KUSUM Solar Pump Size by Borewell Depth 2026 Guide

The single most expensive mistake a KUSUM (Kisan Urja Suraksha evam Utthaan Mahabhiyan) applicant makes is choosing the wrong pump horsepower (HP) for their borewell depth. Pick a 3 HP pump for a 180-foot borewell and the water column never lifts to the surface; pick a 10 HP pump for a 50-foot shallow well and you pay for capacity the subsidy does not cover. With the Ministry of New and Renewable Energy (MNRE) limiting central assistance to the 7.5 HP level and capping the Component B solar array at about 1 kWp per HP, getting the sizing right on day one decides whether you receive the full subsidy or rework the application for months.

This guide explains how borewell depth, static water level, and daily crop water requirement combine to dictate the right pump HP, the matching solar kWp, and the KUSUM subsidy slab you fall into. The rules are pulled from MNRE’s KUSUM guidelines and its specification for solar water pumping systems, and the Central Ground Water Board (CGWB) groundwater depth data we use across our installations; the flow figures are our field estimates.

Direct answer. For a borewell up to 30 feet, use a 1 to 2 HP surface pump; 30 to 100 feet needs a 3 to 5 HP submersible; 100 to 200 feet needs a 5 to 7.5 HP submersible; 200 to 300 feet needs a 7.5 to 10 HP submersible. Under KUSUM Component B the solar array is capped at about 1 kWp per HP of pump, and central assistance stops at the 7.5 HP amount in most states. Match the pump to the dynamic head (depth × 1.2) and the crop’s daily litre requirement, not to your old diesel pump’s HP rating.

The rest of this article walks through the four variables that decide sizing, the depth-to-HP matrix we use on the field, water output benchmarks for each HP class, and the crop-by-crop sizing logic for cotton, wheat, vegetables, and sugarcane. If you’re still at the eligibility stage, read the PM KUSUM complete guide first; for the application workflow, see the KUSUM Component B application guide.

Scheme status, October 2026. PM-KUSUM’s sanctioned period ran to 31 March 2026. MNRE has allowed projects whose PPA was signed, or whose Notice to Proceed was issued, on or before 31 December 2025 to complete by 31 March 2027, and has said there will be no extension beyond that date (MNRE office memoranda of 28 March, 25 May and 28 September 2026, published on the PM-KUSUM national portal). MNRE has said the scheme’s committed liabilities will move into a successor scheme, PM-KUSUM 2.0, which it described in March 2026 as at the proposal stage. Before preparing a file, confirm with your state implementing agency whether any application window is actually open.

Why Borewell Depth Drives Pump Sizing

A solar pump’s job is to lift water from the static water level inside the borewell up to the discharge point, usually a storage tank or field outlet, while overcoming pipe friction along the way. The total energy required is set by the total dynamic head (TDH), measured in feet or metres, and TDH is dominated by borewell depth. Every additional 10 feet of depth adds roughly 0.3 kg/cm² (4.3 psi) of pressure the pump must beat. A 5 HP pump that delivers 10,000 litres per hour (LPH) at 50 feet of head delivers only 4,500 LPH at 150 feet, the same pump, less than half the water.

Solar pumps complicate this further because their output is variable. Unlike a grid pump that runs at full rated HP from 6 a.m. to 8 p.m., a solar pump produces full flow only between 10 a.m. and 3 p.m., tapering at the edges. CGWB’s groundwater assessments classify many blocks in states such as Rajasthan, Maharashtra and Karnataka as over-exploited, and falling water levels directly raise the pump HP required for the same yield.

The takeaway: depth is not the only variable, but it is the dominant one. Get depth right, and the other three variables, flow, head, daily water need, fall into place around it.

The 4-Variable Borewell-to-Pump Sizing Method

We use a four-step framework on every site visit before quoting a pump. We call it The 4-Variable Borewell-to-Pump Sizing Method: measure depth, measure flow, calculate head, then size for daily water need. Each variable feeds the next; skip one and the pump arrives wrong.

Variable 1: Borewell Depth (Static and Dynamic)

Depth has two definitions and both matter. Total borewell depth is the drilled length from ground to the bottom of the casing. Static water level (SWL) is where the water stands when the pump is idle, typically 20 to 40 feet below the surface in north India, deeper in the south. Dynamic water level (DWL) is the level after the pump has been running 20 to 30 minutes; the column drops as water is extracted, and the drop is called drawdown.

