Electrification of road transport is part of the worldwide "decarbonization" process, with particular focus on the most advanced and in-development countries, to reduce the global emissions of GHG (Green House Gases), particularly CO2 responsible for global warming. 

The target is the NZE2050 level (a level of GHG emissions to prevent a further increase of the earth's average temperature of more than 1.5 °C by 2050). In the UE, an intermediate target is to reduce CO2 emissions by 50% within 2030 compared to 1992. 

Electric vehicles are present more and more in the automotive manufacturer showrooms together with the traditional thermal engine models or the recent hybrid ones. In Europe, it is expected to have a 6% market share by 2026, constantly increasing to the expected quote by 2050. 

 

Electric Vehicle Classification

• BEV (Battery Electric Vehicles) with a three-phase A.C. motor powered by electric energy stored in a high-capacity battery module
• FCEV (Fuel Cell Electric Vehicle) with a three-phase A.C. motor powered by the electric energy produced in an onboard fuel cell stack feed with hydrogen stored in a high-pressure bottle. 
• HEV (Hybrid Electric Vehicle) with double powertrain: three-phase A.C. motor powered by the electric energy stored in a low-mid capacity battery module and I.C.E. (Internal Combustion Engine) providing the primary power source to drive the car in non-electric operation. The battery is recharged in deceleration and braking mode to retrieve the inertia energy of the vehicle motion. 
• PHEV (Plug-in Hybrid Electric Vehicle) is the same as HEV, with mid capacity battery able to extend the vehicle range in electric mode. The battery can also be recharged in a power station, thus reducing the I.C.E. mode, mainly in urban and mixed routes.   

BEV and FCEV are classified as ZEV (Zero Emissions Vehicles) since they do not produce exhaust emissions like the vehicles equipped with I.C.E. HEV, and PHEV are classified as LEV (Low Emission Vehicles) or ULEV (Ultra Low Emission Vehicles) since they produce lower exhaust emissions compared to I.C.E. vehicles.   

In the imagination of an average consumer, electric vehicles represent a clean and environment-friendly way of transportation: no exhaust gas, no heat, no smell, no noise.

But how much are they ZEV?

 

Efficiency of Electric Vehicles

Electric motors equipping all E.V.s produce an overall efficiency of 85-90%: the most performant powertrain for road motion. Also, considering a battery charge-discharge cycle loss of 5-15% (depending on how fast the charging cycle is and how high the output demand from the driver is), the E.V.'s efficiency is over double that of I.C.E. vehicles. 

I.C.E.s produce an overall efficiency of 30-32% for Otto cycle engines, 35-38% for Diesel engines, and 38-42% for Atkinson-Miller cycle in hybrid vehicles. 

The homologation tests (Euro 6, Euro 7) certify that the vehicle emission level is performed on vehicles fully charged (electric power in the battery or compressed hydrogen in the storage bottle). 

The question to be asked is: - Where is the electric power stored in the vehicle battery coming from? 

The answer: - From the electric grid network supplied by the power stations ! 

How is the electric power (the kWh stored in the battery) produced in the power plants?

Main primary resources of global electricity production – 2021

Source: Our World in Data (internet)

The above global values change greatly country by country depending on the primary energy source used in the country, the age (and the efficiency) of each electric power plant and the distribution grid network.

 

CO2  Emissions 

CO2 emissions by primary energy source 

• Coal-fired power stations - 765-1093 g CO2/ kWh
• Heavy fuel power stations – 900-950 g CO2 / kWh
• Natural gas power stations – 411-433 g CO2 / kWh
• Thermonuclear power stations – 12g CO2 (long-term pollution of nuclear waste storage is not considered)
• Solar P.V. power stations (or roof panels) – renewable – 41-48 g CO2
• Wind power stations – renewable – 11-12 g CO2
• Hydroelectric power stations – renewable – 24 kg CO2

Source: Volker Quaschning and IPCC (Intergovernmental Panel Climate Change)

Coal is the most pollutant fossil fuel used to produce electricity, and nuclear fuel is a very long-term pollutant since the decay time of the radioactive waste stored in old mines can take from 30 years for low activity to thousand years for high activity ones.

Only renewable energy resources can guarantee the production of fully clean electric power with very low emissions of pollutants in the whole cycle. 

Source I.E.A. - International Energy Agency - World Energy Outlook 2020

In the thermo-electrical power plants (except natural gas ones), in addition to CO2 are to be considered the number of significant and dangerous pollutants as SOx, NOx, Mercury, Arsenic, Nickel, and PMs, very difficult to reduce and recycle and responsible also for acid rains.   

In the E.U., the CO2/kWh average production and GHG (Green House Gases) have been reduced from 520 in 1990 to 300 g in 2018, and it is still decreasing more and more (EEA – European Environment Agency).

CO2 Emissions per kWh of Electric Power by Country in Europe (2020)  

• Sweden – 8 g
• France – 60 g
• Finland – 64 g
• Germany – 314 g
• Italy – 216 g
• Ireland – 281 g
• Spain – 177 g
• Poland – 710 g
• Estonia – 621 g
• Cyprus – 623 g
• Hungary – 215 g 

 

Real CO2 Emissions of Electric Vehicles

The above values are an example to identify the level of CO2 emissions due to the production and use of electricity in some European Countries.

