What is a solar tracker?
A solar tracker is a motorised mounting system that rotates solar modules to follow the sun's daily and seasonal motion. By keeping modules better aligned to direct sunlight, trackers capture more energy than fixed-tilt installations on the same site. The two main tracker types are single-axis (rotation along one axis, typically east-west) and dual-axis (rotation along two axes for both daily and seasonal tracking).
Single-axis trackers are the dominant type in Indian utility-scale solar. They typically have a horizontal torque tube oriented north-south, with modules tilting east in the morning, lying flat at noon, and tilting west in the afternoon. Motorised actuators driven by sun-position algorithms perform the rotation. Field-measured gain over fixed-tilt is typically 15 to 25 percent annual, with the gain higher on light-coloured ground and combined with bifacial modules.
Dual-axis trackers add a second axis to track seasonal sun angle in addition to daily motion. The additional gain is typically 5 to 10 percent over single-axis but at substantially higher capital cost and maintenance burden. Dual-axis trackers are rare in utility-scale Indian solar.
Why solar trackers matter
For utility-scale developers, trackers are now standard in most Indian projects since around 2020. The energy gain materially improves project IRR. SECI auction tariffs reflect tracker assumptions, and competitive bidders deploy trackers to be economically competitive.
For ground-mounted commercial projects, trackers offer an option when land is available and the project size justifies the additional cost and operational complexity.
For Indian tracker manufacturers, the segment is a growing opportunity. Indian-made trackers compete on price and service network with international suppliers.
For policy, tracker deployment is part of the broader Atmanirbhar Bharat manufacturing direction, with some Indian companies building domestic capacity.
How a solar tracker works
- Row layout. Modules mounted on a horizontal torque tube (single-axis) or articulated frame (dual-axis).
- Drive system. Motorised actuator rotates the structure.
- Control logic. Software computes optimal tracking angle every minute based on solar position.
- Backtracking. Early morning and late afternoon, the tracker reverses to prevent row-on-row shading.
- Stow mode. High winds or storms trigger flat stow position.
- Monitoring. SCADA system tracks position, motor health, and sensor data.
- Maintenance. Periodic motor, bearing, and structural inspection.
- Failure isolation. Quality designs allow single-row maintenance without affecting plant.
Real example: Indian utility plant with single-axis tracker
Project. 200 MWp plant near Pavagada, Karnataka. Single-axis horizontal tracker. Bifacial PERC modules.
Performance. Annual generation 372 GWh (1,860 kWh per kWp). CUF: 21.3 percent.
Comparison. Equivalent fixed-tilt mono-facial: estimated 320 GWh (1,600 kWh per kWp). Tracker + bifacial added 16 percent over baseline.
Cost premium. Tracker capital: about ₹80 crore added to a ₹900 crore project. About 9 percent premium.
Revenue impact. Additional 52 GWh per year at ₹2.50 PPA tariff = ₹13 crore per year. Tracker capital paid back in about 6 years.
Benefits of solar trackers
- 15 to 30 percent more annual energy. Substantial yield gain.
- Higher CUF. Pushes utility-scale CUF from 18-19 percent to 21-25 percent.
- Better afternoon and morning generation. Higher output during higher-tariff hours.
- Synergistic with bifacial. Combined gain over 30 percent.
- Better land utilisation. More energy per acre of project footprint.
- Mature supplier base. Multiple Indian and international tracker brands.
- Improving cost trajectory. Tracker prices have fallen over the past decade.
Limitations of trackers
Capital cost premium. 8 to 15 percent above fixed-tilt for single-axis; more for dual-axis.
Higher maintenance. Motors, bearings, electronics need service.
Wind exposure. Stow modes must work reliably.
Not viable for rooftop. Space, structure, and cost preclude rooftop use.
Slope sensitivity. Trackers prefer flat ground; sloped sites need terracing.
Failure modes more complex. Tracker failures can affect rows.
Soil moisture and dust impact. Bearings and electronics need protection.
Solar trackers in India
| Aspect | Status |
|---|---|
| Utility-scale standard | Single-axis tracker, increasingly with bifacial modules |
| Typical gain over fixed-tilt | 15 to 25 percent (single-axis), 5 to 10 percent additional (dual-axis) |
| Rooftop application | Negligible |
| Major suppliers | Nextracker, Array Technologies, PV Hardware, Soltec, Trinatracker, Antaisolar, Indian Tier-2 |
| Cost premium | 8 to 15 percent of project cost |
| Maintenance | Annual inspection + periodic service contracts |
| Indian manufacturing | Growing; PLI-supported capacity expansion |
Quick facts
| Term | Solar Tracker (PV Tracker, Solar Tracking Mount) |
|---|---|
| Types | Single-axis (east-west rotation), dual-axis (also seasonal) |
| Typical Indian gain | 15 to 25 percent (single-axis), 20 to 30 percent (single + bifacial) |
| Standard | IEC 62817 |
| Cost premium | 8 to 15 percent over fixed-tilt |
| Backtracking | Standard feature on quality trackers |
| Stow mode | Standard for wind protection |
| Application | Utility-scale ground-mounted, large commercial ground |
Common mistakes about solar trackers
- Considering trackers for rooftop. Not viable.
