You can request your current capacity from your DNO or energy provider, by sharing the MPAN number of your connection.
You can also find your capacity on your electricity bill under “Assigned capacity”. The value is expressed in kVa (Kilo-volt-amperes).
If you don’t know your MPAN number, your electricity supplier can provide it to you through your client number.
Network usage data such as network availability heat maps, which can indicate where network capacity already exists, can be found on the respective DNOs open data portal.