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Sustainable Buildings – Smart Meters
Stabilizing the Grid
Smart electric meters not only provide the feedback that helps customers cut their energy use—they also give utilities a real-time overview of power demand. Siemens’ Automated Metering and Information System (AMIS) paves the way for the stable power grid of the future.
Telephone calling and Internet surfing at fixed prices—in telecommunications at least, the trend favors flat rates. But there’s no flat rate for electricity, where, to an increasing extent, the ground rule is "use more, pay more." And that rule is likely to be applied even more stringently in the future. If you use your washer and dryer during peak demand periods, you’ll pay a hefty surcharge. But if you do your laundry at night, when demand is low, you’ll get a discount. And on weekends, electric power might even be free. Instead of fixed rates per kilowatt-hour, there may soon be different rates for different times of the day.
Why make things so complicated when customers like them simple? The obvious reason is that the best way to get people to save energy is through their wallets. Variable rates are therefore a key inducement for increasing environmental awareness. Until now, for instance, consumers have received feedback on their electric power usage only once a year on a special bill. But now, legislators are starting to act. The European Union has noted in its directive on energy efficiency and services that customers must receive more information about their energy consumption. Smart meters in the home that can sample consumption at 15-minute intervals are seen as an answer.
Actually, that’s nothing new. Many large industrial users already measure their electric power usage electronically, with the data read automatically via remote query by their utility companies and checked against an agreed-on load profile. "This technology is now also suitable for large-scale use by residential customers," says Josef Kapp at Siemens in Stuttgart, who is in charge of business development in the IT sector for public utility customers. The benefits of smart metering could be huge. According to the German Ministry for Economics and Technology, meters that detect wasteful electricity use could save about 9.5 TWh annually.
Many European countries have already implemented the EU directive, and in June 2008 the German parliament followed suit. Starting in 2010, smart meters will be installed in new buildings. By 2015 one-fourth of the nation’s old meters are slated to be replaced. Starting in 2011, German utility companies will have to provide load-based or time-of-day-based power saving incentives. All major German energy suppliers are now testing smart meters, but only 0.01 % of all meters are smart. The reason for the hesitancy is that, according to a study by Accenture, a consulting firm, replacing one-fourth of the electric meters in Germany would cost about €1 billion and take 5,000 person-years.
Automatic meter reading by remote query will be a significant benefit of smart meters for most utility companies. But the meters will be far more important in answering questions such as: What can be done to reduce load fluctuations in the power grid, so as to eliminate the need for additional power lines while also ensuring a stable supply? And how can ever larger amounts of renewable electric power be fed into the grid? Conventional electric meters can’t solve these problems, because they don’t link the customer’s use to power grid operation. But according to the EU, this is precisely where the greatest opportunity exists. The EU has therefore launched a study into the electric power grid of the future—a network that will be designed to intelligently manage and integrate the energy needs of power companies, power grids and consumers.
One System. In Austria, this vision is already being realized. Energie AG, which is based in Linz, has already equipped 1,000 households with Siemens electric meters. By 2009 100,000 households will have been connected, and by 2014 by as many as 400,000.
Siemens’ Automated Metering and Information System, or AMIS, is unlike any other smart metering system. Its components not only measure consumption in homes, but also cover the entire supply chain, from power plant to consumer. A data concentrator at a local transformer substation collects energy use data gathered by individual meters on a second-by-second basis, monitors the power grid, transmits this data to a control station, and feeds the data into the billing system. "AMIS customers get power grid automation free with their AMIS components," says Alexander Schenk, Business Segment Manager for AMIS at Siemens in Vienna.
? To communicate, AMIS uses powerline technology, in which the power grid transmits data. Other systems require separate radio or GSM communications or an Internet link, which add costs.
? AMIS is open to future interface standards. Such standards don’t yet exist, so in the meantime meters and data concentrators communicate via a proprietary Siemens communications method. But a simple download is all it takes to adopt new standards and to read meters from other manufacturers.
? AMIS will be able to integrate gas, water and district heating information via cable or wireless communications into the remote metering system. The resulting data can then be viewed by the customer, who can access his or her individual use along with load profiles via an Internet portal.
? The AMIS meter will also be able to control the feed-in of electricity from solar cells on the roof or from a combined heat and power plant, or to reduce the feed-in rate if the input is excessive.
