FUELLED BY ELECTRICITY

Thinking Highways
By Thinking Highways March 29, 2017 16:52

FUELLED BY ELECTRICITY


The electric vehicle revolution is only just getting started. In the next year or two, the market could really take off. Do we have the infrastructure to cope with this? Johan Sjöberg investigates

Starting next year, London’s fleet of black taxis will be going electric. From January 2018, a little over a year from now, no new diesel taxis can be registered.

This illustrates the speed at which the world of transport is switching from combustion engines to electric drive. Although the pace of change in the London taxi fleet is accelerated by the need to cut pollution in the British capital, it also shows how technology has reached a point where widespread use of electric vehicles has become not just feasible, but almost inevitable. We are at a tipping point. 

Consumers in the UK market had five electric vehicles to choose from In 2012. Today, the number has grown to 39 while prices have dropped, the operating range of the batteries has improved and incentives have become more generous. Between 2007 and 2010, the number of plug-in electric vehicles sold worldwide totalled just under 12,000. In 2015, sales exceeded hall a million. Over the last five years, global sales have increased more than ten times.

In Norway, the country with the most developed market for electric vehicles, 22 per cent of new vehicle registrations were electric in 2015. Other markets are in catch-up mode. In the Netherlands, plug-in electric vehicles had 10 per cent market share in 2015; Sweden had 2.5 per cent; France 1.2 per cent; UK 1.1 per cent; and Germany 0.7 per cent. When market penetration in large economies start to approach the level as in Norway – and this could start to happen in the next couple of years – this will have a serious impact on the world market for electric vehicles. 

This will reduce the need for fossil fuels, but increase demand for electricity. So where are all these electric vehicles going to charge? When the electric car is stationary and plugged in, it is a rather power hungry device. Charging an electric vehicle takes a minimum of 2300 watt, placing it within the ranks of the greediest household appliances such as heater fans, kettles and hair dryers. But while the hair dryer is only used for five minutes at a time, the car charger will stay on for eight hours, as 2300 watt will only give a slow charge. For semi-fast charging, nearly ten times higher output is needed and for fast charging, twenty times more. 

High power user
While car manufacturers have stepped up to the challenge and bring new technology to the market at a rapid pace, the charging infrastructure shows few signs of changing.

“A plug-in vehicle requires 6 to 10 kWh per day. This is a lot of energy compared to other loads,” says Patrik Lindergren, MD of charging equipment manufacturer Chargestorm. 

“Most installations use 16A, single phase, but if you have more chargers, you require more output. Some vehicles, for instance Tesla, can use three phase current, enabling charging up to 11kW, assuming that you have access to three phase current at your property,” says Lindergren.

But even if appropriate charging equipment is installed in or near homes, the distribution network does not have enough capacity for all households to draw maximum demand at the same time. The network is sized assuming everybody have different patterns of behaviour. This may work when providing energy for cooking Sunday lunches, but when it comes to work commuting, we all tend to move like one herd – just look at the rush hour in our big cities. This crush is about to be mimicked on the electricity network, as everybody get back at night at the same time and put their electric vehicle on charge. 

“Fortunately, cars remain plugged in for much longer than the charge requires, so there are opportunities to stagger the charging over time. Smart chargers can also balance the load between vehicles. For instance, if two vehicles are plugged into a system that would normally supply 22 kW, they can be allocated 11 kW each. By cleverly arranging the charging cycles, up to eight times as many vehicles can be charged during the same time period. Similar technology can also be used at electricity substations to balance the power on a neighbourhood level between households in areas where many draw high loads,” says Lindergren. 

“But this is on the condition that you don’t draw more energy than the electricity infrastructure can provide. Utility companies have a standard tariff up to a specific output, for instance 63A. Above that, a price penalty is applied. This can be very high, perhaps fifty times as high per kWh as the standard rate. This can make some investments unprofitable,” Lindergren points out. 

No room for DIY
However, keeping your vehicle plugged in for a long period of time brings it own issues.