Sizing must use DWL plus a safety margin, not SWL. A borewell drilled to 250 feet with an SWL of 80 feet and 40 feet of drawdown gives a DWL of 120 feet, that is the depth your pump suction sits below water. Ask your driller for the test pumping report; if you don’t have one, measure SWL with a weighted string and assume 30 to 40% drawdown for sizing.

Variable 2: Borewell Yield (Litres Per Minute)

Yield is the borewell’s natural refill rate, how many litres per minute (LPM) the aquifer can supply without running the well dry. A pump rated above the borewell yield will pull air, cavitate, and burn out within months. Yield is measured during the post-drilling test (the driller runs an air-compressor test for 4 hours and notes the steady flow).

Typical north Indian borewells yield 30 to 150 LPM. A 5 HP solar pump targeted at 8,000 LPH (133 LPM) needs a borewell that yields at least 133 LPM steady. If yield is 80 LPM, drop to a 3 HP pump or accept that the pump cycles on and off as the column refills. We always cap pump LPH at 80% of measured yield.

Variable 3: Total Dynamic Head (TDH)

TDH is what the pump actually works against, in feet or metres. Add three components:

• Suction lift / vertical lift = DWL (the depth from ground to dynamic water level).
• Delivery head = vertical distance from ground to your highest discharge point (tank inlet, sprinkler manifold).
• Friction head = pressure losses inside the delivery pipe; rule of thumb is 10 to 15% of vertical lift for a correctly sized pipe.

Rule of thumb for quick field sizing: TDH ≈ borewell depth × 1.2. A 150-foot borewell with a 20-foot overhead tank and properly sized 2-inch PVC delivers a TDH of around 180 feet. Solar submersible pump curves are published against TDH; pick the curve that delivers your required flow at your calculated TDH.

Variable 4: Daily Water Requirement by Crop

Pump HP must deliver enough water within the solar window (roughly 6 hours of usable daylight pumping for a fixed array, 8 hours for a tracker). Calculate daily need first, then back-solve HP.

A 2-acre cotton plot at peak season needs ~1,200 litres/day. With a 6-hour pumping window, that’s 200 LPH, comfortably handled by even a 2 HP pump at moderate depth. A 5-acre sugarcane plot consuming 30,000 L/day needs 5,000 LPH, a 5 HP pump at 100-foot head, or a 7.5 HP pump at 200-foot head. The crop dictates the LPH target; depth and head dictate the HP that delivers it.

Depth-to-HP Matrix, Definitive Table for KUSUM

This is the field matrix we use across every KUSUM Component B installation. It assumes typical Indian conditions: 5.5 peak sun hours, moderate friction losses, and submersible pumps tested to MNRE’s specification (BIS-standard pump sets).

Borewell depth	Recommended pump	Pump type	Solar kWp (KUSUM B cap)	Typical LPH (peak)	KUSUM Component B fit
0 to 30 ft	1 to 2 HP	Surface / monoblock	1 to 2 kWp	6,000 to 9,000	Eligible (low end)
30 to 60 ft	2 to 3 HP	Submersible	2 to 3 kWp	6,000 to 10,000	Eligible
60 to 100 ft	3 to 5 HP	Submersible	3 to 5 kWp	6,000 to 10,000	Eligible (most common)
100 to 150 ft	5 HP	Submersible	about 5 kWp	7,000 to 9,000	Eligible
150 to 200 ft	5 to 7.5 HP	Submersible	5 to 7.5 kWp	6,000 to 8,500	Eligible
200 to 300 ft	7.5 to 10 HP	Submersible	7.5 to 10 kWp	6,500 to 9,000	Allowed; central assistance stops at 7.5 HP
300+ ft	10 HP+	Specialised submersible	10 kWp+	6,000 to 8,000	Allowed; central assistance stops at 7.5 HP

For Component B, MNRE’s guidelines cap the solar array at about 1 kWp per HP of pump (a 3 HP pump cannot have more than 3 kWp), and its specification sets 4,800 Wp as the minimum for a 5 HP system. In low-irradiance areas east of 80° E longitude (Bihar, Odisha, West Bengal), where peak sun hours run 4.8 to 5.2 instead of 5.5, plan for lower daily output rather than a bigger array. For details on the grid-tied variant that bypasses the HP cap and feeds export, see the KUSUM Component C grid-tied pump guide.

