Solar & Off-Grid Coop Power Calculator
Calculates daily power consumption and sizes solar panels, 12V battery banks, and charge controllers for off-grid coops.
Figures reviewed against university extension guidance · Last reviewed August 2026
Appliance Power Selection
- Daily Consumption
- 765 Wh
- 63.8 Ah @ 12V
- Solar Panel Size
- 280 Watts
- Min panel array rating
- Battery Bank Size
- 160 Ah
- 12V LiFePO4
- Charge Controller
- 30 Amps
- MPPT Controller size
Sizing an off-grid coop solar system
A winter coop running a 5W LED light (4 hrs), 60W heated waterer (12 hrs), automatic door, and night predator light draws approximately 765 Watt-hours daily (63.8 Ah at 12V). This requires a 280W Solar Panel, a 160Ah 12V LiFePO4 battery, and a 30A MPPT charge controller.
How the off-grid solar calculation works
Total daily energy consumption (Wh) is calculated by multiplying each appliance's wattage rating by its daily operating hours. A 25% safety margin is applied to solar panel sizing to account for wiring resistance, inverter efficiency, and dust/snow coverage on panels.
Battery capacity is calculated based on safe Depth of Discharge (DoD) limits: 80% DoD for LiFePO4 lithium batteries versus 50% DoD for AGM lead-acid batteries.
A worked example
If you only run a 5W LED light and an automatic coop door (total ~25 Wh/day), a simple 20W solar panel paired with a small 10Ah battery is sufficient. However, adding a heated waterer (720 Wh/day) increases power needs significantly, requiring a 200W panel array and a 100Ah battery bank.
Sources
- National Renewable Energy Laboratory — PVWatts Solar Resource Data
- Penn State Extension — Artificial Lighting for Winter Egg Production
Frequently asked questions
- Can you power a heated chicken waterer with solar power?
- Yes, but heated waterers draw significant power (45W–100W). Running a 60W heater for 12 freezing winter hours consumes 720 Watt-hours daily, which requires a minimum 200W solar panel array and a 100Ah 12V battery array to sustain over cloudy days.
- What size solar panel do I need for an automatic coop door?
- Automatic coop door motors draw very little daily power (less than 5 Watt-hours per day). A small 10W to 20W solar panel paired with a small 7Ah to 12Ah 12V battery or internal lithium pack is more than enough to operate an automatic door year-round.
- Should I choose LiFePO4 or Lead Acid batteries for a coop solar system?
- LiFePO4 (Lithium Iron Phosphate) is far superior for off-grid coops. LiFePO4 batteries allow 80% safe depth of discharge (vs. 50% for lead acid), endure 3,000+ charge cycles, weigh much less, and do not emit corrosive gases during charging.
- How many winter sun hours should I calculate for solar sizing?
- In northern North America and Northern Europe, peak winter sun hours drop to 2.5 to 3.5 hours daily. Always size your solar panels based on your region’s lowest winter sun hours so your system works when heating and lighting are needed most.
- Why do I need a charge controller in a coop solar setup?
- A solar charge controller regulates the voltage coming from the solar panels to prevent overcharging and damaging the battery bank. An MPPT (Maximum Power Point Tracking) charge controller is up to 30% more efficient in cold winter weather than standard PWM controllers.