Mobile Workspace Powered by the Sun
NowStar of Columbus, Ohio designs and manufacturers state-of-the art mobile workspaces that are literally powered by the sun. This particular workspace is a prototype built for Caterpillar, the world’s leading manufacturer of construction and mining equipment. Caterpillar wanted to explore modernizing and de-carbonizing the commercial construction site while reducing onsite operational cost driven by diesel generators, which are as dirty as they are loud. You've probably seen them at construction sites: single or double wide mobile home looking metal boxes, running a generator most of the day to provide lighting, computers, a small break room, and meeting space to discuss on-going aspects of the construction site. Caterpillar, NowStar, and Off-Grid Power Systems knew there was a better way. Meet the NowStar SolarPro 28.
NowStar is a company led by engineers and craftsmen with years of designing and building innovative and beautiful structures. From their roots in high-end home remodeling, and then tiny home construction, and now solar-powered mobile workspaces, NowStar used that experience and delivered an amazing product that checked all of Caterpillar’s requirements with additional functional and aesthetic improvements. In the years to come, you will no doubt see a NowStar trailer at construction sites before you see the first bulldozers arrive. This trailer doesn't need utility power to provide a clean, comfortable, and modern office experience.
Visit the NowStar website here for more information.
The power of collaboration
Chris Brandon is President and Principal Solutions Engineer for NowStar. Chris contacted Off-Grid Power Systems (OGPS) in January of 2025 with some initial questions. He was feeling us out to determine if we were the right company to help them design the power plant for the prototype unit. Chris, an electrical engineer, had done his homework and determined that Victron Energy products would likely play a part in the design, and realized that he had a highly experienced team of Victron experts just across town. In fact, there are several businesses in the area that sell and install Victron products, and after talking to other companies he determined that the experts at OGPS were the best consultants on the project and could deliver on time. In just six months, they were contracted to deliver the prototype and there was little time to spare.
OGPS got busy gathering requirements and making recommendations based on years of experience creating custom-tailored solutions for specialty vehicles. We quickly determined the right configuration, but the real fun was in discussing methods of efficiently heating and cooling the space and finding unique ways to maximize solar production on a relatively small trailer in a way that blended with the aesthetic that NowStar wanted to provide to Caterpillar. For example, the choice of Merlin Solar Trailblazer 240L black-on-black flexible solar panels for the entry side of the trailer added an additional kilowatt of solar production while neatly blending in with Caterpillar's trademark yellow and black color scheme.
The results
NowStar knocked it out of the park! Caterpillar was so impressed that they quickly placed follow-on orders. For the curious, here is what delivers on the promise of a clean, quiet power plant:
- Two Victron Energy Quattro 48/3000 inverter/chargers
- One Victron Autotransformer to balance 120V loads evenly across the inverters
- Ten Hyperion 400W black-on-black solar panels on the roof for 4kW of peak solar production
- S-5! standing-seam roof clamps and PVKIT attachments to mount the Hyperion solar panels to the roof. The S-5! brackets provide a robust means of mounting solar panels to metal roofs with ZERO penetrations
- Four Merlin Solar TBS240L solar panels mounted vertically to one wall of the trailer to deliver an additional 1kW of peak solar production
- Two Victron SmartSolar MPPT solar charge controllers; one for each array
- Lynx power distribution system
- Four Pytes V5° internally heated lithium batteries for 20kWh of energy storage
- A Victron Cerbo GX with Touch 70 screen to monitor and control the entire system
In full transparency, the trailer does utilize a 9kW propane-powered generator for wintertime use when solar production might not be sufficient. The Victron Cerbo GX can start and stop the generator as needed, making this is a hands-off system for the site managers. In reality, the SolarPro 28 by NowStar is so well insulated, and the heating and cooling systems consume such little power that generator use is expected to be minimal. Construction can't stop and wait for the clouds to disperse, so having a backup generator just makes good business sense.
In the customers' own words
But, don't take our word for it. Chris Brandon says:
"OGPS has proven to be NowStar’s most strategic partner. From design through commissioning OGPS remained steadfast and professional contributing expertise, recommendations, and support throughout. OGPS delivers on their commitment to customer success allowing NowStar to deliver disruptive technologies to a rapidly emerging market."