Electric Dreams?

With increased urbanisation comes the challenge of machines operating more closely with people and in food production or hospitals, as well as underground and indoors. Achieving ambitious clean air quality targets through clean diesel– now at Stage V EU emissions levels, with near zero harmful emissions, increasingly, electric plant is an important consideration for any urban plant operator. Construction Worx Lite talks to JCB General Manager, Charles Stevenson who is also the newest member of the CEA’s Executive Board

One of the most important recent developments for Non Road Mobile Machinery has been the launch of fully-electric compact machines–offering zero emissions at point of use without any compromise on performance. This translates directly to real-world applications where contractors are already looking for solutions. London Underground, for instance, has a requirement for diesel fume extraction, so electric machinery is commercially sensible. The reduction of nitrogen oxides and particulate matter is fundamental in improving air quality in our cities and other manufacturers have followed launching a range of battery powered plant.

Another advantage of not having a combustion engine rumbling in the background is a notable decrease in noise. This is of benefit to the operator who can maintain a conversation with a banksman, hear ground-scanning instruments and help reduce overall construction noise in the urban environment – a key goal for any conscientious contractor. With these positives in mind is electric the answer?

The Government has been quick to push electric vehicles as the future of zero emissions transport, but on the `off-road` to zero, NRMM has a very different power demand to cars and trucks. They are working machines which deliver the essential utilities, infrastructure and housing requirements of our growing population, with diverse applications and duty cycles. Some are tracked, others have traditional transmissions; some dig, others lift. Generators fulfil none of these functions.

Mini excavators use around 20kw of energy per day. A heavy excavator can consume up to 1000kW per day. To put this in perspective, the former is comparable to a motorbike and the latter, four times the energy consumption of an HGV It is therefore obvious that current battery technology cannot power the heavy end of NRMM. The enormous size of a battery required to power a 22 ton excavator, along with the prohibitive cost and long charging times means that current technology is not practical and shows that one solution does not necessarily fit all. It is therefore, essential that Government and councils legislate and incentivise the use of the appropriate technology for the right application and not assume electrification is the sole answer. It is one of the ways to reach zero emissions, but not the only way and legislation or client-lead guidelines should have a clear definition of the desired outcome which allows for the best technical solution. In other words, tell manufacturers that you want zero emissions but do not specify how to achieve this.

The Committee for Climate Change has recommended to HM Government that biofuels should be reserved for aviation and that transport and NRMM could switch to hydrogen. This comes with some practical problems. Unlike a lorry, most NRMM cannot drive to a filling station and thus the fuel needs to be delivered and stored on site. The current infrastructure would require road transport, high-pressure storage on site and further consideration regarding the purity of hydrogen and the way it is made. However, it is a technology branch that must be understood and developed if we are committed to a zero carbon, zero emissions future and it is a logical development that JCB has unveiled a prototype 22 tonne hydrogen powered excavator. Whilst still a long way from production and practical application, it is a start of a third stream of future fuels for NRMM and shows that, as an industry, we have more options for future fuels and none we cannot leave unexplored.

Construction Worx Lite will be featuring a Podcast discussing Hydrogen in next month’s edition…