That's an unusually low electric rate for the US - way below the lowest state average which is Idaho at 12.4 cents. It's certainly possible that you are getting 7.5 cents including delivery, but I've had friends say that they're "getting 13 cents per kWh" here in Massachusetts, but that's just the supply rate and the delivery is another ~18 cents.
There are parts of states like Grant County Washington that have cheap hydro power, but it's very rare for power to be that cheap in the US. Even if this applies to you, it won't apply to the vast majority of people on here who will have electric rates 2-4x higher.
Average electric rates by region:
New England 28.1 cents
Mid Atlantic 25.1 cents
East North Central 20.8 cents
West North Central 14.8 cents
South Atlantic 16.1 cents
East South Central 15.5 cents
Mountain 14.6 cents
Pacific Contiguous 26.1 cents
Pacific Noncontiguous 42.1 cents
https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...They are most likely not based in the US, but converting to USD to make comparison easier.
A lot of people quoting low rates are also just referring to their off-peak rate. This is pretty common in EV discussions. It's not exactly a fair argument there, either, because the flip side of having an off-peak rate is that the on-peak rate is usually quite a lot higher. So the true effective rate is a bit higher, somewhere in the middle depending on usage pattern.