SMUD and Sunverge Demonstrate the Potential of Aggregated Distributed Energy Storage & Solar 

Name of Project:
SMUD and Sunverge Demonstrate the Potential of Aggregated Distributed Energy Storage & Solar 
2500 R Street, Midtown, Sacramento, California  
11.64 kWh Sunverge Energy Solar Integration System (SIS) and 2.25 kW PV Installation on 34 homes  
Sacramento Municipal Utility District (SMUD)  
Sunverge Energy Solar Integration System  
Pacific Housing, Inc.  
October 16, 2013

Project Goals

  • Pilot Time-of-Use and Critical Peak Pricing rate tariff (1-R-SPO).
  • Evaluate how high penetrations of renewables can yield maximum value through customer-sited energy storage.
  • Provide reliable backup power and bill reduction for homeowners

*Sunverge energy storage units have provided over 9,000 hours of backup power to residential SMUD

customers over the past several years*

Distributed Energy Assets Combine Customer and Grid Benefits

This project provides a benchmark for how energy storage, solar, and smart devices can be controlled and aggregated to provide multiple grid management benefits. Sunverge successfully integrated SIS units with SMUD’s demand response management system to automate Demand Response events. A key takeaway from this study was that the operational benefits from DERs are highly location specific. Additionally, the study found that adding storage to Photovoltaic (PV) systems can provide incremental benefits that exceed the cost of the energy storage unit.

Combining customer and utility benefits is a promising business case for storage. In most cases, however, these benefits are mutually exclusive and cannot be stacked to provide a compelling business case. SMUD and Sunverge found through this demonstration that enabling utility dispatch during certain high-value hours could combine the high value customer benefits (reliability and bill reduction) and utility benefits (local capacity and distribution deferral) in one application. 

The battery is used to either discharge energy to support gaps in solar PV generation or to charge to smooth out spikes. Individual unit and fleet regulation testing was completed as well and showed very promising results.  The response time of the SIS units during testing was less than four seconds and the responses were within 100 W of the requests.

Realized Benefits of Reliable Backup Power

Customer – Participants on the TOU-CPP rate tariff saved on average more than 50% on their bills by arbitraging energy for peak period compared to non-participants, while still being able to rely on available backup power.

Utility – during peak periods and demand response events, loads to the distribution grid were completely offset and had no net exports, which can be scaled up for greater impact.

Sunverge Control Software and SMUD Demand Response Management System (DRMS)

SMUD and Sunverge partnered for Demand Response (DR) events using the energy storage systems deployed at 2500R. Automating this was extremely important, and Sunverge completely integrated to SMUD test environment server with simple customizations. SMUD was able to easily send event signals and program Sunverge units to respond to DR events accordingly. Anticipating PV spikes using an OpenADR integration was critical for this project, in order to provide value through power quality and reliability