Shape, Shimmy, Shift: The Future of Demand Response
by Bob Shively, Enerdynamics President and Lead Facilitator
“The growing number of connected devices, self-generation and energy management options means that customers have a central role to play in the future of the grid — they will no longer be viewed as passive load, but instead as flexible grid resources.” ~ Patty Cook, ICF
As I make my way around the country working with various utilities and Independent System Operators (ISOs), I hear varying opinions on the value of demand response (DR). At ERCOT in Texas, I’ve heard it said that demand response is their best source of frequency regulation, even better than traditional automatic generation control from a gas or hydro unit. On the other hand, I’ve also heard audiences at other organizations laugh at the concept that consumers will give up control of their energy-consuming devices to provide price-responsive DR. Traditionally most DR programs were sponsored by utilities for one reason – to have a reliability resource that can reduce system peak load during emergency or contingency operations. This resulted in programs designed to find one type of customer – those willing to curtail a limited number of hours usually on summer peak days. A recent study by Lawrence Berkeley National Laboratory (LBL) suggested that DR can do much more to help the grid, and it defines new types of DR programs that can enable grid benefits.
To identify new types of DR programs, we must first ask what grid problems we need to solve. Current challenges include:
- Peak demand resources that are often needed only a few days out of the year
- Excess renewable generation that must be curtailed due to lack of demand
- The need for rapid flexibility in resources to meet system net load ramp
- Periodic rapid fluctuations in the output of variable resources due to changing weather conditions such as moving clouds or gusting wind
- Distribution circuits that need to be upgraded to service loads due to peak conditions that occur only during limited hours
LBL suggested that multiple DR services dubbed “shape, shift, shed, and shimmy” are suited to address these needs in a cost-effective manner and will be acceptable to many energy consumers.
These services can be summarized as follows:
||DR programs that modify load curve shapes through long-run price response or behavioral campaigns. Shape can permanently move consumption patterns through implementation of time-of-use rates or can access loads that can be occasionally curtailed to provide peak capacity through traditional curtailable rates.
||DR programs that encourage the movement of energy consumption for times of high demand to times when there is surplus renewable generation. This is similar to the permanent load shifts under shape programs but is accomplished through different incentives which may result in more flexible shift that only occurs when needed (rather than a permanent load shape change). Shift could also provide a fast-acting flexible resource to help address system net load ramp issues.
||DR programs for loads that agree to be occasionally curtailed to provide peak capacity and to support the system in emergency or contingency events with a range in advance notice times — with curtailment occurring to support the bulk grid, to support local curtailed pockets, or to support the distribution system. Shed is similar to the occasional curtailment capability in shape but is envisioned as more flexible and offering consumers more options in how and when to participate.
||DR programs for loads able to dynamically adjust demand on the system to alleviate short-run ramps and disturbances at timescales ranging from seconds up to an hour. These resources can provide frequency regulation, local voltage support, and ramping reserves.
As utilities and ISOs across the country and elsewhere in the world test such programs, we will learn more about how much flexibility in loads is really out there. LBL suggests there are many gigawatts accessible through well-designed programs and implementation of control technologies, batteries, smart inverters on rooftop solar, and modern communications systems. The key will be design of programs that provide benefits to consumers so that they are willing to become part of the grid. If done successfully, utilities and ISOs will be able to integrate increasing amounts of renewable and distributed supply in an affordable manner.
Interested in a quick overview of demand response? Enerdynamics recently developed an online course in partnership with the Peak Load Management Alliance (PLMA) titled Introduction to Demand Response Fundamentals. See details here or e-mail as firstname.lastname@example.org for more info.