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Path To Net Zero Energy Homes To Be Discussed At 2015 ASHRAE Annual Conference

  • 16 Jun 2015
  • Atlanta

Path To Net Zero Energy Homes To Be Discussed At 2015 ASHRAE Annual Conference

Media Contact:
Allen Haynes

ATLANTA – Use of natural gas can help reduce the size and cost of a solar photovoltaic system used to achieve net zero energy, according to a research study modeling four homes in California that will be shared at ASHRAE’s 2015 Annual Conference.

The research was conducted as part of efforts to help identify strategies to increase the market acceptance of net zero energy residences. The need for such strategies is driven by aggressive targets for new home energy performance set by the U.S. Department of Energy (DOE) and the state of California.

Researchers note that key strategy to achieve these targets is use of on-site renewable energy to offset purchased electricity and natural gas. They will present their findings as part of the Technical Program at the ASHRAE 2015 Annual Conference, June 27-July 1, the Atlanta Hilton, Atlanta, Ga. To register or for more information, visit

The paper, “The Path to Achieving Net Zero Energy Homes – Energy Choices, Consumer Costs and the Environment,” is being presented as part of a paper session, “Advanced Energy Design Guides (AEDGs) and Beyond,” taking place Sunday, June 28. The session is one of several that include topics related to residential applications.

The DOE’s Building America goal is to reduce energy consumption in new homes by 50 percent from the 2009 International Energy Conservation Code. California’s goal is for all new residential construction to be net zero energy by 2020.

Paper authors note there are several metrics, methodologies and values that can be used to determine net zero energy, saying “the approach taken can have a significant influence on energy choices, consumer costs and environmental impacts.” Authors are Larry Brand and Neil Leslie, P.E., Gas Technology Institute, Des Plaines, Ill., and Martha Brook, P.E., California Energy Commission, Sacramento, Calif.

In their study, they modeled energy consumption and used photovoltaic (PV) arrays to achieve net zero energy performance when using all-electric appliances vs. gas appliances for two types of single family houses in four California climate zones at two levels of building energy efficiency. The evaluation was based on time-dependent valuation (TDV) and site energy metrics. Results of the analysis showed that the direct use of natural gas reduces the size and cost of the PV system required to achieve net zero energy compared to an all-electric house using the TDV metric, while providing similar carbon emission reduction benefits. The net present value of the utility costs over 30 years is 6 percent less than the cost of the PV system for the high efficiency house modeled.

“The long-term goal of the research community working in energy efficiency of buildings is to achieve net zero energy buildings through good building design and the appropriate use of renewables,” they conclude. “Applying solar PV systems to residential houses that use either all electric or mixed fuels to achieve net zero energy is a straightforward process…..Policy issues need to be addressed to facilitate mixed-fuel net zero energy houses. Future work includes adding an analysis of the growing renewable content of grid power, PV costs over time and the cost of efficiency vs. the cost of PV.”

Papers and presenters in the “Advanced Energy Design Guides (AEDGs) and Beyond” session include:

Energy Cost Minimization for Net Zero and Positive Energy Buildings with Biomass-Fueled CHP (AT-15-C001), Masahiko Murai, Hiroaki Otake, Masaaki Saito, Hiraku Asakura, Takao Nosaka and Nobutaka Nishimura, Toshiba Corp., Tokyo, Japan
The Path to Achieving Net Zero Energy Homes: Energy Choices, Consumer Costs and the Environment (AT-15-C002), Larry Brand and Neil Leslie, P.E., Gas Technology Institute, Des Plaines, Ill., and Martha Brook, P.E., California Energy Commission, Sacramento, Calif.

Through the Past Decade: How Advanced Energy Design Guides Have Influenced the Design Industry (AT-15-C003), Bing Liu, P.E., Rahul A. Athalye and Jian Zhang, Ph.D., Pacific Northwest National Laboratory, Richland, Wash.
Other session that address residential include:

  • International Perspectives on Residential Energy Efficiency, June 28
  • Analysis for Improved Efficiency of Chilled Water Systems, June 28
  • PM2.5 and Gases' Impact on Environment and Health, June 29
  • Climate Change: ASHRAE Design Day Weather Data, June 29
  • Utility Load Forecasting and Demand Response, June 29
  • Improved Duct System Performance: Leakage Elimination and CFD Modeling, June 29
  • Modeling for Residential Buildings, June 29
  • Optimizing Systems, June 30
  • Comfort and Health, June 30
  • Residential Systems Evaluation, June 30
  • HVAC System Topics, June 30
  • Residential Research and Building Occupants, July 1
  • Important Factors for a High Performance Building, July 1

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