Let's get quantitative perspective on the E-mobility

This article will be nothing more than just bunch of excel tables with comments from my side on various aspects of e-mobility.

The aim of it is to give you quantitative perspective on e-mobility in general.

IMHO just looking at data can give you huge insight and business ides – let’s go!

1.     Energy required to cover distance with particular energy consumption per 1 km [kWh]

We start with something very simple – the statistical car in the EU travels 60 km a day, and the average energy consumption of the BEV is 200 [Wh/km].

If we take those two values, we get average daily energy consumption of the BEV in EU, which is only 12 [kWh] (marked green in the table).

The table shows also different combination of those two variables – it is handy when planning trips or managing fleet of the EV.

BTW the energy consumption of large E-Bus is around 1,5 – 2,0 [kWh/km]

2.     Price of covering distance with particular energy prices [$]

Here we take assumption from point 1 that the energy consumption of the BEV is 200 [Wh/km].

With that assumption we can see that if the price of electricity is 0,3 [$/kWh], then average European will pay 4 [$] for his daily trip.

You may think why I even put such ridicules prices as 0,1 [$/kWh] to my table, but let me explain it for you. As renewables are growing as an electric energy generation source, there is a periodic challenge with overproduction of electricity. During that period electricity price goes very low, or ever below zero – you could potentially earn money for charging your BEV! This is not yet possible, but I am certain that in the future the owners of charging stations will link their prices to the dynamic pricing from the European Energy Exchange. This will build great synergies between transportation and grid operations, so those who think that EVs are only burden for grid are mistaken. It’s only a matter of software and regulations to start real revolution.

3.     Battery pack size required to cover distance with particular energy consumption per 1 km, with assumption that it will not be charged above 80% SoC [kWh]

Here we have the same table as in point 1, just all the values were divided by 0,8. This is because if we want to use BEV for a long time, we should not stress out our battery pack too much, and the best way to improve cycle life of our pack is to never enter CV (constant voltage) charging phase. CC (constant current) charging phase end up at approx. 80 [%] of pack’s capacity, therefore the rest 20 [%] should be excluded from daily use.

The next thing is that although average European travels 60 [km] a day, no one would buy a BEV with such a range. People need some extra capacity to feel safe, so we will focus more on two range options:

·       City car with a range of 200 [km], which needs a battery pack of 50 [kWh]

·       Long distance car with a range of 500 [km] which needs a battery pack of 125 [kWh]

4.     Battery pack energy density as relation between energy density of the cells and cell to pack weight ratio [Wh/kg]

Here is my favorite table.

We all discuss and monitor progress of energy density of the cells, as we need it move our electric revolution forward. But the improvement rate is actually higher than we usually think, and this is because not only energy density of the cells is improving, but also cell to pack mass ratio!

So the old generation of battery packs (scenario red) was based on the cells with energy density of around 250 [Wh/kg], clumped into modules with thick aluminum casing, and then put into frame with multiple crossbars. In that case the effective energy density was only 125 [Wh/kg] – a half!

Today high Nickel cells reach energy density of 275 [Wh/kg] and with evolution of structural battery pack the cell to pack weight ratio is as high as 85 [%], giving overall pack energy density of 234 [Wh/kg]. This has been marked as scenario blue.

Scenario green is the future within 5 to 7 years, and scenario lavender 7 to 15 years.  

What is significance of those values will be shown in the next point where we will see impact of different scenarios on the parameters of the battery pack.

5.     Battery pack mass required to cover distance with particular energy consumption per 1 km [kg]

Remember that the assumption here is that we use only 80% of the battery pack capacity.

Here we can see how our five scenarios (red, blue, green, lavender) affect required mass of the battery pack.

Many people are laughing at BEV that they are extremely heavy, but their knowledge is based on the old generation of the BEV. How much the thing improved? Well – look into the tables.

The scenario lavender looks so good that I’ve added another row for 1000 km range.

6.     Battery pack price required to cover distance with particular energy consumption per 1 km [$]

Remember that the assumption here is that we use only 80% of the battery pack capacity.

Here again we have four scenarios:

Red – [200$/kWh] - old generation EV

Blue – [150$/kWh] - current prices

Green – [100$/kWh] - target which will be met within 3-5 years (much faster in China)

Lavender – [80$/kWh] – ultra ambitious target, currently without any clear timeline

In this case situation is similar to the “BEV is too heavy” stereotype – only this time we hear over and over that the BEV are expensive. Yes, this is truth, but revolution in this matter is coming up quick.

With the 1st gen of BEV the 200 [km] battery pack cost 10 000 [S] – that’s expensive!

But currently the pack allowing safe range (80% capacity used!) of 500 [km] costs 18 750 [$]!

Have you seen the latest Tesla price cuts? This is just the beginning as there is a lot of room for cost improvement, especially within manufacturing process.

7.     Scaling up BEV fleet – grid perspective on ENERGY

So how much energy would be consumed by 1 million BEV over one day? Well, let’s take table from point 1, where we had energy consumption a single vehicle per day in [kWh]. Now to get [GWh] from [kWh] we need to divide the value by 1 million, and then we need to multiply the value by million BEV. As you can see, the digits stay the same, just unit changed into [GWh].

So to cover daily average consumption of European passenger car driver, we need 12 [GWh]

But energy consumption is usually evaluated on the annual basis and to do so, the unit of terawatt hour [TWh] is used. 1 million EV consumes on average 4 [TWh] which is almost nothing compared to the EU annual consumption of electricity which for 2021 was 2785 [TWh].

So let’s check what would be impact of 10 million BEV on the annual energy consumption in Europe – 1,57% not so much, if we consider that the power generation capability of EU is growing.

I also mentioned that with sufficient V2G (vehicle to grid) technology, the BEV can be used to stabilize the grid, by storing excess of energy and returning it to mains when needed.

8.     Scaling up BEV fleet – grid perspective on POWER

Scenario 1 – everyone charging at once

We’ve talked about energy, now it’s time to look on power. If 10 million BEV would try to replenish their daily energy consumption simultaneously within just 1 out of 24 hours of the day, then we would need to divide 120 [GWh] by 1 [h], thus result would be 120 [GW]. The power generation of the EU in 2019 was approx. 830 [GW], so to charge 10 million BEV it would consume almost 15 [%] of the entire grid power!

That is the reason why grid operators start to ban BEV from charging in a time of peak demand (usually 18:00-22:00) there is nothing abnormal in it – BEV should be used to stabilize the grid, not to put it on a verge of blackout.

Scenario 2 – systemized charging

Now let’s imagine that the charging time of the vehicles is evenly spread on 12 out of 24 hours a day. We would need to divide previous value by 12, thus power demand would drop to just 10 [GW]. That is only little above 1 [%] of the EU grid power generation.

So for all who say that BEV will collapse the grid – you don’t know what you are talking about!

Its only matter of building robust system of grid management with dynamic pricing system.

I can imagine that in the future charging protocols will contain information like grid load, local congestions etc. and that EVSE (electric vehicle supply system) will autonomously make decisions weather to limit charging power or not.

This can be linked with market mechanism, where our vehicles can cooperate with grid, giving some energy bac if needed, for financial compensation for the owner of the vehicle.

BEV with OBCM (on board charging module) could even compensate reactive power in the grid – both capacitance and inductance.

Electric vehicle of the future is not a burden – it is complement element of the grid!

That is all for today.

I hope you will find this article useful and that the values provided will help you to get some perspective on the whole electric revolution.

Preparing this article took me a lot of time and effort, so if you like it, please share your thought in comments – it is the thing which gives me motivation to share my knowledge with you J