SIEMENS

It’s the start of a new day for 700 households in Krefeld and Mülheim an der Ruhr, two cities in west-central Germany. The smell of coffee drifts through from the kitchen, the buzz of an electric razor is heard from the bathroom. At first glance, there’s nothing out of the ordinary here. What we don’t see, however, is the work done by smart technology to help these homes save power and prepare the rest of us for a new era in energy management.

Take the Longrée family, for example. They live in a new housing development in Saarn, a suburb of Mülheim. “We were one of the first families to build here 17 years ago. Back then, there were sheep grazing outside the window,” says Susanne Longrée with a grin. “And now look at us. The electricity meter tells us when we should wash our clothes,” laughs Rolf Longrée, her husband. “Ever since we joined the E-DeMa project, our house has developed a mind of its own!”

“E-DeMa is the largest field test of intelligent power use in private households ever conducted in Germany,” explains Michael Hufnagel, project manager at the Siemens Smart Grid Division. E-DeMa stands for the “development and demonstration of locally networked energy systems toward the E-Energy marketplace of the future.” As Hufnagel explains, “All of the participating households are connected with our online marketplace via sophisticated information and communication technology (ICT). The technology allows them, for example, to monitor their power consumption, as well as electricity prices.”

Back in 2009, companies including Miele (appliances), ProSyst (software), Siemens, and the Krefeld municipal utility, teamed up with institutes of higher education from Dortmund, Bochum, and Duisburg-Essen to take part in a project led by power company RWE. To date, the project has been a big success. “The actual field test has been under way since March of this year. It was originally scheduled to run for nine months, but now we’re thinking about extending it beyond the date when funding from the Federal Ministry of Economics and Technology comes to an end,” explains Prof. Michael Laskowski, chief project manager at RWE. “The two pilot regions are located in Germany’s most densely populated federal state and provide us with a representative cross-section of the German demographic.”

Some 5,000 households were initially contacted by RWE and the Krefeld utility. Over 1,000 expressed an interest in being part of the project, and 700 of them met the technical requirements, which included having a home PC and Internet access. “We’re pioneering a technology that may one day be used in all households,” says Rolf Longrée, when asked what motivated him to take part. As the managing director of a building supply company, he has plenty of experience in running big projects, whether in Germany, the U.S. or Dubai. Presented with an opportunity to help pave the way for a new era in energy use, he set about the project with a similar level of enthusiasm. Besides, as Laskowski explains, after completion of the field test, RWE and the Krefeld utility will reward participants in Mülheim with up to €25,000 and in Krefeld with up to €10,000 to spend on energy-efficient and social projects in their respective neighborhoods.

As a first step, each household’s electricity meter was replaced with a digital smart meter. “The households in Krefeld have all been fitted with AMIS meters from Siemens,” Hufnagel explains. These are equipped with a communications module known as a gateway. The module reads data from the smart meter and receives pricing information from the E-DeMa marketplace. That way, households have much tighter control over their power use. Smart meters record power consumption data on an internal memory chip at 15-minute intervals. Once a day these data are anonymized and transmitted via the power lines to an energy-data management system.

Known as Siemens Powerline Communication, this data link operates at transfer rates of over one megabit per second. “EnergyIP is a solution that automatically transmits consumption data from a meter to a power company,” says Hufnagel. Participating households in Mülheim are fitted with technology from RWE. “In place of AMIS meters, we use our own multi-utility communication controller, which transfers consumption data to RWE via the GPRS mobile communications network,” Laskowski explains.

Energy Marketplace. All the households in the field test have one thing in common: access to an online energy marketplace developed by Siemens. This is the core of E-DeMa. “It enables participating households to monitor their consumption,” Hufnagel explains. “At the same time, each day, the power companies determine up to five different tariffs for eight different periods of each day. The prices for the following day can be viewed from 6 a.m. on. This gives participants an opportunity to program their household appliances accordingly.” Households with only basic appliances have to switch them on by hand.

Some 100 households that were selected at random have been equipped with smart appliances from Miele. “These appliances automatically choose the lowest tariff for their operating cycle,” Laskowski explains. This works by means of a communication module that looks like a standard industrial PC. Inside, however, is integrated software specially developed by ProSyst, which connects the household to the marketplace and is also able to execute concrete instructions regarding operation of appliances. “Each appliance is directly controlled by software installed at the RWE data center. We call this an aggregator control system; it calculates the optimal switch-on time for the appliance on the basis of the current availability of power and the stability of the grid,” says Dr. Klaus-Martin Graf, who is responsible for aggregators at Siemens.

In other words, the appliances are switched on only when power is readily available and therefore cheap. Another 13 households, including the Longrée’s, were fitted with combined heat and power units (micro-CHPs). In addition to producing hot water, these can also generate electricity. “If demand for power exceeds the amount currently on offer from the utility, the micro-CHPs can be activated via the gateway to feed electricity into the grid,” Laskowski explains. Eleven of the 13 micro-CHPs in Saarn were installed by Medl, a local utility. Medl will operate these units for the next five years and provide general support for participating households. “We’ve got our own heat and power plant in the basement, and, theoretically at least, it’s earning us money as well,” says Rolf Longrée with a grin.

Valuable Feedback. The savings resulting from the E-DeMa project have not yet had a direct impact on electricity costs. At present E-DeMa is only an experimental game in a virtual power market, with fictional prices and monthly bills that show how much the participating households would have saved in comparison with their normal electricity costs. Yet the Longrées do have one real benefit: They can see when they use the most power and alter their habits accordingly. “As a result, we now turn the washing machine on only when E-DeMa tells us that the power is cheap,” says Susanne Longrée. The results are revealing. Compared to an average German household with average use habits and the same power demand as the Longrée family over the same period in 2011, the Longrées have saved over 10 percent simply as a result of enhanced awareness of how to be more efficient in their use of electricity. This is the first step toward smarter use of energy at home. The challenge now is to make this system suitable for widespread implementation. The people of Saarn and Krefeld are certainly ready to make the change.