Smart technology brings power to the people

Pacific Northwest Gridwise demonstration project is a USA regional initiative to test and speed adoption of new smart grid technologies that can make the power grid more resilient and give consumers the option to save energy.

Imagine you are at home one Saturday morning on the computer, as your son takes a shower, your daughter watches television, a load of laundry is in the dryer and the fragrance of fresh-brewed coffee fills the house. You hear a beep from the dryer that means a high-energy price indicator is displayed on the front panels of some of your appliances telling you that you could save money right now by using less energy.

So you turn off some of the unneeded lights in your home and opt to delay running the dishwasher. Meanwhile, some of your largest appliances have automatically responded to this signal and have already reduced your home’s energy consumption, saving you money.

Earlier this year, demonstration projects were launched in 200 homes in the Pacific Northwest region of the USA to test and speed adoption of new smart grid technologies that can make the power grid more resilient and efficient. Pacific Northwest National Laboratory (PNNL), a USA Department of Energy (DOE) national laboratory based in Richland, Washington, is managing the study called the Pacific Northwest GridWise Testbed Demonstration. The project is funded primarily by the DOE.

Through the demonstration, researchers are gaining insight into energy consumers’ behavior while testing new technologies designed to bring the electric transmission system into the information age. Northwest utilities, appliance manufacturers and technology companies are also supporting this effort. A combination of devices, software and advanced analytical tools is giving homeowners more information about their energy use and cost.

Approximately 100 homes on the Olympic Peninsula, WA, receive energy price information through a broadband internet connection and have received automated demand-response thermostats and water heaters that can adjust energy use based on price. Fifty of those homes, another 50 homes in Yakima, WA, and 50 homes in Gresham, OR, have computer chips in their dryers. These chips sense when the power transmission system is under stress and automatically turn off certain home appliance functions briefly until the grid can be stabilized by power operators.

The technologies the PNNL are testing will turn todays appliances into full partners in grid operations. The overall objective is to project how an intelligent electric power grid might look and operate. The demonstration has two major components – an energy pricing experiment and a smart appliance demonstration.

Rapid real-time pricing

The demonstration is one of the first efforts to provide and have loads respond automatically to pricing data on a very short time scale – every five minutes compared to other demonstrations’ 15 minutes – and the first to include the true costs of transmission and distribution within that price by doing in-the-field demand response with real-time prices. The experiment uses electric energy price as a signal to coordinate the responses from numerous loads and distributed generation resources while accounting for power distribution constraints. The objective is to demonstrate that price signals can be used to manage existing distribution constraints, and help utilities defer distribution or transmission system upgrades by managing loads and distributed generators to reduce power flow and relieve system constraints.

The GridWise chip can sense when the power transmission system is under stress and automatically turn off certain functions in appliances.
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Automated controls will adjust appliances and thermostats based on predetermined instructions from homeowners. The volunteers have their own website on which they manage their responses. There, they can choose from a range of responses from no response to maximum economy response. At any point, homeowners can override their preprogrammed preferences to achieve maximum comfort and convenience.

Unique cash-back approach

Currently, Northwest utilities charge a flat rate per kilowatt hour to homeowners, regardless of the wholesale cost of power or the cost of transmission and distribution. In the demonstration, PNNL are analyzing how customers react to the real cost of delivering energy to their homes through the use of simulated electric bills and pretend money in a mock account that is converted quarterly into cash incentives they get to keep.

If homeowners choose to reduce electric consumption at times of higher prices, the pretend money they save becomes real as they are issued a check from the GridWise programme each quarter. Price-conscious participants are expected to earn about $150 during the year, and nobody will lose money during the experiment.

Appliance controller chip

In the portion of the demonstration focused on the smart appliance technology a computer chip developed by PNNL was installed in 150 Sears Kenmore dryers produced by Whirlpool Corporation. The Grid Friendly Appliance (GFA) controller chip turns off certain parts of an appliance when it senses instability in the grid – about once a day. The chip shuts down the dryer heating element for a few minutes, while the drum continues to tumble. This typically goes unnoticed by the homeowner, but drastically reduces power demand within the home.

Multiplied on a large scale this instant reduction in energy load could serve as a shock absorber for the grid. It would give grid operators time to bring new power generation resources on-line to stabilize the grid.

The version of the chip installed at the demonstration sites is a small circuit board that communicates with the appliance to turn off parts of the appliance load when the grid frequency falls below a threshold. If many such appliances were on the power grid, the ability of loads to drop off temporarily in a controlled fashion in response to a frequency drop would soften the impact of an underfrequency event and create time for the grid operator to fix problems.

At PNNL, researchers have been reducing the size and cost of the GFA controller. The goal is to ultimately make the controller available to manufacturers without increasing the cost of an appliance by more than a couple of dollars.

Bringing it all back home

The home of Jerry Brous, in Sequim, WA, was set up with the gateway that communicates to the GridWise project, a smart dryer, a thermostat controlling his heat pump and a water heater controller. He said: “I can play with our energy usage, working to balance what’s most efficient, making adjustments as I see the price change. I can even tell how solar heat reduces my home’s heating and cooling needs, so I can adjust window coverings to block or let in the sun to make the most of it. One thing it’s led me to consider is how uncomfortable I am willing to be if energy were in short supply – I like the idea of taking a little from everybody to ensure that everyone has enough.”

Benefitting all energy users

The demonstration is also addressing the whole range of users; from residential to commercial to industrial. A component of the demonstration is under way at PNNL’s Marine Research Operations office spaces also in Sequim. The building uses PNNL’s transactive control methods, an internal market-based competition for electrical power within the building. For example, if the temperature in an individual zone is satisfactory, that zone will bid low for the right to heat or cool itself. If unsatisfactory, the zone bids higher. The control system can tell to what degree each thermostat is satisfied, and creates a hierarchy of use.

Over 72 hours the local marginal price increases when the total demand exceeds an imposed constraint of 500 kW, causing controllable loads to shed demand and causing distributed generator resources to start up.
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Five municipal water pumps on the Olympic Peninsula are also plugged into the real-time price signal. Their bidding behaviour is similar to that of the thermostats. They monitor their reservoir water level and if it is low there is a more urgent need for energy which results in a higher bid for the right to run the pumps.

Big cost savings envisaged

Two previous PNNL studies indicated that creating a smarter grid through information technology could save the USA $80 billion or more over 20 years by offsetting costs of building the generators, transmission lines and substations that will be required to meet estimated load growth1,2.

At the end of the demonstration, PNNL will evaluate customers reactions to the chip and their responses to the real-time pricing information to determine their acceptance. This will help government and industry determine whether and how to best make the technologies more widely available to consumers.

One of PNNL’s goals is to show that automation for demand response can deliver valuable, persistent responses from automated appliances. Automation shows its benefit every day, compared to state-of-the-art critical peak pricing, which is called up only 12 times a year. The results should also show the advantage of having a range of users – both load side and resource side – use a common price response signal.

In short, the researchers believe the demonstration will help GridWise bring the electric power system into the information age-one bit at a time.

1 Kannberg, LD, DP Chassin, JG DeSteese, SG Hauser, MC Kintner-Meyer, RG Pratt, LA Schienbein, and WM Warwick. 2003. GridWise: The Benefits of a Transformed Energy System. PNNL-14396, Pacific Northwest National Laboratory, Richland, Washington.

2 Estimating the Benefits of the GridWise Initiative: Phase I Report. RAND, TR-160-PNNL, May 2004.

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