“Not Zero”: EV Efficiency in Cold Colorado

by Dale Klingbeil
Custer County, Colorado
The movement of our transportation modes are being pushed to Electric Vehicles, (EV). By now everyone knows, what EV is and most can relate to Tesla.
I come from an agricultural background. I grew up with horses on a Wisconsin farm. Albeit those were work horses. I commend the riders that I see here, for they are probably the most environmentally friendly of all the modes available here in Colorado.
I have been an engine guy, (they call us, Gear Heads) since I could hold head bolts in my hand. Studied and ground in some of the highest engine production companies in the world. My thermodynamics professor, stated clearly that engines are about 1/3 efficient. One third is dispersed in heat directly from the engine. One third is exhausted straight out the tail pipe. Finally, one third is used for powering the wheels which makes us move on our highways, roads and fields.
My “Thermo” professor at Milwaukee School of Engineering was also clear that the very best electric steam turbine generated electric plant was just less than 40% efficient. I was impressed and amazed at the steam tables to investigate and show the comparisons.
But, since those days, (at the direction of the Government), we are moving toward a different mode of transportation. I wish to provide some considerations to the purchase of an EV. It is clear that Government does not have a clear understanding of this extreme change. We, the public will be the testing ground for their “Green Energy” experiment.
First, I want to try to express the support of our rural electrification that occurred in the years when America was working with gas lamps to see at night. It was a monumental evolution. Edison’s light bulb changed the world.
But, now the perfect application of electric power in a mobile vehicle, is different. The power is created in a large coal fired central location. Again, we are told something around 40% efficient. My information some would indicate that a typical automotive engine is 40% efficient. Either can be argued today.
The electric lines losses have been reported to be 6.8%. In a California report. I would guess that these lines losses are greater in Colorado as a normal result of temperature. This was gleaned from a Stanford report for “Physics 240”. If I could estimate, probably closer to 8% here in Colorado. Further research would be needed to dig in and report or refute this.
The batteries current installed in EVs are very heavy and use many very special minerals. For example, cobalt travels about 20,000 miles from the Congo mines to the California factory to be added in the battery assembly.
Once the battery is installed and you have taken delivery of your EV with grand hopes of providing efficient and clean transportation, you can be happy. That is the best satisfaction that you will receive.
https://news.yahoo.com/brother-sister-had-stop-6-090000489.html
Six charges for the day, as this brother and sister team from Orlando to Kansas. The trip was lengthened by nearly six hours to accommodate the charging of the battery. No unusual weather conditions or accidents were noted.
Electric motors which drive wheels are very efficient. You will normally hear of 90 to 95% efficient. This is true, under full load conditions and ideal temperatures. By the way, ideal temperature as noted in reports available online are; 53 degrees F to 113 degree F for a high temperature. Hmmm…Seems a bit optimistic in Westcliffe or maybe even in Colorado.
https://www.torquenews.com/ 2250/battery-degradation-extreme-temperatures-might-not-be-bad-aaa-says
The article referred to above shows test results. ““The average range of the vehicles was 105 miles at 75 degrees, but it dropped a shocking 57% to just 43 miles at 20 degrees and 33% to 69 miles at 95 degrees. According to Greg Brannon, the director of automotive engineering at AAA, “We expected degradation in the range of vehicles in both cold and hot climates, but we did not expect the degradation we saw.””
As soon as you turn on the windshield wipers, A/C or heat, powered seats, powered windows when in operation and any device, the battery charge diminishes. More rapidly in cold weather.
Another point of exacting motor
performance must be stated. EV has a characteristic that must be understood. It is called, Zero-RPM, maximum torque.
Engines must build up this power by engine RPM acceleration to get to maximum torque. Thus no, gas/diesel engine vehicle will beat an EV off the line with a fully charged battery in ideal temperatures. Once the two imaginary vehicles are off the line all bets are off, the variables become, too great to determine. It is kind of like trying to have a conversation with two technicians… One is an auto mechanic and the other is an electrician. Tough going!
Now that our EV is on the road and cruising along, we need to understand that it only takes, 10 to 15 and maybe pushing 20 HP to keep your vehicle in motion, even at say, 65 MPH. So, the HP ratings provided for either of the EV or our conventional gas/diesel engine are pretty much meaningless.
Throttle position or guidance to our controller providing power to the wheels, is based on, desired speed, load, (weight) and temperature conditions. Electric Vehicles are much heavier than gas/diesel powered vehicles. Of course, wind resistance is a factor. That will produce its very own set of calculations. Wind resistance is a function of square feet of surface exposed to the wind. Vectors aside, we will ignore this.
https://x-engineer.org/wp-content/uploads/2017/06/Electric-motor-efficiency-map.jpg?838290&838290

