What voltage level is typically impractical for electricity to be generated above?

The voltage level that is typically considered impractical for electricity to be generated above is 25 kV. This is because, at higher voltages, the challenges of insulation, safety, and transmission efficiency increase significantly. Generating electricity at levels above 25 kV can lead to complications such as increased risk of electrical arcing, greater demands for insulating materials to prevent leaks, and more stringent safety measures for personnel and infrastructure.

Additionally, while it's possible to generate and use higher voltages, the equipment and infrastructure required to support them become much more complex and expensive. For practical generation and distribution, voltages around 25 kV are often seen as a sweet spot where efficiency can be maximized without the overwhelming challenges associated with generating at even higher levels, such as 50 kV or 100 kV. This is why 25 kV is often cited as a threshold beyond which practicality diminishes for most applications.