Many vendors, from electricians to reflector distributors, will provide free proposals and, in some cases, fairly sophisticated energy studies for potential customers. A good proposal will be clearly laid out with a table of contents. There should be an executive summary so that you can quickly review the proposed measures and their associated costs, savings and paybacks. The proposal should provide enough detail to permit an understanding what went into the estimates. However, it is important to understand what the costs include. For example, you may find that disposal costs have been left out. Also, the quote may be for low output electronic ballasts, but your facility may require 100% lumen output ballasts to maintain acceptable light levels.
Proposals tend to be optimistic because the vendor wants to sell a product. This doesn't mean that the information in the proposal is wrong. It's simply important to check some of the finer points to understand where the numbers come from. Always check to be sure that lighting quality will be maintained. Ask for clarification if necessary, or better yet have the vendor do a sample installation.
Review calculations closely. Do the operating hours make sense? If the cost savings include savings due to maintenance costs, check that these are reasonable. Are the appropriate electricity rates used? Are HVAC savings included and do they make sense? You may want to leave this out to be conservative.