“While the wiring in your house might be fine for bursts of, say, half an hour during normal use, it may not be up to prolonged use with high output, such as required for charging a vehicle. This can result in elevated temperatures and a house fire,” warns Per Höjevik at the Swedish National Electrical Safety Board.. 

“We recommend that a dedicated charge point is used, installed by a qualified electrician who can check that the wiring is sound all the way back to the fuse board.”

Electric vehicles are supplied with a Mode 2 cable designed to plug directly into a wall socket. However, anecdotal evidence suggests that car owners often use extension cables that do not meet the same standards as the charging equipment, even running these through open windows and across pavements. 

“A Mode 2 cable should be used without extension leads on a dedicated circuit protected by a 10A fuse and a residual current device. The output is restricted to 2.2 kW so charging will be relatively slow,” says Jostein Ween Grav, senior engineer at the Norwegian Directorate for Civil Protection, which counts electrical safety among its duties. 

“A wall-mounted Mode 3 charger is a far better alternative. The appliance, with its external cables, can be used for either slow overnight charging or semi-fast charging, from 3.6 to 22 kW, which will likely become the norm in the future. There is no risk of overheating or fire and it has a built-in RCD. Mode 3 can also be used for load balancing and for communication within the electrical installation. This will be especially useful as electricity prices here in Norway will vary on an hourly basis from 2018, with all households being fitted with a new electricity meter for this purpose. If you want to take advantage of all the benefits a modern electrical vehicle can offer, a Mode 2 charger with an ordinary wall socket is no alternative,” says Grav. 

Check incoming
The electrical installation in most private homes can support two 3 kW charge points or one 7 kW charge point. Some older properties with lower capacity supplies may require an upgrade to the incoming supply.

British utility company Scottish & Southern Energy (SSE) has highlighted how local networks may require upgrades due to the effects of clustering, or the tendency of people to be inspired by their neighbours. Driving an electric vehicle has many advantages and users tend to become very attached to the concept. If they manage to rouse their neighbours’ interest, the reasoning goes, there could be a strong uptake in a particular small area. Such clusters could have a disproportionate impact on parts of the network. Scottish and Southern Energy modelled a scenario where 40 per cent to 70 per cent of homes on an average street would have electric vehicles. If this were to happen, one-third of all low-voltage circuits would need to be upgraded 

SSE introduced a solution using monitoring technology in the substation and at the charge points. This way, the company could control the charging when capacity was nearing its peak, allowing all of the cars to be charged through the night without overloading the system. This can be used either on a permanent basis, or as a temporary solution until the network can be reinforced. The company now monitors its network for the growth of potential clusters. 

Cut the peaks
“There is enough energy to run the entire vehicle fleet on electricity. The problem is one of output. If everyone charges their vehicle at the same time, there will likely be a bottleneck situation,” says Stefan Pettersson, associate professor and research manager for electromobility at Viktoria Swedish ICT research institute in Gothenburg.

“There may be problems on a household level, if you charge your vehicle and run the washing machine at the same time; there may local be problems at the substation if the whole neighbourhood try to charge their vehicles at the same time; or three may be major infrastructure problems if the whole nation arrives home from work and start to charge simultaneously. 

“The priority in any demand management system is to cut the peaks. The peaks drive the costs. One obvious solution is to stagger charging over time, for instance throughout the night. At the moment we are running a research project aimed at finding out whether this will be acceptable to users. I suspect that to some users, it will be very important to have their vehicle fully charged and ready to go in the shortest possible time. Others will want to charge at the lowest tariff available. Still others will prefer to charge when green energy is available. By asking the users about their preferences, I think we will be able to find a way to spread charging over time.” 

Payment models
“We are also running a project looking at options for charging at dwellings with shared occupancy, such as blocks of flats. There are different models for sharing the cost. At the moment it seems that the most successful way is to apply a flat charge to all the parking spaces in an area, or to all spaces with charging facilities. The electricity itself is so inexpensive that it is hardly worth the cost for metering the energy and identifying the user.

