Drip irrigation units that generate hydroelectric power from the line pressure using an impulse turbine are described. The energy generated may be used (for instance) to operate automatic irrigation control based on moisture sensors in communication with the units, or other purposes for example, field lighting, speaker power, or the like. The sensing and actuation functions may be separated, such that two different units are supplied, one being a sensing unit with hydroelectric generator, and the other being an actuation unit with hydroelectric generator, and these may be linked by wireless means such that the actuation is performed based on data from one or more sensing units. The use of wireless communications also allows for central control when desired. For instance when it is known that rain is on the way, a general command to stop irrigation for all units (regardless of moisture) may be supplied, or if a particularly hot day is anticipated, a general command to open all valves (again regardless of moisture) may be activated in the early morning.