combined cycle gas turbine
Electric cars cannot be beaten on tank to wheel (motion) efficiency or more appropriately battery to wheel for an electric vehicle. The Nissan Leaf battery holds about 24 kWh of electrical energy. 1 litre of Petrol holds the equivalent energy to 9.66 kWh and 1 litre of Diesel holds the equivalent energy to 10.72 kWh if combusted in a 100% efficient engine. The average internal combustion engine is around 35% efficient the other 65% is waste heat and noise.
So the Leaf battery holds the equivalent of 2.5 litres of Petrol or 2.2 litres of Diesel for approximately 100 miles of driving. You would need a Petrol powered car to achieve 181.6 MPG and Diesel powered car to achieve 206.3 MPG to match the Leaf’s Tank to Wheel efficiency. Clearly there aren’t any fossil fuelled cars now or in the near future that come anywhere close to matching the said figures for the same size of vehicle.
Well to Tank, fossil fuel currently beats electrical power generation and transmission. The most efficient fossil fuelled power station available is a natural gas burning combined cycle gas turbine (CCGT) plant which can achieve efficiencies of around 60%. http://en.wikipedia.org/wiki/Combined_cycle#Efficiency_of_CCGT_plants . So with the transmission losses of around 6.5% only 56.1% of the energy in the natural gas is delivered to the charger. The oil companies quote a figure of around 81.7% for Well to Tank / Pump.
However the 56.1% efficiency Well to Tank for power generation is more than offset by the 3 times greater Tank to Wheel efficiency of the electric vehicle. As the grid starts to add more renewable and possibly nuclear power the said Well to Tank efficiency will increase making the electric car even more compelling. The electric vehicle is the only vehicle that becomes cleaner / greener with age as over time power generation is cleaned up.
The last 24 hours of electricity generation in the UK was provided by the following generation type. Data from my UK Energy i-phone app but ultimately from Elexon
Combined Cycle Gas Turbine 40.4 %
Coal 37.9 %
Nuclear 18.1 %
Wind 0.7 %
Pumped Storage 0.7 %
Non Pumped Storage 1.0 %
French Interconnector 1.1 %
Tesla motors explains all of the above far better than I have on their website at http://www.teslamotors.com/goelectric/efficiency.
Used electric vehicle batteries can have a second life to help store renewable energy and smooth out the grid. Vehicle 2 Grid might also become a reality in a the future. You could make money charging your car battery on cheap over night electricity and then selling it back to the grid during the day at a higher price. Although the number of charge cycles a battery pack can currenly perform would have to increase greatly to make it worthwhile without having too much of a negative impact on the battery pack lifespan.
The status quo will be more expensive in the medium to long term.
“"Britain has been given a second and final written warning by Europe to clean up London's air or be taken to the European court of justice and face fines of up to £300m.
The warning, sent today by the Environment commissioner Janez Potočni refers to minute airborne particles known as PM10s which are emitted by traffic and factories and can lead to heart attacks, strokes, asthma and lung diseases. According to the Mayor of London's Air Quality Strategy, particle pollution is responsible for over 4,300 premature deaths a year in London at an annual cost of up to £2bn. (The figure is drawn from a report commissioned by the Mayor of London whose full findings were not published.) London's air pollution levels rank as the worst in the UK and also among the worst in Europe."
"London air pollution 'worst in Europe'Britain faces court cases and unlimited fines after dangerous levels of minute particles breach EU levels"
London has already been warned to clean up its air quality or face millions in fines from the EU. London has been ranked as having the most polluted air of any city in Europe!”
Well I for one put a deposit down on Leaf on the 1st of September and will be trading in my Audi TT in when the Leaf goes on sale in March. We have recently installed 3.15 kWp of solar photovoltaic panels on the roof and have subscribed to a green electricity tariff for years. The tariff recently rose from 9.3p to 11.7p per kWh. I know the limitations of the car which I am willing to live with and work around by using the train or borrowing a ICE car for the occasional long distance journey. Living in the Chorley Lancashire area I think I have only driven the 240 odd miles to London a couple of times as the train is faster and far less stressful.
Billions of pounds worth of research is going into batteries which will double the range within 3 to 5 years. The current electric cars are a little better than the first mobile phones and they too like the early mobiles will advance at a similar rate over the next 10 to 15 years. The price of Petrol and Diesel is only going to increase as all the easy to extract oil has been extracted and as the world recovers from recession all those citizens of India and China will start to drive their first cars. Supply and demand.
The worlds fossil fuel industry is subsidiesed to the tune of $300 billion a year.