Electric vehicles compared to normal

@swirlieI have often wondered how EVs can be practicable for many residents in continental nations.

A lot of the pro-EV publicity in the UK was based only local use, stating "most journeys total under x miles a week". I forget the usual values of x, but it was really only commuting and shopping.

Although probably correct for some people, it ignored that very many people with cars do travel much further than that, especially at weekends, for "domestic, social and pleasure" purposes, as the insurers have it.

It also ignored that by no means all motorists could recharge a battery-electric car at home so are dependent on public chargers.

So what became called "range anxiety" developed:

"I want to drive to ::::: nearly two hundred miles away. Will I find suitable charging-stations compatible with my car, with pay systems I can use, are even in working order; and how much earlier will I need start to account for possible queues at them?"

Although the fear has lessened as the cars' ranges and number of chargers have increased, it is still relevant - and that in a country physically far smaller and far more densely populated than the USA or Canada. Also with much milder weather generally, though you'd not want to risk your car coming to a halt in the middle of Highland Scotland or the Yorkshire Moors on a cold Winter night.

I have long thought EVs would not really be very practical in continent-size nations, especially those with few towns far apart away from the major cities, unless very many public chargers are installed at least along the main and secondary routes..

It would of course depend on the individual.

An EV might be feasible if you live in a heavily-populated area with plenty of public facilities, you can park and charge your car on your own house drive, and you never drive more than a few tens of miles from home.

Live far out in a rural village with no public transport, or you sometimes need or wish to travel some hundreds of miles for any reason, especially in a very large region subject to severe Winter weather, and I still cannot see an EV being practical.

.....

ME? I live in a fairly densely-populated region. I cannot have an electric car. I cannot afford one. I have nowhere to charge it at home. I can and do use buses for local journeys, but my life entails occasional, much longer journeys by car, sometimes with round-trips of 600 miles and more.

@ArishMell
I've done a lot of research on EV's for cars because I was trying to apply the same EV application to the nautical marine industry which is where my expertise lies in my real world.

According to technical data supplied by Tesla, where all testing and potential range is based on for battery serviceability alone, is between 30 degrees North Latitude and 40 degrees North Latitude, anywhere in the world.

In Europe for reference, 40*N is well-south of France and 50*N is in the vicinity of Toronto Canada and London England.

If you operate an EV in winter that is north of 40*N, expect a 1% decrease in range for every degree below the freezing mark it is outside. 25 degrees below freezing equals a 25% reduction in range for a fully charged EV battery.

For every degree of outside air temperature above 25C or 80*F, expect a 1% decrease in an EV's battery to come to a full charge when placed on a fast charger, due to overheating issues which automatically restrict the amount of charge that a charging unit will put into a battery that's being charged.

This means, at an outside air temperature of 100*F, an EV battery can only be brought to an 80% charge instead of 100% charge. Your resultant range is now decreased by that same 20%, which means your range is based on 80% of max advertised range, not 100% of max advertised range.

Therefore, unless you intend to operate your EV within those two latitude references of 30N and 40N, none of the predicted range potentials actually apply to your vehicle! On a brand new, fully charged battery, your car will typically achieve 20 to 25% less range if it's very cold outside or if it is very hot.

That is why any Tesla's you see running around anywhere in North America will almost always have their car windows open and the air conditioning turned off, just to extend the range of the vehicle in hot weather.

@swirlie Thank you for that - very interesting information.

I knew EVs are not happy in cold conditions but had not previously seen the figures.

I doubt any vehicles of any type really meet their manufacturers' test claims but battery-powered ones seem worse in that respect.

I have not heard of anyone claiming serious range problems due to the air temperature in Britain, at least not in the Southerly half, as our climate is generally milder than that in Canada. Instead I have encountered anecdotes about owners not daring to use the heating in cold weather because that is an extra drain on the battery. The opposite of the American motorists in their hot Summers!

I know small, battery-powered boats for inland waters have been around for some years now but it will be interesting to see how electric propulsion, (battery or fuel-cells?) develops for large sea-going ships.

@ArishMell
One of the many challenges for large sea-going ships is the salt-laden air which corrodes everything that isn't made of wood!

Battery power for a ship works well in theory, but in practice, we are dealing with electrical corrosion at each connection which cannot be sealed from the salt air.

Additionally, the battery itself must be sealed in it's own compartment that is both waterproof and air-proof, which means the battery cannot remain cool through traditional means of air-cooling. As soon as a non-traditional way of battery cooling is introduced, it must be accounted for in the current-draw from the battery which of course reduces the range of the vessel as it uses battery power to cool the battery itself.

Another problem with battery powered sea-going ships is the dead-weight of the battery which never decreases as the power is used from the battery, unlike traditional diesel fuel engines which consume the fuel from within the tank, making the vessel lighter with each gallon of petrol that is consumed.

It takes 20% of the total liquid fuel load of a diesel ship JUST to produced enough energy to carry the weight of the fuel on an ocean crossing. This means that 20% of the fuel that's carried will be burnt just to move the weight of the fuel alone across the ocean. The weight of the ship and it's cargo requires the rest of the fuel to move it across the ocean.

That said, as the ship uses up it's fuel load and becomes lighter and therefore requires less energy to move it near the end of it's ocean journey, the most amount of fuel is used at the beginning of the journey when the vessel is obviously the heaviest.

With this being taken into consideration, the vessel becomes cheaper and cheaper to operate as the fuel is burnt off. But with a battery powered vessel of course, none of this happens! The vessel weighs the same at the end of the journey as it weighed at the beginning, which means a lot of battery storage power is required from start to finish of a voyage just to move the dead-weight of the battery across the ocean!

@swirlie I see the problem there. What of fuel-cells instead?

@swirlie Thank you for all this - it's a fascinating subject!

I must admit I'm a bit surprised that screws and sails can work together because the screw has a fixed pitch and constant rpm. So would there be times when the sails are effectively trying to over-drive the ship? I don't know what would happen if so - I suppose something like a severe slip effect.

Going back all right: the first steam-ships in the 19C combined engine and sails, though initially they were paddle-steamers so how efficient that combination was, might be more questionable.

Odd - the site has marked your post as "Sensitive". I can't think why.