Solarpunk Steve documents the complete build of a mobile solar power station installed on a lawn care trailer, designed to eliminate grid dependence for a fleet of all-electric mowing equipment. The system uses six 200-watt Rich Solar panels wired in series, producing an open-circuit voltage of around 272 volts and a combined operating current of 5.32 amps. That feeds through a 10-amp MC4 inline fuse and a DC-rated cutoff switch into an EG4 3000EH-48 inverter, which accepts solar input up to 500 volts open circuit. A 5kW EG4 server rack battery stores energy and backs up the system during overcast periods or peak demand. The AC output runs two 20-amp GFCI circuits: one powering four smaller Ego battery chargers, the other dedicated to the Ego Z6 mower charger. In practical testing at a job site, the system was measured pulling around 780 watts from the panels while simultaneously running a battery charger load.
The economics of mobile solar for all-electric trades businesses are becoming meaningfully compelling. Commercial electricity rates in many US markets have increased substantially over the past few years, and companies running all-electric equipment that recharges at a facility each night face compounding exposure to grid pricing. A self-contained solar trailer converts that ongoing operating cost into a single capital investment, with sunlight as the fuel from there. For comparison, a portable generator sized to charge a similar load of batteries would typically burn $2 to $3 of fuel per hour in normal use, adding up quickly across a full working season. The solar trailer has no ongoing fuel cost once built, and it charges during working hours, meaning the equipment arrives home partially recharged and ready for the next day rather than starting from depleted. Steve notes he built a second trailer for a friend in a single day after completing this first one, suggesting the build process becomes considerably faster once the component decisions are settled.
The build went through more iteration than the final product suggests. The battery mount required two complete redesigns: a foam-and-strap method was removed and replaced with a rubber stopper and neoprene foam approach using angle iron brackets cut from material that came with the mower at purchase. The roof mounting also took planning: super strut rails run the length of the 14-foot trailer on snap-and-rack base mounts with integrated rubber seals, elevated just enough off the roof surface to account for the warped metal on this 17-year-old trailer. Flexible conduit rather than rigid metal conduit runs the outlet circuits specifically to prevent road vibrations from wearing through wire insulation over time. The inverter grounding in a mobile application is handled as bonding rather than grounding to Earth, with the inverter casing, battery enclosure, and solar panel rack all connected to the metal trailer frame. The full wiring daisy chains the six panels from front to back in series, with a single positive lead from the first panel running back through the roof penetration to the inverter.
Bottom line: This is the right proof of concept for anyone running an all-electric trades fleet and wondering whether on-site solar charging makes financial sense. The 780-watt real-world output in full sun meaningfully replaces what the equipment would otherwise pull from the grid overnight. The build is not trivial, and mobile inverter grounding has specific requirements that differ from a residential install. Steve flags this honestly and invites expert corrections, which is the appropriate posture. If you are considering something similar, this video is a thorough starting point rather than a shortcut.