A microgrid goes around the world

With our microgrid expertise, we installed an intelligent local energy system in our Austrian headquarters. We also develop such solutions for our customers, in addition to Siemens locations around the world. 

The fluctuating power generation from renewable energies is one of the major challenges of the energy transition. This is because generation from wind power and solar plants cannot be produced upon request nor is it based on the electricity demand of users. As a result, gas power plants may have to be deactivated or wind farms switched off to prevent the grid from being overloaded. As more renewable energies are integrated, the more susceptible the grid is to volatility. This is exactly where a microgrid can help: in a #microgrid, peaks can be detected and minimized at an early stage through intelligent control. This reduces the load on the entire network, conserves resources, and ultimately saves costs. 

Pioneering microgrid in Vienna 

After implementing a microgrid at our Siemens Campus in Midrand in South Africa, the microgrid at our Siemens City campus in Vienna, Austria, was set into operation in 2020.

Our colleagues are now supporting not only Austrian industrial customers but also other domestic and international Siemens locations in the design and construction of microgrids. The expertise flows into renowned research projects and is shared at universities. 

The components of the microgrid in Siemens City are as follows: a PV system, an electricity storage system, charging points for EVs, a load management system, and an interface to the building management system.  

Peak shaving is an important functional feature of our microgrid. When a certain threshold value of the required power is reached, consumers limit consumption from the power grid by shedding load for a short time, thereby relieving the grid. "At the Vienna Siemens City campus, we have a basic output of around two megawatts. This is mainly due to the data center on the site, the standby operation of various devices, and the test setups for control systems, some of which must run continuously," says Manfred Haslinger, Head of Sales Energy Automation Systems at Siemens Austria. "Our target for the power drawn from the electricity grid is set at around 3.2 megawatts. If we exceed this, the microgrid controller reacts and energy is drawn from the battery to avoid a higher consumption peak. As the power price is calculated according to the consumption peak, this saves costs," explains Haslinger. The battery is charged as required by the #PV system on our site.

CO2 reduced by 100 tons per year  

The PV system installed on the roof of our campus building, which has a total area of 1,600 square meters, has a peak output of around 300 kilowatts. It generates approximately 300 megawatt hours of electrical energy per year and makes a significant contribution to reducing Siemens' CO2 footprint by around 100 tons of CO2 per year.

"For the EV charging infrastructure currently available on our Vienna campus, the PV system supports a lot. On average, 90% of the energy required for charging can be covered by solar energy from March to October," says Haslinger.

However, it is also an ideal setup for the office building’s consumption to reduce peak loads. The campus' load profile coincides well with the sun's position. Electricity demand rises in the morning, is at its highest at lunchtime due to the employee canteen and falls again in the afternoon. "This is different from the private sector, where a lot of energy is produced when the sun is shining but cannot be used as people are often not at home during the day. We have a perfect match for demand," says the energy expert. 

The microgrid is centrally managed by Microgrid Control from our SICAM portfolio for automation and telecontrol devices. It enables balanced load management to keep the supply and consumption of electrical energy in optimum balance and avoid costly peaks in demand. The Microgrid-Controller fulfills another important load management function, for example when charging electric vehicles: "If a fast charger with 50kW power is in operation, then other charging stations with less power are reduced to avoid overloading the connection cables, in turn, avoiding consumption peaks," explains Haslinger. 

The Microgrid-Controller also plays an important role in the interaction with our building management system Desigo CC. If the energy consumption is too high, it can temporarily intervene in the load management of the charging infrastructure. It goes in both directions, as it is also possible to temporarily reduce selected services from the building management system if too much power is drawn from the grid. "The important thing with such an intervention is acceptance. The employees in the offices should not even notice these processes," says the microgrid expert. 

Know-how from Austria for Siemens locations worldwide 

Thanks to our early and long-standing involvement in the field of smart grids and microgrids, our experts are now also busy passing on their valuable knowledge of microgrid solutions to other Siemens locations. 

In August 2023, a microgrid was installed at our global headquarters in Munich, Germany. This opens many possibilities for the optimal use of resources in terms of energy management at the site. Even in such a sustainable and LEED Platinum-certified building potential savings can be identified with the help of the microgrid. The data analysis that is now available is also helpful, for example when it comes to strategic decisions on how many fast chargers can be connected in the parking garage without overloading the grid at peak charging times. Investment decisions in the electrical system technology (e.g. battery or thermal buffer) can also be optimally planned based on real-time data and simulated for cost-effectiveness for future operation. 

With the microgrid solutions at our headquarters, we are working on a blueprint that is to be rolled out at larger Siemens locations and for our customers worldwide. We are on it!

This article was previously published by hi!tech as Ein Microgrid geht um die Welt. 

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