Keep the streetlights on through smart control networks

By Steve Nguyen and Luc Ashton, Echelon

Economics, the environment, and an increasing desire among people to live a greener lifestyle are driving the U.K. streetlight market. Innovative cities from Norfolk and Gloucestershire to Powys and Milton Keynes have implemented or are planning to implement energy-saving programs involving streetlights.

Why? Because streetlights can account for up to 40 percent of a city’s electricity use, and with rising energy costs, streetlights can consume a huge portion of a city’s annual electricity budget. The Council of Milton Keynes’s 60,000 streetlights accounted for 2.5 million in electricity costs from January 2008 to March 2009.

It seems that an easy solution would be to turn off the lights. Doing so, some would argue, would reduce to zero the electricity costs associated with a lighting segment, yielding the following benefits:
• Zero light pollution for that segment
• Easy implementation
• Zero CO2 emissions

On the surface this sounds great. In fact, many cities have either implemented this solution or are planning to do so. Yet it is far from ideal. According to a recent study by the Cochrane Library reported in the Telegraph.co.uk, street lighting reduced the number of fatal crashes by 77 percent and other collisions by between 32 and 55 percent. Fiona Beyer, one of the study’s authors, noted, “Road crashes are not just the unfortunate culmination of chance, but are events that can be analyzed so the risk factors are identified and then addressed.” According to Beyer, “'Darkness is a risk factor — street lighting is, therefore, a valuable tool.” [1]

As a result, U.K. cities are once again examining their methods of managing streetlight electricity. Our proposal: Embed smart control networks into streetlights. The end result is far better than turning off the lights:
• Decreased energy use – as much as 70 percent less energy use. [2]
• Improved safety – lights stay on. The whiter quality of our proposed streetlights can also increase visual acuity as well as improve the quality of images captured on existing security cameras.
• Lower maintenance costs – advanced monitoring notifies cities of impending light failure and actual failures.
• Better living conditions – lighting can be tuned to residential or commercial preferences.

Milton Keynes Council: An Example of Smart Streetlighting
In looking at its aging street lighting system, the council of Milton Keynes took a hard look at the budgets that were remaining static, or worse, being cut. But the cost of maintaining lighting systems was increasing. For example, the price of electricity in Milton Keynes increased from 3 pence per KW/hour to 11.1 pence per KW/hour. Costs for labor and parts were also rising, but the city budget to maintain streetlights remained unchanged.

The only real solution was to drastically change the street lighting system. It required upfront cost, but it was an investment in a solution that could last for up to 20 years, rather than placing a band-aid on an outdated, inefficient system.

By June 2007, Milton Keynes had completed the first phase of its smart streetlight project. Consisting of 450 lights, the project aimed to reduce energy use, light pollution, and CO2 emissions while simultaneously reducing crime.

Milton Keynes achieved its goals without turning out the lights. Instead, it installed a LonWorks® based smart control network [3] by working with ballast supplier SELC Electronics and software supplier Streetlight.Vision. The council installed ceramic metal halide lamps to replace its aging SON lamps. This alone yielded a 30 percent reduction in electricity use. Each lamp communicates through existing power lines to segment controllers located at each street-side electrical junction box. These segment controllers, in turn, communicate with the council’s Streetlight.Vision Web-based management software.

The results have been impressive:

• Reduced energy costs (40 percent overall). About half is due to dimming, which includes both active dimming (reducing light output to decrease energy use) and optimal lighting (modulating light output to sustain safe, pleasing lighting levels). The rest is due to lower-power-consuming lamps.
• Reduced operating costs (ongoing). Along with inventory savings provided by the lamp technology, the control network supports predictive lamp failure notification. This improves customer service, decreases costs through scheduled maintenance, and helps lower energy use (failing lamps use more energy).
• Improved safety. The use of white lights (which produces about 80 percent of the light quality of natural sunlight) has made the city’s existing security cameras much more effective, allowing them to capture true color and greater facial detail. This enhanced color and resolution, combined with always-on lighting, has helped reduce crime.

An Unfair Tariff Means Frustratingly Slow Pace Going Forward
The project managers describe its pace forward as “frustratingly slow,” despite its unimpeachable success. While this is partially due to the economic situation affecting virtually every city in the U.K., it’s more due to the fact that utilities want to charge a tariff for carrying data over their power lines.

