Solar power (specifically solar photovoltaic cells and arrays) is an excellent option for DC power, especially in remote locations not connected to the grid, or other places where it is difficult to import fuel to generate power. If it is set up and managed correctly, solar power is an excellent power source for equipment that is continuously or intermittently running on a long term basis. Solar cells are almost always arranged in arrays to generate enough current and voltage to be useful.
Solar arrays can vary in output depending on requirements like small projects that just need milliwatts or large arrays to cover kilowatt needs. This could be street lights, weather stations, or the International Space Station (ISS). The ISS has 27,000 sqft of solar panels powering the station with 84 to 120 kilowatts of electricity, and charges Li-ion batteries for energy storage to be used while the station is in Earth’s shadow.
The ISS is a great example of how solar arrays are best used with battery backup or to fill in during times when there isn’t enough light for the array to generate power. In other applications the circuit may be completely dependent on the sun to work, and the device is off the rest of the time. If you need it to work in shade or night, a battery and charging system will fill in the gaps. Energy storage for solar power is important for projects ranging from grid power generation to solar powered keyboards.
Solar panels can be ideal for remote locations and long term projects off grid so you can bring in the system once without the need for cable connection to grid, fuel for generators, or replacement batteries to bring in for those that are discharged. Solar arrays limitations include taking up a relatively large space for larger applications, degraded performance when there is less exposure to light (seasonal sunlight, daily sun movement, dust/dirt on the array, clouds, trees, etc), and cost. The cost is less of a factor these days than it was in the past with the cost per kW coming down significantly.
There are some compelling reasons to use solar PV in your project, if it is for a long term and has limited access to main grid power especially. Even if those aren’t factors in your plan, solar PV cells can be a powerful and effective solution for DC power needs.