What is the difference between a SMETS1 and SMETS2 meter?
The easiest way to tell is to look at your electricity meter. If the serial number starts with 19P, this indicates it's a SMETS1 meter. If it starts with 19M, then this means it's SMETS2.
What is the difference between a first and second generation smart meter?
Aside from some cosmetic differences and a slightly simpler interface in the next generation, the primary difference between SMETS 1 and SMETS 2 is the way they communicate with your supplier. SMETS 1 meters use the 3G network to transmit usage data to your energy supplier.