Environment & 2ndLife
Battery production energetic cost
“Northvolt’s CEO estimates that making 1kWh of battery cells uses between 80 and 100kWh” (source : just-auto.com)
This is about 1kWh for a 8-10Wh cell (80~100 factor)
Should be more for Chinese manufacturers! And unclean sources (coal...)
To reuse a 10Wh cell, testing consumes about 30Wh (1.5 cell cycle + 1.5 2nd life pack cycle).
With bad testing machine efficiency this is about 50Wh per cell
- We consume about 50Wh to save a cell that cost > 1000Wh to fabricate
- Its lifetime is extended (by a factor of??)
In this article:
0.11+0.18+6.22+0.38+0.71+0.77+0.25+0.69+0.07+3.9 = 13.28
“The model was based on a 67-Ah LiNi0.6Mn0.2Co0.2O2 (NMC622)/graphite cell, 100,000 EV battery packs/year plant (Nelson et al., 2019).”
Is it 13.28kWh for 1 cell of about 240Wh, so about 500Wh /10Wh. With smaller cells the individual energetic cost must be higher. This rejoins the Northvolt declaration.
Life Cycle Analysis (LCA)
- Cradle to gate = from the moment it is produced to the moment it enters the store (materials + production + shipping to the store)
- Cradle to grave = full lifecycle, from raw materials to disposal
- Case 2 (NMC batteries) uses 4.13*10^4kWh electricity per GWh of produced batteries. This is 4.13*10^7Wh per 10^9Wh produced, so about 0.4Wh per cell. Does not seem possible... Is it kWh and not Wh?
- Case 2 produces 32254kg of CO² for 1GWh produced. This is about 0.3g per cell. Also not possible. Missed something?
- Cost calculation is also incoherent.
- Between ~50kWh used per kWh produced for efficient facilites (Tesla, Northvolt) and 100 to 150 for less efficient ones. This is a 50~150 factor, which is coherent with Northvolt’s CEO’s previous declaration of 80~100
Circular economy
Nice infographics about circular economy:
EPRS
The supply of raw materials is associated with risks, such as price volatility, availability, and import dependency. The EU currently imports, in raw material equivalents, about half the resources it consumes. The EU is particularly exposed to risks related to the supply of the 27 non-energy and non-agricultural 'critical raw materials' identified by the European Commission.
https://www.europarl.europa.eu/thinktank/infographics/circulareconomy/public/index.html
Cell recycling
Redivivus
2nd Life cost analysis
What is the acceptable cost /cell ?
See machine selection pages
Take recycling cost into account
2nd Life energetic analysis
AC supply
Most multi-channel cell testers, and other big machinery operates on 3-phase 380V AC supply
5V3A with regen is 13kW ⇒ At least 18kVA
18kVA subscription is ~294€ a year
24kVA subscription is ~360€ a year
30kVA subscription is ~428€ a year
36kVA subscription is ~494€ a year
0.184€ /kWh, 0.147€ at night
Electricity cost
Electricity cost for 10000 cells: 300kWh * 0,18€ = 54€
Electricity cost per cell: 0,18€ * 0,030kWh = 0.54 cent /cell
Add subscription cost
Second Life KPIs meeting prep
See:
UL 1974
“Creating a Safe Second Life for Electric Vehicle
Batteries”
We do remanufactured batteries, not repurposed
Informations can be gathered from:
- BMS data - some of these may be available if we can get info from the BMS and if the BMS is functional and not in UVLO:
- Construction date
- Cycle count
- Markings on label, visual inspection
- Construction date on label / info from the supplier
- Cells test
- Actual capacity (grade cells + compare with nominal for SOH)
- Actual impedance (grade cells)
Serial numbers can be deciphered, they sometimes contain the assembly date