Distributed Energy Storage Systems
Inside this Article
Energy storage systems are an essential enabling technology that allows for the increasing integration of renewable resources into the electric power system.
Whether interconnected behind or in front of the meter, utility-interactive energy storage systems can address grid integration issues associated with the increased deployment of variable renewable energy resources, while providing other benefits to both utility operators and consumers. Distribution system operators can use energy storage systems to improve grid resiliency and reliability. Electric customers can use these systems to manage their energy use in new and profitable ways.
Explosive growth characterizes the market for distributed energy storage systems. In the US Energy Storage Monitor, GTM Research and the Energy Storage Association estimate that energy storage deployments will increase from 62 MW in 2014 to 220 MW in 2015. The market is also growing in ways that will interest solar integrators. While behind-the-meter installations accounted for only about 10% of the energy storage market in 2014, analysts expect customer-sited storage to account for 45% of the market within the next 5 years.
Since the energy storage market is many things to many people, I interviewed stakeholders all across the value chain—technology companies, service providers, BOS companies and system integrators—to learn more about energy storage products, business models and integration challenges.
Project manager and microgrid business lead, Black & Veatch, bv.com
In April, Black & Veatch commissioned a microgrid at its world headquarters in Overland Park, Kansas. What power generation and energy storage resources are integrated into this microgrid?
This microgrid includes two 65 kW microturbines, 50 kW of PV technologies, a 100 kWh battery energy storage system and a custom central control system to operate these resources in unison. The PV component is segmented into a 1,000 V system, a traditional 600 V system and a system utilizing microinverters. The objective is to test many alternative microgrid technologies in a real environment to determine the best mix of resources for client projects. We are using our Asset360 platform to perform advanced analytics to monitor the condition of the equipment and the performance of the system. This platform provides both a technical dashboard for our operations personnel and an educational dashboard for the general public.
How much of the campus can the microgrid support in island mode?
The microgrid is designed to operate the Rodman Innovation Pavilion as an island independent from the utility grid. The maximum load for the Innovation Pavilion is approximately 300 kW. The microgrid can export excess generation to the East Building of the Black & Veatch campus.
What were the most challenging aspects of implementing this microgrid?
The biggest technical challenges are integrating the controls for multiple generation sources with the building energy management system. This integration is critical to achieving the largest benefit from the system. Black & Veatch developed a custom controls system that provides the flexibility to operate the system as a living laboratory. We are in the early stages of implementing a testing program to analyze operating modes of the different system components, demonstrate advanced functionality and optimize system operation. Based on this effort, we will develop technical resources and white papers to support clients developing microgrid projects.
Do you think that microgrids and energy storage systems are a threat to or an opportunity for incumbent utilities?
Distributed resources, energy storage and microgrids will facilitate new means of delivering energy services. However, the best application for these technologies is not to create a new electricity delivery model but rather to incorporate them into the existing electric grid, as this results in the most reliable electric system. Utilities are best positioned to apply these new technologies through their networks and in partnership with their customers.