The chart shows that the necessary power required to operate an EV at lower speeds is minimal, (city driving). Thus, the efficiencies drop off considerably.
The cold temperature chart starts to get below 50% efficient. This is where we really get to the point of comparison.
An example in which the battery output is diminished as a result of use. The temperature range could be a factor or not. We can speculate and call today, 40 degrees F, daytime temperature. (Recall that this temp is outside of ideal for battery operation range). Again, we can extrapolate and say that the efficiency is at 45 -50%. My gas/diesel is 40% all day. Same pollution, as the coal fired power source for the EV, and almost same efficiency.
The more expensive EV’s now have heat pumps to maintain the temperature of the battery. Heat pumps are powered by the battery in the EV. Again, this will drain the battery faster. When the battery is exposed to temperatures and will perform based on its physics. In general terms, the colder the temp that lower the output from the battery. Also, note that the power lines to your house or to the charger on the street are performing at less-than-ideal power outputs during colder temperatures. The last charging station I recorded an output of 7,300 watts to charge the EV connected to it. The quick charge of approximately 45 minutes at this rate of charge. (Just imagine 73 100watt light bulbs at this charge station). These outputs will vary with the number of EVs connected to the adjoining charge stations.
My current gas/diesel fired engine runs at about 220 Degrees F, (normal operating temperature). The variation of this temperature is very minimal. It does not matter if is zero degrees or 100 degrees, F. outside. The thermal efficiency of this has been improved over the last 120 years. This is of course when running and warmed up to temp, (we call this normal operating temperature).
Our EV, however, is never up to temperature and is always subject to ambient temps.

Here is my bottom line.
Power generated at 220 Volts is now less by 8% at ideal temps. The local power station will kick this up to match what their requirements are. A loss of power to the atmosphere again.
My normal EV operation puts me at something between 90% and 50% efficient in normal operation. This is dependent on the battery charge, and battery age. The degraded battery at lower temperatures and further degraded charge as is the case as you drive, the efficiency drags to even lower levels.
Again, to be clear, the pollution created is similar with coal fired power plant to our normal gas/diesel engine driven vehicle. We are something pretty close to 80% coal produced electricity here in Southern Colorado. EV implementation has driven coal production to a record high in 2022. Power outages in regions of the USA are becoming more prevalent, and cost is not even a consideration when you add all the shortcomings of EV.
Life expectancies of an ideal battery is stated to be 400,000 miles. Well, no one drives in ideal conditions. The EV warranties seem to be good indicators in these conditions. Most EV warranties have limits of 100,000 miles. Historical information would indicate that 150,000 miles is an actual battery life. The replacement of a battery is somewhere between $12,000 to $20,000 plus installation. The shortcomings may be isolated but could be deadly. The car heater will not operate when the battery is dead. The EV will not move. You can hope that you have enough charge in your phone to call 911 for help.
Leaving your EV outside on below zero nights will provide new experiences with power and drivability. Think about the overnight stay at an high elevation ski resort with subzero outdoor temperatures. Even plugged in will not produce the charge as compared to the indoor heated garage. The accident conditions or stuck in a snow drift, mired in stalled traffic on the freeway will be reported. I can only assume that more death and anguish will be reported during this winter as EV’s become more prevalent.
These EV’s can provide service, but the care given to them needs to indoctrinated and observed. My advice would be to stay close to home and give particular care to this very sensitive piece of equipment. Temperature exposure is critical to operation.
Your gas/diesel can run and stay warm… NOT an EV.