ANALYSTS and experts predict that it will be at least a decade before zero-emission fleets are viable, but in Northern Ireland, that vision of an environmentally-friendly future is already here.
The United Kingdom's three cleanest fleet vehicles are run by a company that aims to revolutionise the way organisations use energy and consume natural resources.
B9 Energy Services may operate just three Citroen Berlingo Electric vans, but it is the way they are powered that makes its efforts so worthwhile.
Instead of charging the vehicles using electricity from coal-fired power stations, it is generated in the most environmentally-friendly way – by a wind turbine situated right outside the firm's office.
Using electricity from an oil-burning power station would merely move the Berlingos' pollution from their tailpipes to the source of power, but the deregulation of electricity supply industry has allowed clean and green generators to supply the national grid.
Businesses wanting to buy 'green' power in Northern Ireland can buy 10%, 50% or 100% of their electricity from renewable sources.
B9 Energy Services, based in Larne, County Antrim, is at the heart of this surge in the availability of green power and its commitment to introducing these benefits to the vehicle fleet have earned it the Fleet News Environmental Star Award, sponsored by BP.
B9 Energy Services was formed in 1992 to develop wind farms in Northern Ireland. Since then, it has built seven wind farms throughout the United Kingdom.
Following the development of their first wind farms, now owned by ScottishPower, a second company, B9 Energy (O&M) was formed in 1994 to operate and maintain wind farms constructed by B9 Energy Services or others.
B9 Energy Offshore Developments was formed in 2002 specifically for the purpose of building up Northern Ireland's offshore wind energy potential.
Currently, the firm operates 23 wind farms and 363 wind turbines, which is enough to power about 200,000 homes.
David Surplus, technical director of B9, who was one of the founders, used the analogy of a bank to explain how the system operates.
If you deposit £10 in an account on Monday and withdraw it on Thursday, you are unlikely to withdraw the same £10, but you had still credited £10 to your account.
Likewise, if you buy 'clean' electricity you cannot guarantee that the electrons you use are 'cleanly' generated – you have paid for the proportion of green electricity which is mixed into the total grid – but the overall impact of such buying decisions remains environmentally-friendly.
A marine engineer, Surplus spent 10 years with Lloyds Register, including six stationed on oil rigs in the North Sea. There he began to read about global warming and how the consumption of fossil fuels produced by the industry in which he worked was part of the problem, rather than part of the solution.
'It made me realise that we had to make a shift,' he said. In 1992, this led to the creation of B9, with four other directors, to develop and maintain wind farms and the company now sees tremendous opportunities among fleets that have genuine environmental commitment.
Although there used to be a price premium for using green electricity, B9 now offers a tariff that means it is equivalent to 'brown energy' such as that created by oil-fired power stations.
B9 has been running Berlingo Electrics for several years without a hitch, using two of the vehicles for its own transport and loaning out the third to local authorities, charities, Government departments and corporate fleets, to spread the word about green motoring.
The vehicles are low mileage considering they have been on the fleet more than five years, with about 12,000 miles on the clock. Surplus said: 'Several companies in the area have tried it. There have been no problems, the batteries are the original ones and apart from standard servicing it has been alright.
'We generally get 60 miles' range during the summer and 40 miles during the winter. Getting around town, you can't beat an electric vehicle.
'People can't hear you because there is no engine, but it just makes you a better driver. You are more alert and you also watch your range because you want to be certain you can get home.'
Even the B9 offices are a model of environmental efficiency and best practice, using wind and solar energy for heat and power.
Solar panels and a 6kw wind turbine outside the insulated, south-facing building generate the electricity to charge batteries. This power is then used for lights, sockets and computers. When the batteries are fully charged, the surplus electricity generated is used to heat water and pump it around the building.
Supplementary heat in winter comes from a woodburning stove, but in a virtuous circle, the wood is grown outside the office in a willow plantation.
This means the overall cycle is carbon neutral, because the carbon dioxide produced when the wood is burnt merely negates the carbon dioxide absorbed during the trees' life.
The firm aims to become a zero emission business, but currently the other vehicles on its fleet are diesel.
It is at the heart of the debate about how to move the country to a hydrogen-based economy, particularly by producing the gas using wind-powered electrolysis to create a truly emission-free fuel cycle.
Currently, the other vehicles on its 15-strong fleet are diesel and it is working to obtain supplies of biodiesel.
But it is also turning its attention to other projects. It is preparing to invest millions of pounds in 'Juggernautical', a 53-metre coastal sailing ship that will be built later this year using recycled steel and batteries from a decommissioned submarine.
The firm has finished the feasibility study and worked out how to go to tender.
The £2.5 million craft would include a system that could change the pitch of its propeller, enabling it to generate electricity while moving through the sea under wind power.