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