If conventional halogen lamps were replaced with LED lights, it would reduce carbon dioxide emissions by 90,000 tonnes in Sweden. As well as the major environmental savings, the new LED lights also use less energy, which saves money, they adapt better to the surrounding light and weather conditions and also offer a solution to the eternal headlight problem when meeting other cars on the road. This is according to Harry Frank, a professor and member of The Royal Swedish Academy of Sciences and Arne Hörvallius, Technical Manager at Audi Sweden.
 
LED (Light Emitting Diode) technology was invented as far back as the middle of the 1920s and is currently used for everything from traffic lights, head torches and Nintendo Wii’s hand controls. The car industry has already been using LED lights for quite some time, primarily for indicator lights on the dashboard; in recent years they have also been used for red and yellow rear lights. However, it has been more difficult to produce a white light, which is why it has been banned for use as a headlamp.
 
If LED lights are used instead of conventional car lights, power consumption can be reduced by up to 90 percent for the same intensity of light. This means that while dipped headlights using standard halogen lights use 0.8 percent of the car's fuel consumption, LED lights only use 0.1 percent. A simple numerical example illustrates the impact LED lights would have on the environment.
 
In 2007 there were around 4.3 million cars registered in Sweden. Only a small proportion of these currently have LED lights, so they will not be included in this calculation. If you look solely at petrol and diesel cars, 9,000,000,000 litres of petrol and diesel were used in the transport sector in 2007. Private cars make up most of this figure. If you then look at carbon dioxide emissions, private cars emitted around 13,000,000 tonnes in 2007.

This simplified model therefore shows that headlights in Swedish cars currently account for 0.8 percent of the 13 million tonnes of carbon dioxide that are emitted every year.

This means that halogen lamps are responsible for around 100,000 tonnes of carbon dioxide emissions every year. Seeing as switching off lights is not an option, we need to have a kind of lighting that is more fuel-efficient. If all cars on the road only used LED lights, and we used the same calculation, headlights would account for 10,000 tonnes of carbon dioxide emissions. This would therefore represent a reduction of 90,000 tonnes.

”I also think that LED lamps present a major advantage as we now move over to having more electric cars. As LED lamps need a very low amount of electric energy, cars can be driven longer,” says Harry Frank, professor and member of the Royal Swedish Academy of Sciences.

Financial and safety benefits
A study that was recently carried out by Carwinism.se shows that Swedish car drivers put the environment at the top of the list when answering the question: ”What kind of technical innovations do you think we need to invest in most to save the car industry?”. 56 percent answered the environment, 31 percent finance and 9 percent safety.

However, when answering the question, ”Which of the following do you prioritise when buying a car?”, both finance and safety came before the environment. 64 percent of respondents thought finance was the most important factor when buying a car, 56 percent chose safety and only 23 percent thought of the environment first. In other words, LED technology needs to provide both financial and safety incentives to have a broad impact.

Based on figures from 2007, 13,000 km is the average distance driven in petrol-powered cars every year. This figure was 30,000 km for diesel-powered cars (source: the Swedish Institute for Transport and Communication Analysis). Using a petrol and diesel price of SEK 12 per litre and an average consumption of 0.87 litres for every 10 kilometres, this means that the average car driver pays around SEK 15,000 for petrol and diesel every year. Transferring to LED headlights would lead to a reduced fuel cost of SEK 0.5 billion every year for Sweden’s car drivers.

As for safety, LED lights make it possible to manage the flow of light based on the colour of the road, the weather and the traffic situation. Changing between dipped and full headlights would take place automatically using LED technology, and would therefore remove the irritating headlight problem when meeting another car on the road.

In 2007 the Audi car company was granted exemption from the ban of using full LED lighting when it launched its R8 model. On 11 July 2008 this ban was fully lifted, opening the doors for all car manufacturers to gradually replace halogen technology with LED.
 
(CO2 emissions from all registered cars in your country per year x 0,008) - (CO2 emissions from all registered cars in your country per year x 0,001) = CO2 emission saving due to shift from halogen to LED in your country