Autonomy and flexibility can support energy resilience, while also benefitting the power grid. This February, the Savona campus of the University of Genoa, Italy, opened a campus-wide microgrid -- the first of its kind in Europe. It combines both electrical and thermal energy resources, as well as thermal and battery storage. All of this technology is orchestrated by a state-of-the-art microgrid management system.
Currently the Savona microgrid encompasses sufficient resources to supply about half of the campus' current energy needs -- and it was designed to accommodate additional resources to eventually power the campus fully.
Integration of renewable (rooftop photovoltaic and concentrating solar generation) and traditional power generation sources is a key aspect of this project. This microgrid also is distinguished by the combination of electrical and thermal energy. It also includes two newly installed cogeneration units, and small gas turbine originally on the campus was incorporated as well.
Other integrated equipment includes electrochemical battery storage, two existing boilers, and an absorption chiller. There are also two electric vehicle charging units.
The total electrical power installed is equal to about -250 kWe plus 140 kWh of available storage capacity. All additional energy is supplied by the national power grid.
The university's Power Systems Research Team (more than 10 researchers representing various engineering disciplines) led this project, in collaboration with Siemens (the primary contractor) and other industry and power grid partners.
How the Savona microgrid works
The heart of this microgrid is a control system featuring the Siemens Microgrid Manager. It includes an electrical SCADA, a thermal SCADA and a centralized energy management system for the microgrid. Together these systems receive signals and data from the field and communicate with installed devices, through a gateway that uses both wired and wireless connections.
The control system dispatches thermal and electrical generation resources as well as energy exchange with external grid, taking into account contributions from renewable resources and the weather forecast. Generation forecasting is conducted daily as well as three days in advance. The system adapts in nearly real time (every 15 seconds) to actual weather conditions.
"If actual weather conditions differ from the forecast, the system can immediately optimize microgrid management," said Federico Delfino, Professor of Power System Engineering at the University of Genoa. "The control system understands that if there's no sun, it needs to adjust the power being produced. It gives the right setpoint to the gas turbine to balance the load on campus."
Claudia Guenzi, CEO of Siemens Smart Grid Division (Italy) explained: "Before the microgrid, the turbine and boilers were mostly operated manually. But now there's a central intelligence to guarantee optimum scheduling and operation of the whole energy resources installed."
One of this project's main challenges was getting all of the equipment to communicate with the control system. All microgrid-connected equipment, regardless of supplier, can interact using the same international standard protocol, IEC-61850.
"Sometimes we spent days figuring out how to connect individual devices to the gateway, or how to define the list of signals, measures and parameters to be exchanged. But this learning will certainly benefit many future projects," Guenzi noted.
Benefits on campus and beyond
The Savona microgrid will cut campus energy costs by an estimated 50,000 per year, reduce carbon dioxide emissions by about 120 tons annually, improve operational efficiency, and demonstrate effective control systems and strategies.
But beyond that, this project is yielding considerable benefits outside the Savona campus by serving as a test bed for innovative microgrid energy management strategies.
Delfino observed that that siting this microgrid project at an engineering research university is vastly increasing the knowledge base and data about microgrids.
"This microgrid is a test bed for ongoing research, and it's getting a lot of attention." said Delfino. "Every week we get e-mails and visits from faculty and engineers from all over Europe. Also, everything we're learning here can be applied in the context of a smart city."
Theoretically, the Savona microgrid also can benefit the national grid. "We are ready to exchange data and information with the national grid, as well as receive dispatching commands from the grid control center. This will allow us to involve on-campus microgeneration in ancillary services to Italy's energy market," said Delfino.
What's next for the Savona microgrid
Regulatory hurdles to realizing this vision are being addressed. "What is currently missing in Italy is a set of regulations to clarify how the national grid can benefit from the microgrid," said Guenzi. "Italian regulators are working on this. We're expecting new rules during the next regulatory period, probably in 2015. This should allow the microgrid to provide full benefits to the national grid.
Currently no campus buildings are directly connected to the microgrid. However, the university recently issued a new public tender to connect a new campus building to the microgrid. This will help with the exploration of extended microgrid strategies for load management.
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