Japanese experts said the Pure electric cars don’t help reduced emissions

The UK and France have issued guidelines to ban the sale of cars powered only by internal combustion engines by 2040.The hope is to cut carbon-dioxide emissions that contribute to global warming and promote the shift to pure electric vehicles (EV).In addition, China, which has the world's largest car market, has also shown a follow.But yuen yuen, a professor emeritus at the university of Tokyo, has sounded alarm bells about the trend, noting in an interview with Japan's economic news that it is "not helping carbon dioxide emissions."

Consider the energy consumption of  Automobile manufacturing

How to look at what is called the "turn to pure electric car" trend? Mr Yuen believes that the rapid adoption of pure electric vehicles is not an option from current technology.After there is point out that according to the theory of "from the Well to Wheel (Well to Wheel, from oil production stage to the car stage)", for car emissions of carbon dioxide "Life Cycle Assessment (Life Cycle Assessment)", will find pure electric vehicle's capacity not less than gasoline vehicles.

Mr Yuen said he was based on an estimate of the amount of energy consumed when making cars.Energy consumption can be thought of as basically equivalent to carbon dioxide emissions.If combined with energy consumption at the time of manufacture, pure electric vehicles can consume more energy and emit more carbon dioxide.In other words, it is highly unlikely that a pure electric vehicle will produce a carbon reduction effect.

The company said that nissan's "LEAF" (Chinese name: LEAF, electric car) and gasoline car "NOTE" are examples.Compared with the carbon dioxide emitted when driving, the gasoline vehicle emitted 9.9 tons and electric vehicles emitted 5.3 tons, and the emission reduction was 4.6 tons.Let's look at the co2 emissions from the two.Car manufacturers rarely disclose emissions of carbon dioxide when they make vehicles, so I made a bold assumption that the price of cars is proportional to the amount of emissions they produce.

Japan's total carbon dioxide emissions in 2015 amounted to about 1.23 billion tons, while nominal gross domestic product was about 530 trillion yen, so the carbon dioxide emissions per million yen were about 2.32 tons.The leaf's price is the price of a naked car without air conditioning, but it is still more than 1.76 million yen.If the ratio of carbon dioxide to GDP is calculated, each leaf is expected to emit about 4.1 tons per leaf (2.32 tons x 1.76).This basically cancels out the emission reductions.

The premise of this calculation is that the price of the car is proportional to the carbon dioxide emissions, and maybe some people will talk about whether the hypothesis is reasonable.In addition, the carbon dioxide emissions of pure electric vehicles are influenced by the power emission factor (the amount of carbon dioxide emitted per kilowatt-hour).While the calculations are sketchy, the calculations suggest that the effects of carbon-dioxide emissions from pure electric vehicles may be less obvious.

There is another way to calculate it.The life cycle assessment data released by the Japan national institute of environmental research (2005) showed that the production of a car worth 1 million yen ($1 million) emitted 3.6 tons of carbon dioxide while producing equivalent batteries of 4.2 tons.Assuming that half of the price of a pure electric car is the body and half of the battery, the pure electric vehicle, which produces an average of 1 million yen, emits 3.9 tons of carbon dioxide.Since a pure electric car costs 1.76 million yen more than a gasoline car, the amount of carbon dioxide emitted per pure electric vehicle would be about 6.9 tons (3.9 tons x 1.76).Even when it comes to reducing emissions, pure electric vehicles overall still emit about 2 tons more than gasoline cars.

If you consider the fact that pure electric cars are more expensive than gasoline cars, you need to carefully assess the effect of reducing emissions before they become widespread.

The advantages of pure electric cars are reduced by reliance on thermal power

At present, many Japanese nuclear power plants have ceased to operate, and the reliance on coal-fired power generation is improving.Basic plan, the Japanese government's energy to make electric discharge coefficient dropped to 2030 per KWH 370 grams, such, pure electric car about 3 into carbon dioxide emissions are expected to improve.Mr Yuen points out that it is not clear that the emissions coefficient will fall under government plans, from the situation of restarting the plant.Even from the point of view of emission factors, he does not think that pure electric cars have obvious advantages.

Can the technological innovation of pure electric cars be expected?For that, Mr Yuen said he was looking forward to technological innovation.But the battery does not immediately triple the performance of the technology.In addition to improving battery performance, the environmental load of pure electric vehicles may also be reduced by lightweight and so on.But at the same time, gasoline cars will continue to increase fuel efficiency.Pure electric vehicles need to build new infrastructure, and if they are counted, carbon dioxide emissions from society as a whole are likely to increase.

He also said China is developing pure electric vehicles, not just to combat climate change.In addition to preventing air pollution, it hopes to cultivate its own car industry by popularizing pure electric vehicles.The future trend depends on the strategy of each country and enterprise.Including building cars and building infrastructure, it is essential to master the overall carbon dioxide emission reduction in the formulation of strategies.