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ABSTRACT
The increasing residential air-conditioning demand and the growing number of solar photovoltaic (PV) systems installed in the residential sector have increased electrical net energy demand fluctuation. These severe fluctuations lead to a need for flexible generation capacities that can rapidly meet the fluctuating demands. To combat these fluctuations, utility companies have introduced different price plans to financially incentivize customers to reduce their demand during certain hours of the day, in essence, attempting to make residential electricity demand constant (or "flat") for the daytime hours. Flattening the net demand not only reduces homeowners' operation costs, it also enhances stability of the electricity grid by decreasing the need for flexible generation plants that typically use more fossil fuels. Therefore, shifting electricity consumption from peak to off-peak hours promotes economic and environmental savings. This paper leverages simulation modeling and experimental work to explore the feasibility of coupling precooling with photovoltaics (PVs) to achieve flat residential net demand in three Phoenix, AZ area homes. Results show that precooling coupled with PVs provides economic benefits of up to $160 annually for homeowners while simultaneously reducing demand fluctuations by up to 90%.
INTRODUCTION
Solar energy has received growing support from the United States government in the past several years through various programs. State governments, in particular, have introduced various incentive programs in the form of rebates, tax incentives, and mandates to promote solar installations (Moosavian et al. 2013; Ogimoto et al. 2013). In buildings equipped with solar systems, if the solar electricity generation is greater than the building's energy demand, the excess power from solar photovoltaic (PV) panels can be either stored in electrical batteries or sold to the grid. Due to the high prices of electrical batteries for most residential buildings, excess generation is most often sold to the grid. As the solar peak production occurs a few hours before the residential peak demand, utilities will observe a valley followed by a peak in the net load profiles, particularly with a high penetration of rooftop PV resources. This leads to a challenging issue that will require rapid response in operations, such as rapidly bringing on or shutting down generation resources to meet the fluctuating electricity demand. Utilities have introduced timeof-use tariffs that make selling excess electricity an unprofitable...