Ultra low emission vehicles (ULEVs)

ultra low emission vehicles

The UK Government defines Ultra Low Emissions Vehicles (ULEVs) as cars or vans with tailpipe CO2 emissions of 75 g/km or less. Currently all models categorised as ULEVs have an electrified powertrain of some sort, but include a number of different technoloies to achieve these low emissions figures.

Funding worth hundreds of millions of pounds has been committed by the UK Government through projects such as the plug-in car grant (PiCG), and investment in supporting the Automated and Electric Vehicles Bill. Other initiatives include the Go Ultra Low campaign, a project backed by Government and the automotive industry to promote the awareness and uptake of ULEVs.

Types of ULEV

Electric Vehicles (EVs) - also known as battery electric (BEV) or pure electric vehicles - have zero tail-pipe emissions as they are fuelled by electricity. All EV's have a rechargable on-board battery to power the electric motor, which is used to turn the wheels. This battery is charged by pluging the car in to an exterior power source, such as a mains socket (for emergency use only), home charging unit, or public charge point. Visit the Next Green Car EV microsite for more information.

Plug-in-Hybrid Vehicles (PHEVs) include both an electric powertrain and an internal combustion engine. The battery has a lower capacity than an EV's and as a result, electric-only range is limited - typically to between 15-40 miles depending on the model. Both the electric motor and engine are able to drive the wheels, either seperately or combined. Often the internal combustion engine is used at higher speeds or when the battery has been drained, with most PHEVs defaulting to electric-mode each time they are started. Find out more about plug-in hybrid vehicles on the Next Green Car microsite.

Extended Range Electric Vehicles (EREVs) - or Range Extended Electric Vehicles (REEVs) - are a type of PHEV, but with the driven wheels powered only by the electric motor. A compact internal combustion engine is fitted, but it acts as an on-board generator to top up the battery's charge - placing an EREV somewhere between a PHEV and pure-EV. The EVEV's battery can also be charged externally, with the car capable of being used as a conventional EV, but with the added safety net of the on-board generator extending the car's range.

Fuel Cell Electric Vehicles (FCEVs) are often powered by hydrogen. These use electricity generated by a fuel cell stack to charge the car's battery and power the electric motor that drives the wheels. Similar in concept to an EREV, the electric powertrain results in zero-harmful tailpipe emissions, with the only by-product being water. Although a small capacity battery is normally fitted, the ability to carry hydrogen in an on-board tank means that a range of 300 miles or more is possible, with only a few minutes required to refill the tank.

There are also a few Conventional Hybrids on the market that are categorised as ULEVs using the CO2 emissions limit as the deciding factor. Using an internal combustion engine supported by an electric motor, the most efficient hybrids can achieve this sub-75 g/km CO2 figure, though most sit between 75-100 g/km. A small battery is not able to be recharged externally, and instead is topped-up either under braking or by the engine, offering a an electric-only range of just a few miles.

ULEV benefits

While the initial prices for ULEV's tend to be higher than for conventional vehicles, there are a number of benefits to owning a ULEV.

Most ULEV models will be eligible for the plug-in-car grant of up to £4,500 or £2,500 depending on OLEV category. On top of these grants reducing the initial purchase price, on-going running costs should be much lower than a petrol or diesel equivilent.

Fuel costs can be as low as 3p per mile and there are Vehicle Excise Duty (car tax) benefits too. Models rated 0 g/km CO2 qualify for zero VED each year if costing under £40,000, or £310 if more than that.

ULEVs with a tailpipe CO2 output will pay £130 each year if under £40,000 - or £440 if over - since all qualify for the £10 alternative fuel discount. First year rates are lower than conventional cars too with ULEVs up to 50 g/km CO2 charged nothing, and those over charged £15.

Other advantages are exemptions from the London Congestion Charge and T-Charge, and significantly lower Benefit-in-Kind (BIK) rates for company car drivers.

ULEV’s also have associated environmental benefits. Many have the option to be or are constantly zero-emission at point of use. This means a reduction in harmful greenhouse gases such as carbon dioxide (CO2) and regulated emissions such as nitrogen oxides (NOx) and particulates (PMs). This is especially important in cities where poor air quality caused by road transport emissions is creating a public health issue.

Furthermore, ULEVs tend to be easy to drive, quiet and powerful thanks to high torque electric motors. Regenerative breaking means breaking is generally gentler than in a petrol or diesel vehicle.

Chris Lilly

Author:Chris Lilly
Date Updated:16th Nov 2017

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