Cooling solar modules with nanofluids based on graphene oxide, Mxene

<p class="p1"><span class="s1">An international research group has developed a novel solar module passive cooling system that integrates three-dimensional oscillating heat pipe (3D-OHP) with different combinations of nanofluids based on hybrid graphene oxide (GO) and a two-dimensional titanium carbide known as MXene (Ti3C2Tx). MXene compounds take their name from their graphene-like morphology and are made via selective etching of <a class="more-link" href="https://www.pv-magazine.com/2026/04/13/cooling-solar-modules-with-nanofluids-based-on-graphene-oxide-mxene/">[&hellip;]</a></span></p><p>An international research group has developed a novel solar module passive cooling system that integrates three-dimensional oscillating heat pipe (3D-OHP) with different combinations of nanofluids based on hybrid graphene oxide (GO) and a two-dimensional titanium carbide known as <a class="topic-link" href="https://www.sciencedirect.com/topics/engineering/mxene" title="Learn more about MXene from ScienceDirect's AI-generated Topic Pages">MXene</a> (Ti3C2Tx).</p>
<p>MXene<span class="aCOpRe"> compounds take their name from their graphene-like morphology and are made via selective etching of certain atomic layers from a bulk crystal known as MAX. Recently, these materials have also shown promise for <a href="https://www.pv-magazine.com/2025/11/25/perovskite-solar-cell-based-on-mxene-achieves-record-breaking-efficiency-of-25-75/" rel="noopener" target="_blank">use in PV technology</a> due to their unique optoelectronic properties, such as their large charge carrier mobility, excellent metallic conductivity, high optical transmittance, and tunable work function (WF). </span></p>
<p>“The main novelty lies in integrating a 3D-OHP with a surfactant-free hybrid GO–MXene nanofluid for urban PV cooling, and evaluating it comprehensively from thermal, electrical, exergy, and economic perspectives in real outdoor conditions,” corresponding author Mahyar Kargaran told <strong>pv magazine</strong>. “To our knowledge, this is the first experimental study to combine 3D-OHP + GO–MXene and evaluate it holistically for urban PV.”</p>
<p>Kargaran explained that the system is passive, stable, and surfactant-free. “We are currently exploring the simultaneous use of multiple 3D-OHP units, two or three operating together, to cool larger PV arrays and evaluate multi-unit thermal behavior,” he added. “Additional follow-up work includes optimization of geometry and concentration, integration with PV-battery systems, and comparisons with other advanced nanofluids and surface treatments.”</p>
<p>The OHP is a sealed tube in which liquid and vapor naturally move back and forth, carrying heat from a hot area to a cooler one without a pump. In this research, the 3D-OHP was attached to a 50 W PV module, with an efficiency of 13.82%. The cooling device was constructed from red copper tubing, with an internal diameter of 2 mm and an external diameter of 4 mm. It had a 7-turn configuration that comprised three distinct sections: a 200 mm evaporator, a 109 mm adiabatic zone, and a 200 mm condenser.</p>
<p>Half of the tubing volume was filled with nanofluids based on deionized water. GO, MXene, or a 1:1 hybrid of both was added at concentrations of 0.1 wt% and 0.2 wt%. The 3D-OHP system was therefore tested using GO, MXene, and the hybrid fluid at both concentrations, and compared to a reference PV panel without cooling. Experiments were conducted in August in Mashhad, northeastern Iran, under solar irradiance ranging from 660 to 1,090 W/m².</p>
<p>“Two findings were particularly notable,” said Kargaran. “First, the performance gains exceeded expectations, with temperature reductions of over 24 C, a 14.9% increase in power output (from 42.1 W to 48.3 W), and efficiency improving from 10.02% to 11.51%. Second, despite a 31% increase in viscosity, the hybrid nanofluid maintained excellent stability and delivered strong exergy performance of up to 30.9%, while remaining economically competitive, with a levelized cost of electricity (LCOE) of $0.083/kWh and a levelized cost of storage (LCOS) of $0.273/kWh.”</p>
<p>The system was presented in “<a href="https://www.sciencedirect.com/science/article/abs/pii/S0378778826004305" rel="noopener" target="_blank">Hybrid GO-MXene nanofluids in 3D oscillating heat pipes for efficient urban PV cooling: Improved energy, exergy, and economic performance</a>,” published in <em>Energy and Buildings. </em>Researchers from China’s <a href="https://www.pv-magazine.com/2025/08/04/lng-solar-collectors-improve-round-trip-efficiency-of-laes-systems/" rel="noopener" target="_blank">Xi’an University of Science and Technology</a>, Iran’s <a href="https://www.pv-magazine.com/2024/01/03/photovoltaics-may-increase-safety-in-nuclear-power-plants/" rel="noopener" target="_blank">Islamic Azad University</a>, <a href="https://www.pv-magazine.com/2025/04/10/scientists-testing-perovskite-silicon-tandem-solar-cells-with-interdigitated-back-contacts/" rel="noopener" target="_blank">University of Tabriz</a>, the United States' <a href="https://www.pv-magazine.com/2026/01/12/capex-driven-strategies-can-reduce-solar-lcoe-by-20/" rel="noopener" target="_blank">Texas A&amp;M University</a>, and the United Kingdom’s <a href="https://www.pv-magazine.com/2025/08/12/indoor-perovskite-solar-cell-built-with-triple-passivation-strategy-achieves-37-6-efficiency/" rel="noopener" target="_blank">London South Bank University</a> have participated in the study.</p>