Energy efficiency and lighting. Are lighting upgrades / retrofits always sensible?
When it comes to energy efficiency measures, lighting retrofits are one of the most popular options. Unfortunately, information regarding payback and return rates on these investments are not always accurately presented. Many have proceeded with upgrades only to find out that the results did not meet original expectations.
Electrical energy is consumed in a light fixture to produce light and a natural byproduct of this process is heat.
If you upgrade to more efficient lighting, the new light fixtures will generate less heat. During the heating season this heat is useful and not entirely wasted. To accurately assess this upgrade, you should consider the penalty that during the heating season you will spend more money on gas or electricity to heat your building. Conversely, during the cooling season, these cooler running light fixtures can result in additional energy savings based on reduced cooling needs. Therefore, in order to perform an accurate lighting audit along with the associated financial analysis, one can not ignore the heat generated by the light fixtures.
We’ve come across many cases where decisions on large lighting capital projects have been based on over simplified lighting analysis which ignore the above mentioned costs. Building owners and managers should be cautious about “free lighting energy audits” which in some cases lead to hardware sales and installations. When considering upgrades, we encourage working with qualified firms capable of complete analysis to help you understand the entire picture specific to your building and conditions. A complete report should help you not only get technical information but present you with a full financial cost-benefit analysis.
Important points to consider:
- Is your building heated with gas or electricity?
- Does you building have central air conditioning/cooling?
- Age of the current fixtures and their remaining useful life
- Lighting maintenance requirements and the associated costs (example: accessibility)
- Operating hours (intermittent or constant)
- Environmental benefits and mandates
- Current lighting levels and requirements
- Utility costs, available funds & financing costs