ARCHIVED - Case Studies: Balancing Wind Generation Using Electric Thermal Storage and Electric Water Heaters

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Authors: Marc-André Moffet and Dr. Frédéric Sirois, École polytechnique de Montréal
David Beauvais, CanmetENERGY

CETC number: 2012-067

Publication date: 2012-07-17

Abstract:

Integrating a large proportion of variable renewable energy, such as wind, is a challenge for power grid operators, who must ensure a constant balance between the supply and demand of power, according to different time frames and different contingencies.

Recent studies and experiments with wind power integration have shown that it is possible to integrate a high penetration of energy from various sources on most power grids. However, as mentioned in previous studies, when wind power penetration reaches approximately 20% of a grid’s peak demand, the cost of this resource increases by up to 10%.

Depending on the region, wind power integration of over 20% may require improvements to a power grid’s flexibility. According to the International Energy Agency, this flexibility may increase by improving the generating system, by interconnecting with other markets, or by storage and demand management.

The introduction of dynamic rates and the development of demand management programs (demand response) reward clients who adjust their energy use in order to reduce stress on the grid. These programs may be offered on the wholesale market, as well as on retail markets by public utilities.

The industry’s fascination with smart grids has led to the marketing of consumer products that include equipment with the possibility for smart management of their use. In the commercial sector, power management solutions have been added onto building automation systems for easier interaction with the grid. Over the long term, it is expected that smart electric vehicle charging may also be used to balance wind generation. All of these applications could one day make it possible to increase power grid flexibility and absorb greater wind power penetration.

Although new technologies are in development, a large capacity for heat storage in client homes can already be used to offer power grid services. Many demonstration projects are already underway in this field.

In this report, the possibility of controlling water heater load and thermal storage units in order to balance wind generation will be explored in three case studies. The proposed control approach focuses on smoothing out wind generation variations, storing surplus and recovering heat during low production periods. In one case, the distributed resource is also used to reduce grid peak. In addition to balancing wind generation, this approach will also help postpone grid investments or prevent polluting or expensive power plants from operating.

The methodology required to model the system and the simulation results will be presented in this document. However, the results of these studies are only valid for the given context.

For more information about CanmetENERGY’s activities related to the smart grid, visit the Smart Grid section of the website.