“Another aspect is that we may see car ownership come down in the future. Owning a car seems less important to young people of today than for previous generations, with fewer of them learning to drive. The high purchase price of electric vehicles, combined with another social trend, the sharing economy, may result in a drop of the overall number of vehicles purchased. This will have knock-on effects on the need for infrastructure.” 


Infrastructure is key

“I have worked with this for about seven years. When we started working with plug-in hybrids at Volvo, we naïvely thought that all we had to do was to replace the driveline in the car. As far as the car goes, that holds some truth; it’s still an ordinary car with a different driveline. But the infrastructure is the bottleneck. There has to be an infrastructure that works for people,” says Johan Konnberg, senior advisor for E-mobility at Volvo Car Corporation.

“For as long I’ve worked with this, sales volumes of electric vehicles have doubled each year. Do I think this will continue? I think it will accelerate. Several car manufacturers are now launching some very attractive models that are entering the market in 2017 and 2018. I don’t have a crystal ball, but I think we will see a significant growth,” says Konnberg.

One organisation that has crunched the numbers is Transport for London (TfL), the local government body responsible for the transport system in Greater London. 

TfL believes that ultra-low emission vehicles, which includes battery electric vehicles, plug-in hybrid
vehicles, range-extended electric vehicles and hydrogen fuel cell electric vehicles, will represent 100 per cent of sales by 2040. In its most ambitious scenario, these vehicles will have reached 60 percent of sales by 2030. In a more conservative scenario, sales will have reached 30 percent by 2030. Under the conservative scenario, the number of these vehicles in London will be over 20,000 in 2020 and will be approaching 100,000 in 2025. This means a 25-fold increase in these vehicles in London, assuming the conservative scenario. In the more ambitious scenario, the number of these vehicles in London is estimated to reach 50,000 in 2020 and reach 220,000 in 2025.

Longer range available
Like Konnberg at Volvo Car Corporation, TfL recognises that the key to getting more electric vehicles on the road is a large number of charge points, giving users the confidence they can charge up when they need to. The organisation plans to use its own fleet and public sector procurement to accelerate uptake. A rapid charge point network will be deployed by 2018. Plans to provide charge points for residents without off-street parking are also taking shape.

“Electric vehicle technology is now sufficiently well developed for a wide market breakthrough. Many customers are asking for longer range, and this is something we see being delivered by major manufacturers, says Francisco Carranza, managing director for Renault-Nissan Energy Services.

“The trend towards shared mobility works great in tandem with electromobility, reducing the number of cars on the road. This is a complementary ownership model; we don’t see it as cannibalising the private ownership market. More efficient use will drive down costs and make car travel affordable for new users in markets where mobility would otherwise be too costly.

Carranza also sees opportunities for using the batteries of stationary electric vehicles as an energy store, a concept known as vehicle-to-grid. 

“Private cars are under-utilised. Average usage time for cars is 4 per cent and average occupancy is 1.3 passengers. Vehicle-to-grid charging could make use of the vehicle during the time it is not being driven. It could even open up for new ownership models. Imagine, for instance, that you might get paid to own a car. 

“The battery capacity of parked electric vehicles can be used to stabilise the power supply when using alternative energy sources such as solar or wind power. Millions of cars can be consolidated to make up one large energy store. This can be a huge help to decarbonise the energy sector. 

“No big changes are needed to the physical infrastructure to achieve this. The main obstacle is the national regulatory framework in different countries, as provisions have to be made for selling electricity to the network,” concludes Carranza. 

So although a cursory look at an average traffic queue may suggest that fossil fuelled private transport is here to stay, radical change may be just around the corner. 

‘The stone age did not end for lack of stone and the oil age will end long before the world runs out of oil,’ predicted Saudi Arabia’s oil minister Sheikh Zaki Yamani back in the 1970s. 

It seems he might have had a point.

Johan Sjöberg is a freelance technology journalist specialising in electric vehicles. He is based in Epsom, UK and Motala, Sweden
Email: johan@sjoberg,co.uk

Thinking Highways
By Thinking Highways March 29, 2017 16:52