If you want to worry about emissions, add another term (emission per unit energy) which is where clean energy comes in. (dotearth.blogs.nytimes.com)
Size, configuration (e.g., top freezer, bottom freezer, or side - by - side) and features have a big impact on overall unit energy consumption. (aceee.org)
Therefore, throughput per unit energy increases and hence energy efficiency improves. (scientificamerican.com)