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Generating Auxiliary Power from the Sun

Generating Auxiliary Power from the Sun

By Sean M. Lyden, Staff Writer
Posted Apr 27th 2015 8:00AM

It's not "breaking news" that excessive engine idle is bad for your truck, the environment and your bottom line. We've known this for years, as a growing number of state and municipal governments continue to enact (and enforce) anti-idle legislation.

The challenge has been this: How do you significantly reduce engine idle, without skimping on the power required to operate sleeper amenities, heating and air conditioning systems, refrigeration systems, liftgates, and other accessories.

Sure, there are both diesel and battery-powered auxiliary power units (APUs) available to address this problem. But the diesel APU still creates some greenhouse gas emissions (albeit smaller amounts), while the battery-electric APU can take hours to recharge when it loses power (potentially at an inconvenient time).

What if there could be an all-electric APU that virtually self-charges by harnessing the sun's energy?

Panel Power

That's what eNow, a clean technology company based in Warwick, Rhode Island, has sought to achieve.

In March 2014, the company launched its full line of solar-powered APUs that can capture and store the sun's energy to power a truck's onboard equipment without having to idle the engine.

The panels, installed on the roof of the truck box, are 1/8th of an inch thick and weigh less than a pound per square foot, minimizing wind and weight resistance that might impact fuel economy. And the solar charging systems are available in several configurations, with charging capacities ranging from 25 watts (for keeping batteries charged) to 5,250 watt systems (for operating refrigeration equipment).

Business Case

In terms of cost of the system, that depends on the configuration. But as a frame of reference, eNow's online "Cost Savings Chart" uses $11,367 as the estimated cost for its No-Idle HVAC product. (To obtain a copy of the chart, Click Here.)

So, what's a realistic payback on your investment? According to a presentation by eNow's CEO Jeff Flath last summer, the project payback period from operating cost savings ranges from 7 to 22 months, based on the application. There's also the federal solar energy tax credit (30-percent of the product and installation costs) that can accelerate that payback period.

(To access the complete presentation slide deck, Click Here.)

There's also the cost-savings from operating an solar power APU versus a diesel and battery-powered APU. According to highlights from a white paper produced by eNow, the fuel cost of producing a kilowatt-hour (kWh) of electricity using eNow's solar powered system is $0, compared with $3.00 for truck stop electrification, $2.76 for a diesel auxiliary power unit (APU), and $0.75 for a battery-only APU.

Bottom Line

As an expediter, what do you think? Do you see solar panels as a viable (and practical) option for idle reduction in expedite applications?

1 Comment

  • - June 3, 2015
    So cool we can now use the power of the sun to power our devices. A few decades ago that was the stuff of science fiction. Now it is possible, and one of the coolest technologies that has been invented in my opinion.

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