THE CAUSES AND EFFECTS OF DISCREPANCY BETWEEN PROJECTED AND ACHIEVED ENERGY SAVING IN BUILDING ENERGY RETROFIT PROJECTS

Abstract

Building energy retrofits are known to have many benefits such as energy reductions, lower utility cost of building and an improved quality of environment. In Singapore, a broad portfolio of strategies and schemes has been laid out to encourage building owners to engage in retrofit projects. However, there are certain risks associated with building energy retrofits that may hinder the progress and uptake of building energy retrofits. In this study, the risk of energy savings uncertainty is studied.

Underlying this risk is the discrepancy observed between projected and achieved energy savings in retrofit projects. There is a need for reliable estimates of energy savings as they are integral to building owners and Energy Services Companies. The amount of energy savings from a retrofit project will determine whether or not the project is successful and how ESCOs will be paid once the project is completed.

The main aim of this study is hence to identify and understand the causes and effects of the discrepancy observed between projected and achieved energy savings. The factors identified can be used to educate building owners of the risk associated with energy retrofits and hence, may facilitate risk planning activities.

Literature review and interviews with energy professionals from LJ Energy Pte Ltd, CBM Solutions Pte Ltd, Johnsons Control Pte Ltd, Barghest Building Performance Pte Ltd and National Institute of Education Singapore (NIE) were conducted and it was found that the causes of discrepancy are associated with poor inputs of parameter values when conducting baseline study and the improper selection of procedure in validating and verifying energy savings.

Recommendations were provided to suggest ways to manage risks with regards to energy savings uncertainty. They include statistical inference technique when estimating parameter values. Also, to minimize uncertainties and reduce risk, a shift in attitude towards attaining a high level of accuracy in energy estimates is encouraged.