Gas vs Electric: Sustainability Performance of Heating Fuel Options in the NIST NZERTF

Published

September 28, 2020

Author(s)

David H. Webb, Joshua D. Kneifel

Abstract

Recent updates to the underlying cost and environmental data have recently been implemented in the BIRDS database. This study evaluates the updated results for validation as well as determine potential changes in the results relative to those found in O'Rear, Webb, Kneifel and O'Fallon (1). The updates are found to have a minor impact on the total LCC and the LCA results, but there is a shift in some energy efficiency measures (EEMs) in optimal designs. The continued reduction in solar PV installation costs leads to the larger system sizes being utilized in LCC designs while including few additional EEMs while reducing the efficiency of some building components while still reaching net-zero energy performance. As in the previous study, net-zero energy performance is reached at the lowest LCC using an all-electric design. The incremental increase in initial construction costs relative to the code- compliant design in Maryland is $28 222, which has continued a trend in decreasing premium for net-zero energy performance. Over the 30- year study period, NZLCC-E saves the homeowner $34 063. Although the homeowner could save more designing to meet the lowest LCC design using natural gas heating (LCC-NG), the additional savings is only $527 while still consuming about 50 % of the baseline building design. The concept of low-energy buildings must be reconsidered to determine whether new targets should be set, such as a combination of total consumption and net consumption or net-zero goals that include embodied energy. These results are limited in their generalization because they are based on a case study using validated simulation models based on in-situ performance of the NIST NZERTF located in Gaithersburg, MD. The implications should not be extrapolated to buildings with different climates, energy costs, building codes, or occupancies. The assumptions on the economic analysis are also important factors to consider when using the results and implications in this study for

Citation

Technical Note (NIST TN) - 2120

Report Number

2120

NIST Pub Series

Technical Note (NIST TN)

Pub Type

NIST Pubs

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DOI Link

Keywords

Space heating, domestic water heating, low-energy, net-zero energy: life-cycle assessment, life-cycle costing

Citation

Webb, D. and Kneifel, J. (2020), Gas vs Electric: Sustainability Performance of Heating Fuel Options in the NIST NZERTF, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.2120 (Accessed April 26, 2024)