I can't see the problem either.

I don't think it's a capitalisation problem; when using 'Watt' as a name, e.g. James Watt, you need to capitalise. But the unit is 'watt', with a lower-case 'w'. The symbol is an uppercase W. Reference: Table 3, in "NIST Special Publication 330: The international System of Units (SI)", Taylor et al (2008).

Nor do I think there's a problem with confusing energy and power, as there currently is in the original title.

So, what's the problem? Jaquesm's "And you still got it wrong" comment is unhelpful because it doesn't identify a specific problem. Maybe he feels that the sound doesn't actually come from the cable. Or maybe the cable isn't carrying 50 kW. I don't know. Maybe there is an obvious problem I'm missing.