Sunny side up

Throughout Europe, bus stops and shelters are increasingly being fitted with lighting to enhance security and safety on public transport.More and more suppliers are looking at alternatives to traditional grid connected electricity supply – with solar photovoltaic panels leading this expansion.

Solar photovoltaic works by generating electricity directly from the sun, which can be stored in rechargeable batteries for night time use. Since the technology contains no moving parts and the solar cells can be easily incorporated into the roof of a bus shelter, it is proving an attractive option for illuminating bus waiting areas. Leading product development suppliers are providing easy, custom-built and durable lighting solutions across a diverse range of everyday and more surprising arenas. At the core of the system is a microprocessor that can manage the light output in accordance with the energy in the battery. Solar photovoltaic microprocessor based electronic control systems are developed to harness the synergy between solar energy and high output LED based lighting. The stops have solar cells on a coiled panel on the top of the ‘flag’, which is lit by an LED automatically from sunset until sunrise. Pressing a button on the timetable case lights it for 20 seconds. In addition, lines of customised technologies, that provide solar-powered LED lighting solutions for transit applications, amenity lighting, signage and other specialised products, have been developed. Suppliers can customise bus shelters and stops, incorporating the solar-powered lighting solution with minimal disruption, to suit the needs of the client.

Traditionally, bus shelters are connected to the mains supply. The lifetime cost of the grid connections (utility connection, trenching/termination, standing charge and maintenance) as well as long lead time for connections, has made solar power an economic and feasible alternative.

A prime consideration is that, because the stops are self contained and not reliant on mains power, they can be effortlessly and inexpensively relocated as bus routes are altered. A solar solution for almost any kind of bus shelter, from urban glass designs to rural wooden structures, can be manufactured with a vandal-resistant flexible technology and PV polycarbonate laminates. This also makes the bus stop more noticeable at night and should help to improve passengers’ feelings of security. In addition, tariffs are being imposed on utilities to dig up the highway under street works legislation, plus the rise in the wholesale cost of electricity in the last few years; all combine to make a non-grid source of electricity an ever more attractive option. Not only can it take from two weeks up to twelve months to connect a bus stop or shelter to the grid, but the connection costs are required at the start of operation and also every time a bus stop is out of action after being damaged in a traffic collision. Solar photovoltaics, however, provide the perfect solution when energy is required in remote locations, where grid connection is unavailable or prohibitively expensive.With no moving parts, off grid photovoltaics systems offer increased reliability and speed of installation, minimised maintenance requirements and considerable cost savings in comparison to grid connection.

The financial benefits

The key benefit lies in cost savings.According to Solar Century, a typical example of the life cycle costs – initial capital costs and ongoing maintenance costs – of illuminating 400 bus shelters using a mains connected fluorescent tube compared to the photovoltaics system, demonstrates significant cost savings. The traditional system has to account for initial connection charges, ongoing electricity costs, maintenance costs (capital and labour) for fluorescent tube lighting and electrical inspection costs required for mains connected street furniture and disconnection and reconnection charges in the event of accidents or streetworks.

On the contrary, the photovoltaics system bears no cabling costs, as it can cost up to £50 per metre with grid connection. There are no connection charges, saving an average of £800 per application and in some cases, it can provide up to £25,000 of free electricity. There is a service/maintenance saving of £100 per bus shelter per year, no annual connection check, which saves £70 per bus shelter every year and instant, on-site, high lux illumination with no cabling required. There are no annual connection checks required, demonstrated security of electricity supply in all seasons, case of installation, retrofitted or installed in new systems, vandal proof – photovoltaics is discretely integrated or retrofitted and has no glass components, no traffic disruption as roads do not need to be dug for cabling and safe and secure environment, providing reliable illumination throughout the night.

The final arguments are the longevity of lighting with no maintenance, LED lighting has an operational life of more than 100,000 hours compared to 5,000 hours for lights used in traditional shelters. The flexibility of infrastructure means that it can be easily relocated to reflect changing passenger use and in particular, the offset of greenhouse gas emissions means that each application of the lighting solution saves 50 kg of CO2 a year – a visible commitment to Agenda 21, Chapter 9, Protection of the Atmosphere; Promoting sustainable development, transportation, released by the United Nations Conference on Environment and Development (also known as UNCED or the Earth Summit) held in Rio de Janeiro, Brazil, 1992.

Obvious environmental and cost-effective reasons are categorically persuading more and more European countries to use solar-power lighting at bus stops.

