Low Emission Technology
Low emission technology (LET) is quite different to renewable energies in that the source is often traditional fuels like coal, gas and oil. Low emission technologies use a range of key advanced technologies to significantly reduce greenhouse gas emissions levels, air-borne pollutants and other environmental impacts.
Electricity and Power
In the power and electricity generation sector, these technologies focus on a suite of innovative engineering associated with CO2 capture and storage, as well as complementary advanced power generation systems. These include integrated gasification combined cycle (IGCC), oxy-fuel and post-combustion capture. Other technologies such as ultra supercritical pulverised fuel, coal cleaning and treatment, poly-generation, waste heat recovery, hydrogen production, enhanced coal bed, waste coal mine methane, coal gasification and liquefaction can also be termed low emission technologies.
All internal combustion engines produce tailpipe emissions—the by-products of burned fuel that is discharged from the exhaust pipe into the atmosphere. Whether diesel- or gasoline-powered, all combustion engines expel noxious gases such as unburned hydrocarbons and particulates into the air. Low emission technology can also refer to vehicles that are electric, hybrid, propane, gas, hydrogen or air powered. Most of us are now familiar with unleaded vehicle fuel developed to reduce air pollutants, which in itself is a form of low emission technology.
California in classifying vehicles has the following definitions which are now often referred to, although there are a host of others:
• TLEV – Transitional Low-Emission Vehicle. Early standard, phased out in 2004.
• LEV – Low-Emission Vehicle. This standard was the required average for all light vehicles sold nationwide by 2001.
• ULEV – Ultra-Low-Emission Vehicle. Vehicles with this designation are 50 percent cleaner than the average new vehicle.
• SULEV – Super Ultra-Low-Emission Vehicle. Vehicles with this designation are 90 percent cleaner than the average new vehicle.
• PZEV – Partial Zero-Emission Vehicle. Vehicles with zero evaporative emissions idle cleaner than the average new vehicle at idle.
• AT PZEV – Advanced Technology PZEV. Compressed natural-gas or hybrid vehicles that meet PZEV standards.
• ZEV – Zero-Emissions Vehicle. Electric and hydrogen fuel cell vehicles that have zero harmful tailpipe emissions.
The latest hybrid-electric hybrid-electric vehicles (those powered by a small internal combustion engine and one or more electric motors) typically fall under the AT PZEV classification. The vehicles are clean burning, examples include the 2006 Honda Civic Hybrid, Ford Escape Hybrid, and Toyota Prius.
We do need to be a bit careful about using terms like, ‘Zero emission’ as very few vehicles really fall into this category. Also, when considering zero emission the full life cycle should be considered. For instance, a lot of carbon dioxide can be emitted when materials for the vehicle are mined from the ground and throughout the manufacturing process. It is unlikely that renewable energy fuelled the production process, and so there is a carbon cost embedded even before the vehicle reaches the road. Once the vehicle is on the road, what about the fuel? Are the batteries charged from coal fired power generators? Are fuel cells manufactured using dirty coal? To be truly a zero emitter, the full life cycle of the vehicle with total carbon dioxide emissions needs to be calculated.
The price of emissions-intensive goods must increase if we are to drastically cut greenhouse gas emissions. Predicably, ExxonMobil in its annual long-term energy forecast in Dec 2006, said that despite a spike in energy demand, they do not expect to see any increase in the use of renewable energy sources from 2006 levels. The release went onto to say; that it expects the world will use 60% more energy in 2030 than in did in 2000. Obviously companies like this have an invested interest in fossil fuel, rather than renewable energy. Exxon said the cost of avoiding a ton of carbon emissions is less than $50 (per tonne) for most using technologies like gas, nuclear or a coal plant that buries its carbon underground as opposed to a conventional coal power plant.
The US Department of Energy (DOE), claims that in using present technology, estimates of sequestration (burying carbon) costs are in the range of $100 to $300/ton of carbon emissions avoided. The DOE expresses a goal by 2015, to reduce the cost of carbon sequestration to $10 or less per net ton of carbon emissions. In an attempt to bring this target to fruition the $US 1 billion Future Gen initiative is underway, a 10-year demonstration project to create the world’s first coal-based, zero-emissions electricity and hydrogen power plant.
From this short discussion you can see there is a lot of discrepancy in the price to have clean fossil fuels using low emission technology. Low emission technology is quite new and in development, so it is difficult to provide accurate costs. However, as the Stern Report points out it is false economy not to reduce our carbon emissions, and simply has to be done.