Irrigation costs in India drain farmer income. Every year, you spend thousands on diesel or face erratic grid power. But what if you could pump water for free using sunlight? That’s where the PM‑KUSUM Yojana and a properly sized solar pump change the game. However, choosing the wrong pump size leads to low output or wasted money. That’s exactly why we built this Solar Pump Sizing Tool – to help you calculate the right HP, solar array, and net subsidy in seconds.
Let’s break down how it works, what data you need, and how to maximise your government subsidy. No fluff, just logic and facts.
Most farmers oversize or undersize their pumps. An undersized pump won’t lift water to the required head, leaving your crops dry. An oversized pump wastes money on extra solar panels and hardware. A solar pump size calculator removes the guesswork. It uses your land area, water depth, and daily crop requirement to recommend the exact pump horsepower (HP).
For example, a 2‑acre farm with a 50‑meter borewell requires a different HP than a 1‑acre vegetable plot. Our tool factors in all variables – total head, sun hours, and pump efficiency – to deliver a custom result.
The Pradhan Mantri Kisan Urja Suraksha evam Utthaan Mahabhiyan (PM‑KUSUM) is a government initiative launched by the Ministry of New and Renewable Energy (MNRE) to promote solar energy in agriculture. It covers standalone solar pumps up to 7.5 HP for farmers with cultivable land.
Under the standard subsidy structure:
For special category states (North‑East, Himachal Pradesh, Jammu & Kashmir, Uttarakhand), the total subsidy goes up to 80%.
Let’s illustrate with real numbers. A 5 HP solar pump system might cost roughly ₹2.5–3 lakhs. With a 60% subsidy, your net investment drops to around ₹1 lakh. You can finance the remaining 40% through an agricultural loan. The tool automatically applies your state’s subsidy percentage so you see the exact net cost.
Using the calculator takes less than a minute. Here’s what you input:
1. Crop & AreaSelect your crop type (paddy, wheat, vegetables, sugarcane, or orchard) or enter a custom water requirement. Then enter your irrigated area in acres. The tool auto‑fills daily water need based on crop data. For instance, paddy requires approximately 15,000 litres per acre per day, while vegetables need about 10,000 litres.
2. Total Head (Water Depth + Delivery Height)This is the vertical distance the pump must lift water – from the water source to the highest delivery point. Measure it in metres. A typical borewell might have 40‑60 metres of total head.
3. Pump Type & EfficiencyChoose DC (solar direct) or AC (via inverter). DC pumps generally work better for standalone solar systems. Pump efficiency varies between 30‑70%. We set a default of 50% – a realistic industry average.
4. Sun Hours & StateEnter average daily peak sun hours (typically 4‑6 hours across most Indian states). Select your state from the dropdown to apply the correct subsidy percentage.
Hit “Calculate”. The tool instantly returns:
How does the tool calculate pump HP? It uses a standard hydraulic energy formula:
Hydraulic Energy (kWh) = (Daily litres × 9.81 × total head) ÷ 3,600,000
Then it divides by (sun hours × pump efficiency) to get the required pump shaft power in kW. Finally, it converts kW to HP (1 HP = 0.746 kW). The solar array size adds an oversize factor of 1.4x for DC pumps and 1.6x for AC pumps to account for efficiency losses.
Example: If you need 10,000 litres daily with 50 metres head and 5 sun hours, the tool calculates approximately 2‑3 HP depending on efficiency. This matches real‑world requirements – a 1 HP solar pump can irrigate about 1 acre of vegetables with drip irrigation.
Solar pump prices in India vary by HP, type, and quality. Based on 2025‑2026 market data:
The solar water pump price includes panels, pump, controller, mounting structure, and installation. For a 5 HP DC system, the total might be ₹3.5‑4 lakhs. After a 60% subsidy, your net cost falls to ₹1.4‑1.6 lakhs.
Flow rate – measured in litres per hour (LPH) – determines how quickly your pump delivers water. To match crop demand:
Required Flow Rate (LPH) = Daily water need (litres) ÷ Pump operating hours per day
For example, if your farm needs 10,000 litres daily and the sun provides 5 hours of effective pumping, your flow rate must be at least 2,000 LPH. If you undersize the flow rate, crops suffer. If you oversize, you waste energy and money.
Our tool calculates the exact discharge rate based on your inputs, so you never guess.
Subsidy percentages vary because states add their own contribution. Here’s the current landscape:
Special category states (North‑East, Himachal, J&K, Uttarakhand): Up to 80%.
The MNRE also sets a benchmark cost for each HP category. Your subsidy applies to the lower of benchmark cost or tender cost. The tool uses realistic benchmark estimates derived from MNRE guidelines.
As of October 2025, PM‑KUSUM has achieved 9,466 MW of installed solar capacity across India, with the government releasing INR 7,089 crore in financial support.
Farmers often make three errors when buying a solar pump:
Our tool accounts for all three factors automatically.
Getting the subsidy is straightforward if you follow these steps:
You can also apply through your state’s renewable energy agency. Most states have dedicated portals for faster processing.
We built this tool using:
Every formula is transparent. You can see the exact calculation for hydraulic energy, pump power, and solar array size. No black boxes, no fake data.
Every farm is different. Your water depth, crop pattern, and land area are unique. Run the calculator multiple times with different scenarios – try varying the total head or crop type. You’ll quickly see how each variable affects the recommended HP and net cost.
Once you have your sizing and subsidy estimate, consult an MNRE‑empanelled vendor for a final quote. They’ll handle the installation and warranty.
Disclaimer: All cost estimates and subsidy calculations are indicative and based on MNRE guidelines and 2025‑2026 market data. Actual costs may vary by vendor, location, and time of purchase. Always verify with official state nodal agencies before making a purchase decision.