Powerenz Case Study
Pilot finds Portable Solar Power Solution for Avionics
A commercial pilot, who also owns a single-engine, four-seat airplane, was looking for a better way to power his avionics system. The all-glass cockpit in his airplane is a Garmin G1000, and is a 24-volt system. In order to power up the airplane's avionics, either the battery must be turned on (with the engine off), or the airplane's engine must be started and running. This either drains the airplane's battery, or burns and wastes high-cost aviation gas, and creates heat, loud noise and exhaust fumes. On the front right side of the airplane, there is an electrical DC power port that can be used to externally power the airplane's electrical systems, jump-start the airplane’s engine in case of battery failure via a spare battery, or to charge the airplane battery using AC power and a transformer. The pilot flies his airplane to several remote locations where there is no AC power.
The pilot approached Powerenz and asked if we could design a custom portable power system that would allow him to power up the airplane's 24-volt avionics system with the airplane engine off. He needed a unit that would:
a. utilize solar energy for fuel instead of liquid fossil fuel or the plane’s battery,
b. be stored and carried in one waterproof, protective case, by one person,
c. be charged by AC power when available, and
d. provide durable, long-term independence from the power grid.
A portable solar panel-battery system was assembled that included the following components:
a. two high-quality, 12-volt, sealed lead acid batteries,
b. one 42-watt foldable solar panel,
c. two 7-amp solar charge controllers, one for each battery,
d. proper fusing and wiring, and
e. one connecting adapter that mates with the aircraft DC power port.
The two 12-volt batteries were linked in series to provide a nominal 24 volts at the airplane DC port. Each battery was assembled with its own solar charge controller. Using one solar panel, each battery would have to be charged separately. Using two solar panels, both batteries could be charged simultaneously.
One, or more, solar panels could be draped over, and secured to, the surface of the airplane's right wing using Velcro straps, and left in place while parked until the next flight. Solar panels could also be positioned on the ground. To solar charge each battery, the power output connector from one solar panel is linked to one of the two solar power input connectors of the power unit, both accessible inside the case. LED lights on each solar charge controller indicate when its battery is charging and fully charged. To recharge the batteries when low on charge requires 5-6 hours of good sunlight per battery when using one 42-watt solar panel.
The portable solar power system can power up the airplane's avionics silently, without exhaust fumes, and without wasting aircraft fuel. The unit can be used for 2-2.5 hours before the batteries require recharging. Two hours of power is more than sufficient time to flight plan, check weather, etc. During these preflight checks, the airplane's engine does not have to be running, nor does the airplane's battery have to be used. When not in use, the portable system can be stored inside the airplane until it is needed again.