Instead of a house fitted with solar panels collecting up the energy from the daytime for use during the night, this stored energy should be passed onto a national gird. This is the outcome of a comprehensive review for the Cockrell School of Engineering at The University of Texas at Austin. The finding is important given the growth of solar power in the U.S. Here some estimates put the number of homes fitted with solar panels at one million.
According to Professor Michael Webber his study shows “storage isn’t required to make solar panels useful or cost-effective.” He follows this up in a research brief by saying: “this also counters the prevailing myth that storage is needed to integrate distributed solar power just because it doesn’t produce energy at night.”
To arrive at this conclusion, the research team analyzed the impact of home energy storage using electricity data gathered from some 100 Texas households. The homes were part of a smart grid test bed operated by Pecan Street Inc. Pecan is a renewable energy and smart technology company located at The University of Texas.
This analysis showed that storing solar energy for use at night increases a household’s annual energy consumption. This was based on a comparison of homes using solar panels without storage. This happens since the act of storage consumes some energy each time it charges and discharges. By adding energy storage to a household with solar panels this raises the annual energy consumption from 324 to 591 kilowatt-hours.
The report also found that adding storage increases emissions of carbon dioxide, sulfur dioxide and nitrogen dioxide. This arises because of the increase in energy consumption needed to account for storage inefficiencies.
Simply put, if the aim of solar panels on a home is to make a home more ‘green’, storage should avoided. The research has been published in the journal Nature Energy. The research paper is called “The impacts of storing solar energy in the home to reduce reliance on the utility.”