The UK story

In England, Transport for London (TfL) is showing the way with the application of new technologies.After a free three years trial of 200 installations from three suppliers, TfL, which has 4000 shelters, was seeking tenders for the installations of 7000 solar powered bus stops over the next five years, a network of innovative bus stops combining the latest white LED technology with photovoltaics. Each bus stop will feature a photovoltaic covered canopy that collects energy from the sun. The power is gathered during the day, then stored in batteries and used to illuminate the timetable display, signage and passenger waiting area during the night. Canadian solar product company Carmanah has been awarded the contract to provide the 1200 LED-illuminated bus stops needed in the first phase by Trueform Group (the contracted solutions provider of bus shelter infrastructure for London Bus Services) in Britain. This is for the supply of a minimum of 1,200 solar LED-illuminated bus stops, scheduled for installation throughout the City of London in the first phase between October 2005 and March 2006.

In 2003, the first solar-powered bus shelter in the UK went on trial in North Lanarkshire. Others have since followed in Leicester, Birmingham, Plymouth and Southampton. In Edinburgh solar power is to be used to light up more than 100 of the city’s busiest bus stops and the city already boasts hundreds of solar-powered parking meters in the city centre, which allow drivers to pay by mobile phone. In answer to concerns, many companies in the area prove that systems are designed to work in the toughest conditions Britain can offer and be able to cope with a number of days of continuous overcast winter weather.

Solar Century, one of the bidders for the TfL project, already has 1000 solar-powered bus stops and shelters across UK, including Manchester, Liverpool, Glasgow, Nottingham, Leicester,Aberdeen and Plymouth. In one extreme example, Southampton City Council turned to Solar Century to provide illumination for ten of the city’s bus stops after waiting 12 months for a power connection to the grid.

Solar Century’s innovative Streetsmart – the photovoltaics lighting system installed by SC – won Product of the Year at the Bus Industry Awards 2004. Since 2002, Solar Century have installed more than 900 Streetsmart systems for the world’s leading outdoor media company JCDecaux in 11 cities across the UK- France, Spain, Slovakia, Holland, Germany and Denmark. The Streetsmart system demonstrated a cheaper option than traditional grid connection and required considerably lower maintenance.With all these advantages, the solar JCDecaux shelter is absolutely identical to a grid connected shelter and consequently JCDecaux have now specified Streetsmart shelters across Europe.

Germany and France move one stage further

Germany is going solar as well. Bus stops, shelters, parking ticket machines and speed warning signs powered by photovoltaic cells are starting to appear all over the country. Fraunhofer Institute for Solar Energy Systems in Freiburg develops energy-efficient components essential to the tailormade energy management system which controls the cycle, while the light comes from ultra-bright light-emitting diodes and low-energy lamps. The Fraunhofer Institute’s next project will be to develop a solar-powered timetable, which will use a radio link to inform passengers when the next bus will arrive.

France is looking to expand the use of solar power for bus shelters with the government willing to subsidise these installation in some cases.

The city of Lyon has put into place an innovative new idea which improves the service provided to public transportation customers. Every bus-stop is now equipped with a sign indicating the exact time of arrival of the next bus… and this is in real-time!

Every bus is equipped with a radio transmitter, which sends a signal indicating the bus’s position, allowing the system to calculate the time when the bus will arrive at the next stop. In order to be able to use this system, each busstop had to be supplied with electricity: and solar energy was the most widely adopted solution. The solar panel installed at each site produces the electricity needed for the indicator to function properly.

These systems were installed by TENESOL (previously TOTAL ENERGIE) which is headquartered in the region of Lyon.With more than 23 years of experience in the field of solar energy, TENESOL is one of the historical leaders in this field.

The solar photovoltaic systems supplied by Tenesol (former Total Energie) are already installed in the electricity department of Calvados in the framework of the FACE programme (concession and maintenance insured by EDF), the city of Mordelles (Brittany)- financed by ADEME/EDF, the city of Liffre (Brittany) – financed by ADEME/EDF and the Electricity Department of Vienne as part of the FACE programme.

Increasingly, in Europe and around the world, solar bus shelters provide an environmental solution for the community, help reduce emissions leading to global warming and lay down an infrastructure that future generations will benefit from. There is no doubt that solar photovoltaic installations are poised to see rapid growth and solar-powered bus shelters will speedily replace the traditional grid connected electricity supply.

Acknowledgements

Thanks to Simon Gerrard from Solar Century and Stéphane MAUREAU from Tenesol (members of the European Photovoltaic Industry Association) for providing valuable information for this article.