In August 2018, the DesignLights Consortium (DLC) released Energy Savings Potential of DLC Commercial Lighting and Networked Lighting Controls, which projects energy savings for LED commercial lighting and networked lighting controls. The report makes a case that to continue getting big energy savings from lighting for another decade, utility rebate program administrators should transition to supporting LED luminaires and networked controls.
Currently, rebate programs favor LED screwbase products, which represents about 90 percent of the residential market but only 10 percent of the nonresidential market. The report points out that this technology is reaching saturation because of energy standards and market adoption. The nonresidential market, however, continues to offer strong potential for energy savings, based on national and regional adoption data based on the Department of Energy and other sources.
“Lighting product types used by commercial and industrial facilities are primarily indoor linear fixtures (72% of installed products), followed by outdoor fixtures (10%) and indoor non-linear products (8%),” the report states. “In each of these C&I product categories, the large installed base, coupled with relatively low LED market saturation, offers significant potential for future energy savings, particularly when paired with networked lighting controls.”
DLC points out these markets are in a growth phase, though none have yet exceed 50 percent adoption. LED area and roadway lighting has led the market, while adoption has been slower in indoor applications and is not expected to peak until the middle of next decade, offering strong energy savings potential.
This potential is accelerated when networked lighting controls, which can reduce these LED loads by nearly half, are included in the mix. In this market, adoption is growing but at a slower rate than for LED luminaires. Reasons include a lack of understanding of benefits, perceived cost and complexity, under-trained contractors, and limited utility support. Utility support of TLED replacement lamps is also limiting opportunities for networked controls.
The report states: “Unfortunately, if commercial and industrial LED products are installed without networked lighting controls, the opportunity to capture much of the savings potential that they offer can become stranded for many years because retrofitting networked lighting control systems onto already installed LED products is both expensive and technically challenging.”
DLC argues that aggressive utility promotion of networked lighting controls will increase peak energy savings in the mid-2020s and maintain lighting energy savings at or above 2017 levels until 2030—effectively doubling the term of savings achievable with LED lamps and luminaires alone. Another benefit for utilities supporting this category is lighting controls have a very low level of free ridership—owners who would install networked controls without the incentive but taking the incentive anyway—which provides solid net energy savings.
To take advantage of this opportunity with networked lighting controls, the report urges utilities to adopt simple and easy-to-understand prescriptive and midstream (via distributors) rebate programs. These programs are particularly suited for promoting networked lighting controls integrated with LED luminaires.
“When establishing prescriptive and midstream networked lighting control rebate levels, utilities should consider shifting resources away from standalone LED lighting measures and toward the system solution of LED + networked lighting controls,” the report said.
Performance- or space-based rebate programs can also work and typically save more energy, but they are typically complicated and should be reserved for large-scale and very complex projects.
“Commercial and industrial utility programs have the potential to capture significant lighting savings—and associated carbon reductions—for many years to come with ongoing support of LED and networked lighting controls,” the DLC report concludes. “Regardless of state or region, a path exists to maintain C&I lighting portfolios at or above current levels until at least 2028. Utility programs must aggressively pursue these opportunities using a multitude of strategies and service delivery models. The promotion and adoption of networked lighting controls is critical to ensure that utilities and customers capture the full benefit of LED systems being installed today.”
Click here to get the report.
Craig DiLouie refused my offer to write an article for him, so I crammed what I could into this reply.
Although controls can be cost effective saving energy with hibays in many warehouses, halls and stairwells that lights are on 24/7, etc., but most other applications when there is at least a basic time clock or somebody turning off switches or breakers, even occupancy sensors, dimmers and interior daylighting controls are often not cost effective for retrofits, even though Jim Benya recently wrote that they are.
Most of the case studies that I have read supporting lighting controls are very flawed, including a large portion of the savings coming from high end trimming, which means that too high wattage and lumen lighting was installed. Also ambient lighting providing about 150 – 200 horizontal lux and good tunable LED task lights are usually better than dimming ambient lighting for task tuning.
With today’s LED products, which are often 140 LPW, retrofitters including Rod Heller, me and many others can get down to 0.25 WSF, so each 20W troffer or troffer kit will only consume $7.50 of electricity per year, based on 3000 hours a year and U.S average KWH rate of $0.125. Even if controls would save DLC’s outlandish 46% average in its Energy Savings Potential of DLC Commercial Lighting and Networked Controls, the payback would still be way too long for most end-customers.
These two reports from Pacific Northwest National Laboratory, which does most of the lighting work for the DOE, show how little lighting controls really save.
Impacts of Commercial Building Controls on Energy Savings and Peak Load Reduction
Advanced Lighting Control System Performance: A Field Evaluation of Five Systems
The second one shows that there can be negative savings with occupancy sensors, which can be the result of people manually turning lights off before sensors are installed and then allowing for the 10 – 15 minute automatic delay after they are installed.
At least one provider in the Pacific Northwest is giving a $50 rebate for luminaire level lighting controls, I would feel totally ripped off if I was a rate payer there.
For networked controls to be cost effective now they would usually have to be less than $20 for parts, labor, commissioning, etc., instead of the typical $40 – $60 cost now. Rebates to get the price down to below $20 to end-customers can be considered a waste of rate payer money. Much more can be saved cost effectively with additional lighting retrofits. A good report is Energy Solutions’ Incremental Cost of Luminaire Level Lighting Controls (LLLC), which shows the added cost for the Clever System is $53 and higher for Clever-Hybrid and Smart System.
SSL will probably get down to 0.20 WSF or less in five years in offices, schools and some other applications, so controls will have to become even less expensive to be cost effective.
You don’t have to believe me. Check with Dr. Robert Karlicek at RPI, who may be the best expert in the country. Craig DiLouie interviewed him earlier this year, and Karlicek stated that controls are usually not cost effective saving energy with current LED products.
Manufacturers, organizations, contractors and individuals should focus on the non-energy benefits of smart controls, which dwarf the benefits of saving energy cost effectively. I just presented my first half day webinar on that for the Association of Energy Engineers and may write an article that is more comprehensive than the one Steve Mesh recently wrote.