An EU scheme could use “smart streetlights” to cut energy bills and create Wi-Fi hotspots

Image: Skitterphoto at pixabay.

There are at least 60m streetlights in Europe. This, of course, is a good thing: they make roads safer and far more pleasant to walk along, and do much to minimise the chance of something horrible happening to passers-by.

But most of those street lights – as many as three-quarters – are at least 25 years old. And until relatively recently, lighting technology wasn't very efficient. As a result, the need to light up the streets can cost local government anywhere between 20 and 50 per cent of its energy bills.

Lucky for councils, then, that the EU is on hand to ride to the rescue. Even at this very moment, the European Commission’s “European Innovation Partnership on Smart Cities & Communities” (or EIP-SCC, if you prefer something snappier) is working to replace 10m streetlights across Europe with new, low-energy models.

That means more LED bulbs, which can cut energy costs by 50 to 75 per cent, mounted on lightweight poles, made from fibreglass or wood. Emissions-wise, replacing 10m streetlight bulbs with LEDs is equivalent to removing 2.6m cars from the road.

There’s more. The lights could also be raised or dimmed centrally – if an incident was playing out over CCTV and security needed a better view, for example. Some of the streetlights also have “smart” features, such as air quality monitors and Wi-Fi hubs: after all, since these things are inevitably going to be all over the place, we might as well use them.

Of course, replacing millions of streetlights is a pretty expensive business – so the initiative will be based on what Graham Colclough, the partner at consultancy UrbanDNA, who’s leading the project, calls “open component-based design”. That basically boils down to encouraging manufacturers to produce different parts which could combine to make street lights smarter, without the need to fully replace millions throughout Europe.

Late last year, representatives from different European countries met to discuss how to put the plan, which was launched early in 2014, into action. “ Ministers get it, leaders and mayors get it,” Colclough says. “Lots of smart city ideas are quite abstract, but street furniture is something you see and use every day, so the benefits are much clearer and more immediate.”  

And, he says, the challenge has also been taken up by designers and manufacturers: “Nine months ago, if you searched Google for images of streetlights, you just found pictures of bog-standard models. Now, the results page is full of new, funky designs.”

Without finalised designs, it’s impossible to say how long it’d take for energy savings to pay back smart streetlight investment. Estimates from the Green Investment bank, however, show that the switch from standard to low-energy lighting generally pays for itself within five to 15 years.

Maintaining the lights would be cheaper, too: LED bulbs offer around 100,000 hours of light, as opposed to the 15,000 hours supplied by a standard bulb. And because LED streetlights use collections of bulbs rather than just one, the street wouldn’t be plunged into darkness when one went pop.

These “smart” streetlights would be more appropriate for some roads than others, of course: Oxford Street has greater need for Wi-Fi and air quality sensors than residential areas would. For village roads and country lanes, meanwhile, we’re still rooting for those bioluminescent tree streetlights

 
 
 
 

How bad is the air pollution on the average subway network?

The New York Subway. Image: Getty.

Four more major Indian cities will soon have their own metro lines, the country’s government has announced. On the other side of the Himalayas, Shanghai is building its 14th subway line, set to open in 2020, adding 38.5 km and 32 stations to the world’s largest subway network. And New Yorkers can finally enjoy their Second Avenue Subway line after waiting for almost 100 years for it to arrive.

In Europe alone, commuters in more than 60 cities use rail subways. Internationally, more than 120m people commute by them every day. We count around 4.8m riders per day in London, 5.3m in Paris, 6.8m in Tokyo, 9.7m in Moscow and 10m in Beijing.

Subways are vital for commuting in crowded cities, something that will become more and more important over time – according to a United Nations 2014 report, half of the world’s population is now urban. They can also play a part in reducing outdoor air pollution in large metropolises by helping to reduce motor-vehicle use.

