Technology

I was contesting the general logic of this sentiment:

Which "experts" do you need for what's common knowledge?

I took this to mean "If common knowledge suggests an obvious understanding, an expert's assessment is can add no value, as they would either agree or be wrong." Put differently: "If it seems obviously true to me, it must be true in general."

TL;DR: If you think you know more than experts on a given topic, you're most likely wrong.

On a fundamental level, this claim in general holds no water. Experts in a given field are usually aware of the "common knowledge". They also usually have special knowledge, which is what makes them experts. If they claim things that contradict "common knowledge", it's more likely that their special knowledge includes additional considerations a layperson wouldn't be aware of.
Appeal to Authority as a fallacy applies if the person in question isn't actually an authority on the subject just because they're prominent or versed in some other context, but it doesn't work as universal refutation of "experts say".

For this specific case, I'm inclined to assume there is some nuance I might not know about. Obvious to me seems that large, central power plants are both easier targets and more vulnerable to total disruption if a part of their machinery is damaged. On the other hand, a distributed grid of solar panels may be more resilient, as the rest can continue to function even if some are destroyed, in addition to being harder to spot, making efforts to disrupt power supply far more expensive in terms of resources.

However, I'm not qualified to assess the expertise of the people in question, let alone make an accurate assessment myself. Maybe you're right, they're grifters telling bullshit. But I'd be wary of assuming so just because it seems true.