Everyday, we hear how bad we treat the environment, and how big our
carbon-footprint is. Internal combustion engines are so passé,
we all have to drive and ride green, and "thus" electric. Well, I'm
not convinced: I did some calculations and the results are remarkable:
In 2017 only 28% of all electrical energy in the UK was produced from renewable sources. 40% was made from gas, 20% was nuclear power and some 8% was from coal. Burning gas and coal produce CO2. According to carbon-calculator.org.uk the UK produce 400 grams of CO2 per kWh of electricity. So if, or rather "when", you recharge your batteries you produce CO2. By the time the electricity is in your battery, the CO2 footprint will be about 500 gram per kWh, including losses in transport, heat generated, losses by transformers, battery chargers, etc.
Two Swedish scientists, Lisbeth Dahllöf and Mia Romare, made a study of the production process of Li-Ion batteries. These are the most environment-friendly batteries, but still contain harmful metals like cobalt and nickel. They concluded that the production process of these batteries will emit 150 to 200 Kilogram CO2 per kWh capacity. You can download a pdf-copy of the report HERE (1.5 Mbyte)
Taking these factors into account, let's take a look at the electric mopeds and scooters that are on the market these days. The engine power varies from 800 Watt to 4000 Watt, the average battery capacity is between 2 and 4 kWh. One charge of a 3 kWh battery will average a 30 Miles ride.
Per 3 kWh charge, the e-scooter itself produces "zero"gram CO2, but the electricity production will average a footprint of 3 x 500 = 1500 gram CO2.
The life-cycle of electric batteries is around 500 charges. After this number of charges, you will need to replace the batteries. Battery prices for e-mopeds and e-scooters range from £500.- to £1000.- When we add the CO2 emissions from the electricity production to the CO2 emission of the production of the battery, then we get a total of how much CO2 is produced. Let's be optimistic and assume one charge will result in a range of 30 Miles. After 500 charges the total elapsed distance is 500 x 30 = 15000 Miles. The total CO2 emission is 450 Kilogram CO2 for the production of the battery, plus 750 kilogram for the electricity produced.
Your “green” e-scooter has produced (450 + 750) : 15000 = 0,080 kg, or 80 gram of CO2 per Mile.
At an average UK price of 13 pence per kWh, 500 charges will set you back £65.-... plus the price of the battery! Total cost for 15000 Miles is between £565 and £1065.- Calculating with an average battery price of £750.- the total energy cost over 15000 Miles is £815.- or 5.44 pence per Mile.
Now let's see what a gas-guzzling moped will cost. A modern 4-stroke moped will average 110 MPG (UK) easily. At 125 pence per liter, or £5.68 per Gallon, your 110 MPG moped will set you back... 568 / 110 = 5.16 pence per Mile, while your footprint is 100 gram CO2 per Mile. So petrol is slightly cheaper to run and has a footprint 20% larger than an electric moped.
A petrol moped or scooter can be refueled in minutes, while charging a battery takes hours, and taking the price of new batteries, has about the same cost per Mile than an electric moped. So even if you can charge your batteries on your own solar panels "for free", the price of the batteries is the Achilles heel in the equation. The only certainty is that your batteries will need replacing after 500-odd charges, and that the cost of replacing them is high. Even if you find a crafts-person that can rejuvenate your batteries. Not to mention the need for public charging sites, and what if we "all" decide to go electric?
Conclusion: i.m.h.o. it is better to ride petrol and wait until hydrogen will be available. As we write this, there is a project along the South coast of Norway, where hydrogen is produced autonomously in small energy stations. There lies the future.