Patio heaters outside a restaurant in Paris

"Posing a challenge to an issue, rather than identifying what it is you want and put out a tender, is good for us. It helps us develop a vision for how the city can evolve."

So speaks Georges-Etienne Faure, the adviser to the Deputy Mayor of Paris, Jean-Louis Missika, who is responsible for innovation, research and universities. This attitude has helped the city develop several innovative solutions to some of its problems including a datasharing system for helping people get around the city using public transport.

At Paris' bourse recent second Innovation Award for example the winners were: Anaxago, a crowdfunding platform, Track.it which links smartphones to music lists, and echy, which is developing a system using Fresnel lenses and optical fibres to transmit sunlight deep inside a building. A roof-mounted sensor of three square meters (yards) is able to illuminate a room with a 15 times greater floor area with natural light.

The latest idea, though, is much more ambitious in terms of potentially reducing carbon emissions. Nowadays, smokers around the world in areas where smoking has been banned inside cafes, bars and restaurants, meet on the streets beneath gas-fired patio burners, especially in the winter.

Spewing carbon dioxide and wasted heat into the atmosphere these devices are the scourge of environmentalists but very popular amongst the owners of catering establishments anxious to attract clientelle. Each heater produces 2.6 kg of CO2 per hour.

Andrew Warren, Director of the British Association for the Conservation of Energy, hates them: "There is no more visible symbol of the unacceptable despoilation of the environment than patio heaters. A ban on their sale would send a strong signal that people have to change their attitudes if we are to meet the challenges posed by climate change."

Dr Des Turner, a previous member of Parliament in England, failed in an attempt to introduce a Bill in the UK to have the heaters banned in 2009. "The use of patio heaters accounts for about 1m tonnes of CO2 emissions a year, which immediately cancels out, for instance, the savings made by government changes to vehicle taxations," he said at the time.

Many municipalities now regulate, or are trying to, the use of these gas heaters, although not in the UK. Since December last year the French cities Paris, Lyon, Lille and Perpignan have tried to ban the use of gas patio heaters amidst great controversy. But in Paris this decision was overturned in a victory for cafe terrace owners. The problem is traditional: people like to gather on the streets in the evening, even when it's cold.

So if someone could come up with a cheap, sustainable alternative, it would have many champions. This was the challenge set by Faure to innovators anywhere in the world.

Now a winner has been announced: a San Diego-based architecture design firm called Amorphica has came up with a solar powered solution called an urban parasol.

Its spokeswoman, Leemor Chandally, describes the urban parasol, which was prototyped in San Francisco, "as a solution for cities to provide an urban amenity that creates comfortable and interactive urban spaces year-round. For example, it can be easily affixed to existing urban fixtures, such as bus stops, to improve the experience of waiting for a bus during the winter by providing a warm semi-enclosed space."

She continues: "It harnesses and efficiently utilises renewable energy and integrates path-tracking and responsive solar panels, thermodynamic solar panels and space blanket insulation. Light sensors allow the parasol to accurately follow the sun's natural path and therefore maximise energy absorption, and heating and LED-lighting activation is controlled using sensors to avoid any waste of energy. And the parasol re-orients to create a semi-enclosed protective shelter for the user in dark and cold weather."

She adds: "it can be used in outdoor spaces that turn unaccommodating and empty during the harsher months. It can also be used in public transitional spaces, such as waiting areas, which in many areas lack protection from such weather conditions."

Amorphica Design Research Office is an emerging architecture, urban design and research collective studio that evolves projects internationally with the intention of developing a responsive design intelligence dedicated to the service of the public through profound social compromise.

In the past the company has worked on a revitalisation and regeneration project for abandon urban plots in Baja California, Mexico, built a series of furniture and a rooftop space using recycled materials, and helped to develop a self-sufficient preparatory high school in Baja California.

Faure says the next step is to "experiment with the parasols, test them and above all see how Parisians like them. The experimentation is decisive. Socially it's important for us to test products with real people, so we'll put them all over the city. If Parisians like the parasols, we'll take them large-scale."

The urban parasol prototype in San Francisco.

Photography: Berenice Jimenez