How to solar power an ambulance or fire truck
Solar-capturing technology has made it easier to keep ambulances and fire trucks fully charged without leaving them running, and saves money
Updated April 22, 2015
Do you know the KOPL for your fire apparatus or ambulances? KOPL stands for key-off parasitic load, which sounds sort of scary but really isn't — unless of course you're an apparatus battery.
KOPL is the electrical load created by radios, computers, climate-controlled drug-storage cabinets and other portable electrical devices found on today's fire apparatus and ambulances when the ignition is turned off.
That electrical load has increased substantially over the years as departments have increased their scope of services. The increased amount of time that apparatus spend out of quarters — and away from plug-in power to address KOPL — requires continually running the apparatus motor to ensure that the apparatus batteries don't run down to a level where the apparatus cannot be started.
Enter apparatus-mounted solar panels that capture solar energy to keep those apparatus batteries at full charge — along with all those parasitic devices — with the apparatus motor turned off. And the benefits of using solar panels to help maintain the battery charge go beyond improved battery performance. Here are five of those benefits.
- Reduced operating hours on the vehicle motor.
- Reduced maintenance costs (less frequent replacement of filters and lubricants).
- Reduced fuel consumption.
- Reduced diesel engine emissions.
- Reduced energy use at the station as the apparatus can be outside during the daylight hours in lieu being plugged into a shoreline.
Tale of two cities
The technology necessary to harness electricity from sunlight continues to become more effective and efficient — and smaller. As always, the more direct the sun, the better, and today's solar panels produce electricity even on a cloudy day, as well as in urban areas with tall buildings that can obscure the sun. Only the rate of charge is affected.
The San Rafael (Calif.) Fire Department and South Metro (Colo.) Fire Rescue Authority have each rolled out programs to outfit their fire apparatus and ambulances with solar panels. The purpose is to keep their 12-volt systems charged so they don't need to remain at idle at an incident.
San Rafael began its commitment to solar energy five years ago with the installation of solar equipment on one engine in their fleet. Since then, the success from that initial installation has led to the department to outfit all 22 vehicles in their fleet with solar panels.
The use of solar panels to address KOPL addresses two big concerns regarding ambulances: electrical load and carbon footprint. Using solar panels can extend the vehicle's service life in terms of the batteries because the electric load is not killing the system.
Ambulances present a special challenge to fleet managers. A vehicle sits in the station until a call comes in. The crew starts the engine, responds to the scene and then the engine idles. Then the patient is ready for transport and brought to the hospital, where the truck idles again.
Finally it goes back to the station. All of that driving and idling time quickly racks up the vehicle's operating hours and has a major influence on the longevity of the ambulance chassis.
PL Custom offers its Solar Power System, panels mounted atop an ambulance to provide energy from the sun. The system is designed to power a 10-amp DC electrical load for eight hours without starting the vehicle, or connecting to a shoreline.
The system is made up of two 110-watt solar panels, measuring 2 feet by 5 feet, a solar regulator for system voltage and a deep cycle battery. The panels are placed on top of the ambulance without interfering with radio antennas or rooftop lettering.
Using solar panels to reduce the amount of idling time reduces a vehicle's carbon footprint by reducing the amount of engine emissions, engine lubricants used for maintenance (fewer changes needed) and spent lubricants that require proper disposal.
Making a commitment to the use of solar energy can have another financial benefit beyond savings on maintenance and fuel costs. Several departments have found success in obtaining grant funding for new vehicles by applying to their respective states citing the green initiative aspect of solar charging.
What's on the market
Pulsetech's 2-watt solar pulse battery charger and conditioner/maintainer charges and maintains 12-volt batteries using solar power energy. The system cleans battery plates of large, damaging lead-sulfates so batteries can accept, store and release maximum power when you need it. Military grade construction makes it ideal for fire apparatus and ambulances.
Kussmaul Electronics' solar power charging system comes with instructions and parts to ensure proper installation and eliminates installer guess work. The system includes: an industrial-grade solar panel with 10-year warranty; charge controller with temperature-compensated, three-step output and battery type selection; heavy-duty vibration-dampened mounting system; 20 feet of duplex wire, terminals and cable ties; and waterproof wire feed-through fitting and all mounting hardware for various truck installations.
The Pure Sine line of solar power charging systems, available from The Inverter Store, provide solar charging capabilities ranging from 1,000 to 7,000 watts of power. The kit comes with all the necessary components and mounting hardware and is constructed to military-grade specifications making it an ideal application for emergency response vehicles.
So take a look at what solar charging systems can do to improve your department's bottom line and reduce the carbon footprint for your apparatus fleet.
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