Complete Solar System for a 1HP Well Pump (Off-Grid)
1HP well pump running 2 hours per day plus a cabin load of refrigerator, lights, laptop, and a fan. Total approximately 4,000Wh per day.
Quick Answer
The 3,000W pure sine wave inverter provides a 6,000W surge rating — well above the pump's 2,250W startup requirement. The 48V LiFePO4 bank delivers surge current with minimal voltage sag, preventing pump restart loops. Six 200W panels (1,200W) at 5 peak sun hours generate 4,500Wh daily — slightly above the 4,000Wh load for daily surplus. The 313Ah at 48V stores 3.75 days of autonomy for extended cloudy periods. The plug-and-play solution is the EcoFlow Delta 2 Max + 400W Solar Panel ($1,848), which delivers 2,048Wh of storage and 2,400W of AC output with solar recharge built in.
System Specification
Sized for 4,000Wh/day at 48V.
| Component | Specification |
|---|---|
| Daily Energy Use | 4,000 Wh/day |
| Solar Panel Array | 1,200W |
| Battery Capacity | 15,000Wh (313Ah at 48V) |
| Charge Controller | 40A MPPT |
| Inverter | 3,000W Pure Sine Wave |
| System Voltage | 48V DC |
Option 1: EcoFlow All-in-One Bundle (Easiest Setup)
EcoFlow Delta 2 Max + 400W Solar Panel
2,048Wh expandable to 6,144Wh with 400W panel. 2,400W output covers heavy appliances and tools.
- Capacity: 2,048Wh
- AC Output: 2,400W continuous
- Price: $1,848
No wiring required. Plug the solar panel into the station and plug appliances into the AC outlets.
Option 2: DIY Mid-Range Build (Best Long-Term Value)
Higher upfront cost than a bundled station but significantly more capacity and expandability. Best for permanent installations.
renogy-200w-x6
litime-100ah-48v-x3
victron-100-40-mppt
aims-3000w-inverter
Option 3: DIY Budget Build (Lowest Upfront Cost)
The lowest-cost path to solar power. AGM batteries cost more to operate long-term due to shorter cycle life, but work well for occasional or seasonal use.
newpowa-200w-x6
weize-200ah-agm-x6
epever-40a
renogy-3000w-inverter
Why This System Works
The 3,000W pure sine wave inverter provides a 6,000W surge rating — well above the pump's 2,250W startup requirement. The 48V LiFePO4 bank delivers surge current with minimal voltage sag, preventing pump restart loops. Six 200W panels (1,200W) at 5 peak sun hours generate 4,500Wh daily — slightly above the 4,000Wh load for daily surplus. The 313Ah at 48V stores 3.75 days of autonomy for extended cloudy periods.
Frequently Asked Questions
Why does the inverter need to be 3,000W for a 750W pump?
The pump's running wattage is 750W, but it starts at 2,250W (3x running) for 1–2 seconds. Your inverter's continuous watt rating determines how much steady power it delivers. Its surge rating (typically 2x continuous) determines the peak. A 2,000W inverter's 4,000W surge handles the startup. But to provide safety margin, size for 3,000W continuous (6,000W surge) — keeping the startup well within the inverter's surge range prevents trips, extends inverter life, and protects the pump motor from brownout restarts.
Can I use an AGM battery for a well pump solar system?
AGM works but is poorly suited. The 2,250W startup surge draws over 46 amps from a 48V AGM bank. AGM batteries suffer significant voltage sag under high current draw, which can cause the inverter to shut down mid-startup — exactly the restart loop that damages pump motors. LiFePO4 batteries deliver surge current with far less voltage sag due to lower internal resistance. For a well pump application specifically, LiFePO4 is the strongly recommended battery chemistry.
How do I size a water storage tank to reduce pump cycling?
A pressure tank (20–80 gallons) between the pump and the house plumbing reduces pump cycling significantly. Instead of the pump starting every time a faucet opens, the pressure tank maintains system pressure for 3–5 gallon draws before the pump kicks on. This means instead of 50+ pump cycles per day, you get 5–10 cycles — dramatically reducing surge current events and extending pump and battery life. Size the pressure tank at 20% of daily water demand: for a household using 100 gallons/day, a 20-gallon tank is appropriate.
Different loads? Customize for your setup.
The calculator sizes your exact system based on your appliances, location, and budget.
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