The reason for selecting Energie AG as a pilot customer for AMIS has to do with its competitive environment. By providing services that offer distinct customer benefits along with innovative electric power products, Energie AG intends to not merely defend, but to actually expand its market share. As a first step, according to Alexander Schenk, a varying rate scale for different times of day will be introduced. The owners of night storage heaters have long been familiar with this principle, but that system is inflexible. With AMIS, however, the Austrian firm enjoys a full range of marketing options, from energy discounts during vacation periods to combinations with low insurance rates.
Austria isn’t the only pilot area where Siemens is active. In Milan, Italy, Siemens is helping municipal utility company A2A to install 60,000 ENEL smart meters every month. ENEL is Italy’s largest power company. The goal is to convert a total of one million customers to such systems.
Siemens is integrating the meters into an automated system and establishing a link with an SAP software system. But neither energy conservation nor new billing models are key issues for ENEL in this project. The company’s main objective is to track down high power losses in the grid and to stabilize the grid, which is being pushed to its limit by the installation of more and more air-conditioning systems. The company’s smart meter program is likely to continue, since about 30 million existing smart meters in Italy are no longer state-of-the-art. Powerline communications, for instance, are only available 60 to 80 % of the time in older meters, which is inadequate for smart grid applications. AMIS meters, on the other hand, can communicate more than 99.5 % of the time.
Getting Consumers to Do their Part. Technology is only part of the solution; consumers also have to do their share. The Fraunhofer Institute for Solar Energy (ISE) Systems in Freiburg, Germany, examined how consumer behavior can help stabilize power grids. In a research project in Karlsruhe-Stutensee, approximately one hundred private households were equipped with communication-capable electric meters that were connected to a computer at a transformer substation.
Under the slogan "Let the sun do your laundry!" the households received a text message encouraging them to wash their laundry whenever there was bright sunshine. Those who complied received a discount of €0.50/kWh. According to Sebastian Gölz of the ISE, customers tend to go along with such power-saving policies in the long run, but only if the savings are considered substantial.
"We want energy saving to be fun," says Gölz. This means that customers must receive feedback regarding their electric power consumption and costs within a short time frame. "If you only get an electric bill once a year, you can’t possibly figure out why you used more energy," he explains.
"The electric power grid is the last big unintelligent physical network on our planet," reports The Daily Deal, a business information service. That’s bad for our budget and for the environment. However, according to the Electric Power Research Institute in the U.S., implementation of a smart grid would save five to ten % of electric power without reducing comfort levels. That’s because renewable energy could be fed in to match consumption, and peak loads would be reduced.
It will take many years to implement a continental smart grid. But even today the power grid can be endowed with some intelligence, and energy can be saved. For instance, Jackson, Mississippi-based SmartSynch, a company in which Siemens Venture Capital (SVC) holds shares, provides the infrastructure for data communication between smart meters and network operators. The technology offers the capability of remote metering and information feedback to customers, which could support load-dependent management for consumers. Seventy-five electric utility companies with a total of 115,000 electric meters in North America are already using SmartSynch technology. Unlike Siemens’ AMIS meters, SmartSynch meters (photo) communicate via wireless. "Public Wireless (GPRS) is widely available and therefore better suited in sparsely populated areas," notes Gerd Goette, Managing Partner at SVC in Palo Alto. Powerline communication, on the other hand, is limited in range and is therefore best suited for densely populated areas.
Energy can be saved even without a smart grid if air conditioning and heating systems are properly adjusted and defective controls are replaced. Prenova, an Atlanta-based company in which SVC also owns shares, supplies energy cost reduction software that is used by about 50 retail and restaurant chains, such as Eddie Bauer and Burger King. Sensors installed in the buildings monitor the air conditioning and lighting systems as well as other power-hungry equipment, measure power consumption, and transmit such data to Prenova headquarters, where they are matched against weather information, time of day, and other factors.
When appropriate, the software intervenes via remote control and optimizes the operating parameters of the lighting, air conditioning, and other equipment. This method can reduce energy consumption by 10 to 20 %, a parameter that’s included in the cost calculations of Prenova’s business model. Prenova’s earnings as an energy management contractor are linked to the customer’s energy savings. Prenova also provides customer consultation on energy purchases, from the mix of electricity and natural gas all the way to the choice of utility companies.