At present we don't have our own content on this topic but suggest you look at the 2007 report
Food & Drink Industry Refrigeration Efficiency Initiative
Guide 5 - Site Guidance Topics available from the
Institute of Refrigeration's web site.
Although specifically written for the food and drink industry, it contains a wealth of material that is applicable
in all sorts of contexts.
Further material and suggestions would be welcome - contact the editor
Other free advice on energy saving is available from the Energy Management Register