Switching your borehole pump to solar is one of the smartest ways to cut energy costs and enjoy uninterrupted water supply—especially with the cost of diesel, petrol, and unstable PHCN power.
But the biggest question everyone asks is:

“How many solar panels do I need to power my borehole pump?”

In this guide, you’ll get a clear, step-by-step answer based on pump size, depth, daily water demand, sunlight availability, and system type.

---

🔍 First: Understand What Determines the Number of Solar Panels

The amount of solar panels you need depends on 5 key factors:

1. Pump Horsepower (HP) or Wattage

This is the biggest factor.
Here’s a quick guide:

Pump HP	Typical Wattage
0.5 HP	370W – 450W
0.75 HP	550W – 750W
1 HP	750W – 1100W
1.5 HP	1100W – 1500W
2 HP	1500W – 2200W

2. Pump Type

• AC Pumps → Require inverter + solar panels + batteries (optional).
• DC Solar Pumps → Connect directly to panels (no inverter needed).

3. Starting Current

AC borehole pumps need 2–3× their running power at startup.

4. Depth of Borehole

The deeper the borehole, the more power required.

5. Sunlight in Your Area

Most parts of Nigeria get 4–6 peak sun hours daily.
We use 5 hours as a standard.

---

📌 Formula to Calculate Solar Panels Needed

Step 1: Determine Pump Wattage

Use the nameplate or the HP → Watt chart above.

Step 2: Add 30% Efficiency Loss

Solar power is never 100% efficient.

Required Power = Pump Wattage × 1.3

Step 3: Divide by Solar Panel Output

Most solar installations use 550W, 600W, or 650W panels.

Number of Panels = Required Power ÷ Panel Wattage

---

⭐ Real-World Examples (Most Accurate Guide)

Example 1: 0.5 HP Borehole Pump

• Pump wattage: 400W
• Add 30% losses: 400 × 1.3 = 520W
• Using 550W panel → 1 panel is enough

Conclusion:

0.5 HP pump = 1 × 550W solar panel (for DC pump)
For AC pump (with inverter): 2 panels recommended

---

Example 2: 0.75 HP Borehole Pump

• Pump wattage: 600W
• 600 × 1.3 = 780W
• Using 550W panel → 780 ÷ 550 = 1.4 panels

Conclusion:

0.75 HP pump = 2 × 550W solar panels

---

Example 3: 1 HP Borehole Pump

• Pump wattage: 1000W
• 1000 × 1.3 = 1300W
• 1300 ÷ 550 = 2.3 panels

Conclusion:

1 HP pump = 3 × 550W solar panels (minimum)
For AC pump, it’s safer to use 4 panels.

---

Example 4: 1.5 HP Borehole Pump

• Pump wattage: 1500W
• 1500 × 1.3 = 1950W
• 1950 ÷ 550 = 3.5 panels

Conclusion:

1.5 HP pump = 4 × 550W solar panels
AC pump users should consider 5–6 panels due to starting current.

---

Example 5: 2 HP Borehole Pump

• Pump wattage: 2000W
• 2000 × 1.3 = 2600W
• 2600 ÷ 550 = 4.7 panels

Conclusion:

2 HP pump = 5 × 550W solar panels (minimum)
For AC pumps → 6–8 panels recommended depending on depth.

---

🔥 Quick Cheat Sheet (Bookmark This)

Pump HP	Panels Needed (550W)	AC Pump Panels
0.5 HP	1 – 2	2
0.75 HP	2	3
1 HP	3	4
1.5 HP	4	5–6
2 HP	5	6–8

---

🌓 Should You Use Batteries for Borehole Pumps?

DC solar pumps:

❌ No batteries needed
✔ Pump works when the sun is out
✔ Cheaper system

AC pumps:

Optional batteries, but recommended if:

• You want pumping early morning or evening
• Your location has low sunlight
• You use an inverter with backup

If using batteries, add:

• Inverter
• Charge controller
• Battery bank (200Ah – 400Ah recommended)

---

💧 How Depth Affects Solar Requirements

Depth	Effect
0–50m	Low power use
50–100m	Medium power use
100–180m	High power use
180m+	Very high power use

Deeper boreholes require stronger pumps, which means more panels.

---

☀ Best Time of Day for Solar Pumping

Solar pumps work best from:

10:00am – 4:00pm

This is when sunlight intensity is highest.

---

🔧 Recommended Solar Pump System (Practical Setup)

For 1 HP AC Pump

• 4 × 550W solar panels
• 1.5–2 kVA solar inverter
• Optional: 2 × 200Ah batteries
• 80A MPPT charge controller

For 1 HP DC Solar Pump

• 3 × 550W panels
• No inverter
• No battery
• Direct connection via controller

---

💡 Pro Tips for Accurate Solar Borehole Sizing

✔ Always check pump nameplate
✔ Avoid oversizing or you’ll waste money
✔ Avoid undersizing or the pump won’t start
✔ Use MPPT controllers for maximum efficiency
✔ Choose monocrystalline panels (they work best in Nigeria’s climate)

---

📌 Final Answer: How Many Solar Panels Do You Really Need?

If you want a fast summary:

0.5–0.75 HP pump

➡ 1–2 solar panels

1 HP pump

➡ 3–4 solar panels

1.5 HP pump

➡ 4–6 solar panels

2 HP pump

➡ 5–8 solar panels

Your exact number depends on:

• Whether it’s AC or DC
• Depth
• Starting current
• Sunlight in your area