Thermal Storage Technology Assessment
The Thermal Storage Technology Assessment was sparked by a strong interest in using thermal storage to supplement home heating systems.
Thermal storage can take many forms: water storage tanks that allow residents to increase the firing time on an outdoor wood boiler so they can burn more efficiently; a storage tank for an electric heating system to enable off-peak power use; storing heat gathered from solar panels in the ground during the summer for a heat pump to extract in the winter; and many others.
Space heating accounts for 74% of energy consumption in single-family residences in Alaska (ARIS, 2012), while domestic hot water heating accounts for 15 – 25% of home energy use in America (U.S. Department of Energy, 2011). As such, researchers and residents of Alaska and other heating-dominated climates are continually searching for methods to raise efficiencies and reduce costs. One such method that has recently attracted attention in Alaska is thermal storage, which is currently being used in Alaska and other cold climates in conjunction with heating systems. For instance, a thermal net-zero home was recently built in Fairbanks. The heating system uses solar thermal panels and a masonry heater to charge a 5,000-gallon thermal storage tank that provides heat to a radiant floor for space heating. The thermal storage tank also provides heat for the domestic hot water system. The potential of thermal storage to enhance the use of renewable heating systems in cold climates, increase the efficiency of heating systems, and reduce emissions has raised interest in its use.
In spite of its potential, there are few informational resources on the successful application of thermal storage in cold climates. Currently, there are limited educational materials and literary articles on thermal storage systems in cold climates, and on how thermal storage can be best integrated into a heating system. This report aims to provide an informative, though introductory, assessment of the current status of thermal storage in residential construction in cold climates. The authors’ primary motivation is to provide building researchers and building owners living in cold climates with a document outlining the applications and potential of thermal storage in heating systems. This document can also be used to inform and define future research on thermal storage in cold climates.