The Component B subsidy values mean a 5 HP standalone solar pump system costing ₹3.2 lakh draws ₹96,000 central + ₹96,000 state, leaving the farmer with ₹1.28 lakh. Confirm your state’s exact share with its implementing agency, because states can add more than the 30% minimum; see our DREBP PM-KUSUM page. For a plain-language walkthrough of how the three components differ, Heaven Designs’ PM-KUSUM explainer is a useful side reference.

Submersible vs Surface Pumps, Which Suits Which Depth

Surface pumps (also called monoblock or centrifugal) sit above ground and suck water up. Submersible pumps sit inside the borewell, below the water line, and push water up. Suction physics limits surface pumps to roughly 25 feet of vertical lift (a perfect vacuum can only lift water 33 feet at sea level; real pumps lose efficiency well before that). Beyond 30 feet DWL, surface pumps cavitate.

In our installations across Rajasthan and Maharashtra, more than 85% of KUSUM Component B sites use submersibles because the dynamic water level sits below the 25-foot suction limit. Surface pumps remain useful for canal-fed plots, large open wells, and tank-to-field boosters.

Get a free borewell sizing review. Send us your borewell test report and crop plan, we’ll match the right HP, kWp, and KUSUM slab in 24 hours. Talk to our solar pump team →

Daily Water Output: Litres per Hour by HP and Head

Pump curves are non-linear: doubling head does not halve flow, and doubling HP does not double flow at the same head. Use this table as a conservative field reference for solar submersibles operating at peak solar irradiance (around noon, clear sky, 1,000 W/m² plane-of-array). KUSUM systems must also meet MNRE’s minimum daily output per watt-peak of array at their rated head, which works out higher than these figures, so ask for the model’s test report.

Pump HP	30 ft head	60 ft head	100 ft head	150 ft head	200 ft head	300 ft head
1 HP	4,500 LPH	3,200 LPH	2,000 LPH	,	,	,
2 HP	8,500 LPH	6,500 LPH	4,500 LPH	2,800 LPH	,	,
3 HP	12,000 LPH	9,500 LPH	7,000 LPH	5,000 LPH	3,000 LPH	,
5 HP	18,000 LPH	14,000 LPH	10,000 LPH	8,000 LPH	6,000 LPH	3,500 LPH
7.5 HP	22,000 LPH	18,000 LPH	13,500 LPH	11,000 LPH	8,500 LPH	5,500 LPH
10 HP	28,000 LPH	23,000 LPH	18,000 LPH	14,500 LPH	12,000 LPH	8,000 LPH

Daily output depends on sunshine, not the full daylight stretch. MNRE’s specification requires an AC system to deliver at least 35 litres per watt-peak per day at 30 m (about 100 ft) total head on a standard day of 7.15 kWh/m² of sunshine, which for a 5 HP system with its 4,800 Wp minimum array is about 1.68 lakh litres. Hazy, cloudy or low-radiation days deliver much less. Always design for the lower number, the buffer prevents irrigation gaps in cloudy weeks.

For an honest cost comparison against the diesel pump you may already own, walk through the numbers in diesel vs solar pump ROI. The solar pump pays back in 4 to 5 years; the diesel pump never stops costing you fuel.

Common Undersizing and Oversizing Mistakes

Eight out of ten KUSUM sizing errors come from the same handful of patterns. We tag each one with the rework cost we’ve seen across the field.

1. 1
   Matching the diesel pump's HP rating. Solar pumps deliver variable output; a 5 HP diesel running 12 hours equals a 7.5 HP solar pump running 6 hours. Up-size when shifting from diesel.
2. 2
   Using static water level instead of dynamic. SWL is the at-rest depth; DWL is what the pump fights against. Skipping drawdown leads to a pump that runs dry in 20 minutes.
3. 3
   Ignoring delivery head and friction losses. A 50-foot delivery line and a 25-foot overhead tank can add 40% to the TDH the pump must beat.
4. 4
   Buying for peak summer yield only. Cloudy monsoon weeks drop output by 30 to 40%. Size with a winter and monsoon buffer if your crop cycle covers those months.
5. 5
   Picking 10 HP without checking state cap. Central assistance under Component B stops at the 7.5 HP amount, so the 8th–10th HP comes out of your pocket unless your state tops it up.
6. 6
   Over-sizing the solar array vs the pump. Under Component B, MNRE caps the array at about 1 kWp per HP, and the controller caps motor draw at rated HP anyway, so extra panels on a 5 HP pump are wasted and can fail inspection.
7. 7
   Forgetting borewell yield cap. A 7.5 HP pump on a 60 LPM borewell short-cycles, burns the motor, and voids warranty. Pump LPH must stay below 80% of measured yield.
8. 8
   Skipping the test report. KUSUM systems must be tested to MNRE's solar water pumping specification by an approved lab. Always ask for the model's test report and confirm the vendor is empanelled before ordering.

