The challenges of energy costs, climate change and food security are at the top of the UK's domestic agenda. This project aims to present the UK's fruit and vegetable industry with a solution capable of addressing all of these issues. Lambda Agri (trading name of Lambda Energy Ltd) are developing a cheap, non-toxic and sustainable greenhouse coating with the potential to reduce artificial light energy consumption by around 21%, while also increasing crop yields.
The application of active film is simple, consistent with existing greenhouse treatment practices and will, in due course, be compatible with a range of greenhouse materials. This technology can benefit all existing greenhouse structures, including those without lighting infrastructure. It requires no additional electricity and works by modifying the ratio of the short- and long-wavelength light that plants receive from daylight by converting ultraviolet light into red light. This photosynthetically active light is what enables the film to increase crop yields.
Currently, farmers in the UK and around the world are using artificial lighting solutions (LED and sodium), in greenhouses to supplement this photosynthetically active light, and to stimulate produce growth. Given the steep increases in electricity costs and increase in unpredictable weather, resulting from climate change, these lighting solutions are simultaneously becoming unsustainable yet necessary. Growers are, therefore, seeking environmentally benign solutions which can reduce operating costs, without compromising crop yield or quality. We believe that our greenhouse coating can help them reduce those costs, and decrease their greenhouse gas emissions.
The potential to increase crop yields with Lambda's technology extends beyond addressing global food security. While the UK produces around 60% of our food and over 50% of our vegetables, we grow only 16% of the fruit we eat. British growers are innovative and are keen to compete with imported produce from sources which have the advantages of a warmer climate. With greater productivity from within UK greenhouses, the average greenhouse size can reduce along with the volume of imported fruits and vegetables. This will not only lessen pollution from transportation, but will protect wild lands from being farmed, preventing the environmental impact of farming from escalating.
A project of this ambition requires Lambda Energy to be supported by first class industrial partners: The National Institute of Agricultural Botany (NIAB), who will conduct plant growth trials, and Charles River Laboratories, who will perform toxicological testing of our materials.
Lambda Energy aims to increase the crop yield of plants grown in greenhouses by circa 20% using sunlight changing materials. The active material will constitute the greenhouse sidings and modify the ratio and amount of Photosynthetically Active Radiation (PAR) that plants receive by converting ultraviolet and part of blue light to red light. To boost yields in greenhouses, currently PAR from natural sunlight is often supplemented by artificial (LED) lighting; our technology will reduce or eliminate the need for supplementary lighting, providing a means to achieve high yield while drastically reducing the use of electricity. Such a large increase in crop yield will help to increase food security around the globe sustainably.
Governments and companies across the globe have issued numerous pledges to reach net-zero CO2 emissions in the coming decades. However, the long term trends of energy consumption are clear, and the US Energy Information Administration predicts that global energy consumption will double by 2050\. Currently, global primary energy sources are more more than three quarters from fossil fuels. Meeting these pledges, and preventing catastrophic climate change, therefore requires the development of clean energy technologies.
Lambda Energy is a clean energy technology company that exploits the unique optical properties of semiconductor quantum dots to improve the efficiency of silicon solar panels (which account for approximately 95% of installed solar power). Silicon solar panels perform poorly at short wavelengths (i.e., UV, and to some extent also blue) because short-wavelength light is very strongly absorbed by silicon, and so the electron-hole pairs that are generated by the absorption of light are not created in the optimal region of the solar cells, rather at the front surface.
The idea of Lambda Energy's technology is that we absorb these shorter wavelengths using quantum dots before they reach the solar cell itself, and re-emit the light at longer wavelengths (i.e., red) where silicon solar cells exhibit optimal operation, by placing a layer of quantum dots at the surface of the solar panel. This approach is termed luminescent downshifting (LDS).
The idea is not new, however, and in fact the effect was first demonstrated in the 1970s. Despite promising results, however, it has not yet been commercialised. The reasons for this relate to the difficulties of creating stable dispersions of materials that have suitable optical properties, and can survive being exposed to strong sunlight for 25 years or so (the expected lifetime of a solar panel), and moreover doing so in a cost-effective manner.
Thanks to recent developments in nanomaterials processing, we believe it is now feasible to commercialise this technology. This project will develop a prototype LDS film that has the required optical properties to enhance the efficiency of silicon solar panels, can withstand the UV exposure that a solar panel is subjected to, and is suitable for application to existing solar panel arrays that are already installed. This will position us to carry out trials of the technology on existing solar panel arrays that are already installed, with the aim of increasing the power output of these installations by 10%.