Large amounts of breathable particles (particulate matter, or PM) and nitrogen dioxide (NO2), produced in part by industrial emissions and road traffic, are responsible for shortening the lifespans of city dwellers. Public transportation systems such as subways have thus seemed like a solution to reduce air pollution in the urban environment.

But what is the air like that we breathe underground, on the rail platforms and inside trains?

Mixed air quality

Over the last decade, several pioneering studies have monitored subway air quality across a range of cities in Europe, Asia and the Americas. The database is incomplete, but is growing and is already valuable.

Subway, Tokyo, 2016. Image: Mildiou/Flickr/creative commons.

For example, comparing air quality on subway, bus, tram and walking journeys from the same origin to the same destination in Barcelona, revealed that subway air had higher levels of air pollution than in trams or walking in the street, but slightly lower than those in buses. Similar lower values for subway environments compared to other public transport modes have been demonstrated by studies in Hong Kong, Mexico City, Istanbul and Santiago de Chile.

Of wheels and brakes

Such differences have been attributed to different wheel materials and braking mechanisms, as well as to variations in ventilation and air conditioning systems, but may also relate to differences in measurement campaign protocols and choice of sampling sites.

Second Avenue Subway in the making, New York, 2013. Image: MTA Capital Construction/Rehema Trimiew/Wikimedia Commons.

Key factors influencing subway air pollution will include station depth, date of construction, type of ventilation (natural/air conditioning), types of brakes (electromagnetic or conventional brake pads) and wheels (rubber or steel) used on the trains, train frequency and more recently the presence or absence of platform screen-door systems.

In particular, much subway particulate matter is sourced from moving train parts such as wheels and brake pads, as well as from the steel rails and power-supply materials, making the particles dominantly iron-containing.


To date, there is no clear epidemiological indication of abnormal health effects on underground workers and commuters. New York subway workers have been exposed to such air without significant observed impacts on their health, and no increased risk of lung cancer was found among subway train drivers in the Stockholm subway system.

But a note of caution is struck by the observations of scholars who found that employees working on the platforms of Stockholm underground, where PM concentrations were greatest, tended to have higher levels of risk markers for cardiovascular disease than ticket sellers and train drivers.

The dominantly ferrous particles are mixed with particles from a range of other sources, including rock ballast from the track, biological aerosols (such as bacteria and viruses), and air from the outdoors, and driven through the tunnel system on turbulent air currents generated by the trains themselves and ventilation systems.

Comparing platforms

The most extensive measurement programme on subway platforms to date has been carried out in the Barcelona subway system, where 30 stations with differing designs were studied under the frame of IMPROVE LIFE project with additional support from the AXA Research Fund.

It reveals substantial variations in particle-matter concentrations. The stations with just a single tunnel with one rail track separated from the platform by glass barrier systems showed on average half the concentration of such particles in comparison with conventional stations, which have no barrier between the platform and tracks. The use of air-conditioning has been shown to produce lower particle-matter concentrations inside carriages.

In trains where it is possible to open the windows, such as in Athens, concentrations can be shown generally to increase inside the train when passing through tunnels and more specifically when the train enters the tunnel at high speed.

According to their construction material, you may breath different kind of particles on various platforms worldwide. Image: London Tube/Wikimedia Commons.

Monitoring stations

Although there are no existing legal controls on air quality in the subway environment, research should be moving towards realistic methods of mitigating particle pollution. Our experience in the Barcelona subway system, with its considerable range of different station designs and operating ventilation systems, is that each platform has its own specific atmospheric micro environment.

To design solutions, one will need to take into account local conditions of each station. Only then can researchers assess the influences of pollution generated from moving train parts.

The ConversationSuch research is still growing and will increase as subway operating companies are now more aware about how cleaner air leads directly to better health for city commuters.

Fulvio Amato is a tenured scientist at the Spanish National Research CouncilTeresa Moreno is a tenured scientist at the Institute of Environmental Assessment and Water Research (IDAEA), Spanish Scientific Research Council CSIC.

This article was originally published on The Conversation. Read the original article.