Low Income Multi-Family Battery Storage, Solar PV and Data Collection - Mosaic

"Battery energy storage systems work by capturing electricity produced by both renewable and nonrenewable resources and storing it for discharge when required. The solution allows users to come off the grid and switch to stored electricity, at a time most beneficial, giving greater flexibility and control of electrical usage." These systems need to be better understood so SCE can provide better customer support, improved grid infrastructure design, and gain higher Customer Satisfaction scores from these customers. The documented results will identify the technology and interface benefits and gaps within this emerging market and necessary technology advancements. Low Income Multi-Family Battery Energy Storage Systems, Solar PV and system software will continue to grow and align potential GRID opportunities through customers that can shape their loads, reduce demand and shift demand in support of GRID and Market resilience.

PROJECT GOAL This project was designed to conduct research related to the design, interconnection, installation, commissioning, system performance, customer objectives and grid impacts of the installed energy storage system and solar photovoltaic array at Mosaic Gardens at Pomona. The lessons learned and best practices were captured and delivered as knowledge transfer to key constituents within various departments in Southern California Edison. The primary objective of this project was to demonstrate how customer storage can be leveraged and to quantify impacts to both customers and grid stakeholders. TECHNOLOGY DESCRIPTION This project was conducted at an apartment complex operated by Linc Housing in Pomona, California. Linc Housing partnered with SCE for technical and funding assistance to take their building from LEED Platinum design to Zero Net Energy. The building is a three-story low-income residential development consisting of forty-six apartment units on an infill lot. The units vary in size from one to three bedrooms. Designed to the LEED Platinum standard, this development includes underground parking, community laundry, management offices, a community lounge with internet terminals, and a courtyard playground area. The targeted tenants are low-income qualified, with half the units designated for those who are identified as displaced or without shelter. The units are projected to reduce energy usage by as much as 1,350 kWh compared to a current unit built to code. Energy storage was added to the site, with a rooftop photovoltaic solar system. The project pairs four battery energy storage systems totaling 60 kW with two solar arrays providing a total power capacity of 34 kW. Two 11.4 kW smart inverters connect with the batteries and the PV systems, while a third inverter operates in solar-only mode. The solar-plus-storage systems allow operation in a variety of modes to serve both customer and grid needs. Project Findings Time-of-Use rates encouraging energy storage systems to discharge in the evening, combined with solar only charging, may leave energy storage systems without adequate capacity for backup during the evening hours. Incorrect placement of current transformers may create significant issues post installation, and can be prevented by standardized best practice material, as described in the project recommendation section, below. Installation of data monitoring prior to project installation provides historical data essential to some analyses. Full utilization of BESS requires planning at building design in ordering to avoid the need for complicated conduit and network connections that may be difficult to impossible. Effectively scaling efforts in multifamily contexts is made difficult by the complication of having a site that is a hybrid of residential and commercial 1). Combination of three-phase and single-phase systems 2). Mix of residential and commercial entities and incentives Project Recommendations In multi-tenant buildings, electrical components and sub-panels are often spread out. Depending on distance and access to conduit, it may be difficult to backup a variety of loads as intended. Additionally, startup currents and 3-phase loads need to be investigated for backup potential.  Product support is often limited for end users. Utilities may be able to provide helpful resources to their customers, including information on what modes of operation are of greatest benefit and why. Standardized requirement and best practice materials will assist the utility in ensuring successful installs and documentation are delivered. Consider providing installers with incentives to encourage success. Recommended materials include: 1). Description of parties responsible for documentation, and specific documentation required should be provided 2). Standardized hardware photos to be taken at installation site 3). On-site post-installation checklist Comprehensive and properly configured monitoring systems are critical to achieving optimal operation and reaching the full potential of any battery energy storage system 1). Standardized, automated monitoring techniques can find issues and report back on data and performance quickly Utilities may desire to use AMI data from pre- and post-installation to verify correct operation of energy storage units. For instance, analysis of AMI data would help determine when energy storage units. For instance, analysis of AMI data would help determine when energy storage units are not being used for Time-of-Use Management and bill savings.