Shared on September 28, 2012 written by USAT Corp
Part 1: How Is a Solution Considered Wireless If It Needs to Be Plugged Into a Grid Power Source?
We are fielding more and more calls from clients looking to have wireless devices be truly wireless. Data goes over the air, we have that part nailed, however the electricity to power the device comes from a wire stretched to a transformer, through the transmission and distribution plant of the electric utility—power is hardwired and dependent on the "grid". The answer to being truly wireless is gathering energy from the sun and storing an adequate supply local to the device. This solution has the added benefit of removing dependence on grid power, shielding the wireless router gateway from area power supply outages.
Much time is spent considering the cost per watt of solar. In off-grid wireless applications, however, the cost of the solar system is offset by the often costlier alternative—having a transformer and meter installed and running wires to an electric distribution pole. In some instances, having hardwired electric installed isn't an option, in others, the time and costs required for construction permits, permissions to cross roads, streams and property all contribute to making the lead time and cost untenable.
The great news is that solar photovoltaic is an excellent match to wireless data communications. USAT has modeled power consumption profiles for many different intelligent wireless gateways and routers or 'cellular modems'. With a single panel, a single NEMA enclosure, properly sized solar batteries, and the right solar charge controllers, we can reliably run cellular modems effectively in perpetuity. With modems we consider percentage of transmit and idle times, keep alive times and other elements discussed in another USAT Tech Talk post.
We can also attach other power drains to the system without making the solar setup unwieldy. It all comes down to modeling the demand, and understanding the nuances of solar, all while choosing the attached equipment carefully. Our systems are often paired with one or two cameras for remote situational awareness, RADAR to sense traffic issues, and Power-Over-Ethernet (POE) to power other network aware equipment and sensors.
One concern some might raise is the longevity of the solar equipment. Most of our photovoltaic panels have a 25 year lifespan warranty that they will retain 75% of their generation capability for this duration. Sealed gel and Absorbed Glass Mat 'solar batteries' are carefully chosen to be used in outdoor enclosures across broad temperature swings and carry 5 year warranties. We use charge controllers, such as those by Morningstar, that monitor ambient temperature and adjust charging rates automatically; this further protects the batteries.
Solar is an excellent and reliable power source for making wireless modem setups truly wireless. The essential ingredient is having an experienced partner who understands wireless data, and solar power used in small off-grid applications. Have USAT explore solar power options with you.
Continue reading, Building A Truly Wireless Data Communications Solution.
Keywords: Data Communications Solutions