Thermal Performance Optimization of Parabolic Trough Solar Collectors

Parabolic trough solar collectors (PTCs) are among the most mature concentrating solar power technologies, employing curved mirrors to focus diffuse and direct solar irradiance onto a linear receiver tube. Optimising their thermal performance is crucial for reducing levelised cost of energy and enhancing grid reliability. Key strategies focus on minimising heat losses and maximising convective heat transfer within the receiver. Optical enhancements include selective coatings that reduce emissivity, improved mirror alignment and novel cavity designs that trap radiation. Thermal optimisation rests on the choice of heat transfer fluid—ranging from synthetic oils and molten salts to advanced nanofluids—and on internal receiver modifications such as twisted tapes, fins or swirl generators. Computational fluid dynamics and reduced‐order analytical models have become indispensable tools for predicting temperature profiles, pressure drops and overall efficiency. Experimental prototypes validate these models, revealing trade-offs between increased heat transfer and parasitic pumping losses. Recent advances also consider system-level integration, including thermal energy storage and hybridisation with conventional power plants. Collectively, these developments address practical challenges of long-term durability, material ageing and economic viability, underscoring the global potential of PTCs in decarbonising industrial heat and grid-scale electricity generation.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Research from all publishers

A comprehensive review of heat-loss mechanisms in linear concentrating collectors categorises studies into analyses of geometric and structural configurations, alternative heat transfer fluids, coating materials and hybrid analytical-experimental assessments. It reveals that efforts to reduce radiative, convective and conductive losses increasingly rely on multi-objective optimisation of receiver geometry and advanced fluid selection.

Three-dimensional numerical investigations have explored the insertion of periodically spaced fins within the absorber tube. Simulations demonstrate that six optimally positioned fins yield up to a 40 per cent increase in local heat transfer coefficient compared with a smooth tube. Comparative analysis of circular, elliptical and square fin cross-sections indicates that circular fins deliver the highest enhancement at moderate flow rates, offering a path to passive performance gains without complex moving parts.

Studies combining swirl-inducing inserts with nanofluids have reported synergistic effects in thermal-hydraulic performance. By tailoring strip-insert geometry and nanoparticle concentration, researchers achieved over a 50 per cent rise in Nusselt number alongside a 22 per cent reduction in thermal losses. These findings underscore the value of coupling fluid‐property modification with internal flow disturbance to attain higher thermal efficiencies while maintaining acceptable pressure‐drop penalties.

Thermal Performance Optimization of Parabolic Trough Solar Collectors publication trend

The graph below shows the total number of articles in thermal performance optimization of parabolic trough solar collectors across all publications each year (not limited to Nature Index journals).

Technical terms

Parabolic trough collector: A solar concentrator featuring a curved reflective surface that focuses sunlight onto a linear receiver tube along the focal axis.

Heat transfer fluid: A medium circulated through the receiver to absorb concentrated solar energy and transport it to storage or a power cycle.

Nanofluid: A base heat transfer fluid with uniformly dispersed nanoparticles designed to enhance thermal conductivity and convective heat transfer.

Swirl generator: An internal insert configured to induce helical flow, thereby increasing turbulence and heat transfer rates at the expense of higher pressure drop.

Nusselt number: A dimensionless parameter that quantifies the ratio of convective to conductive heat transfer across a fluid boundary layer.

Thermal efficiency: The fraction of incident solar energy on the collector aperture that is converted into useful thermal energy in the working fluid.

References

1. Heat loss analysis review: Parabolic trough and linear Fresnel collectors. Renewable and Sustainable Energy Reviews (2024).
2. An extensive review of various technologies for enhancing the thermal and optical performances of parabolic trough collectors. International Journal of Energy Research (2020).
3. Enhancing the Performance of Evacuated and Non-Evacuated Parabolic Trough Collectors Using Twisted Tape Inserts, Perforated Plate Inserts and Internally Finned Absorber. Energies (2018).
4. Parabolic trough solar collectors: A general overview of technology, industrial applications, energy market, modeling, and standards. Green Processing and Synthesis (2020).
5. Modeling and simulation to determine the thermal efficiency of a parabolic solar trough collector system. Case Studies in Thermal Engineering (2019).
6. Solar-assisted steam power plant retrofitted with regenerative system using Parabolic Trough Solar Collectors. Energy Reports (2020).
7. Assessment and Evaluation of the Thermal Performance of Various Working Fluids in Parabolic Trough Collectors of Solar Thermal Power Plants under Non-Uniform Heat Flux Distribution Conditions. Energies (2020).
8. Thermal-Hydraulic Analysis of Parabolic Trough Collectors Using Straight Conical Strip Inserts with Nanofluids. Nanomaterials (2021).
9. Heat Transfer Enhancement in Parabolic through Solar Receiver: A Three-Dimensional Numerical Investigation. Nanomaterials (2022).
10. Study on the Optical Properties of Triangular Cavity Absorber for Parabolic Trough Solar Concentrator. International Journal of Photoenergy (2015).
11. Thermal performance analysis in a parabolic trough solar collector with a novel design of inserted fins. Case Studies in Thermal Engineering (2023).