Smart meters: finally on the market after over 15 years of development
The concept isn’t new. People were already talking about smart meters that could communicate with the power grid via a router 15 years ago. One of the first ideas that caught on was to have smart meters turn on devices when electricity was cheap on the energy exchanges. For a long time, though, customers weren’t really involved in the conversation. “The demands placed on smart meters were high,” recalls Prof. Sebastian Lehnhoff, board chairman of the OFFIS Institute for Information Technology in Oldenburg. “They were supposed to do lots of things at the same time.” In addition to following the price of electricity, for example, they were expected to help stabilize the power grid. They also needed to be secure against hacker attacks and transmit data in an encrypted manner. Furthermore, the question of how smart meters would protect people's data remained unanswered for years. It was feared that the devices could reveal a great deal about residents’ habits. “The development took an extremely long time,” Lehnhoff affirms. “It was a difficult process.”
In the meantime, local networks have undergone a change or two. Transformers are now being equipped with sensors and communication interfaces, and there are smart meters on the market that are versatile and safe. “For about two years now, this technology has been spreading much faster than before,” Lehnhoff reports.
The roadmap “Towards a climate protection grid by 2030”, which was presented by the Forum Network Technology/Network Operation in VDE (VDE FNN) at the end of March, is meant to solidify this progress. It explains that a crucial factor in climate-neutral electricity is an intelligent measuring system that controls customer applications such as heat pumps and wallboxes in a targeted manner. Electricity consumption needs to be postponed to times of day when plenty of renewable energy is available. “We have the technology for the necessary infrastructure. The rollout is underway,” the roadmap states. “However, it is still not clear who has what rights and obligations and which incentives should be set to encourage end customers to participate.”
As valuable as a small power plant: swarms of batteries and charging stations
A project led by Lehnhoff’s OFFIS colleague Prof. Astrid Nieße is showing what attractive solutions for more intelligent local networks might look like. Nieße, an executive board member of the energy R&D division at OFFIS, collaborated with the startup be.storaged to develop software agents for battery storage like the ones used in electric car charging stations. To promote electromobility even in places with poorly developed power grids, it makes sense to equip charging stations with batteries that can charge electric vehicles in the event of grid issues. The software agents add an interesting dimension to this simple battery function by configuring battery storage for electricity trading – thus creating a completely new business model in the process. When the electricity price is high, the agent tells the charging station to sell power from its battery. When the price is low, the battery is charged. What makes the arrangement even more unique is the agents’ ability to communicate with each other and thereby link many batteries in a region to form a swarm. This swarm acts as a complete system and can feed in or consume large amounts of electricity as needed. In the future, intelligent software agents will also be able to learn the typical usage profile of each charging station – for instance, how much electricity vehicles consume on which days and at what times. The agents will be able to use this data to determine how much power can be delivered to the network and when. A swarm of charging stations ultimately functions like a small power plant in the grid, meaning it can one day also be used for nationwide power plant planning – also known as the dispatch system. In dispatching, all the power plant operators in a region coordinate how much power each plant will produce one day in advance. They take both the expected price of electricity and the power plants’ costs (such as the price of coal or natural gas) into account. The dispatch process produces a precise timetable for all power plants that indicates when each plant will be switched on and how long it will feed in electricity, as well as the output at which it will operate. Once they are linked into a swarm, it’s also possible to use charging station batteries for dispatching.
If a charging station is unable to supply power because its battery is too low, the agents automatically determine which charging station will provide more. “The big advantage of this distributed intelligence is that the technology is more robust than a large control center that controls everything,” Prof. Nieße explains. If the control center were to fail, the entire system would come to a standstill. At most, only individual software agents in charging stations can fail using the agent concept. Another advantage is that it doesn’t require a huge amount of data to be sent back and forth between a control center and hundreds of charging stations because the agents coordinate with each other directly. According to Nieße, the way in which they help minimize data transfers makes such approaches to on-site data processing crucial for the intelligent power grid of the future.