Balancing, and planning for, the power grid is an increasingly complex responsibility.
The traditional way utilities have been handling distribution system planning is no longer sufficient or applicable for advanced strategies such as distributed generation, household appliance control, demand response, electric vehicles and energy storage. Meanwhile, utilities face growing expectations of reliability and cost effectiveness.
Making distribution networks work today requires innovative solutions. This means gathering and using more data about current status of the network and its components. It also means that utility distribution planning teams must understand and gain experience with advanced smart grid applications.
In Germany, Siemens has helped the transmission and distribution system operator Allgäuer Überlandwerk GmbH (AÜW) to install a large number of measurement devices, as part of a comprehensive project to monitor distribution network status. In this part of southern Bavaria, a large number of PV generators are already connected to the network -- and by 2020 the goal is to supply 70% percent of annual electricity demand from solar.
Also in this project, Siemens has used their Smart Grid Diagnostic Kit to create provide precise profiles for renewable generation input and load consumption. These are based on exact measurements, which makes it possible to analyze voltage and current characteristics on the grid. Other factors such as active and reactive power, harmonics, and asymmetries can also be recorded and analyzed.
"Today many utilities are intensively integrating distributed energy resources to the distribution network, such as roof-mounted solar photovoltaics," said Holger Mueller, Department Head for Network Consulting, Siemens Smart Grid.
"Since solar PV input is intermittent, it causes headaches for utility distribution planners because it creates distribution system issues concerning voltages, overloading and outages. This phenomenon is notorious when solar input reaches peak generation during light-load conditions. Traditional planning studies might no longer apply, and understanding the behavior of new devices behavior is essential. Being able to adequately model solar PV output as well as energy storage behavior yields a better understanding of system capacity. This can help utilities deploy costly system improvements only when and where they are needed."
Utilities that are integrating distributed energy resources often find that continuing to rely on traditional distribution planning methods can yield inaccurate and ineffective results. This, in turn, can lead to problematic choices with unfortunate ripple effects. It complicates the task of balancing the grid, and it may cause utilities to make unnecessary system improvements -- or to make needed improvements sooner than necessary.
In contrast, when key grid decisions are based on real-world measurements, it becomes easier for utilities to keep the grid balanced, while making more effective and efficient long-term plans for the grid.
AT DISTRIBUTECH: Tuesday Jan. 28, 3-4:30 pm. Siemens' measurement-based distribution planning will be discussed at this session: DER Integration in Electric Distribution Grids. The paper, Smart Grid Distribution Planning Based on Measurements, will be available to DistribuTECH 2014 attendees in the conference proceedings.
More about Siemens at DistribuTECH 2014.
And read more stories at Smart Grid Watch Blog!