When Pacific Gas & Electric broke the news six weeks ago that it had signed a deal with Solaren Corp. to buy 200 MW of solar energy from satellites launched into geosynchronous orbit, the idea...
Opportunity for advancement or exercise in futility?
resources, and to reduce the need for spinning and non-spinning reserves, as was demonstrated in the Olympic Peninsula pilot (see Figure 2) .
This pilot project, led by Battelle and Pacific Northwest National Laboratory (PNNL), showed that with proper value signals and automated controls, customer loads could be effectively and rapidly engaged to stabilize the aggregate load of a feeder. This virtually eliminated the need for regulation for periods lasting many hours, all without inconvenience to the consumers.
The demonstration utilized an automated premise dispatch agent that acted in accordance to previously defined customer preferences, in response to five-minute interval market signals. The trial also included very fast-acting (~1 sec), autonomous, short-term load shedding for clothes dryers and water heaters to provide a stabilizing force when the grid gets into trouble or needs to support renewables.
The Olympic Peninsula pilot led to three major conclusions:
• Demand-management resources are capable of responding to ancillary service signals on short (minutes) to very short (seconds) time scales. Peak demand reductions of 16 percent and average demand reductions of 9 percent to 10 percent were realized over extended periods;
• The ability to measure and confirm response of resources was evidenced, at least for groups of customers if not individually;
• A structure for incentives can be offered to customers for short-term response; and
• While providing ancillary services wasn’t a direct objective of the experiment, the observations provided an important foundation for launching a directed effort to engage demand response in providing these benefits.
A fifth factor is the expanding role of storage. Energy storage forms a key part of the portfolio that will be required to support the integration of renewables. Storage is needed to manage or regulate the variable nature of wind, allowing it to be relied on as a semi-firm energy resource.
Much work is being done to target operational principles, algorithms, market integration rules, functional design and technical specification for energy storage that mitigates the intermittency and fast ramps that occur at higher penetration of renewable generation. Some of the technologies that are being studied and deployed include:
• Field experiment design and monitoring of the flywheel energy storage for existing and future renewable penetration;
• Addressing the characteristics and the role of battery storage facility and the regulatory issues to create feasible, economic applications for the battery storage devices; and
• Deploying virtual storage applications, such as Ice Energy’s system for freezing water to shift air conditioning load to off-peak hours ( see “Cold Storage in Cali ”).
A sixth factor involves the need for active demonstrations. While several options have been presented that can serve as mechanisms for managing and operating renewable resources, it’s important to note that both the applicability to specific locations, as well as the acceptability to different operating conditions, will vary. This only can be mitigated through performing continued active demonstrations of the available mechanisms. Active demonstrations in real-life will allow the different stakeholders to understand and validate the costs and benefits of each solution.
While many people see the pursuit of