Alternative Energy-Solar Energy – What Are Solar Balloons?
Last year a unique concept in alternative energy won the “Forward Thinking” award in the RE:VOLT Electrifying Ideas competition. What was this new concept? Solar balloons developed by Israeli scientists Joseph Cory and Dr. Pini Gurfil for Sun Hope.
What are Solar Balloons?
Historically the term “solar balloon” has referred to simple black balloons that were filled with air. According to Wikipedia, “as sunlight shines on the balloon, the air inside is heated and expands, causing an upward buoyancy force, much like an artificially-heated hot air balloon. Some solar balloons are large enough for human flight, but usage is limited to the toy market as the surface-area to payload-weight ratio is rather high.”
As technology evolves, terminology evolves as well. Now the title of “solar balloon” can also refer to a balloon like “platform” that contains embedded photovoltaic arrays or solar arrays in order to convert solar energy into electrical energy. In the case of the Joseph Cory and Dr. Pini Gurfil’s Sun Hope design we see a lighter-than-air helium filled fabric balloon as the platform or base. Each fabric balloon is tied to the ground with two cables – one for helium refills, the other for passing generated electricity to a control panel.
Sun Hope isn’t alone in their quest for a cost effective, functional solar balloon design. Another solar balloon design comes from Cool Earth Solar. Cool Earth Solar uses plastic balloons that are suspended on wires. To get a visual, imagine a 2 meter wide mylar balloon. These plastic balloons also have concentrated solar photovoltaics where light is magnified onto solar cells to maximize electricity generation output. A common concern about solar balloons is their ability to stand up in high wind environments, according to Cool Earth Solar, their system can withstand wind speeds of up to 100 miles per hour.
While solar balloons show promise as a photovoltaic implementation there are some concerns to be noted. These concerns however, are no different than those found with medium to large wind power installations. Depending upon the size and location of installation one may have to consider items like air traffic regulations and potential bird collisions.
Solar balloons provide impressive value in isolated, off-grid locations as well as temporary portable power supplies. In situations such as these, solar balloons provide a route to escaping a fossil fuel dependency.
Concentrating Solar Power
In both of examples of solar balloons, the efficiency of the photovoltaic cells are improved by concentrating solar power (CSP). According to the US Department of Energy, “concentrating solar power’s relatively low cost and ability to deliver power during periods of peak demand – when and where we need it – mean that it can be a major contributor to the nation’s future needs for distributed sources of energy.”
Concentrating solar power system work by using mirrors or other reflective surfaces to intensify the energy of the sun to a specific point. This concentration of energy can improve the efficiency of photovoltaic cells. According to Cool Earth Solar, “multi-junction, high efficiency cells derived from satellite technology allow CPV systems to generate the same amount of electricity as traditional flat panel PV systems while using up to 500 times less solar cell material.” With diminishing supplies of raw materials required to manufacture photovoltaic cells, concentrating solar power can provide more energy with less raw materials.
While today solar balloons are a new technology, in the near future they may be a solution to curing our nation of it’s dependence on fossil fuels. The Cool Earth team recently received $21 million which they plan to use to build a 10 megawatt plant using their solar balloon technology. Thanks to forward thinking, environmentally conscious investors, a solar balloon based solar power plant may be a reality in the next few years, someday it may even power your home.