Farm solar is different from rooftop solar in ways that matter. More available land, different load profiles (often pumping-dominated), different economic drivers, different maintenance realities. This guide covers the three main approaches.
Three types of farm solar
- Ground-mount on non-productive land. Traditional solar arrays on parts of the farm that don't produce crop revenue — fence lines, slopes, marginal ground. Most common and most straightforward.
- Solar pumping. Direct-drive solar systems for irrigation, borewell water, or livestock watering. Sometimes the fastest-payback solar application on a farm.
- Agri-voltaic. Solar arrays mounted high enough that crops can grow underneath. Dual revenue from the same land — but only economic for specific crop types.
Each has different economics and different suitability conditions. Most farms benefit from one or two; few benefit from all three.
Ground-mount basics
The simplest approach: install arrays on land that isn't currently producing crop revenue. Common candidates: corners of fields bordered by infrastructure, sloped or rocky areas, easements, or buffer zones around farm buildings.
Land requirements
Approximate rule of thumb: 1 hectare produces 0.8–1 MWp with standard row spacing. Tighter spacing increases capacity but reduces access for maintenance. Wider spacing for tracker systems or agri-voltaic reduces capacity per hectare.
Fixed-tilt vs tracker
- Fixed-tilt: panels mounted at a fixed angle. Simpler, cheaper, more reliable. Standard for most sizes.
- Single-axis tracker: panels rotate through the day to follow the sun. Adds 15–25% to annual yield. Higher capex and ongoing maintenance. Typically worth it only for larger arrays (500 kWp+) in high-irradiance regions.
Structural considerations
Ground-mount structures need foundations sized for soil type and local wind loading. Ramming pile foundations (driven into the ground) are cheaper and faster than concrete-set piles, but require soil conditions that allow driving. Typhoon-prone regions require heavier structural design and certified hardware.
Connection and grid export
On-farm systems are usually sized against the farm's own electricity consumption first (pumping, cold storage, milk coolers, farmhouse loads) with any surplus exported. Larger systems may be sized for export as the primary business case — but the economics of pure-export solar depend heavily on local feed-in tariffs or PPA availability.
Solar pumping
Solar pumping is often the fastest-payback solar application on a farm — especially where the alternative is diesel pumping or grid extension to a remote borewell.
Direct-drive solar pumping
Simplest architecture: panels → inverter/controller → pump. When the sun shines, the pump runs. No batteries, no connection to the grid. Ideal for irrigation where water can be stored in soil, storage tanks, or pond buffers.
Hybrid solar pumping
Adds grid or battery backup so the pump can run regardless of sun. More complex, more expensive, but necessary when on-demand pumping can't wait for daylight.
Economic case
Where you're currently running a diesel pump, the payback on replacing it with direct-drive solar is often 3–5 years — and after that, zero fuel cost. Where the alternative is a grid extension over a long distance, solar pumping can save the entire extension cost.
The key question is daily water volume, not pump kW. A right-sized solar pumping system matches the day's water demand to the day's solar production, with buffer storage to smooth out cloudy spells. Storage tanks, ponds, or soil moisture all count as buffer.
Agri-voltaic
Agri-voltaic (also called agrivoltaics or agri-PV) is solar arrays mounted high enough and spaced widely enough that crops can grow underneath. Same hectare produces both electricity and food.
When it works
Partial shading is beneficial for shade-tolerant crops, particularly in hot climates:
- Leafy greens (lettuce, spinach, kale)
- Many berries
- Coffee, cacao
- Some herbs
- Livestock grazing (especially sheep)
For these, partial shading can reduce heat stress, cut water demand, and sometimes improve yield.
When it doesn't
Many staple crops need full sun and lose yield under shading:
- Rice
- Wheat, maize, soybeans
- Most fruit trees
- Sugar cane, cotton
On land producing these, standard ground-mount on a separate parcel is almost always better than agri-voltaic.
Economic premium
Agri-voltaic mounting structures cost 15–40% more per kWp than standard ground-mount. Worth the premium when: land is constrained, the crop benefits meaningfully from shading, and the farm's electricity demand absorbs much of the production on-site.
Deciding what to build
Here's the framework:
- Is there a pumping load? If yes → solar pumping is probably the first project to scope. Simple economics, fast payback.
- Is there non-productive land available? If yes → ground-mount sized to farm consumption + surplus export (if favourable).
- Are shade-tolerant crops part of the operation? If yes and land is constrained → consider agri-voltaic for that specific crop area.
- Is grid export economic? Check feed-in tariff rules. In many Asian markets, export rates are low enough that sizing for self-consumption gives better ROI.
Most farms benefit from a mix: solar pumping on one borewell, ground-mount sized to the farmhouse and cold storage loads, possibly agri-voltaic over shade-tolerant plots. The right answer is project-specific and requires looking at the actual farm, the actual crops, and the actual electricity tariff.