SMUD Demonstrates Demand Response Benefits

Demand response is part of Sacramento Municipal Utility District’s strategy to manage peak demand.
Published: Tue 14 Oct 2014

Anticipating that demand response will provide a sustained contribution to its resource into the long-term, Sacramento Municipal Utility District (SMUD) has undertaken four pilots on which to base its forward strategy.

The pilots were undertaken during the summer of 2012 and 2013. In addition to managing SMUD’s peak load, they were designed to provide customers with more choices for managing their energy costs, enabled by new time-of-use tariffs and other incentives associated with the planned programs. The goal of this element of the DR strategy was to increase customer engagement and satisfaction, including allowing customers to bring their own devices and connect them to the utility network.

Smart thermostat program

The Direct Load Control PowerStatPilot involved 850 customers during June-September 2013. Groups were offered critical peak pricing, direct load control or both.

The pilot demonstrated the feasibility of reducing peak load during the peak hours of 4 pm to 7 pm. An average of 2kW reduction in peak demand per customer was realized, with the reduction almost identical for the three programs.

Smart electric vehicle (EV) charging program

The EV Innovators smart charging pilot began in March 2013 and involves 215 customers. Pricing plans include a combined whole house and EV TOU for Level I (120V charging) customers, and separately metered EV-only TOU with a dynamic critical peak demand charge

For this pilot, the critical peak period was considered to be from 2 pm to midnight, and the super peak time was 4 pm to 7 pm. Using dynamic pricing and other customer incentives, the pilot successfully induced customers to charge their EVs mainly between 1 am and 6 am, thus avoiding those critical peak periods.

Key to this success was the use of a scheduling capability in the EV to manage the charging.

Home Area Network (HAN) device testing for interoperability

During 2013 SMUD deployed 6,700 HAN devices, of which slightly more than half have joined and are communicating.

Many systems had to be connected and integrated in order to implement SMUD’s DR programs. However, interoperability gaps were detected among different ZigBee SEP 1.1 devices, and also there was incompatibility between OpenADR 1.0 devices.

The pilot experience also required SMUD to build a HAN lab, modeled after a meter shop, to test HAN devices.

Planning and testing for a retail HAN deployment model

The HAN gateway is a demarcation point, limiting utility support to one device (i.e. the gateway, owned by SMUD).

SMUD is still looking for a device supplier to provide a SEP 2 compliant HAN gateway.

Demand response value going forward

Going forward, SMUD intends to plan and develop the resources, business processes, programs and infrastructure to enable Energy Trading and Grid Assets organizations to utilize the SMUD DR portfolio for economic dispatch and to meet reserve requirements. Flexibility to offer different programs for different needs (day-ahead, real-time) is required. Assessment will be made of solar and wind effects on the system and how DR programs will need to adapt to meet these increasing impacts.

SMUD also intends to give customers more choice to manage their energy costs, including customer-centric offerings such as an integrated approach to energy efficiency and DR. [Engerati-Energy Efficiency and Demand Response Bundling for Better Results] Customer engagement will also be increased.

Further reading

SMUD: Demand Response Strategy, Results, and System/Device Interoperability