with enormous implications for the future prosperity of humankind. The importance of their discovery cannot be overstated since it opens up the door for developing new technologies for energy production thus reducing our dependence for fossil fuels and addressing the global climate change problem”.

Tags: climate change, energy, fossil fuel, Imperial College London, Renewable, solar cell, solar energy, Technology

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