I can&#x27;t see the problem either.<p>I don&#x27;t think it&#x27;s a capitalisation problem; when using &#x27;Watt&#x27; as a name, e.g. James Watt, you need to capitalise. But the unit is &#x27;watt&#x27;, with a lower-case &#x27;w&#x27;. The symbol is an uppercase W. Reference: Table 3, in &quot;NIST Special Publication 330: The international System of Units (SI)&quot;, Taylor et al (2008).<p>Nor do I think there&#x27;s a problem with confusing energy and power, as there currently is in the original title.<p>So, what&#x27;s the problem? Jaquesm&#x27;s &quot;And you still got it wrong&quot; comment is unhelpful because it doesn&#x27;t identify a specific problem. Maybe he feels that the sound doesn&#x27;t actually come from the cable. Or maybe the cable isn&#x27;t carrying 50 kW. I don&#x27;t know. Maybe there is an obvious problem I&#x27;m missing.