Yes! There are options and we have customers using solar power to power their systems. The systems can be expensive due to the inverters and batteries. (The inverter is what converts the electricity from the solar powered DC to the standard air conditioner AC power.) The air conditioner can work like this, but the cost of batteries makes it significantly more expensive than a standard grid set-up.
Another option is to use a back-up generator for situations where the grid is unreliable.
For folks who are using solar power, the key is keeping the cooler as small and well insulated as possible.
We're happy to help with any specific information for any one who wants to do it.