Electric and hydrogen cars are often praised as the CO2-free technologies of the future. After all, hydrogen cars basically only emit steam, and an e-car from Tesla that is powered by green electricity cannot possibly cause any harm, right?
We believe that a number of often overlooked flaws apply to e- and hydrogen cars. This article will shed some light on these flaws from an environmental and Germany-focused perspective and argue why the future may belong to CNG-powered cars.
An e-car is indeed “CO2-free” with respect to its local emissions, as the car itself does not emit greenhouse gases into the atmosphere. However, one should distinguish between local and overall greenhouse gas emissions. While the use of a certain energy source (like electricity) may not cause the car itself to emit greenhouse gases (like CO2) into the atmosphere, the production of such energy may actually do so.
Statements like “my e-car is powered exclusively from wind-energy” do not help in this regard. The reservation of “green electricity” (i.e. wind power) for a particular purpose such as recharging an e-car only shifts the more “dirty” electricity (i.e. from coal) to other consumers. On the bottom line, the overall burden of the earth’s atmosphere with greenhouse gas emissions remains the same, and the cherry-picking of “good electricity” for one’s own e-car ultimately does not save one gram of CO2 emissions.
This is why EU Directives and 98/70/EC and 2015/652/EC prescribe Member States and utility companies to compute the greenhouse gas emissions of all cars on the basis of the so-called life cycle analysis. In essence, to calculate any car’s emissions, one has to also look at the way its energy source is produced – in the case of electricity, a country’s entire electricity-mix, and not just some exclusively selected form of green electricity.
Once you use the legally mandated life cycle analysis approach and look at how electricity is produced, you will see that electricity is far from CO2-free. The German electricity-mix is heavily dependent on natural gas and coal, both fossil energy sources. According to the German Federal Environment Agency, the 2014 greenhouse-gas emission rate of electricity in Germany amounted to 609 gCO2/kWhel. Therefore, an e-car’s greenhouse-gas reductions compared to petrol cars “only” amount to 35%.
The often proclaimed greenhouse-gas reductions of 100% would only hold true if the entire German electricity-mix were to consist of green electricity. So even if one buys an e-car and powers it with green electricity only, the proclamation that “my e-car is 100% eco-friendly” remains false.
Hydrogen mobility is considered a particularly clean technology, as hydrogen cars merely emit steam. However, hydrogen is largely produced from compressed natural gas (CNG, a fossil energy source) by steam reforming.
The steam reforming process has a conversion efficiency rate of about 66%, which means that for every energy unit (1 kWhHi) provided to the fuel cell of an H2 vehicle, 1.5 energy units (1,5 kWhHi) of natural gas have to be fed into the steam reforming process. Considering the greenhouse-gas advantage of natural gas of only 25% over regular petrol, CNG-based hydrogen mobility ultimately has a greenhouse-gas disadvantage of 12.5% over petrol. In essence, these hydrogen cars emit 12.5% more greenhouse-gases than petrol cars.
There is also the option of using electricity for electrolysis (of water to H2 and O2, although that would bring us back to the national electricity-mix and its greenhouse-gas emission rate of 609 gCO2/kWhel. Due to its conversion efficiency rate of only 75%, this electricity-based hydrogen would burden the atmosphere with 812 gCO2/kWhi. Despite the relatively high efficiency fo the fuel cess, the CO2 foot print of a hydrogen vehicle is actually about 60% larger than that of a petrol car. Hydrogen mobility, therefore, is currently no viable option.
The benefits of CNG-powered cars:
We argue that CNG-powered cars will be the most viable alternative energy option in the near future, simply because of the various fuels they can use, which currently include natural gas, BioMethane, SynMethane and StrawMethane. What these fuels have in common is their principal component, methane – which is the substance that propels a CNG-engine.
For example, a CNG-car powered by natural gas reduces 25% of CO2-emissions compared to a petrol-fuelled car. The use of BioMethane (methane produced from organic materials) reduces emissions by about 80%. The use of StrawMethane (methane made from straw) reduces emissions by about 90% and the use of SynMethane reduces emissions by 95%. The use of our patented StrawMethaneZer0Emission would reduce emissions by 100%!
Why is that? The production of StrawMethaneZE involves the removal of atmospheric carbon from the air (“sequestration”) and the earth’s surface (decarbonisation) in such amounts that remaining carbon emissions resulting from of the use, production and utilisation process of StrawMethaneZE and the removal of carbon from the air and earth’s surface remain balanced.
As prescribed by EU Directive 2015/652/EC, a propulsion technology is CO2-free when the amount of CO2 in the atmosphere has not been increased after its use. Thus, driving a car with StrawMethaneZE, however much and however far, will not have any negative consequences for the environment and the earth’s atmosphere, nor will it contribute to climate change.
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