The controller needs to be powered by a power adapter, so if you don’t have a power outlet where the remote controller is to be installed, that can be tricky. One option is solar power — one of the reasons to go with DC-powered OpenSprinkler is if you need to power it off-grid. I’ve seen customers using solar power (usually with a backup battery) to power it. It can accept input voltage of 12VDC, which is what solar usually outputs. But I have no idea about the cost of it — installing a small solar panel should be relatively cheap, I just don’t have any specific number in mind.