Intelligent buildings: from energy waste to energy storage
Buildings are among the largest consumers of energy in the world. Change is thus imperative. The aim is not just to make buildings much more efficient in terms of consumption. In future, they could even be used to store electricity generated from renewable sources, thereby making a significant contribution to grid stability and security of supply.
Solar and wind power on the increase
Germany has adopted a pioneering role with its “Energiewende” programme for renewable energy transition. The gradual exit from nuclear energy and decommissioning of large power stations have radically altered the German electricity landscape, with a new, decentralised structure emerging. More and more producers – in some cases very small – are generating electricity from wind power, biomass, photovoltaics and hydropower, and feeding it into the public grid.
However, wind and sun are intermittent, making them an unpredictable energy source. Such (often extreme) feed-in fluctuations pose a major challenge for grid security and reliability.
The future belongs to smart grids
Smart grids are a hot topic for suppliers and grid operators as they wrestle with these problems. The vision is of an adaptive grid that can balance out fluctuations in supply and demand.
Alongside intelligent control technology, this will require massive storage capacity. When plentiful wind and sunshine provide a rich energy harvest, a way is needed to store surplus electricity and release it again when the wind drops or the sun goes down.
Researchers and engineers are working on plans for many millions of energy storage systems, both small and large, to provide the necessary buffer. The batteries of electric cars could be incorporated into the smart grid, for example. Similarly, batteries, heat pumps, thermal storage systems and even thermo-active building materials in smart buildings could provide valuable storage capacity.
Pilot projects in progress
Much of the talk surrounding smart grids may sound very futuristic, but corresponding research initiatives and pilot projects are already under way. One such example is a research project sponsored by Germany’s Federal Ministry of Economics and Energy, which will run until 2017. The PV Host (Home Storage Systems) project is addressing the technical and economic optimisation of small battery storage systems with a capacity of up to 10 kilowatt hours. These could be used for decentralised storage of excess solar electricity, which would only be fed into the public grid when required. The problematic feed-in spikes that occur during periods of strong sunshine could then be largely smoothed out.
Technological progress and falling battery prices should help to make the smart grid a more technically feasible and economical proposition within the foreseeable future. With effective insulation and modern heating systems, intelligent buildings will then not only be highly energy efficient. As part of the smart grid, they could also make a sustainable contribution to providing the country with reliable and affordable power.