A complete mobile energy trailer: 7kW of solar panels and 72kWh of batteriesBlogRenewable Energy
By Céleste Léal
How to solve the problem of bringing energy to remote sites without constantly relying on a generator? The situation is further complicated when the energy source must be moved regularly to power different locations.
The solution: install the energy source in a mobile trailer and collect solar energy wherever it goes!
This is the challenge recently taken up by the Volts Énergies team for a logging company in order to provide them with a mobile energy solution for their logging camps.
The trailer was built expressly to accommodate a structure of solar panels and a system of batteries and inverters / chargers inside. The latter equipment is far from occupying the entire interior space, but the size of the trailer is primarily intended to be able to install a large number of solar panels.
No less than 16 photovoltaic panels of 72 cells were installed so as to be able to deploy a solar field of more than 6kW. Divided into two sections of 8 panels, they fold to the side and to the roof of the trailer when it is on the road. Upon arrival at the camp, less than 20 minutes are enough to lift the panels and fix them. A solid aluminum structure was custom made in the workshop to support the panels and withstand the vagaries of the road when transporting the trailer.
The roof section is made up of bifacial panels, with photovoltaic cells on their front and rear sides. When deployed, the reverberation of the sun on the white roof surface produces up to 30% more energy, bringing the total power of the panels to more than 7kW.
All this makes it possible to charge three 24VDC battery banks of 1012Ah (C20) each, bringing the total energy reserve to 72kWh. Using AGM (Absorbed Glass Mat) technology, the batteries are made up of 2V cells assembled in series.
The weight of the batteries was a challenge for the system assembly (the three banks weigh more than 1400 lbs each for a total of 4200 lbs). In order not to endanger the trailer structure, the batteries were installed directly above the axles, built to support the load. They were insulated in a wooden structure to remove access to the battery poles, while leaving openings to dissipate heat during heavy use.
The rest of the equipment (solar charge controllers, inverters / chargers, distribution and electrical protections) was mounted and wired on a wooden plate in the workshop, before being installed on the wall in the trailer.
Two Victron Energy SmartSolar MPPT 150/100 solar charge controllers manage the solar production of the panels on the roof. The panels on the side are managed by two SmartSolar MPPT 150/70 from Victron Energy.
An Orion DC-DC 24V to 12V converter was installed to power the trailer’s 12V lights.
The energy from the batteries is converted into 120 / 240V alternating current by two MultiPlus 24VDC 3kW 120V inverters / chargers from Victron Energy. This equipment can provide a peak power of 12kW, which is perfect for supporting the start-up of the air conditioning systems on site.
Remote monitoring of the system will be provided by the Color Control GX control panel, connected to the satellite internet at the logging camps. Through this device, it is possible to monitor system performance, receive alerts in the event of a problem, and monitor the batteries state of charge. This reading is possible thanks to the presence of a BMV-712 battery monitor, installed between the batteries and the rest of the system.
The control panel also manages the automatic start of the 13kW generator present at the camp. If the solar resource is insufficient or the energy required is high, the generator will start and then stop automatically to recharge the batteries. This start-up can also be controlled remotely
All electrical protections are included in the system. At the outlet of the two inverters, long extensions will be provided to route the current to the three construction trailers that the system supplies. When traveling, these extensions are disconnected, rolled up and stored in the trailer during transport. Everything has been designed to facilitate the installation and removal of equipment quickly and safely for future users.
This trailer will join the first energy storage system built for this customer, delivered by Volts Energies in 2019. A construction trailer, supporting a similar structure of 12 solar panels for a total power of 4,8kWp, houses a reserve of batteries of 35,5kWh.
Thanks to this first system, our client was able to run his camp without using his generator all summer long and achieved impressive fuel savings. Very satisfied with this new energy source, he ordered a second, even more efficient system!
Another great achievement for Volts Energies !