Well this is beyond my knowledge. You may want to ask someone who does solar installation to see what are the options. What I can tell you is that OpenSprinkler Latch draws very little power: at resting state it only needs about 100 to up to 200mA current. So even with 12VDC input voltage, this is about 1 to 2 Watt of power. It draws a bit more when opening or closing valves, but since latching valves only require instantaneous power and does not draw any power when the state doesn’t change, that power is basically negligible.