According to Luc Ashton, the Milton Keynes streetlight project manager, “The electricity company is reacting to the power line signaling technology that the solution employs. This despite the fact that it is a global standard for smart control networks. [4] We need to prove there is no impact to the electricity company by allowing our communications over their power lines.”

Milton Keynes believes the electricity company is concerned about allowing this communication over its power lines since U.K. power lines are not explicitly licensed for communications. However, this is an administration issue, not a technical nor electricity grid performance issue. In fact, many utilities in the E.U. and the United States use existing power lines for data communications. The cities of Oslo [5], Norway; Ville de Quebec, Canada; San Jose, CA (U.S.), and others are all successfully using power line communications for some, or all, of their smart streetlights.

Yet in the U.K., there is a persistent fear that streetlight communications is a broadband link that will flood the electricity wires with data, crippling the local grid and denying service to customers.

“This is patently untrue,” says Ashton. “The system we have employed at Milton Keynes and that is also used in the city of Oslo communicates at a tiny fraction of broadband speeds — in fact, at an entirely different frequency. There is absolutely no impact on the performance of the electricity grid whatever.”

Central Networks (a subsidiary of E.ON), the local energy provider in Milton Keynes, wants to test every segment controller, every power line, and every lamp for possible impact on the grid. In the view of Milton Keynes and others, “This is no more than an attempt to create a new revenue stream out of a new market.”

What is the impact of this tariff? “This supplemental tariff costs more than the savings generated by the new streetlight solution. It eliminates the cost benefits of smart lighting,” said Ashton.

In the meantime, the next phase sits in waiting. The council hopes to add 1,200 lights in new residential developments currently under construction and 7,000 additional lights throughout the councils’ roadway system. Although the economic downturn has slowed the construction, the new lights are still scheduled to be installed using the same project specifications and will be part of the overall system.

No New Tariffs: A Call to Action for the U.K. Smart Streetlight Market
While the project makes a clear energy-saving case for smart streetlight networks and new lamp technology, impediments to a nationwide adoption persist in the form of unfair tariffs imposed by electric utilities. The LonWorks control technology that is key to the Milton Keynes project — the only smart streetlight project successfully implemented in the U.K. — uses existing power mains installed years ago to transmit data between lamps and service centers. Tariffs imposed by utilities are artificial, having no grounds in performance- or service-related issues. They are a roadblock to smart streetlights, and by extension, an impediment to energy independence for the U.K. Tariffs from smart streetlight systems over power mains must be removed, today. Let’s keep the lights on and keep our streets safe.

Contact details of the authors:
Steve Nguyen, Director of Corporate Marketing
Echelon Corporation (NASDAQ:ELON)
E: qnguyen@echelon.com

Luc Ashton, Streetlight Project Manager for Milton Keynes Council
Mouchel Business Services Ltd
E: Luc.Ashton@Milton-keynes.gov.uk

References:
[1] “Turning off street lights could put motorists at risk.” Telegraph.co.uk, David Millward, Transport Editor. Last updated: 12:24PM GMT 20 Jan. 2009.
[2] Assumes a switch from mercury vapor to LED lights. Switching yields as much as a 50 percent reduction in electricity use. An additional 20 percent savings is delivered by dimming features enabled by control networks.
[3] The LonWorks platform for smart control networks was developed by Echelon Corporation and introduced in 1998. It is currently used by hundreds of manufacturers for control applications including commercial building systems, smart streetlights, homes, trains, planes, passenger ferries, and smart residential metering systems for utilities. LonWorks is an internationally registered trademark of Echelon Corporation.
[4] The communications protocol, power line, and twisted-pair signaling technology, and IP methodology used by the LonWorks platform has been ratified as an ISO/IEC standard under the designation ISO/IEC 14908.
[5] The City of Oslo has reported a 70 percent reduction in electricity use and Euro 450,000/year operating cost reduction due to its LonWorks based smart street lighting system that began operations in 2004. More information can be found at the Clinton Climate Foundations website: http://www.c40cities.org/bestpractices/lighting/oslo_streetlight.jsp