Dollars and Sense

Oct 14, 2021
Dollars and Sense
The author makes a seven-point business case for smart street lighting

By Cindy Brewbaker

Traditional streetlights are “dumb.” That’s because they lack the in-built intelligence which makes it possible for them to be managed dynamically. Dumb streetlights, by definition, can’t play an active role in providing responsive services to the citizens they serve. Such legacy streetlights are expensive to maintain and operate, and come with sizeable carbon footprints. In short, they are woefully outdated in the context of emerging technologies capable of delivering real advantages to the American public. There are 43.2 million streetlights in the U.S. today, of which just over 28 million1 remain, well, “dumb.” Analysis by the League of California Cities puts the net value of shifting to LED combined with smart controls as just over $200 per streetlight. That’s a whopping $5.7 billion of potential maintenance and energy savings available.

But intelligence is in the air, if you will. There are pioneers out there; investor-owned utilities (IOUs), such as Florida Power & Light, Georgia Power and Oklahoma Gas & Electric, as well as cities like Harrisburg, PA, Chicago, Los Angeles and Cleveland, are adding intelligence via smart control technology to hundreds of thousands of streetlights and realizing significant savings each year. These projects are contributing to an upswell in connected streetlight deployments expected to reach 35% of all streetlights by 2029. With that, here are seven reasons why smart street lighting makes good business sense.

1. Asset management.
To add smart control technology to streetlights, a wireless controller is fitted onto each light. The wireless controller communicates bi directionally with a management application accessed via a desktop or tablet. Not all jurisdictions have comprehensive and complete asset registers for all their light poles, so this first step in a smart streetlight deployment can be very useful. As street lighting control devices now commonly include GPS receivers, these can be used to automatically generate an up-to-date asset register and simplify installation. Streetlights with control nodes fitted make themselves known to the central management application as they get commissioned and go live. The subsequent “self-populating” inventory forms the basis of good asset management and in some extreme cases has identified circumstances where payments are being made against lights which don’t even exist.

2. Energy Savings.
The wireless controller controls the light and monitors its performance and status. By making use of the adaptive lighting capabilities which this technology enables, smart street lighting systems reduce the amount of energy streetlights consume by as much as 25% on top of the savings made by a shift to LED. Variable lighting policies may include dimming or raising lighting levels for specific sets of lights at certain times. Lighting profiles may include fine-tuning or trimming the burning hours, curfew switching of certain lights or the entire system, or running a constant light output strategy which matches the lighting power with degradation of the lamp over its lifetime and even takes account of increased light output after cleaning. The variable lighting policy will reduce the amount consumed without any degradation in the lighting service offered to the public, lowering carbon emissions, extending asset life and, depending on the tariff, reducing energy costs—but more on that later.

3. Locally responsive.
It’s easy to see how the improved flexibility described here translates into a more responsive public lighting service. Street lighting no longer needs to be a static, one-size-fits-all service. With each light represented digitally in the central management system, it can then be grouped and allocated a lighting profile and managed according to its group. Lights, for example in residential areas, industrial zones, crime hotspots and on major highways, can be managed differently and, as the needs of a neighborhood change, then adapted without any need to visit the site.

This flexibility could be taken one step further with traffic adaptive lighting. Here streetlights react to the presence of traffic, pedestrians or cyclists to tailor light levels accordingly. The result is a customizable lighting service aligned to the needs of the community and in keeping with the principles of the International Dark-Sky Association.

4. Lighten the labor load.
Streetlight maintenance routines will be leaner and more efficient when guided by smart controls. Automated fault detection and reporting will drive down the cost of streetlight maintenance. A good streetlight management system will feature a series of alarms, thresholds, automated polling and on-demand interrogation. Faults will show themselves in the system in real-time and be diagnosed proactively with electrical performance and lamp condition monitored 24/7.

5. Standard interfaces.
Streetlight owners, whether it’s the city or the power company, may decide to have the streetlight management platform integrated with their existing asset management system to make this even more seamless. The industry should establish open interfaces between streetlight central management systems and the asset management systems or building management systems with which they need to integrate. Standardization here is currently being driven by the leading vendors in specific markets and more work needs to be done to agree on a common protocol which can be accepted and adopted by industry.

6. Revenue-grade metering.
Now we return to the point made earlier about energy consumption and how this might flow through to reduced energy costs. The wireless technology) being used. Most of these tariffs are effectively fixed, charging an amount per light, by type, per month.

The most forward-thinking power companies are introducing suitable tariffs which reflect the way smart streetlights can be managed proactively for improved energy consumption. Of the 100 or so investor-owned utilities only about 10 have a “metered streetlight” tariff, in which the consumption may be measured by a conventional electricity meter. There are thought to be only about five2 “metered streetlight” tariffs, ratified by the relevant Public Utility Commission (PUC), that can take consumption data directly from the metering chips in the controllers on individual streetlights. As an additional requirement, these tariffs also carry the proviso that the controllers and smart street lighting system must have been evaluated and approved by the utility.

7. Pay for what you use.
While there is movement, the use of adaptive tariffs has lagged behind the capabilities of connected streetlight systems. PUCs have a clear role here to support end-user cities and municipalities by requiring utilities to offer tariffs which reflect actual consumption—not just a flat-rate fee regardless of how much energy is used. Now with smart connectivity to each individual streetlight, the amount of electricity each light consumes can be fine-tuned because they are more than just on or off. A meter can monitor precisely how much electricity is consumed by the light, making it possible to pay on a consumption basis. For now, the prevailing tariff is still a fixed fee, so there is a gap developing between usage and the amount paid, which cities don’t get to see.

Despite some challenges around electricity tariffs, there is, nevertheless, steady growth in the roll out of smart street lighting technology. Not least because, even with the potential monetary value associated with energy savings put to one side, the opportunity for far easier and more cost-effective management and maintenance, as well as the ability to offer residents a highly responsive lighting service, makes smart street lighting difficult to ignore. In the U.S., cities such as Los Angeles, San Diego and Cleveland have already adopted connected streetlight systems. Others, such as Kansas City, MO, Washington D.C., San Jose, CA, and Philadelphia are in the process of procuring smart technology to control their LED upgrades. We can see that smart street lighting deployments are well underway. With suitable utility tariffs thrown into the mix, those organizations doing the right thing by adopting greener streetlight technologies would be rewarded with lower energy bills.

References:

1 Northeast Group: United States Smart Street Lighting & Smart Cities Market Forecast (2020-2029)
2 PECO in Pennsylvania, Georgia Power, Eversource (NStar) in Massachusetts, San Diego Gas and Electric, National Grid