About the Concrete Volume & Mix
Concrete volume calculation estimates the total quantity of concrete (in m³) required for all civil works in a solar plant — including foundations, cable trenches, cable duct banks, equipment pads, access roads, and bunding — for material procurement and cost estimation.
How to calculate it
- 1List all concrete works: mounting structure foundations, inverter room floor/slab, transformer bund, cable trench lining, equipment pads (ACDB, DCDB, weather station), access road sub-base, perimeter drain.
- 2Calculate each volume: L × W × H for rectangular elements; use standard formulas for trapezoidal trenches.
- 3Sum all volumes. Add 5–10% wastage factor.
- 4Specify concrete grade: M20 (fck = 20 MPa) is standard for lightly loaded foundations; M25 for inverter room slabs and equipment pads.
- 5Estimate cost: M20 RMC (Ready Mix Concrete) ₹5,500–7,000/m³ delivered; site-mixed ₹3,500–5,000/m³ depending on location.
Worked example
A 500 kWp ground-mount plant: foundations (18 m³) + inverter room slab 10 m × 5 m × 0.15 m (7.5 m³) + transformer bund 3 m × 3 m × 0.3 m base + 3 m × 4 × 0.1 m walls (2.7 m³) + cable trench 200 m × 0.4 m wide × 0.5 m deep (40 m³) + equipment pads (2 m³). Total = 70.2 m³ + 7% wastage = 75 m³. At ₹6,000/m³ RMC: ₹4.5 L for concrete.
What you can calculate
- M15/M20/M25
- Bags of cement
- Sand & aggregate
- IS 456:2000
Frequently asked questions
Is ready-mix concrete (RMC) better than site-mixed for solar projects?
RMC offers consistent quality (guaranteed grade), faster pouring, and no on-site mixing equipment. For large projects (> 100 m³) in urban areas near an RMC plant, RMC is preferred. For remote rural projects (far from an RMC batching plant), site-mixed concrete is often more practical — material can be transported and mixed on-site. The critical factor is the water-cement ratio: poorly mixed site concrete with excess water is weaker than the specified grade, risking foundation failures.
What concrete grade should be used for solar mounting foundations?
M20 (characteristic compressive strength 20 N/mm²) is the minimum grade specified for plain and reinforced concrete foundations per IS 456. M25 is recommended for: (1) foundations in aggressive soil conditions (high sulphate, coastal areas); (2) slabs and equipment bases subject to dynamic loads; (3) any element exposed to weather with thin cover. Avoid M15 for structural elements — it is only permitted for mass concrete filling and levelling work.
Ready to build your solar project?
Get free quotes from verified EPCs and installers across India.
You might also need
Pedestal Height
Calculate front and rear pedestal heights for target module tilt on flat rooftops
OpenModule Layout Planner
Plan tables, rows and string configuration for a rooftop array
OpenSetback from Parapet
Calculate minimum module setback from parapet walls to avoid shading
OpenBallast Weight
Calculate ballast required to resist IS 875 Part 3 wind uplift without penetrations
OpenWind Load (Rooftop)
Calculate uplift and lateral wind forces on rooftop PV modules per IS 875 Part 3
OpenAnchor Bolt Sizing
Determine anchor bolt count, diameter, and embedment depth for structural loads
Open