Zero-emissions vehicle

A zero-emissions vehicle, or ZEV, is a vehicle that emits no exhaust gas from the onboard source of power. Harmful pollutants to the health and the environment include particulates (soot), hydrocarbons, carbon monoxide, ozone, lead, and various oxides of nitrogen. Although not considered emission pollutants by the original California Air Resources Board (CARB) or U.S. Environmental Protection Agency (EPA) definitions, the most recent common use of the term also includes volatile organic compounds, several air toxics (most notably 1,3-Butadiene), and global pollutants such as carbon dioxide and other greenhouse gases.

Examples of zero emission vehicles include muscle-powered vehicles such as bicycles; electric bicycles; gravity racers; battery electric vehicles, which may shift emissions to the location where the electricity is generated (if the electricity comes from coal or natural gas power plants–as opposed to hydro-electric, wind power, solar power or nuclear power plants); and fuel cell vehicles powered by hydrogen. Emissions from the manufacturing process are thus not included in this definition, and it has been argued that the emissions that are created during manufacture are currently of an order of magnitude that is comparable to the one of the emissions that are created during a vehicle’s operating lifetime. However, these vehicles are in the early stages of their development; the manufacturing emissions may decrease by the development of technology, industry, shifting toward mass production and the ever increasing use of renewable energy throughout the supply-chains.

Vehicle structure
The classification is carried out in different ways according to the type of drive system, the energy used, the type of storage or the substances emitted.

ZEV with electric drive system
Electric car as a battery electric vehicle with traction battery (Example: GM EV1)
Fuel cell vehicles with pressure accumulator (Mercedes-Benz F-Cell), liquid hydrogen storage (cryogenically stored hydrogen) or liquid fuel methanol (Ex.: Honda FCX -Concept) [Note. 1]
Vehicles with flywheel storage (ex.: gyrobus)

ZEV with mechanical drive system
Vehicles with hydrogen combustion engine, (ex.: BMW Hydrogen) [Note. 2]
Vehicles with hydrogen gas turbine [Note. 2]
Vehicles with gas expansion engine (pneumatic car)
human powered vehicles [Note. 3]


1. Water is not considered a harmful exhaust gas when it comes to ground-level emissions.
2. Since these drives are based on air breathing, among other things, nitrogen oxides are ejected. The vehicles are therefore not emission-free in the narrower sense, but are classified as ZEV according to the California legislation.
3. Carbon dioxide is emitted, which is disregarded according to the ZEV guidelines. Also, these vehicles are not motor vehicles because they have no technical drive machine.

Technology and industry

Well-to-wheel emissions
The term zero-emissions or ZEV, as originally coined by the California Air Resources Board (CARB), refers only to motor vehicle emissions from the onboard source of power. Therefore, CARB’s definition is accounting only for pollutants emitted at the point of the vehicle operation, and the clean air benefits are usually local because depending on the source of the electricity used to recharge the batteries, air pollutant emissions are shifted to the location of the electricity generation plants. In a broader perspective, the electricity used to recharge the batteries must be generated from renewable or clean sources such as wind, solar, hydroelectric, or nuclear power for ZEVs to have almost none or zero well-to-wheel emissions. In other words, if ZEVs are recharged from electricity generated by fossil fuel plants, they cannot be considered as zero emissions.

However, the spread of electrical-powered vehicles can help the development of systems for charging the EV batteries from excess electricity which cannot be used otherwise. For instance, electricity demand is the lowest at nights and the excess generated electricity at this time can be used for recharging the EVs’ batteries. It’s worth mentioning that renewable sources such as wind turbines or nuclear power plants are less controllable in terms of the amount of generated electricity compared to fossil fuel power plants; most of renewable energy sources are known as intermittent energy sources. Therefore, development of these resources will lead to excess energy which can be better used by development of EVs. Moreover, most of EVs benefit from regenerative brakes and other optimization systems which increases the energy efficiency in these vehicles.

