I put my question in this forum because, apparently, the answer is yes? Things I don’t understand: There must be a law of physics which prevents a principle from being scaled up or down with simple equivalent offsets. It probably has something to do with the introduction of variables or whatever, I don’t know. But, as a liberal arts lay person, I don’t understand it. I don’t know if I could, or even would want to understand it; I just want to make sure the physicists and engineers understand it and know for sure that law is valid. I hope they are not just accepting that law because that’s what their text books told them in school. Example: Take a wind turban of a given size and configuration designed to generate electricity from cubic feet of moving air thrown against it. Why can’t the principles involved in the size and configuration simply be scaled to permit the generation of electricity from cubic feet of much heavier water thrown against it in an in-stream, low-flow micro hydro situation? Conversely, when people have argued the benefits of high head water turbans relative to the in-stream, low-flow micro hydro situation they convince me. But why can’t those principles be scaled up to the wind turban application? I have heard the wind turbans must actually be shut down during high wind situations to keep them from flying apart or generating too much electricity. Isn’t a high wind situation something like a high head situation, where you have more, bigger, better, faster? If it’s such a boon in the water context, then why waste it when there is a high wind situation? When comparing the four conditions (1. low head hydro; 2, high head hydro; 3. low wind; and 4. high wind), can’t all the various measurements and engineering principles (blade tilt, configuration, materials, size, etc.) be scaled with offsets to reach an ideal size and configuration based on the weight of that which is thrown against it, and creating an equivalent generation of electricity? In other words, if “low head air” is capable of generating X, then why can’t a much smaller low head water contraption generate X? If the lightweight nature of air requires a giant turban, why can’t the heavyweight of water generate the same amount of electricity with a much small, scaled-down and reconfigured contraption? I sit by my river and watch countless tons of water go by every second of every minute of every hour of every day of every year for many years; and it’s been doing that for hundreds of thousands of years. I am not allowed to dam it, and I am not allowed to divert it through a penstock or a waterwheel. However, I am allowed to affix something to the boulders on the bottom where it won’t interfere with rafters or kayakers. If a wind turban is 100 feet across generating X electricity with air that weighs 1 pound, why can’t I have a water turban that is 1 foot across to generate X electricity with water that weighs 100 pounds? On a side note, but with similar curiosity, and using the scaling referenced above, if a given solar panel is optimally configured as it is, couldn’t it be reconfigured smaller to handle sun brought to it after passing through a simple magnifying glass? We all know what can be done with a child, a magnifying glass and the sun. I’m just me, but if I were Bill Gates and willing to pay billions, or if I was an evil tyrant holding loved one’s hostage, and I said “Get it done!” Would it be done? Or is there a law of physics that would tell me to go pee up a rope?