The Active Building Technology Showcase is the latest document from my Toolkit soon to be uploaded to SPECIFIC’s website. This contains information on some of the technologies that would be suitable for use on an Active Building project.
While our current Active Buildings utilise solar energy, other renewable energy generating technologies can also be considered depending on site specific conditions. For example, a site in a built-up area, surrounded by taller buildings or trees and with no opportunity to incorporate south facing roofs may not yield much energy from the sun and may be more suited to other renewable energy generating technologies. Even if renewables are not an option, electrical storage with intelligent controls could still be incorporated, which would enable the building to benefit from controlled import and export of electricity to and from the grid, utilising agile tariffs and easing grid pressures. If control strategies are linked to the carbon intensity of the grid, the building could utilise low carbon electricity, without generating its own.
Feedback from my focus groups included a desire to have sight of emerging technologies that, if not ready now, could be retrofitted into a building at a later date. One such example is the PV window in our Active Classroom, developed by one of our main industry partners, NSG. This was not available at the time of building the classroom in 2016 but the first prototype of this window was installed, replacing a standard window in 2017. Another example is the combined solar thermal and PV (PVT) tubes on the Active Office, which the building was designed to incorporate. As these were not quite available at the time of building the office in June 2018, the heating system was designed to be able to operate without the system (using an ASHP instead), with the ability to add the PVT system once it was available. It was finally installed in December 2018, significantly reducing the heat pump usage, as per the original intention. Naked Energy, who manufactured and supplied the PVT system have developed an interesting case study on the installation, as well as taking part in a Q and A with SPECIFIC.
We are often asked about the embodied carbon in the technologies used on our Active Buildings and whether the proven savings in operational carbon outweigh their embodied carbon. While some of the technologies used in our buildings do have high embodied carbon currently, we have research groups within SPECIFIC developing the next generation of technologies with much reduced carbon. For example, our PV research group are developing printable PV which uses low cost, earth abundant materials, combined with low cost, low energy and low carbon manufacturing techniques, such as screen printing (the same technology used to print on t-shirts, for example).
As I become aware of new technologies, I will add these into the document. For example, I recently learned about a breakthrough in PV technology by a company called Oxford PV, who are applying the perovskite technology (one of the technologies the PV group at SPECIFIC are investigating) to traditional silicon solar panels to produce a perovskite-silicon tandem module, thereby increasing their efficiency from 20 – 22% to potentially over 30%.
We have an electrical storage group researching the life cycle analysis (LCA) of batteries, as well as new manufacturing techniques for batteries. Meanwhile, a company called Cornish Lithium have developed an environmentally sustainable way of extracting lithium using naturally occurring geothermal waters, which the company claims to have a net zero carbon footprint. Having a UK source of lithium to supply UK batteries will provide us with a more resilient battery supply as we move to decarbonise both heat and transport. By 2035, all new cars and vans will be electric, all requiring lithium-ion batteries, most of which use lithium currently sourced from South America, using energy intensive methods of extraction. As buildings decarbonise alongside transport, storing energy generated from renewable sources, the demand for lithium is soon to vastly increase. Therefore, this project is of huge significance to the UK.
Separating the Technologies from the main Design Guide into another document enables me to update it regularly as and when I come across new technologies. It also helps emphasise the fact that the Active Building concept is more about the principles, which are detailed in the Design Guide, and that a variety of different technologies could be considered in Active Building projects. The document will be uploaded to this section of our website within the next few weeks.