Fuel Cell Vehicles (FCVs), can help even more in terms of the development of sustainable energy sources because these cars use hydrogen as their fuel. Compressed hydrogen can be used as an energy storage element, while electricity must be stored in batteries. The Hydrogen can be produced by electricity through electrolysis, and this electricity can come from green sources. Hydrogen can be produced in situ, e.g.excess at wind farm when the generated electricity is not needed, or it can be connected to the grid to use the excess electricity from the grid and produce electricity, e.g. at Hydrogen pump stations. As a result, development of FCVs can be a big step toward sustainable development and reducing GHG emission in long term perspective.

Other countries have a different definition of ZEV, noteworthy the more recent inclusion of greenhouse gases, as many European rules now regulate carbon dioxide CO2 emissions. CARB’s role in regulating greenhouse gases began in 2004 based on the 2002 Pavley Act (AB 1493), but was blocked by lawsuits and by the EPA in 2007, by rejecting the required waiver. Additional responsibilities were granted to CARB by California’s Global Warming Solutions Act of 2006 (AB 32), which includes the mandate to set low-carbon fuel standards.

As a result of an investigation into false advertising regarding “zero-emissions” claims, the Advertising Standards Authority (ASA) in the UK ruled in March 2010 to ban an advertisement from Renault UK regarding its “zero-emissions vehicles” because the ad breached CAP (Broadcast) TV Code rules 5.1.1, 5.1.2 (Misleading advertising) and 5.2.1 (Misleading advertising- Evidence) and 5.2.6 (Misleading advertising-Environmental claims.)

Greenhouse gasses and other pollutant emissions are generated by vehicle manufacturing processes. The emissions from manufacture are many factors larger than the emissions from tailpipes, even in gasoline engine vehicles. Most reports on ZEV’s impact to the climate do not take into account these manufacturing emissions., though over the lifetime of the car the emissions from manufacturing are relatively small.

Considering the current U.S. energy mix, a ZEV would produce a 30% reduction in carbon dioxide emissions. Given the current energy mixes in other countries, it has been predicted that such emissions would decrease by 40% in the U.K., and 19% in China.

Types of zero-emission vehicles
Apart from animal-powered and human-powered vehicles, battery electric vehicles (which include cars, aircraft and boats) also do not emit any of the above pollutants, nor any CO2 gases during use. This is a particularly important quality in densely populated areas, where the health of residents can be severely affected. However, the production of the fuels that power ZEVs, such as the production of hydrogen from fossil fuels, may produce more emissions per mile than the emissions produced from a conventional fossil fueled vehicle. A well-to-wheel life cycle assessment is necessary to understand the emissions implications associated with operating a ZEV.

Other zero emission vehicle technologies include plug-in hybrids (e.g. ICE/electric battery) when in electric mode, some plug-in hybrids in both recharging and electric mode (e.g. fuel cell/electric battery, compressed air engine/electric battery), liquid nitrogen vehicles, hydrogen vehicles (utilizing fuel cells or converted internal combustion engines), and compressed air vehicles typically recharged by slow (home) or fast (road station) electric compressors, flywheel energy storage vehicles, solar powered cars, and tribrids.

Segway Personal Transporters are two-wheeled, self-balancing, battery-powered machines that are eleven times more energy-efficient than the average American car. Operating on two lithium-ion batteries, the Segway PT produces zero emissions during operation, and utilizes a negligible amount of electricity while charging via a standard wall outlet.

Finally, especially for boats (although Wind-powered land vehicles operating on wind exist (using wind turbine and kite) and other watercraft, regular and special sails (as rotorsails, wing sails, turbo sails, skysails exist that can propel it emissionless. Also, for larger ships (as tankers, container vessels,…), nuclear power is also used (though not commonly).

In the mid-19th Century bicycle ownership became common during the bike boom predating mass car ownership. In the 1960s, the Flying Pigeon became the single most popular mechanized vehicle on the planet. Some 210 million electric bikes are on the road in China.

Subsidies for public transport
Japanese public transport is being driven in the direction of zero emissions due to growing environmental concern. Honda has launched a conceptual bus which features exercise machines to the rear of the vehicle to generate kinetic energy used for propulsion.

Due to the stop-start nature of idling in public transport, regenerative braking may be a possibility for public transport systems of the future.

