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June, 2009:

Calculating The Real Carbon Footprint Of Vehicles

environmentalresearchweb – Jun 8, 2009

Examining the energy requirements and greenhouse-gas emissions over the entire life cycle of a vehicle, including processes such as manufacture rather than simply operation, reveals that the new combined values increases by 63% for cars and buses, 155% for rail and 31% for air transport. So say researchers at the University of California at Berkeley, US, who believe that their work will be critical in determining the true environmental footprint of all vehicles because until now only tailpipe analyses have been considered.

Mikhail Chester and colleagues calculated the amount of energy required, and the quantity of emissions produced, over the entire lifetimes of automobiles (both buses and cars), trains and aircraft. The analysis included the energy, greenhouse-gas emissions and the production of air pollutants – such as sulphur dioxide, nitrogen oxides and carbon monoxide %ndash; associated with vehicle manufacture, the transport infrastructure required, fuel production and the supply chain, as well as actual operation of the vehicle itself.

“Including life cycle-component inventories results in around a 40% energy and greenhouse-gas increase over direct vehicle operation for autos, while for rail there is about a doubling,” Chester told environmentalresearchweb. For aircraft the increase is around 30%.

Chester says that it is all too common to evaluate transport emissions based simply on the amount of fuel that vehicles consume. Often we see rankings based on these numbers, and global-warming mitigation schemes are subsequently based on such figures. But we need to analyse a vehicle’s life-cycle components to evaluate properly how much energy it consumes and thus the amount of emissions that it produces, he explained.

The researchers say that the amount of occupancy can easily change the relative performance of the transport modes.

The work will be critical for policy and decision makers because the researchers have also analysed which life-cycle components have the most impact on the environment. “While policy has often focused on the vehicle’s tailpipe emissions (for example, in the US Corporate Average Fuel Economy Standards, and removal of lead from petrol), our study shows that you may not want to focus on this component but somewhere else in the mode’s life cycle,” said Chester.

One of the best examples of such a strategic error is that of sulphur emissions, he stressed. Much has been done to remove sulphur from petrol and diesel fuels in recent years but, according to the new study, the bulk of sulphur emissions for transport actually comes from the electricity needed to manufacture a vehicle. This is particularly true for vehicles that are fabricated using electricity that is produced in coal-powered plants.

The team has already applied its inventory to several major metropolitan regions in the US. “We have also gone on to evaluate the life-cycle environmental impacts of the proposed California high-speed rail,” revealed Chester.

The researchers used models that calculate the amount of electricity needed to produce the components of the three modes of transport. From this, they were able to determine the amount of polluting emissions created during different manufacturing processes. They then compared these values with the emissions produced by the same vehicles when they are on the road – the classical tailpipe scenario. The data employed were taken from previous literature, such as government reports, and more detailed modelling software like the US Environmental Protection Agency’s Mobile Software for vehicle-operation emissions and the US Federal Aviation Administration’s Emission Data Modelling Software for aircraft emissions.

The work is published in Environmental Research Letters

200MW Wind Farm off Sai Kung Viable, CLP Power Says

Cheung Chi-fai, SCMP – Updated on Jun 03, 2009

An offshore wind farm at Sai Kung, capable of generating enough power for 80,000 households, was technically feasible and environmentally acceptable, CLP Power said yesterday.

The project, which the utility has been developing for three years, calls for 67 wind turbines 135 metres high near the Ninepin Islands, about 10km east of Clear Water Bay in Sai Kung. The turbines have been shifted 1km east in response to residents’ concerns about the visual impact.

“You won’t be able to see it clearly most of the time, especially in hazy weather as it is quite far away from land,” said Joseph Law Ka-chun, the project manager for CLP Power.

The farm would have a capacity of 200 megawatts – enough power for 80,000 households – avoid carbon emission, and help towards Hong Kong’s goal of getting 1 to 2 per cent of its energy from renewable sources in the next decade, the utility said.

CLP Power and its partner in the project, Wind Prospect, which designs and builds turbines, are today releasing their environmental impact assessment report, which they have submitted to the Environmental Protection Department for approval. The bureau still needs to review the business plan, and the project financing would then have to be arranged. Work would begin after 2011 and take three years.

But once completed, the wind farm, spread across 16 sq km, would be comparable to the world’s largest – 91 turbines with a 209MW capacity in the North Sea off the west coast of Denmark.

Hongkong Electric is also studying building a 100MW offshore wind farm adjacent to the CLP Power’s near Ninepin or south of Lamma Island. The utility said an estimate of the cost would only be available after detailed studies on the wind and the waves, which affect the size of the turbines. An earlier estimate by the utility, however, put the cost of a 100MW wind-farm development at about HK$3 billion.

Each CLP turbine would be set between 500 and 650 metres apart. The electricity would be transmitted via a 25km undersea cable that connected to CLP’s grid at Tseung Kwan O. If the wind was sufficiently strong and the technology worked, an alternative plan of installing 40 wind turbines of 5MW each would be considered.

The turbines would be coated only with non-reflective paint, and the air-traffic warning lights would point skywards, with the intensity carefully planned, CLP Power said. For security reasons, marine traffic in the area would be restricted to authorised vessels. But the utility has not ruled out some form of limited tourism at the site.

Mr Law said the construction method, similar to that used for offshore oil and gas drilling platforms, was endorsed by the Buildings Department after a pilot test last year.

It did not require dredging and avoided the negative impacts of conventional drilling and piling into the bedrock beneath a 30 metre layer of mud and sand.

No offshore wind farms had been built with this technology yet and the cost was similar to that of conventional piling.