Polysiloxane Radiative Cooling Paints for the Decarbonisation of Cooling in the Built and Transport Environments (PolyCool)
Lead Research Organisation:
UNIVERSITY COLLEGE LONDON
Department Name: Electronic and Electrical Engineering
Abstract
Cooling of indoor spaces is a fundamental means to attain peoples' Good Health and Well Being, yet is one of the most energy intensive and highly polluting processes associated with human activity. The statistics are staggering; air-conditioners (AC) and electric fans account for ~20% of the total electricity consumed in buildings around the world today and contribute over 1.2 GT of CO2 emissions per year. Likewise, AC may be responsible for 40% of an electric vehicle's battery usage on a hot day. To combat climate change and accelerate the transition towards carbon neutral economies, paramount targets of EU's Green Deal, energy efficient and sustainable indoor space and vehicle cooling technologies are imminently required.
PolyCool's overarching objective is to develop zero-energy input, zero-emissions (during usage) radiative cooling coatings/paints, which also combine cost efficacy and low-maintenance for commercial, industrial and residential buildings. With proper modifications, the technology will also be able to be deployed in the automotive and more broadly in the transportation industry as well. The proposed technology is leveraging the infinite heat capacity of the cold Universe, converting it in essence into an inexhaustible heatsink for the thermal radiation emitted by the built environment and vehicles on Earth. Crucially, it is completely passive and does not require electric pumps, fans or coolers to operate. PolyCool coatings will be able to provide a cooling power of >100 W/m2, able to cover at minimum 30% of a typical residency's cooling needs. The key objectives of this project are; i) Develop a large -scale prototype (>20 cm x 20 cm). ii) Perform extensive testing of the prototype in the field, in various geographical locations and under various climatic conditions. iii) Consolidate a strong intellectual property position and, iv) develop a commercialisation roadmap to translate PolyCool technology from the lab benchtop to the market.
PolyCool's overarching objective is to develop zero-energy input, zero-emissions (during usage) radiative cooling coatings/paints, which also combine cost efficacy and low-maintenance for commercial, industrial and residential buildings. With proper modifications, the technology will also be able to be deployed in the automotive and more broadly in the transportation industry as well. The proposed technology is leveraging the infinite heat capacity of the cold Universe, converting it in essence into an inexhaustible heatsink for the thermal radiation emitted by the built environment and vehicles on Earth. Crucially, it is completely passive and does not require electric pumps, fans or coolers to operate. PolyCool coatings will be able to provide a cooling power of >100 W/m2, able to cover at minimum 30% of a typical residency's cooling needs. The key objectives of this project are; i) Develop a large -scale prototype (>20 cm x 20 cm). ii) Perform extensive testing of the prototype in the field, in various geographical locations and under various climatic conditions. iii) Consolidate a strong intellectual property position and, iv) develop a commercialisation roadmap to translate PolyCool technology from the lab benchtop to the market.
People |
ORCID iD |
| Ioannis Papakonstantinou (Principal Investigator) |
Publications
Ramirez-Cuevas F
(2024)
Infrared thermochromic antenna composite for self-adaptive thermoregulation
in Nature Communications
| Description | We have developed a coating formulation which has shown >95% solar reflectance and >0.9 heat emissivity. With this coating we showed that completely passive cooling of up to 4C below ambient can be achieved, as was verified by extensive outdoors tests performed in London, UK. Similar results were replicated in Sydney (Australia), Paris (France) and Madrid (Spain) proving the versatility of our technology and compatibility with different climates and geographical regions. While original tests were performed with small scale prototypes (<20 x 20 cm2) we are now in the process of scaling up our coatings aiming to cover a full 20m2 roof by Summer 2025 and performed tests on a mock building provided by industrial collaborator ACCIONA in Madrid. Such tests, if successful, will unlock the potential for commercialisation. |
| Exploitation Route | The technology has attracted interest from a wide range of stakeholders. TfL is keen to improve thermal comfort of their passengers in the Summer as one of the most common complaint they receive is related to the temperature in their buses during hot weather. They have offered us 5 electric buses to test next Summer. Electric vehicle companies (JLR) are keen in such technologies as according to their data, on a hot day 30-40% of a car's battery may be consumed on the AC unit, limiting the useful range. Construction companies (Acciona) have stressed the importance of passive cooling solutions in buildings and their direct correlation of inhabitant comfort. Utility companies (ENGIE) iterated the need for passive cooling to mitigate the sudden spikes in electricity consumption during heatwaves among other things. Overall, there is a consensus that cooling may become one of the biggest obstacles in our path to net-zero and passive solutions should be a priority. |
| Sectors | Construction Energy |
| URL | https://www.scienceopen.com/hosted-document?doi=10.14293/PR2199.000782.v2 |
| Description | Together with UCLB - UCL's commercial arm we have filed for a patent on a new radiative cooling film. This patent is currently under review. Patent no: P140740PCT-DJC |
| First Year Of Impact | 2024 |
| Sector | Energy |
| Description | Acciona |
| Organisation | Acciona |
| Country | Spain |
| Sector | Private |
| PI Contribution | We have supplied Acciona with painted samples (20x20cm) which were installed on the roof of a mock building in Madrid. We are planning to coat the entire roof (20-25m2) of one of the mock building in Summer 2025 and perform comprehensive testing. |
| Collaborator Contribution | Acciona has built four mock sites that have been installed with HVAC units that maintain their temperature constant. They have made available the roof of one of the mock buildings to cover with our radiative cooling paint. In addition to the buildings, the have installed a full weather set up that allow us to take relevant measurements such as dry bulb temperature, humidity, solar radiation, pollution levels and other. |
| Impact | - Dataset on radiative cooled samples for 3 months - Weather data |
| Start Year | 2023 |
| Description | Akzo Nobel |
| Organisation | AkzoNobel |
| Country | Netherlands |
| Sector | Private |
| PI Contribution | We have developed some radiative cooling coatings that will be sent to Akzo Nobel for testing. We plan to have these tests conducted within the next 6 months |
| Collaborator Contribution | They have provided us with proprietary paint formulations to test for radiative cooling. They have also agreed to run some accelerating tests for us to assess the durability of our PolyCool paints. |
| Impact | this is an ongoing collaboration. the outcome will be a verification of whether polycool coatings meet industrial standards for coating technologies. |
| Start Year | 2022 |
| Description | ENGIE |
| Organisation | Engie |
| Country | Global |
| Sector | Private |
| PI Contribution | We have exchanged information on radiative cooling, informing them about our progress and exchanging know-how on measurement techniques and methods. |
| Collaborator Contribution | ENGIE is a leading utility company in France. They have supplied me with two letters of support for grant applications and they have made available their testbed in Paris, France where we verified the performance of our coating. We plan to send them more samples for testing in Summer 2025. Our collaboration has resulted in a joint publication. |
| Impact | https://www.scienceopen.com/hosted-document?doi=10.14293/PR2199.000782.v2 |
| Start Year | 2023 |
| Description | Conference presentation - |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | presentation by Dr Lingxi Li with the title: Simulation of Light Scattering in Porous Polyethylene for Radiative Cooling Applications at Bremen Workshop on Light Scattering, 2024 |
| Year(s) Of Engagement Activity | 2024 |
| URL | https://scattport.org/index.php/conferences-menu/768-bremen-workshop-on-light-scattering-2024 |