Sprinkler / Irrigation Controller Wattage for Generator Sizing
About the Sprinkler / Irrigation Controller
An electronic sprinkler or irrigation controller with solenoid valves. The controller draws minimal power, and each solenoid valve draws about 10 to 25 watts when active. There is no starting surge. While lawn irrigation is not essential during outages, greenhouse and garden irrigation systems may need generator power during extended outages to protect plant investments.
Generator Sizing for a Sprinkler / Irrigation Controller
Running a sprinkler / irrigation controller by itself requires a generator with at least 63 W of capacity (1 kW), which includes a 25% safety margin. However, you rarely run a single appliance on a generator. When combined with other appliances, the sprinkler / irrigation controller contributes 50 W to the continuous running load.
The sprinkler / irrigation controller is a resistive load, meaning it uses a heating element or simple electronic circuit rather than a motor. Resistive loads draw the same wattage from the moment they turn on until they turn off, with no starting surge. This makes them the easiest type of appliance to run on a generator. When calculating your total generator load, the sprinkler / irrigation controller adds a flat 50 W to your running total with no impact on peak surge calculations. Resistive loads also produce a power factor of 1.0, meaning they use electricity very efficiently with no wasted reactive power.
To determine the total generator size you need, use our interactive calculator to combine the sprinkler / irrigation controller with your other appliances. The calculator automatically handles the starting surge calculation and applies the 25% safety margin to give you an accurate recommendation. Alternatively, browse the scenarios below to see common generator setups that include the sprinkler / irrigation controller.
Tips for Running a Sprinkler / Irrigation Controller on a Generator
Running a sprinkler / irrigation controller on a generator is straightforward since it is a purely resistive load. There are no special starting procedures or surge considerations. Simply ensure your generator's continuous (rated) wattage exceeds 50 W plus the wattage of all other appliances running simultaneously.
Since the sprinkler / irrigation controller draws a constant 50 W whenever it is operating, you can accurately predict generator fuel consumption. At typical generator fuel efficiencies, running the sprinkler / irrigation controller continuously adds approximately 0.0 gallons of gasoline per hour to your fuel consumption. If the sprinkler / irrigation controller operates intermittently (like a thermostat-controlled heater), the actual fuel impact will be lower.
For sensitive electronic components within the sprinkler / irrigation controller, an inverter generator provides the cleanest power output. However, most resistive appliances work fine on conventional generators as well. If you are running the sprinkler / irrigation controller along with sensitive electronics like computers, the inverter generator protects all connected devices.
Sprinkler / Irrigation Controller Wattage Compared to Similar Appliances
The following table compares the sprinkler / irrigation controller to other appliances in the water & plumbing category. Understanding relative power requirements helps you make informed decisions about which appliances to prioritize on your generator and where you might find opportunities to reduce your total load.
| Appliance | Running Watts | Starting Watts |
|---|---|---|
| Sprinkler / Irrigation Controller (this appliance) | 50 W | — |
| Well Pump (1/2 HP) | 1,000 W | 2,100 W |
| Well Pump (1 HP) | 2,000 W | 4,200 W |
| Sump Pump (1/3 HP) | 800 W | 1,300 W |
| Sump Pump (1/2 HP) | 1,050 W | 2,150 W |
| Electric Water Heater | 4,500 W | — |
| Hot Water Recirculation Pump | 100 W | 200 W |
Frequently Asked Questions
How many watts does a sprinkler / irrigation controller use?
A sprinkler / irrigation controller uses approximately 50 watts of continuous (running) power during normal operation. As a resistive load with no motor, it has no starting surge above its running wattage.
What size generator do I need to run a sprinkler / irrigation controller?
To run a sprinkler / irrigation controller by itself, you need a generator rated for at least 63 W (1 kW), which includes a 25% safety margin above the running wattage of 50W. However, most people run additional appliances alongside the sprinkler / irrigation controller, so your actual generator needs will be higher. Use our calculator to add your other appliances and get a comprehensive recommendation.
Can I run a sprinkler / irrigation controller on an inverter generator?
Yes, a sprinkler / irrigation controller runs perfectly well on an inverter generator. As a resistive load with no motor starting surge, it is one of the easiest appliances to power with any generator type. The clean sine wave output of an inverter generator is a bonus for any electronic components.