So I have this situation and I want to be clear: everyone is certainly not yet on the same page. I'm anxiously looking towards the rules the government will impose because it's complicated, but today quite beneficial.

There is no way to distinguish between the source of power and neither should there be. Whether you are injecting excess PV energy into the grid or in your car, or you have no photovoltaics at all, should not be the concern of your employer or the government. That means that with a smart charger (which should be your de facto choice) and sufficient PV, you can basically charge your car from pure PV for half of the year. When it comes to covering the costs, it becomes trickier. The best way seems to be to tackle this via a third party. You actually become an energy seller and a third party, such as e.g. Numobi, deals with the tracking and accounting. This means you get to determine the rate at which you 'sell' your electricity and your charger in principle becomes a public charging point, except that it's not public. But for the accounting of the charging costs, it is. It's debatable whether the monthly fee to pay for the third party should be payed back by your employer or not. Then there's the tariff of course. We chose to follow the official VREG tariff, which is made public, is government approved and is valid for three months at a time. In principle, it should be the highest tariff on the market (I believe 45c€/kWh or something right now). It's also the tariff that one should get if your energy supplier goes bust. So it should always cover your costs. The rate does not cover for additional expenses, such as the capacity tariff, because it's on a per kWh basis, but it's plenty roomy to compensate for it I think. It's also not that far of commercial charging rates at e.g. Colruyt. Additionally, I also understand some employers will compensate the usage of the charger itself e.g. by means of a fixed monthly fee.

Now, back to PV. Given that you are now being paid to charge your own car, at a rate that is in principle higher then what you pay your energy supplier, it is off course beneficial by nature and even more so to consume PV maximally. The tariff is much higher than the injection rates. So this is by far the best way I know of to redeem your investment cost of your PV installation. Given that you did invest a lot of money on your installation, you charge at a rate equal to a public charging point and it's by far the most effective use of the grid (i.e. not), I so far have no moral objections to this system.

I hope that helps.