Streetlamps burn all night long, 365 nights a year, yet they also spend all day soaking up the Sun’s rays. This combination of regular usage alternating with sunlight exposure would seem to make them ideal candidates for the solar-power treatment. Indeed, companies such as Sharp and several others currently offer solar-powered streetlamps. Spain’s University of Seville, however, has developed a streetlamp that harnesses the power not only of sunlight, but also of wind.
The device was invented mainly by María Jesús Ávilais, and is known as the Holonic Streetlamp – “holonic” referring to the fact that it is one unit composed of more than one system. It incorporates two top-mounted polycrystalline photovoltaic panels, along with a vertical axis wind turbine built into its galvanized steel supporting structure.
Power generated by the panels and turbine is piped down to two 12-volt lead gel batteries (although lithium-ion is an option), contained in an underground compartment beneath the lamp. When an integrated photocell detects that night is falling, those batteries power up an array of LED bulbs, providing an output of up to 3,520 lumens – lower intensity can be programmed, as can specific on and off times.
The system can reportedly withstand winds of up to 140 km/h (87 mph), and operates in temperatures ranging from -30 to 40ºC (-22 to 104ºF). Unfortunately, that temperature range would disqualify it for use in many parts of the world.
Although the lamps themselves can operate off the grid, they can also be remotely monitored and adjusted via a telemanagement system. Additionally, they can be wired into a municipal power system, allowing traditionally-sourced electricity to be available if needed. The bulbs should be good for at least 50,000 hours of run time. Once the streetlamp as a whole is past its prime, approximately 95 percent of its materials can be recycled.
The university’s technology transfer office, OTRI, currently has a working prototype of the Holonic Streetlamp, and is seeking buyers for the technology. It may face some competition from Urban Green Energy, however, which is also marketing a solar/wind turbine hybrid streetlamp system.