Considering an average electric power consumption of 0,15-0,20 kWh/km (about 5-6 km/kWh) for a small/medium size passenger car is possible to identify the real CO2 emissions by country. 

In Sweden (the lowest of the above list), an electric vehicle produces just 1,3-1,6 g CO2/km, while in Poland (the highest of the above list), it produces 120-140 g CO2/km, higher than several I.C.E. vehicles of the same size. A similar HEV car produces only 50-80 g CO2/km and is still more convenient in such a scenario.

The reduction of CO2 emissions with BEV cars depends significantly on the country where the vehicle is charged and driven.

Also, consider the additional pollution from the secondary compounds produced in the coal-fired or oil-fired electric power plants, as previously mentioned.

The table shows a projection of the electricity generation and the relevant emissions (g CO2/kWh) considering the current trend of coal, nuclear, and renewable resources. 

 

The table shows a projection of the electricity generation and the relevant emissions (g CO2/kWh) in a sustainable scenario with a radical change in the primary energy resources currently used in the thermal electric power plant and the increase of renewable energy resources to achieve the target of NZE2050. 

BEV and FCEV are part of this process, which includes the production of "Green Hydrogen" from renewable resources for transport with FCEVs.

 

 

This article was contributed by our expert Gianni Chillemi 

 

Frequently Asked Questions Answered by Gianni Chillemi 

Q1. What are the pros and cons of electric cars?

Pros: Quietness, smooth driving, fast response and acceleration, no local pollution, long-life engines (motors), reduced service costs (except battery). 

Cons: Low vehicle range considering the weight of the stored energy (350-400 kg battery for 500 km range, versus 60-70 kg of tank + diesel fuel for the same range), long waiting time for a full battery recharge (40-60 min.) versus five min., a limited number of charging station available on the road, battery life variable with the use of the car, very high cost of battery pack replacement. 

NOTE: At present, in most countries, a BEV car is convenient as a second small-medium size car for local use in a range (i.e. 70-150 km) where the battery can be recharged during the night with low charge power and reduced electricity cost, or during the day with photovoltaic panels.  

Q2. Will all cars be electric in the future?

Not easy to predict in a short time. Passenger cars, yes (BEV and FCEV type) - As explained in the article, electric motors present many advantages considering the low weight and the high efficiency of 85-95% (depending on the type of motor used – three phases induction asynchronous or three phases permanent magnet) against 30-40 % of ICE (Internal Combustion Engines). 
The electricity production in the power plants is not enough to feed the same number of current circulating vehicles converted to electric cars BEV. The demand for base materials (lithium, cobalt, rare earth, etc.) for battery and motors production is very high (something like 250-500 kg of lithium battery for each car). But with new battery technology (solid state), electricity production from renewable resources shared in the grid and nuclear (fusion?), and the use of green hydrogen on fuel cells FCEV, the future of private mobility in the long term will be electric.   

Q3. What do decarbonization of the transport sector and heat generation mean?

Decarbonisation means the use of non-fossil fuels producing CO2 emissions and other relevant pollutants – in other words, it means replacing petrol and diesel engines of cars, trucks, and buses with electric motors. Heavy-duty diesel engine vehicles can be replaced only with hydrogen FCEV. 
Heat generation for home and living/working ambient can be reduced with optimization of heat exchange, use of co-generation power systems, and use of fuel cells powered by green hydrogen (hydrogen produced from renewable resources such as solar or wind). Hydrogen fuel cells can produce heat and electric power from the same energy source (gaseous hydrogen).  

Q4. How do you Decarbonize the transport sector?

By using BEVs and FCEVs instead of ICE (Internal Combustion Engine). I.e. Toyota Mirai FCEV is present in the market with its second generation, which uses only 5 kg of compressed hydrogen for a 600 km range. The relevant CO2/km emissions would be close to zero using green hydrogen from photovoltaic, hydroelectric or wind farms. But full decarbonisation also means changing how electricity for BEVs is produced now in the thermal power plants (combustion of coal, oil, gas) with limited production from renewable resources. BEV vehicles use electricity stored in batteries but produced in thermal power plants. FCEVs use electricity produced with grey hydrogen, not green hydrogen from renewable resources. Nuclear is almost zero CO2, but radioactive waste disposal is still an issue. A geopolitical issue that involves several strategic economic sectors.   

Q5. Will utility companies benefit from electric vehicles?

Companies producing and/or distributing electricity through the public grid will increase their turnover and profits since the energy needed for transport will swap from oil and derivative products sale and distribution (i.e. petrol, diesel, LPG, etc.) to electric power production and distribution. Photovoltaic farms (or wind farms) will benefit from the direct sale of electric green power through local recharge stations for BEVs or PHEVs. New hydrogen H2 refuelling stations will benefit from the sale of compressed hydrogen for FCEVs; the same is already operational in countries like Japan, Germany, Austria, Switzerland, Italy, etc., to supply private cars and public transport powered with fuel cells and electric motors. 

Q6. Will power grids handle increased electric demand from EVs?

Not now. At the moment, the current power grid is not enough to supply electric energy to recharge the existing circulating car park converted to electric (i.e. not any more ICE cars, but only BEVs). This needs a radical change in how electricity is produced and distributed, and it is a geopolitical issue.