By Tony Hughes CEO of Platinum Energy Solutions
In the coming decade advances in green technology will increasingly allow properties (especially ones built in developed economies) to meet their own energy needs, independent of a country’s national grid. These developments are not in any one field or type of green energy, rather they are a combination of improving efficiencies in different energy generating technologies with more effective methods of reducing energy wastage in buildings. In Europe, the first steps are being taken to create entire neighbourhoods of so-called “energy-positive” buildings which will deliver a net surplus of energy to their inhabitants over the course of a year. The development would revolutionise architecture and have significant implications for the future design of both urban and rural communities as countries move into a more sustainable economic era.
One recent breakthrough has been the announcement in the journal Nature Energy by scientists at the University of Queensland in Australia that they have developed a form of solar power technology which can produce energy even when it is indoors, wet or cloudy. Unlike traditional solar panels the technology (which uses tiny nanoparticles called quantum dots to pass electrons between one another to generate electric current inside a solar cell device) can also be produced in a liquid form. This means that it can be printed onto surfaces, where it hardens to form a flexible layer on an object or surface; potential applications include using it as a transparent skin to power homes, vehicles such as planes, or even new forms of wearable technology. The new material has not yet been approved for commercial use but Professor Lianzhou Wang, the man who led the research, claims his team have achieved a 25% improvement in solar cell technology over the previous world record.
While researchers have looked at improving energy generation methods and usages, architects have focused redesigning the building concepts for new housing stock. Traditional methods are grossly energy inefficient and rely upon energy being produced elsewhere and transmitted to the building over great distances. The new zero-energy building concepts with which architecture firms hope to populate the positive energy districts that will form the building blocks of a sustainable urban development in the future are very different. Using new forms of green technology on-site to generate power, new building codes that improve energy efficiency to minimise power and heat losses, and suitable storage systems to keep the energy generated available (for example during the hours of darkness) for later use, the new zero-energy buildings will allow the harvest, storage and supply of energy through micro-networks to neighbouring buildings.
One recent example of this would be the Powerhouse Brattørkaia building located in the city of Trondheim in Norway’s deep north. Designed by the architecture firm Snøhetta, the studio demonstrated its shift in thinking by re-wording the guidelines which characterised the 20th century modernist school of industrial and architectural design (colloquially summed up as “form follows function”) with the new guideline “form follows the environment”. Deliberately built in the poorly-lit deep north, the Powerhouse Brattørkaia building has successfully demonstrated that it is possible to create a functional office building capable of producing more energy than it consumes (including during its construction and during its demolition), even in a challenging environment close to the Arctic circle. There sunlight varies greatly by season, with only a few hours of darkness in the summer, but long winter nights. Nevertheless, the new building not only can not only satisfy its daily consumption needs, but it also powers several local means of transport (including electric buses, cars and boats).
Despite legal and regulatory challenges (many building codes and other restrictions still dating from a time when very different assumptions about the energy market, technology and construction were in play) in Europe, the European Commission published an implementation plan for positive energy districts in 2018 which is being closely scrutinised by China and the US for signs of progress. Retrofitting older neighbourhoods will be challenging for European cities, but most positive energy district pilots are so-far focused on new development projects. If the concept of an energy positive building can be scaled up quickly to that of a neighbourhood (which in turn can be designed to form new types of urban communities), then scientists and engineers will begin to examine ways to upgrade older housing stock in line with the new standards. Another big challenge will be how to reform city administration to integrate energy-autonomous neighbourhoods with their surroundings; most forms of local political organisations are siloed, making it difficult to build the sort of holistic planning process that could achieve a collaborative planning process between different areas of authority in a city.