Biomimicry of heliotropic plants – more efficient solar panels

Many plants are heliotropic, gradually tilting towards the sun to optimize solar energy capture. Current sun-tracking solar panels involve the use of motors and electronic control systems, but we believe a biomimetic heliotropic solar panel can be created with the use of alternative materials and designs. Practically, the heliotropic solar panel could be useful in developing areas, where motor-based sun-tracking panels are not affordable. From an expressive standpoint, a solar panel that tilts towards the sun (like a sunflower) can help the public see a connection between the natural and the high tech. 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.

A team of three MIT students (Forrest Liau, Vyom Sharma, and George Whitfield) designed such a system. Their 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 that imitates 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. Unlike the systems which are currently being used the biomimetic system, once built, is completely passive, requiring no power source or electronics to control the movement. 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.

They 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.

MIT researchers have hit upon a simple, inexpensive, highly efficient process regarding storage of the 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.

Thou many systems which produce power for households already exist, these 2 concepts will help by increasing the efficiency of the systems as well as the cost reductions. It’s only a matter of time when all of the world countries step up and allow households to generate power for themselves and the electricity-by-wire from a central source could be a thing of the past.