Adding storage is becoming an increasingly popular solution to solve issues faced by traditional generator and solar systems. This is true for this government building where 700 kW of solar and 3120 kW of generators previously existed without any storage. On sunny days, they were forced to curtail excess solar due to the zero export limit. During the frequent outages, when the generators were used to meet the load, cloud cover and fluctuating solar production resulted in repeated generator start/stops. This operation of the generators deteriorates their lifetime, increases maintenance needs and the risk of frequency imbalances. To learn more about the benefit of adding storage to a generator plant check out our blog post. Adding energy storage to an off-grid generator plant: is the complexity worth the headache?.

By introducing 1.5 MWh of Li-ion storage, and the ARC microgrid controller to the system, this government building solved both of these problems and added valuable benefits. ARC is able to send commands to the assets in order to meet site goals:

• Tell the storage system to charge from excess energy, negating the need for solar curtailment
• Tell the storage system to discharge during cloud coverage to minimize generator usage, often negating the need to start additional generators

Not only were the needs of the system met, ARC provided additional visibility. Since data is visualized in Initium, Ageto’s customer monitoring dashboards, the team was able to view all the power readings in the system. This lead to a discovery of a potential loading issue with their HVAC system.

Other site specific needs were time-of-use shifting and zero export to the utility. As a result, the ARC controller implemented these controls as well to create the right solution for this site.