SIEMENS

The environmentally-friendly city of the future is being built in a desert in the United Arab Emirates. Not far from Abu Dhabi, workers from all over the world are building Masdar City. When complete, the city is expected to have 50,000 inhabitants, meet its energy requirements entirely from renewable sources, and produce zero carbon dioxide, a major greenhouse gas (see Pictures of the Future, Fall 2008, Oil-Free Future?). Power is to be generated primarily by solar-thermal power plants and photovoltaic facilities.
City planners expect improved efficiency to offset the high cost of implementing advanced energy solutions. In fact, the energy required per Masdar resident is projected to be only one fifth of today’s consumption.
This goal can be achieved if forward-looking planning and modern technology complement each other. In line with this philosophy, buildings in Masdar will be built close together, thereby providing each other with shade and thus reducing air conditioning requirements. In addition, buildings will be built on concrete pedestals, thus helping to maintain cool temperatures by allowing air to circulate beneath them. Today, 70 percent of the energy consumed in Abu Dhabi is used to cool buildings. Planned architectural measures are expected to dramatically reduce that figure in Masdar.
Masdar’s green, high-tech vision, which was developed by British architect Sir Norman Foster, is scheduled to be completed in 2016. If it proves a success, urban developers and architects from around the world may orientate their plans according to the technologies that prove themselves here. Naturally, Siemens is involved in the project. "The Masdar initiative is not only a fascinating project; it also fits in very well with our energy efficiency program and the solutions offered by our Environmental Portfolio," says Tom Ruyten, who manages Siemens’ activities in Dubai.
Masdar is, of course, unique. After all, how often do you have the opportunity to build a complete city with a focus on minimizing its environmental footprint right from the start? However, intelligent building management technology is in demand everywhere. In industrialized countries, for example, buildings are being transformed from mere energy consumers to active participants in the electricity market, where they offer self-generated power for sale. "More and more buildings have photovoltaic or small wind power plants on their roofs," says Volker Dragon, who works in the area of energy efficiency at Siemens’ Building Technologies Division in Zug, Switzerland. "Intelligent electric meters — the smart meter — will usher in a lot of change in this area."
These small boxes will not only measure energy consumption, but will also be able to communicate with household appliances and utilities (see article "Transparent Network"). Starting in 2010, a European Union directive and legal regulations in Germany will require all new and modernized buildings to be equipped with smart meters. Customers will have better insight into their electricity costs, while utilities will be able to more accurately predict demand, and thus offer new products, including dynamic rates, which can change every 15 minutes.
Entire grids will benefit as it will be easier to spread energy consumption. In fact, experts predict a savings potential of up to 20 %.
Small cogeneration plants in buildings (see Pictures of the Future, Fall 2008, How to Own a Power Plant) could also be better integrated into power networks in the future. "If electricity demand is high, a cogeneration plant will deliver energy to the network, while the waste heat will be fed into a local heat storage system or into the thermal capacity of the building," predicts Christoff Wittwer from the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany. "This heat can be used later by residents."
Well-insulated water tanks capable of acting as heat stores are already available. In contrast, heat storage based on phase change is still at the R&D stage. Here, for example, surplus heat is used to melt a salt. Later, when demand for heat increases, the melted salt releases its stored heat and solidifies. Yield is very high: "These types of cogeneration plant have an overall efficiency of over 90 %," says Wittwer. "In terms of primary energy, that’s much more productive than large-scale fossil fuel power plants that don’t exploit waste heat."

Managing Demand. Conversely, consumers can also selectively switch off devices at peak times to ease network loads. The key is to know when rates are lower. For example, washing machines and driers can be run at night when electricity is cheaper. But which hours offer the best prices? "Many appliances are already capable of determining this through signals in power lines," says Dragon. "On and off times can be determined by a smart meter."
This scenario would give utilities the advantage of being able to manage demand within their networks. It would also help them to prevent sudden peak loads from occurring — for example, when large numbers of consumers turn on appliances at the same time.
However, consumers would have to consent to having their appliances turned on or off by a utility depending on the network’s load — based on the premise that they would be paying less for their power. Ultimately, both parties have an interest in a flat load curve, which is achieved by leveling demand over each 24-hour period.
The challenge is to coordinate each building’s sub-systems with one another and control their communication with their surroundings. In other words, all isolated solutions should be combined.
"That is not a trivial matter because these systems have developed independently over many years," says Dragon. "We therefore need interfaces that allow control systems to communicate with one another."
Software solutions that address this challenge are being developed by Siemens Building Technologies under the name "Total Building Solutions" (TBS). Here, a variety of systems are being linked into one unit. They include building control and security technologies, heating, ventilation, air conditioning, refrigeration, room automation, power distribution, fire and burglary protection, access control, and video surveillance.
"Only if all of these systems harmonize perfectly can their economic potential be fully realized," says Dragon. "Whether in a stadium, an office complex, a hospital, a hotel, an industrial complex or a shopping mall — TBS will ensure that the facility is working productively, users are being reliably protected, and energy is being used optimally."

Large Savings Potential. The amount of energy that can be saved through the intelligent networking of power utilities and consumers varies from case to case. However, experts generally agree that savings of 20 to 25 % are realistic. "This figure fluctuates depending on the type of building," says Dragon. "Shopping malls often have a savings potential of up to 50 %, while office buildings have between 20 and 30 %. For hospitals, we’re talking about 5 to 10 %." These differences depend on how buildings are used. For instance, in Europe many shopping malls are open ten to 12 hours a day and closed on Sunday. But a hospital operates around the clock. "That’s why hospitals don’t have much scope for saving large amounts of energy. The heating can be turned off in an office building but not in a hospital," says Dragon.
Advanced technologies not only save energy in hot and temperate zones; they can also do so in icy areas. Take the new Monte-Rosa Hut of the Swiss Alpine Club, for instance, which is perched at an altitude of 2,883 m. It will be largely self-sufficient — thanks to sophisticated building technology and components supplied by Siemens (see Pictures of the Future, Spring 2008, Forecasts that Come Home). Power will be supplied by a photovoltaic system, supported when necessary by a cogeneration unit.
In order to maximize efficiency, the building’s control system will use weather forecasts and information on guest bookings, thus helping it to coordinate its power and heating systems as well as energy storage and applicate power demand. A smart algorithm will periodically calculate the best end temperature, so that the desired room climate can be realized with the least resources — thereby ensuring that not even the smallest amount of energy is wasted.