By Mark Kinver
Science and nature reporter, BBC News
Once the symbol for inspiration or a eureka moment, the incandescent lightbulb has taken on a whole new iconic status - that of public enemy number one in the battle against climate change.
In a speech to the recent Labour Party conference, Environment Secretary Hilary Benn outlined government plans to phase out the sale of the traditional bulbs in the UK by 2011.
Mr Benn's announcement follows on from the decision made by the Australian government in February to ban the bulbs by 2009.
The European Commission is also toying with the idea of an EU-wide ban as part of its target to cut energy consumption by 20% by 2020, as outlined in its Energy Action Plan.
Even the lighting sector's representative body, the European Lamp Companies Federation (ELC), is calling time on the technology that has lit the world since the 19th Century.
Its members support the phasing out of household incandescent bulbs by 2015, which it says will cut carbon dioxide emissions from lighting by 60%.
Philips, a member of the ELC, has set itself a target of doubling sales of its "green" products to 30% of its total revenue over the next five years.
Theo van Deursen, chief executive of Philips Lighting, says the target is based on the simple formula of customers-saving-energy equals customers-saving-money.
"Globally, 19% of electricity is used for lighting," he told BBC News. "We think you could save 40% of that, which means there are potentially huge savings."
While there seems to be consensus on the home front, Mr van Deursen believes more attention needs to be paid to the way we light our cities.
"If cities renewed their lighting systems, then it is a free ticket; there has to be some investment, but the payback (period) is relatively fast," he says.
Before and after: A street in Redbridge using modern lighting
"The renewal rate should increase, because the current rate for (renewing) street lighting is once every 30-40 years.
"This means that many streets are still lit with technology from the 1960s."
Mr van Deursen says the demand for lighting is only going to increase as more and more people live in cities.
"Today, one out of every two people live in an urban area. One hundred years ago, this figure was only 10%.
"If you go forward to the middle of this century, then we expect 75% of the world's population to live in a city."
A number of cities, including London, Sydney and Paris, have staged mass switch-offs as a symbolic gesture to highlight the problem of energy waste.
But Mr van Deursen says switching off is not the answer.
"If you think of major urban areas with 20 million people, if you switch all the lights off then you get a lot of crime and vandalism, and that is not what we want," he explained.
"There is modern technology that means you can do the job in a much better way."
He cites the London Borough of Redbridge as an area that is benefiting from using new ways of lighting its streets.
"The light quality has improved a lot and there have been energy savings of
50%. House prices in the street went up because people love to live in a street that is nicely lit."
Philips Lighting has published the results of a global research project called city.people.light, which invited leading luminaries from the worlds of urban planning and architecture, including architects Lord Rogers and Richard Meier, to share their vision of how they think cityscapes should look in 2020.
Examples ranged from simple ideas, such as placing screens on shop windows that will deflect light onto pavements, to light-emitting asphalt.
Mr van Deursen thinks the exercise will help shape his company's research and development.
"We did this because we want to look into the future," he says. "We have always participated in urban lighting, and we want to stay ahead in this sector."
Stella Bland, director of communications for the Commission for Architecture and the Built Environment (Cabe), says streets have often been a design dead-end.
"Streets are used by everyone everyday, yet they are the most badly designed part of the urban environment," she told BBC News.
"Up until now, they have pretty much been designed with motorists in mind, which is why you get lighting at heights of 25ft."
Ms Bland is also critical of offices that pour light into the night sky.
"I wonder whether the people who run these offices think they look like beautiful beacons. But it is just profligacy; there is an obscenity about it."
Light pollution is a big problem in major urban areas, such as London
She blames the energy waste on a lack of control: "In many big office blocks, workers are unable to switch off the lights when they leave."
However, she says it is hard not to be impressed by the night-time vistas created by the office blocks of Manhattan, London or Hong Kong.
But Ms Bland suggests that as people become more conscious of the need to conserve energy, this perception may change.
"Lighting is being used much more carefully now, and if it is done well it can really add to the sense of a place.
"One of the problems has been that some people think design quality is about aesthetics, whereas others think it lies in technical solutions," she explains.
"We think that the two areas reinforce each other, so design quality is not defined by how it looks but how it functions as well."