HOMER Energy partner Aquion Energy has published a case study demonstrating that a solar-battery hybrid system can effectively provide power for off-grid telecom towers. In developing parts of the world (and even in many rural areas in the U.S.), the demand for cell phone access precedes grid connectivity. Cell phone towers in remote locations, then, are often powered by diesel generators, which are costly to operate and polluting to the environment.
Aquion’s solution includes their Aqueous Hybrid Ion (AHI) batteries. AHI batteries provide better performance and reliability than lead-acid batteries, which can degrade rapidly from variations in temperature and from variable and partial state of charge cycling.
Aquion describes their testing set-up and results:
“[W]e used a 20-footshipping container that became known as the ‘Boxcar.’ On the roof of the Boxcar, we installed roughly 2 kilowatts (kW) of solar panels. Inside, we installed 12 S-Line Battery Stacks (approximately 25 kilowatt-hours (kWh)) wired in parallel along with a number of different inverters and charge controllers, allowing us to test various configurations. To simulate a telecom tower’s load, we installed several household appliances and an always-on HVAC unit.”
“The Boxcar has been autonomous and operational since the summer of 2012.
During that time, we have
operated the system at various cycle profiles that represent real-world use cases for telecom towers. This
testing has generated extensive data demonstrating the robustness of AHI batteries in this application.”