The objective of this project is to demonstrate dramatic peak demand reduction (65% compared to an equivalently sized house just meeting the basic building code stipulations) in residential new construction via distributed generation, centralized electrical energy storage, energy efficiency, direct load control or price-responsive load control. Work in underway in moving forward on all of these topics at a Pulte Homes Development called Villa Trieste. This is located in the Summerlin area of the City of Las Vegas, and it will consist of 180 houses when completed in 5 years.
Current status related to the Villa Trieste project as of October 2009 includes the following (Follow the link to the graphical presentation of the Project):
a) Highly energy conserving building design has been under construction for several houses since late in 2008 (Link to Villa Trieste Construction Progress). Floor areas of these single-family, two-story houses range from 1487 to 1960 sq ft. These houses have roof-integrated photovoltaic systems (more on this below), and the buildings are extremely energy conserving with a HERS rating of 62 (this is for the Roma model at 1487 sq ft) without considering the effect of the PV generation. Standard features in each home include a tankless water heater, a dashboard that gives the resident energy consumption/generation information, R-7 exterior doors, 92 AFUE furnace, 100% CFL lighting, 2x4 and 2x6 construction with 1 inch of EPS and blow-in cellulose (R-13 and R-19 depending upon the stud size), windows with a 0.34 U factor and a 0.32 SHGC, 15 SEER air conditioner, unvented (semi-conditioned space) attic, as well as other features. As part of the current project, the energy consumption of these houses has been numerically simulated using building energy computer codes. Additionally, instrumentation as been temporarily located in the houses for detailed energy flow analyses, and this is in addition to the measuring equipment that is used to furnish data to the dashboard. Comparisons have been used to calibrate the computations. The houses have garnered the prestigious LEED Platinum classification. A view of the model homes is shown in the figure below. (go to top) (Follow the link to the graphical presentation of the Project)
b) Each home has photovoltaic (PV) tiles incorporated in an integrated fashion on its roof. (Link to Energy Simulation Task)The addition of this component to the house decreases the HERS rating for the Roma model (for example) from 62 to 41. The size of these SunPower arrays is rated at 1.764 kW peak output. They are connected to the NV Energy grid in a net metering arrangement. Each kWh sent to the utility is treated to be the same economic value as each kWh used from the utility. Because of the nature of the development plan for Villa Trieste, all of the houses will have a PV system with a nearly south exposure, nearly west exposure, or nearly east exposure. Minor decreases in power generated over a year’s period will result for the off-south exposures compared to the nearly south arrangement. (go to top) (Follow the link to the graphical presentation of the Project)
c) Communication System, Intelligent Agent, and Load Control (Link to Task)
An internet communication system is being developed to allow signals to be relayed from the utility to the customer, and from the customer to the utility. One of the purposes of this communication link is to transmit (nearly) instantaneous power cost information to the customer and to allow the customer to respond to this. In general, power costs increase during peak demand periods, so this information could be reacted to by the customer to shed load. In addition to active participation in the cost information exchange, an intelligent agent is being developed. In simple terms this would be a dial that the customer could set to any choice from “No modification of loads” to “Full modification of loads.” These could be also named “No control” to “Maximum money saved.” For the latter setting, an arrangement between the utility and customer will be developed in advance where each event of load shedding that the utility is allowed would have some type of reimbursement associated with it. Included in the events might be control of the home thermostat for predefined periods, ability to turn off pool pumps, on through a variety of other actions including controlling plug loads. Each of these elements would save both the utility and customer money. By operating on a whole community the utility strategy will be such that each home is affected for short periods of time. The staggering of the load control throughout the community, however, would result in a net decrease in load at the substation. (go to top) (Follow the link to the graphical presentation of the Project)
d) Battery Storage at Substation (Link to Task)
A Battery Energy Storage System (BESS) will be installed at the substation feeding the Villa Trieste development as well as some neighboring ones. The Villa Trieste power demand will be closely monitored separately from the other developments. The BESSS will be scheduled to assist the load demand during the hours of summer peak period in an effort to meet the targeted 65% peak shaving. Whenever the battery is used for an excursion, it will be recharged during off-peak power cost periods. Part of the work related to the design of this system is the sizing of the battery in terms of its power and energy ratings. From careful analysis of the current feeds of similar types of substations, as well as including insights gained from building simulations on Villa Trieste, it is estimated that this will require a 1 MW maximum power rating and a 6 MW-hr energy rating. Work continues on the selection of the actual battery system, the associated housing and controls required, and the development of the operational strategy. (go to top) (Follow the link to the graphical presentation of the Project)