I have no idea about the actual number, but saying the power is decreased by 30 GW does make sense, though... Of course it is not energy, but they might not have meant "solar energy" in the sense of a physical quantity. The sentiment is bullshit of course.
ok so technically, a watt is directly convertable to a joule, which is a unit of energy. So he isn't wrong. But he is also wrong because he is using name plate production capacity, rather than the total produced capacity, that or he is simply fucking up the numbers. But lets be honest, homie is NOT doing the math.
in this scenario it wouldn't be speed, though, it would be speed over time. Speed is velocity.
Watts are just joules but arbitrarily defined. Joules are a unit of total energy. A collective amount of work potential. Watts are an in situ measurement of those joules doing work.
If we want to talk about confusing units, W and VA are the units to be talking about.