To mitigate global warming, it is essential for households to reduce CO2 emissions. Saving electricity is one solution for the reduction. To promote this reduction, saving electricity by households should be considered because household consumption is growing rapidly. In this paper, we developed a system for metering electricity consumption and providing it to households as feedback on electricity usage. Previous studies on how to promote household energy savings found that feedback in real-time on electricity usage could be effective. Our system provided two types of information through web pages, (1) nearly real-time electricity consumption information, and (2) action lists for how to save energy. To test the effectiveness of these types of information, the system was installed in four households in an extremely cold district in Hokkaido, Japan for 378 days. During 30 days, data on electricity consumption was collected and stored. In the following month, a web page, which visualized nearly real-time electricity consumption, was opened to each household. After the experiment, an Internet-based questionnaire survey was conducted. The results obtained suggest that environmental awareness was an important aspect for inducing electricity saving behavior. (C) 2014 Elsevier Ltd. All rights reserved.