- Choosing dual-axis when single-axis suffices. Cost rarely justified.
- Skipping backtracking configuration. Row-on-row shading destroys morning yield.
- Underestimating maintenance. Budget annual service and periodic motor replacement.
- Picking lowest-cost tracker. Reliability and service support matter for long-term performance.
- Ignoring wind-stow verification. Critical for monsoon and storm safety.
- Quoting tracker gain without bifacial context. Most modern utility uses both.
- Selecting tracker without slope assessment. Sloped ground requires terracing or different mounting.
Key takeaways
- A solar tracker rotates modules to follow the sun, adding 15 to 30 percent annual energy.
- Single-axis trackers dominate Indian utility-scale; dual-axis is rare.
- Capital premium 8 to 15 percent, justified by yield gain.
- Backtracking and stow modes are essential features.
- Bifacial + tracker is the high-yield Indian utility-scale combination.
- Trackers do not work for rooftop.
- Indian tracker manufacturing is growing; multiple international and domestic suppliers.
Frequently Asked Questions
What is a solar tracker?
A solar tracker is a motorised mounting structure that rotates solar modules to follow the sun. Trackers add 15 to 30 percent annual generation over fixed-tilt mounting. The two main types are single-axis (rotates east to west through the day) and dual-axis (also tracks seasonal sun angle).
What are the types of solar trackers?
Single-axis trackers (the dominant utility-scale type) rotate along one axis, typically east to west. Dual-axis trackers rotate along two axes, following both daily and seasonal motion. Dual-axis adds 5 to 10 percent over single-axis but costs more and is rarely deployed at scale.
Are trackers used on rooftops?
Rarely. Roof space, structural constraints, and the cost premium make trackers impractical for rooftop installations. Fixed-tilt is universal for residential and commercial rooftop. Trackers are for ground-mounted utility-scale and large commercial ground projects.
How much extra energy does a tracker generate?
Single-axis adds 15 to 25 percent over fixed-tilt. Dual-axis adds another 5 to 10 percent over single-axis. Combined with bifacial modules, single-axis + bifacial can exceed 30 percent gain in good Indian sites.
What is backtracking?
Backtracking is the tracker control mode used in early morning and late afternoon to prevent row-on-row shading. When the sun is low, modules tilted to face it would shade the adjacent row; the tracker reverses to prevent the shading at the cost of some sun alignment. All quality trackers include backtracking.
How do trackers handle wind?
Trackers include stow modes where modules flatten to minimise wind loading during storms. Anemometers and weather forecasts trigger stow. Structural designs account for stowed wind load. Tracker reliability under monsoon and storm conditions is a key procurement criterion.
Are trackers more expensive than fixed-tilt?
Yes, by about 8 to 15 percent of project capital cost for single-axis. Dual-axis is significantly more. For utility-scale, the energy gain typically justifies the premium; for rooftop the economics do not work.
What is a horizontal single-axis tracker (HSAT)?
HSAT is the most common single-axis tracker type. The axis of rotation is a horizontal torque tube oriented north-south. Modules rotate east-west through the day. This is the type used in most Indian utility-scale solar.
Do trackers need a lot of maintenance?
More than fixed-tilt but manageable. Motors, bearings, sensors, and control electronics need periodic inspection. Good trackers operate for 25-plus years with structured maintenance programs.
Are trackers compatible with bifacial modules?
Yes, and the combination is synergistic. Tracker-mounted bifacial modules see better rear-side light access throughout the day. Many modern Indian utility-scale projects combine single-axis tracker with bifacial modules for maximum yield.
What are common tracker manufacturers in India?
Nextracker, Array Technologies, PV Hardware, Soltec, Trinatracker, Antaisolar, and Indian Tier-2 manufacturers. The Indian tracker manufacturing base is growing under the broader manufacturing localisation push.
Can a tracker fail and how is that handled?
Single-row failures isolate the affected row. Quality tracker designs allow individual row maintenance without affecting plant operation. Failures include motor breakdowns, sensor drift, structural fatigue, and stow-mode failures. Spare-parts inventory and rapid-response maintenance contracts are standard for utility-scale projects.
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- NREL. Tracker performance modelling and field data. nrel.gov
- IEC 62817. Standard for tracker design qualification.
- Tracker manufacturer datasheets. Nextracker, Array Technologies, PV Hardware, Soltec, Trinatracker, Antaisolar.
- Fraunhofer ISE. Tracker design and performance research.
- SECI tender documents. Tracker requirements in Indian utility-scale auctions.
- Bridge to India and Mercom India. Indian tracker market analysis.
- Indian utility-scale plant operational data. Field-measured tracker gain.
Written by QuickEstimate Editorial, QuickEstimate Editorial (Surat).
Last updated: 4 June 2026.