Control Strategies for Industrial Lighting
Read any article about lighting these days and you will see the words: controls, advanced controls, wireless controls, advanced controls strategies and more. LED lighting has broadened the possibilities when it comes to controls integration. The challenge is to apply the strategies in a cohesive framework appropriate for the lighting solution being requested, then quantifying the economics and functional benefits to the decision-makers.
Why all the fuss over lighting controls?
Controls enhance the energy savings opportunities and extend the life of the fixture. Many jurisdictions are becoming more rigorous in the enforcement of local and federal energy codes. Title 24, Ashrae 90.1 and the IECC2015 all impact buildings and their usage. Controls allow designers, ESCO’s and facility managers to develop solutions appropriate to their business.
Longer term, constant changes in local, state and federal regulations, along with other nations’ energy reduction programs, make this an ideal time for the astute businessperson to examine their own business and determine a path forward. An emphasis on sustainability and energy conservation is likely to remain high on the agenda. As people working in the lighting and energy service fields, we have an opportunity to influence and determine the path forward for our clients.
The challenge for controls is how to accurately quantify the economics. Many believe that “green” business is good business only if the economics pencil out. Most of us must go through the ROI and IRR presentations to the CFO and C-Suite to get projects moving. Knowing how controls could impact those conversations may help in winning those projects.
For this article, controls strategies will be categorized into 2 distinct groups: direct and indirect. We will present ideas to effectively calculate their economics related to improving total energy savings.
Controls strategies offering Direct Project Savings:
- Luminaires are only used when the space is occupied. Sensors automatically turn lights off or to a predetermined level when the space is unoccupied and turn them on when it is.
- Daylight harvesting uses sensors to detect the available light in a space. They adjust automatically to preset criteria based on the amount of natural light in space and change as conditions change.
- Lighting can be scheduled to be on or off, per the needs of the building or space. Control could be astronomically controlled sunrise/sunset or set time periods, where the controls are grouped and scheduled.
- Customization of light to meet the needs of the user, more commonly used in office environments but can be used in industrial settings such as quality control and inspection.
High End Tune/Task Tune
- Lighting can be trimmed/tuned to less than 100%. The conventional wisdom is that the human eye perceives reductions of light at around 70%-80%.
Controls strategies offering Indirect Project Savings:
Demand Response/Load Shedding
- The lighting control system can be set with sensors to react to demand reductions signals sent out during periods of peak demand. The control system can turn off groups or dim lighting in line with the agreement with the utility.
- Typically found on more advanced controls systems, both wired and wireless. The lighting controls are integrated to HVAC controls. The sensors can detect occupancy and adjust both lighting and HVAC controls to match the situation. Savings tend to be focused on the HVAC load, but these are still very valid energy savings.
- The control system can detect the health of the lighting system:
- Number of hours luminaire has been running.
- It can help with predictive maintenance. All things fail eventually.
- It allows the facility managers to be able look at their facilities at a micro level and implement more strategies to enhance the performance of the lighting system.
Looking at the Economics of Lighting Controls.
Like maintenance savings in the traditional ROI calculations, controls savings are never precise. Unlike moving from a 458w fixture to a 150w fixture, where it’s easy to recognize a 67.25% energy savings, it is often more complicated with controls. However, there are some good guidelines we can apply.
The Lawrence Berkeley National Lab (LBNL) did some testing and came up with some average savings which seem to be a reasonable benchmark.
We can establish the initial energy savings for the base project with pretty good accuracy if we follow a few fundamental steps:
- Audit of existing fixture types, quantities and energy consumed.
- Proposed new fixture type, quantities and proposed energy consumption.
- The utility rate charged.
- The run hours of the existing system.
This is any standard audit most companies that offer upgrade services can provide. There are several good third-party auditing tools available that will help to do the math, or you can use a custom spreadsheet.
Next, you can do the assumed maintenance savings calculation. This is always subjective, however, you but must determine a realistic number or one that the owner will trust. Remember, any CFO worth their salt will ask you to validate your numbers, so be realistic!
In this simple example, the initial Energy Savings is 67.25%. Next, we want to estimate the controls savings.
We will focus on the Direct Savings, as most often these are the controls measures that earn additional rebates from the utility company The Advanced Indirect Control Strategies are more subjective but certainly worthy of consideration in a larger picture discussion. Whenever we are looking at controls, getting the client’s involvement is key. If they don’t believe the numbers, your proposal is likely dead in the water. BE REALISTIC.
Pick a control solution appropriate to the job. No need to load the job with unnecessary cost if it won’t support it. The more sophisticated your solution, the more likely you are to want to move past a simple PIR and into wired or wireless controls. This is where Flex can help you determine what the best solution is. We have energy efficient fixtures with multiple control options which provide class leading life, at various ambient temperature ratings (don’t overlook the maintenance savings as part of the solution). We also have an excellent auditing and proposal tool , utility rebate tool, and an application team that will be happy to work with you on the controls design and layout.
Examples of Lighting Control Strategies:
Using our 458w and 150w scenario we will deploy an Occupancy/Vacancy Strategy for 30% additional savings, time scheduling for 10% and a high-end trim to 80% (20% energy savings).
Here we have improved our overall energy savings from 67.25% to 83.49%. This substantial reduction in energy should positively impact the ROI and earn extra rebate money from many utilities.
Adding Daylight Harvesting
Using our 458w and 150w scenario, we will deploy a daylight harvesting scheme for 35% additional energy reduction, time scheduling for 10% and a little less aggressive high-end trim to 90%.
Again, a nice increase in energy savings and well worth the extra effort to provide the client with an option for enhanced performance of their investment, extra rebate and extended maintenance cycles.
In addition to these direct savings, demand response, and EMS integration can provide additional savings. As you can see from the calculation, each measure provides an incremental savings of the previously reduced energy usage. Most of the better auditing tools can include control savings into their calculation. This enables you to present the best information for key decision makers to consider. This should position you as an educated resource, encourage deeper discussions, and lead to more project wins.
Hopefully this has given you a few ideas as to how to approach selling controls on industrial lighting projects. Our team at Flex is on hand to help. Just give us a call and we will help with the design, costing and proposal. There is value in selling controls.