A utility-scale microgrid that uses energy storage has slashed the use of diesel fuel and allowed for up to 70 percent renewables to serve a Portuguese Island, Graciosa.
The microgrid is made up of a 6-MW, 3.5-MWh battery system from Switzerland-based Leclanché, about 1.5 MW of wind energy, 3 MW of solar and an existing diesel system that provides backup, said Bryan Urban, executive vice president, stationary storage solutions, for battery provider Leclanché, .
The company recently upgraded an existing project — originally developed by another European company — that included the solar, wind and diesel. Leclanché added the battery energy storage and associated controls, he said.
“It was a microgrid, and it took awhile for it to be operational. Software needed to be updated and replaced,” Urban said.
What makes this utility-scale microgrid unique is the important role of energy storage, he said. The wind, solar and diesel resources all flow through the battery first, and the battery decides how to distribute the energy to the grid that supplies the whole island.
Energy storage as cog in wheel
“The battery controlling everything is quite a bit different,” said Urban. “It is controlling the resources and integrating with the grid that supplies all the power to the island.”
That’s different than what happens in many other areas where the grid is larger, he noted. For example, in California, batteries store solar during the day and release the energy at night. “The battery and solar can function independently because the solar and storage are intertied to the larger grid,” he explained. In the Graciosa project, on the other hand, the resources go to the battery first, and the battery is in control.
“The battery becomes the cog in the wheel with different types of generation capacity,” Urban said.
The company plans to replicate this microgrid project on other islands, using its own energy management system, he said. The system is software that allows the batteries to interface with numerous types of generation, including renewable energy and diesel. In this project — before Leclanché, acquired its own software system — an energy management system from Greensmith Energy was used.
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