If the pump installed under your KUSUM claim has failed, you may be eligible for a replacement under the warranty mechanism, see the KUSUM pump replacement claim guide.

Crop-Specific Sizing, Vegetables vs Wheat vs Cotton vs Sugarcane

Crop water demand is the final filter before locking the HP. The numbers below assume drip irrigation efficiency (90%); flood irrigation roughly doubles the requirement.

Crop	Litres/acre/day at peak	1-acre HP need (100 ft head)	5-acre HP need (100 ft head)
Vegetables (tomato, chilli, brinjal)	800 to 1,200 L	1 to 2 HP	3 to 5 HP
Wheat	400 L	1 HP	2 HP
Cotton	600 L	1 to 2 HP	3 HP
Sugarcane	1,500 to 2,000 L	2 HP	7.5 HP
Paddy (irrigated dry)	1,800 L	2 HP	7.5 to 10 HP
Banana / orchard	1,000 L	1 to 2 HP	5 HP

For a walkthrough of the same method applied to other crops, see our sizing guides for wheat, sugarcane, and paddy farming.

A 5-acre cotton farmer at a 120-foot borewell needs ~3,000 L/day. A 3 HP solar pump at that head delivers ~7,000 LPH peak, roughly 35,000 to 40,000 L/day. The pump exceeds need by 10x because cotton’s daily demand is low, the rest of the capacity goes to filling a buffer tank for early-morning or cloudy-day irrigation. For cotton specifically, see our dedicated solar pump for cotton farming sizing notes.

Verdict. Size your KUSUM solar pump to the maximum-demand crop in your rotation, not the average. A farmer running wheat in rabi and cotton in kharif sizes for cotton; one running sugarcane sizes for sugarcane. The pump’s variable output handles low-demand seasons fine, but it cannot exceed its rated curve in high-demand months.

For most KUSUM Component B applicants across north and central India working borewells in the 60 to 150 foot range with 2 to 5 acres under irrigation, a 5 HP submersible with about a 5 kWp solar array (MNRE’s minimum for 5 HP is 4,800 Wp) is the sweet spot, within the 7.5 HP cap, deep enough into the subsidy stack to make the payback work, and large enough to handle a full crop rotation.

How Heaven Green Energy Designs Solar Pumps by Borewell Profile

Heaven Green Energy is empanelled for KUSUM Component B across Rajasthan, Madhya Pradesh, Maharashtra, and Haryana. We’ve installed solar pumps from 1 HP to 10 HP across borewells ranging from 25 feet to 320 feet, and our sizing playbook is built from the failures we’ve fixed on competitors’ rework jobs. Our process:

• Borewell test report review: we ask for your driller’s air-compressor test, or send a field engineer to measure SWL, drawdown, and yield ourselves.
• CGWB depth verification: we cross-check your block’s water level data against your reported borewell depth to flag risk of further drawdown.
• TDH calculation: depth + delivery + friction, with safety margin built in. No back-of-envelope sizing.
• Tested pump selection: only models tested to MNRE’s specification, with curves matched to your TDH.
• State-cap-aware quoting: we won’t pitch a 10 HP system to a state with a 7.5 HP cap; the rejected subsidy isn’t a problem we’ll create for you.
• 5-year O&M coverage: annual panel cleaning, VFD inspection, and pump health checks under the standard KUSUM warranty plus our service stack.

If you want a broader primer on how the agricultural solar subsidy stacks up nationally before narrowing to your state’s slab, QBits Energy’s KUSUM Yojana subsidy guide is a useful companion read.

Explore the services that match your project:

• PM KUSUM Complete Guide: eligibility, subsidy stacks, and how the three components compare.
• KUSUM Component B Application Guide: step-by-step portal walkthrough.
• Rajasthan DREBP PM-KUSUM: state-specific subsidy stacking for Rajasthan farmers.
• Solar Calculator: quick pump HP and subsidy estimate in 60 seconds.

