The Sun's thermal energy can be collected and effectively exploited to offset dependence on combustion of fossil fuels. Applications include heating a fluid to drive a turbine producing electricity or providing hot water and space heating in buildings and residences. Replacing current metallic thermal collectors with plastic ones could provide significant benefits. Scientists working on the EU-funded project THERMALCOND developed a new family of low-cost polyolefin compounds compatible with extrusion into pipes and sheets for the manufacture of flat-plate solar thermal collectors. In order to be useful for the desired application, they had to overcome current barriers in thermal conductivity and absorption resistance. Researchers increased conductivity with a mixture of conductive nanofillers. They increased conversion efficiency with a novel metal oxide self-assembled monolayer (SAM) surface coating. Materials were used to form a new family of sheets, pipes and fittings. THERMALCOND's thermally conductive nanocomposites with a SAM corrosion-resistant coating are expected to have major impact on the plastics industry by providing a lightweight and cost-effective alternative to metal in many applications. The targeted solar thermal collector market is an obvious beneficiary.