NEM only give 10 years buy back. So after 10 years, you give free PV electricity to TNB during day and buy your electricity at night from TNB.

Here is how the old EV comes into play.

If the EV when new, battery capacity is 60kWh.

The EV after 10 years say degrade 30% capacity, owner decides to buy a new EV battery to replace. But 10 years into the future already, better 3rd party battery availability, improved battery tech and larger capacity. (Imagine Nokia 3310 with new big capacity battery which can be standby for 30 days) So the battery has more energy but still can fit into the same space, +30% of original 60kWh = 78kWh, range also increased from 400km to 520km. Maybe the battery is even lighter in weight as added bonus.

The old battery bring back home become powerwall. 30% degrade still gives 42kWh capacity, enough to run 2 units of 2.5hp A/C for 8 hours or 4 units of 1.5hp A/C for 8 hours.

So after 10 years, the old EV have +30% more range when compared to when new, and one free powerwall for PV to charge during day and use during night.

It was demonstrated with old BMW battery convert to mobile powerbank DCFC charging by Gentari, if not mistaken. So why can't use at home as powerbank for PV?

Tong gas explosion fire risk too. Quickly change to induction cooker.

Gas regulator swap together? Usually the leak is from the regulator.