Subsidies for development of electric cars
In an attempt to curb carbon emissions as well as noise pollution in South African cities, the South African Department of Science & Technology (DST), as well as other private investments, have made US$5 million available through the Innovation Fund for the development of the Joule. The Joule is a five-seater car, planned to be released in 2014.

Low Emission Program
The California Air Resources Board (CARB) introduced the Zero Emission Program in 1990 based on the 1987 California Clean Air Act. It is here a part of the low-emission program, which is referred to by the abbreviation LEV (English Low-Emission Vehicle or German low-emission vehicle) and the respective single-digit version number as an index. This exists now in its 3rd version as LEV 3and is valid. This framework program has already established that, by 2018, the proportion of newly registered vehicles meeting the ZEV requirements must be 18% of the total number of newly registered vehicles. In 1997, the Big Seven – the seven automakers that sell the largest number of vehicles in California – first developed and produced a zero-emission vehicle. However, the originally strict regulation was clearly revised in favor of the automobile manufacturers. In the meantime, have not been adopted, these provisions only in California validity, but are over time by a number of US states and are used in applications.

The entire body of legislation applies exclusively to certain pollutant emissions from vehicles that are released to the environment during operation (tank-to-wheel): carbon monoxide, unburned hydrocarbons NMOG and nitrogen oxides NO x. The CO 2 emissions, which have gained a new value in the course of the climate discussion, as well as a consideration of the energy supply well-to-tank or the entire energy chain from energy generation to conversion into kinetic energy (well-to-wheel), are not taken into account., Also ignored is a holistic pollutant balance orLife Cycle Assessment.

For the environmental performance of a vehicle, however, not only the vehicle-related emissions in operation are relevant, but also the burden of

Production of the vehicle
Production and preparation of the fuel or the electric current
Maintenance of the vehicle
Disposal of the vehicle
Logistics-related emissions for production, distribution, maintenance and disposal

Unlike the European emission standards, which require all automakers to meet a tightened limit on a given date for all new models, in the US and California new standards are being introduced with stricter limits of so-called phase-in and phase-outintroduced the old standard. This is a multi-year implementation that requires the new standard to be increased by an annual percentage increase of all new models, while the old standard can be met by a yearly percentage of all new models. This applies individually for each manufacturer, as the basis for the said percentage applies the entire newly launched on the market vehicle fleet of the manufacturer.

This was also the case for the transition from LEV 1 to LEV 2. LEV 1 had already been in existence since the model year (a new model is already on the market in the period August-October of the previous year) in 1994 with the corresponding phase-in validity. In the period 2004-2007 it was replaced with a corresponding phase-in or phase-out by LEV 2 in 25% increments.

The transition from LEV 2 to the new regulation LEV 3 takes place again as phase-in or phase-out, but this time in 20% steps. It has already started in 2016 and will end in 2020. However, at the same time, a continuous reduction of the mean fleet value for the sum of NMOG and NO x in the extended period from 2015 to 2025 applies, in which the final value of 30 mg per mile is ultimately specified.

Both transitions are shown in the following tables broken down by year.

Phase-In / Phase-Out LEV 1 / LEV 2

model year 2004 2005 2006 2007
LEV 1 75% 50% 25% 0%
LEV 2 25% 50% 75% 100%

Phase-In / Phase-Out LEV 2 / LEV 3

model year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
LEV 2 100% 80% 60% 40% 20% 0% – remains 0% –
LEV 3 0% 20% 40% 60% 80% 100% – remains 100% –
– linear reduction of the fleet average for sum NMOG + NO x

The limit values listed in the following two tables refer to a mileage of 50,000 miles. For the mileage 100,000 miles, which is also commonly referred to as “Useful Life”, the limit values to be demonstrated are each set slightly higher.

