The paper on the 10% increase of lithium-ion battery life as a result of operating in a vehicle-to-grid (see previous post) is an interesting read. I was initially fascinated by the validation of their battery degradation model, but the actual result came from the integration of that model in a smart grid algorithm. This algorithm was then used in a simulation of load balancing of a building by means of electric cars and resulted in the 10% increase of battery-life figure.
That number is therefor not obtained by measuring the battery degradation in reality, it is the outcome of a mathematical model. Personally, I don’t have a problem with models and this particular model seems to have potential (the battery degradation part is validated). Models are useful for sure, but that doesn’t mean they are necessarily right. It depends for example on the data that goes in the model and the assumptions that are made. It seems that this is where it went wrong in this simulation.
The data that was fed to the algorithm came among other things from an actual building (the International Digital Laboratory). This is the description of that building:
The International Digital Laboratory (IDL) is four story office building located on the University of Warwick campus near Coventry. The University is situated in the centre of England, adjacent to the city of Coventry and on the border with Warwickshire. The building compromises of a 100-seater auditorium, two electrical laboratories, a boardroom, 3 teaching laboratories, eight meeting rooms and houses approximately 360 researchers and administration staff.
That is not a small building and it draws quite some electricity (my emphasis):
Trust, yet verify 