Three alternative fuel choices are now available to customers of Johnston Sweepers as part of the company's programme of research into new environmentally-friendly fuel technologies.

The green alternative fuel line-up from Johnston Sweepers includes the CityCat 2020ev electrically-powered compact sweeper, a brand new VS651 CNG truck-mounted sweeper powered by compressed natural gas, and the very latest HVO (hydrotreated vegetable oil) drop-in fuel.

'Each fuel option has been developed as a result of careful investigation, clever engineering, and close collaboration between Johnston engineers and engine and chassis manufacturers to find the best solution for each class of sweeper,' says Graham Howlett, sales and marketing director.

'In addition, in another new initiative, Johnston is also developing what we believe to be the world's first autonomous, driverless sweeper, the Autosweep'

Graham explains that the Autosweep is being designed for city centre pedestrian area sweeping. It will also be suitable for removing foreign objects from the aprons and runways at airports, replacing diesel-powered machines with all-electric, quiet, clean-technology driverless sweepers.

'The electric option is generally accepted as the way forward for small vehicles, and the CityCat 2020ev all-electric sweeper has been well-received throughout Europe,' says Graham.

'This zero emissions 2m3 machine uses a lithium ion battery, which supplies enough power for eight hours in drive-mode, and it is many times quieter and cheaper to run than a diesel-powered sweeper, with almost the same payload'

Savings on energy and maintenance
Over the long term, Graham says customers should see significant savings on energy costs and maintenance, service and repair costs. 'With its surprisingly low total cost of ownership and beneficial impact on the environment, this is a serious contender for any customer wanting to switch from diesel'

However, Graham acknowledges that the electric options isn't as viable for larger vehicles because of the size of the batteries that would be required. Therefore Johnston has worked closely with Iveco to develop its new CNG-powered VS651 CNG hydrostatic truck sweeper, mounted on a 16T Iveco chassis and driven by a single 210Hp engine.

Cheapest and cleanest natural gas fuel
Compressed natural gas is drawn straight from the natural gas pipeline grid, compressed and dispensed at 250 bar. Alternatively it can originate from methane producing waste sites, which turn rubbish into fuel. 'Natural gas contains less carbon than any fossil fuel and so produces less carbon dioxide emissions when burned, as well as far less NOX (nitrogen oxide) and particulate matter than diesel engines,' says Graham.

'When drawn from the high pressure gas grid, CNG is the cheapest and cleanest fossil-based natural gas fuel. It costs around 60% of the price of diesel, thanks to its low processing, electricity and transportation costs and generous fuel duty levels set by the Government'

Johnston believes that compressed natural gas is the fuel of the future for truck sweepers and many fleet operators and local authorities are already looking to make the switch from diesel.

'At Johnston we firmly believe that CNG is by far the best well-to-wheel fuel solution going forward because it causes the least all-round damage to the environment and is in plentiful supply'

Hydrotreated vegetable oil
However, those companies looking for an immediate fix in the search for alternative fuels should consider HVO, says Graham. HVO (hydrotreated vegetable oil) is a colourless liquid that has the same chemical composition and productive output as diesel but with none of the harmful properties, burning more cleanly and reducing NOx emissions by 28%, hydrocarbon emissions by 27% and CO2 emissions by 13%.

In addition, the use of HVO requires no vehicle modifications, making it the ideal solution for operators looking to move away from diesel quickly. In the UK it is approved for use in the CN101, CX401 and entire V Range of truck-mounted sweepers, which Graham says is a first for the sweeper industry.

'The main advantage of HVO is that it is a drop-in fuel that can be added to existing fuel tanks without any modifications or loss of warranty, and with no need to clean out storage tanks. You can just fill and go,' explains Graham. 'It can be mixed with diesel if required, and is fully interchangable from fill to fill.

'This is Johnston's most environmentally-responsible alternative fuel range yet, and we believe it is the future for sweeping,' Graham concludes. 'These options are helping customers do their bit in terms of saving the planet as well as assisting local authorities in saving money and meeting their clean air targets'