If you’ve already paid the diesel-pump tax for years, the simplest way to start is to send us your last bill and borewell depth, we’ll tell you whether KUSUM saves you money in the first 12 months.

Frequently Asked Questions

What pump HP do I need for a 100-foot borewell under KUSUM?

For a 100-foot borewell with a dynamic water level around 60 to 80 feet, a 3 to 5 HP submersible pump is correct in most cases. At 5 HP, MNRE’s specification requires at least about 1.68 lakh litres a day at 30 m (about 100 ft) total head on a standard sunny day, ample for 3 to 5 acres of vegetables, cotton, or wheat under drip irrigation. The matching solar array is about 5 kWp (4,800 Wp minimum). Both fall within the 7.5 HP level up to which central assistance is paid.

How is solar pump HP linked to solar panel kWp?

Under KUSUM Component B, MNRE’s guidelines cap the array at about 1 kWp per HP of pump: a 3 HP pump cannot have more than 3 kWp, and MNRE’s specification sets 4,800 Wp as the minimum for a 5 HP system. Outside the scheme, installers sometimes oversize arrays for longer pumping hours, but a KUSUM system must stay within the cap.

Can KUSUM Component B fund a 10 HP solar pump?

Yes, but only partly. MNRE’s guidelines allow pumps above 7.5 HP, with central assistance limited to the amount for a 7.5 HP pump (in North-Eastern and hill states, up to 15 HP for up to 10% of installations). Water user associations and FPOs can get central assistance above 7.5 HP, counted at up to 7.5 HP per member. Any extra support for larger pumps depends on the state, so confirm your state’s current tender circular before ordering a 10 HP pump.

What is the difference between static and dynamic water level when sizing a pump?

Static water level (SWL) is the depth at which water stands inside the borewell when no pump is running, the natural rest position of the aquifer. Dynamic water level (DWL) is where the water drops to once the pump has been running for 20 to 30 minutes; the drop is called drawdown and is typically 30 to 40% of the column. Pump sizing must use DWL plus a safety margin. Sizing against SWL leads to a pump that runs dry as soon as the column draws down.

Will my borewell yield support the pump HP I want to install?

A pump’s litres-per-hour rating must stay below 80% of the borewell’s measured yield, otherwise the pump will short-cycle, cavitate, or pull air. Borewell yield is measured during the post-drilling air-compressor test (the driller runs the well for 4 hours and notes steady flow). A 60 LPM borewell, 3,600 litres per hour, can support at most a 2 to 3 HP pump. Pushing 5 HP onto a 60 LPM well burns the motor inside one season.

Does KUSUM accept any solar pump or only certified ones?

KUSUM accepts only solar water pumping systems tested to MNRE’s specification and testing procedure by an approved test lab, with pump sets and motors meeting the relevant Bureau of Indian Standards standards, supplied by a vendor empanelled in the state tender. Modules must also be domestically made with domestic cells. Non-compliant systems are rejected at the field inspection stage, and the subsidy is not released.

How long does a KUSUM solar pump last and what maintenance does it need?

A BIS-certified solar pump lasts 8 to 12 years on the pump end and 25 years on the solar panel side. Annual maintenance is light, panel cleaning every 15 days in the dry season, VFD inspection once a year, and a borewell test (yield, DWL) every 2 to 3 years to confirm the pump is still matched to the well. The KUSUM warranty mechanism covers pump replacement during the first 5 years if certified defects are documented through the implementing agency.

How do I check my state’s PM-KUSUM Component B subsidy share and HP cap?

Each state’s implementing agency (for Component B, the Horticulture Department in Rajasthan, MEDA in Maharashtra, HAREDA in Haryana, and so on) publishes its tender and scheme notices with the subsidy share (at least 30% state, alongside the 30% MNRE share) and pump sizes. Check the state agency website and the national PM KUSUM portal. For Rajasthan specifically, the DREBP PM-KUSUM portal page lists the active slab.

Can I retrofit my existing diesel pump’s borewell with a KUSUM solar pump?

Yes, most existing borewells used by diesel pumps are suitable for solar conversion, provided the casing is sound and the yield is documented. You will replace the diesel pump head with a solar-rated submersible (or surface unit, depending on depth), add the solar array, and install the variable frequency drive. The KUSUM subsidy applies to the full new system; the salvage value of the diesel pump is incidental. Use the diesel vs solar pump ROI calculator to model the payback.