Limits of the California Low Emission Program (LEV 1)

emission class CO g / mile NMOG g / mile NO x g / mile
TLEV – Transient Low Emission Vehicle 3.4 0,125 0.4
LEV – Low Emission Vehicle 3.4 0,075 0.2
ULEV – Ultra Low Emission Vehicle 1.7 0.04 0.2
ZEV – Zero Emission Vehicle 0 0 0

Limits of the California Low Emission Program (LEV 2)

emission class CO g / mile NMOG g / mile NO x g / mile
TLEV – Transient Low Emission Vehicle 3.4 0,125 0.4
LEV – Low Emission Vehicle 3.4 0,075 0.2
ULEV – Ultra Low Emission Vehicle 1.7 0.04 0.2
ZEV – Zero Emission Vehicle 0 0 0

emission classCO g / mileNMOG g / mileNO x g / mileLEV – Low Emission Vehicle3.40,0750.05ULEV – Ultra Low Emission Vehicle1.70.040.05SULEV – Super Ultra Low Emissions Vehicle10.010.02ZEV – Zero Emission Vehicle000

CO = carbon monoxide – NMOG = non-methane organic gas (hydrocarbons except methane) – NO x = nitric oxide

The following US states have already adopted the California LEV regulations:

Arizona, MY 2011
Connecticut, MY 2008
Maine, MY 2009
Maryland, MY 2011
Massachusetts, MY 2004
New Jersey, MY 2008
New Mexico, MY 2011
New York, MY 2004
Oregon, MY 2009
Pennsylvania, MY 2008
Rhode Island, MY 2008
Vermont, MY 2004
Washington, MY 2009

The following US states are still in the discussion as to whether the provisions should be adopted:

North Carolina

Further development of the ZEV requirements since the introduction
Following the announcement of the introduction of the ZEV Mandate, after lengthy discussions with representatives of the automotive industry, for the 2003 model year, for the first time a percentage of 10% of all newly registered vehicles meeting the ZEV requirements was defined. However, the original intention to recognize only those vehicles as zero-emission vehicles that did not actually emit anything was dropped after severe interventions by the automotive industry. For such vehicle drives, according to the original version, only fuel cell vehicles and battery-powered electric vehicles could be usedact. While hydrogen powered vehicles were still under development in 2003, battery electric vehicles had been developed early by all major manufacturers. However, their production was not economical, which is why the manufacturers pushed for a loosening of the CARB laws and after their implementation almost completely broke off the development of the ZEV and even partially scrapped the existing, functioning ZEV vehicles. This documentary is about the documentary Who killed the electric car? from the year 2003.

Examples of ZEV vehicle developments from this phase:

Toyota RAV4 electric
Honda EV Plus
Ford Ecostar
Ford Ranger EV
Daimler A-Class electric
Golf CitySTROMer

For this reason, from 2003 (launch of the ZEV vehicles) also partially recognized vehicles that had small or very clean drives, or – like the recently introduced hybrid vehicles – could cover a small distance purely electric. This resulted in a “dilution” of the original share of 10% ZEV vehicles, which is why the name of LEV (literally, “low-emission vehicle”) has increasingly been established by the manufacturers. Currently, a gradual increase of the ZEV share from 4.5% in 2018 to 22% from 2025 is planned.

Which car manufacturers are concerned
The development of battery-powered electric drives, or those that derive their required energy from a fuel cell and have a hydrogen tank, is not something that all automakers selling automobiles in California sell at all. The Air Resources Board, as the responsible authority, was always aware of this. For such smaller companies, therefore, a staggered solution was created that looks like this:

Concern of automobile manufacturers

Independence of the company Sold quantity per year in California Affected by the ZEV mandate comment
Not independent up to 4,500 not affected
independently up to 10,000 not affected
4,501 to 60,000 affected but the ZEV requirements can only be met with PZEV vehicles (bronze status)
more than 60,000 fully affected the manufacturers concerned are: Daimler, VW, General Motors, Ford, Toyota, Honda, Hyundai (the “big seven”)

For these manufacturers, a sample calculation might look like this:

example calculation

Sold vehicles of a manufacturer 100000
From this obligation for the manufacturer to offer 10% vehicles that meet ZEV criteria: 10,000
The number could then be composed like this:
Credits by ZEV vehicles 2000
Credits by AT-PZEV vehicles 2000
Credits by PZEV vehicles 6000

Source from Wikipedia