The first solar-powered transport refrigeration unit on a city delivery truck has been successfully tested over five months in California's San Joachin Valley, according to eNow, which supplied solar panels for the test.  

Compared to a diesel truck reefer unit, the "Rayfrigeration" reduced nitrous oxide by 98%, carbon dioxide by 86%, and particulate matter by 97%, said Jeff Flath, president & CEO of eNow.  

The 1,800-watt eNow solar system provided more than enough energy to maintain proper temperature throughout a typical day of opening and closing the doors while the refrigerated truck delivered fresh dairy products in California's summer heat. The Rayfrigeration system worked on a Johnson Truck Bodies refrigeration unit and an Emerson high-efficiency compressor.

The unit's cold plates and batteries are initially charged from utility power overnight, but while on a delivery route, power is provided by eNow's solar photovoltaic (PV) panels mounted on the truck's roof.

The eNow team calculated that average emissions of CO2 were reduced from 2,525 lbs/week to 159 lbs. Nitrous Oxide emissions were reduced from 7162 grams to 1. This is after adjusting for the emissions from the power plant supplying grid electricity overnight; missions from solar are zero.

In addition to eliminating emissions, the Rayfrigeration unit is projected to reduce operations costs by up to 90%, Flath said. The savings are achieved through eliminating diesel fuel and maintenance costs, and an increased battery life thanks to consistent charge maintenance by eNow solar.

"Rayfrigeration is an important step forward in reducing emissions while maintaining the highest levels of efficiency and customer satisfaction for companies delivering perishable goods," he said. "eNow's solar technology is powerful, reliable, and efficient, and provides emissions-free energy for critical tasks such as refrigeration. We are proud to be part of this important project."

The San Joaquin Valley Air Pollution Control District funded the Rayfrigeration initiative through its Technology Advancement Program.

Flath said eNow designs and sells solar-powered idle-reduction systems that reduce fuel and maintenance costs, save energy, and reduce emissions. More information is at www.enowenergy.com 

Watch local TV news coverage of the project: