A facility can benefit from implementing measures to improve energy efficiency. In some cases, the energy efficiency project will cover only one measure e.g. retrofit of a chiller by installing a new chiller. In other cases, it will be a whole of the chiller plant with new chillers, variable speed drive pumps and efficient cooling towers. It can also be a comprehensive energy efficiency project where insulation of the building, improvement of the air handling system, chiller plant retrofit, lighting system retrofit, etc. are combined into a larger project.
A facility will often have some low hanging fruits, being measures that have no or very low investment costs, but will provide energy savings. Other measures require some investment to buy and install new equipment, but will provide savings in a magnitude that can repay the investment within a short time frame. Finally, some measures are of a higher cost, but will still be able to repay themselves over their lifetime.