Solar Pump for Borewell in India: Complete Sizing & Selection Guide

The Short Answer

The right solar pump for your borewell depends on depth to water level and daily water requirement. A 100-foot borewell needs a 3 HP pump, a 300-foot borewell needs 5 HP, and a 500-foot borewell needs 7.5 HP or more. All are submersible pumps — the only type that works for borewells. KUSUM Yojana subsidises up to 60% of the cost.

How to Size a Solar Pump for Your Borewell

Two measurements determine your pump size:

Total Dynamic Head (TDH) = static water level + delivery height + friction losses (typically add 15% to account for pipe friction). Measured in feet or metres.
Daily water requirement = farm area × crop water need. Measured in litres per day.

With these two numbers, use this sizing table:

Water Level (feet)	Up to 60,000 L/day	Up to 1,80,000 L/day	Up to 3,00,000 L/day	Up to 5,00,000 L/day
Up to 100 ft	1 HP	2 HP	3 HP	5 HP
100–200 ft	2 HP	3 HP	5 HP	7.5 HP
200–350 ft	3 HP	5 HP	7.5 HP	10 HP
350–500 ft	5 HP	7.5 HP	10 HP	10+ HP
500+ ft	7.5 HP	10 HP	10+ HP	15+ HP

Understanding Total Dynamic Head (TDH)

TDH is the single most important number for pump sizing. It measures the total effort the pump must make:

TDH = Static Water Level + Delivery Head + Friction Losses

Static Water Level (SWL) — depth from ground to the water surface in your borewell when the pump is NOT running. This varies seasonally — use the lowest level (typically pre-monsoon) for sizing.
Drawdown — how much the water level drops when the pump is running. Typically 10–30 feet depending on aquifer yield.
Delivery Head — height from ground level to where the water is delivered (overhead tank, hilltop field, etc.)
Friction Losses — resistance from pipe bends, length, and diameter. Add 10–15% of total head as a rule of thumb.

Example: Borewell SWL 200 feet + drawdown 30 feet + delivery to tank 20 feet above ground + friction (25 feet) = TDH of 275 feet. A 5 HP pump is appropriate.

Borewell Diameter and Pump Compatibility

Borewell Diameter	Compatible HP Range	Pump Motor OD
4 inch (100 mm)	1–3 HP	95 mm
4.5 inch (115 mm)	1–5 HP	95–100 mm
5 inch (125 mm)	3–5 HP	100–115 mm
6 inch (150 mm)	5–10 HP	115–140 mm
8 inch (200 mm)	7.5–15+ HP	140–175 mm

Critical: Measure the inner diameter of your borewell casing. The pump motor OD must be at least 10 mm smaller than the casing ID for safe installation and water flow around the motor (which needs water flow for cooling).

Borewell Solar Pump Prices

Borewell Depth	Recommended HP	System Price	After KUSUM
50–100 ft	1 HP	₹60,000–₹90,000	₹18,000–₹36,000
100–200 ft	3 HP	₹1,40,000–₹1,80,000	₹42,000–₹72,000
200–350 ft	5 HP	₹2,00,000–₹2,80,000	₹60,000–₹1,12,000
350–500 ft	7.5 HP	₹2,80,000–₹3,60,000	₹84,000–₹1,44,000
500+ ft	10 HP	₹3,50,000–₹4,50,000	₹1,05,000–₹1,80,000

These are guide prices. Actual cost depends on pump stages, brand, and controller type. Complete price guide →

Common Borewell Problems and Solutions

Low yield borewell — if your borewell yields less than expected, the pump may run dry during peak hours. Solution: install a pump with dry-run protection (standard in modern solar controllers) and use a smaller pump that matches your borewell yield rather than depth.
Sandy water — sand particles erode pump impellers rapidly. Solution: use pumps with stainless steel (SS 304/316) impellers rather than noryl (plastic). CRI and Kirloskar offer SS impeller variants.
Hard water (high TDS) — causes mineral deposits on impellers. Solution: SS impellers resist scaling better. Plan annual descaling maintenance.
Seasonal water level fluctuation — water table drops 50–100 feet in summer vs monsoon. Solution: size the pump for the lowest pre-monsoon water level to ensure year-round operation.

Installation Best Practices

Borewell yield test — pump the borewell for 4–6 hours using a hired diesel pump and measure sustained flow rate. This determines the maximum pump size your borewell can support.
Pump setting depth — set the pump at least 30 feet below the lowest expected water level to prevent dry running during peak summer.
Delivery pipe selection — GI pipes for depths up to 300 feet, HDPE pipes for deeper installations (lighter, easier to handle).
Safety cable — always attach a stainless steel safety cable to the pump assembly to prevent it from falling into the borewell.
Panel placement — mount panels within 30–50 metres of the borewell to minimise cable losses.

Get Your Borewell Assessed

Every borewell is unique. Your dealer should conduct a site visit to measure casing diameter, static water level, and yield before recommending a pump. Solar Vipani connects you with verified dealers who provide free assessments.

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Common questions

Which HP solar pump is best for a 200-foot borewell?

A 3 HP solar submersible pump is optimal for a 200-foot borewell. It delivers 80,000–1,20,000 litres per day at this depth and costs ₹1,40,000–₹1,80,000 before KUSUM subsidy. If your daily water demand exceeds 1,50,000 litres, consider stepping up to 5 HP.

Can a solar pump work with a low-yield borewell?

Yes, but you must match the pump to the borewell yield, not just its depth. If your borewell yields only 500 litres per hour, a smaller pump (1–2 HP) with dry-run protection is better than a large pump that outpaces the aquifer and runs dry repeatedly.

How do I know my borewell depth?

Check your borewell drilling report if available. Otherwise, lower a weighted string or measuring tape into the borewell until it hits water (static water level) and then until it hits bottom (total depth). Your solar pump dealer can also perform this measurement during the site survey.

Should I use GI or HDPE pipes for the borewell delivery?

GI (galvanised iron) pipes are standard for borewells up to 300 feet — they are rigid and durable. HDPE pipes are lighter, cheaper, and corrosion-resistant, making them preferred for deeper installations (300+ feet) where the weight of GI pipe becomes difficult to manage.

What happens if the water level in my borewell drops below the pump?

Modern solar pump controllers include dry-run protection — they detect when the pump is no longer submerged and shut it down automatically to prevent motor damage. The pump restarts once the water level recovers. This is a standard feature in all KUSUM-approved solar pump systems.

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