While generators have always been a necessity for most job-site work, such may not the case anymore, thanks to a brilliant idea by Andy Naggy, a general foreman for VEC Inc. (Girard, Ohio). His idea? A solar-powered job-site trailer.
According to Naggy's calculations, work generators were requiring an average of four gallons of gas per day. For those generators, he estimated a cost of over $2,500 a year, not even accounting for the cost and time associated with driving to purchase the gas on a regular basis, storing the gas, cleaning up spills, maintaining containment areas around the generator and storage area, and performing regular maintenance and oil changes on the generator. It was also inconvenient to have to load up the generator when moving the work trailer to a new job-site.
Something else that he took into account: the noise. It was often a problem for workers trying to communicate with each other, who often had to yell to be heard over the noise of the generator.
He came up with the idea for a solar-powered job-site trailer from his personal experience.
"My wife and I like to travel, so we decided to start traveling with the company, and rather than have to pay to stay in hotels, we decided to travel around in an RV," he said.
However, with both of them being really outdoor types, Naggy and his wife didn't want to have to deal with campgrounds.
"We really wanted to be off the grid," he said.
As such, he began researching the idea of installing a solar system on his RV. The idea worked.
"I soon realized that it could be applied elsewhere, such as to the work-site trailer," he said. "I was getting tired of dealing with and hearing generators all day long."
For the work-site trailer, Naggy installed the following:
- An eight-piece Hanwha Q CELL solar panel system
- A 3,000-watt Victron Multiplus inverter/charger
- A Victron Blue Solar MPPT solar charge controller
- A Victron Color control GX system controller and monitor
- Two 12-volt (V), 100-ampere-hour, deep-cycle batteries wired in series
The total cost was just under $3,500.
The solar panels are wired into a 35 2P (3 series, 2 parallel) configuration that produces 25 amperes (A) at 60V DC during peak power. The solar charge controller takes the power and converts it to 24V DC and charges the battery bank. The inverter takes power from the battery bank and inverts it to 120V AC.
Naggy and his team use the solar unit to provide juice to pipe benders, cutters and threading machines.
"We can also run sump pumps off of it when it rains, so we can keep ditches from flooding," he said. "Other trades will also plug in what they need to, so they don't have to bring generators."
The inverter can also be plugged into a small (2K) generator or the power grid if there is a need to boost power, and it will allow up to 50A of power to pass through it without needing to use the batteries onboard. While plugged in, the inverter also acts as a battery charger and maintains the batteries at full charge, so they are ready to go off-grid when needed.
This comes in handy not only when solar power is limited after a few cloudy days in a row, but when extra power is needed.
"For example, if we have a need for a 4,000W load, we can plug the inverter into the generator or the grid to pull the extra power required," he said.
"So far, we have only needed to run a generator on a couple of rainy days, and that was because other trades were plugging sump pumps into our trailer at a time when there wasn't much solar power being produced," Naggy said.
Naggy recently added a second inverter, bringing power up to 6,000W. The two units are paralleled together. Using a standard ethernet cable, they are in sync and run in unison.
"Before, we had to run all of the equipment singly," he said. "With the extra power, we can now run multiple things at the same time."
And, according to Naggy, there is no reason that even more units can't be added.