THERE’S ENERGY EVERYWHERE

Researchers at Stanford University recently succeeded in generating energy from the cold nighttime sky. They used what is known as the Seebeck effect, the ability to generate electricity from a temperature differential. The prototype the researchers built, which cost just 30 US dollars, takes advantage of this phenomenon. An aluminum plate heats up during the day and radiates the absorbed heat toward space at night. This results in a temperature differential that a thermoelectrical generator beneath the aluminum plate converts into energy. With the first prototype, the scientists were able to generate 25 milliwatts per square meter—enough to power an LED lamp. Newer prototypes have already achieved up to two watts per square meter.

Smart hard-rubber tiles that convert movement into electricity: this is the idea that the London-based company Pavegen hopes will revolutionize energy supplies in cities. Induction generators that trigger a rotational movement are built into triangular tiles, thus generating energy when they’re tread upon. So far, the tiles have been installed in 200 pilot projects in 36 cities. Companies such as Siemens and Google are cooperating with Pavegen on the project.

What sounds like science fiction could become science fact in the next decade or so: systems in space that convert solar radiation beyond the atmosphere into microwaves, which are then radiated down to the earth’s surface. Special antenna receivers would collect these microwaves and supply us with energy. Working from this concept, Japan is hoping to have a photovoltaic power plant with an output in the gigawatt range in space by 2030 and is cooperating with firms such as Mitsubishi. The technology holds particular appeal for regions with poor infrastructure since it requires only receiver antennas. It is also designed to assist with power outages after natural disasters.

The new era of alternative energy is going nowhere without storage units for the power being generated. Yet current methods for this are expensive and can only be used in a few places. The Hamburg University of Technology and Siemens are researching the use of volcanic rocks. In a pilot plant in Hamburg, heating fans warm around one thousand tons of stone, which stores the energy in the form of heat. As needed, ventilators extract the heat from the rock storage facility and send it to a steam turbine that drives a power generator. Stone storage is quite inexpensive compared to other types of storage units—Siemens and the university are aiming to achieve storage prices of less than 10 cents per kilowatt hour for commercial plants.

The idea of generating energy from the powerful forces of the ebb and flow of the tides has been around for a while. Now researchers have anchored the world’s largest tidal turbine off the Scottish coast. It’s called Orbital O2 and, unlike more conventional approaches, interferes only minimally with existing ecosystems, is suitable for many different locations and is much less expensive. The turbine’s rotor blades, located at the end of a 73-meter-long floating mechanism, can be rotated 360 degrees. Because of this, only the rotors have to change position to take advantage of the tide’s direction, not the entire float. Researchers are planning to test how reliable and powerful the Orbital O2 is over the next fifteen years.