felis-parenthesis's profile

felis-parenthesis 11mo ago

The energy in the wind scales as the cube of the wind speed. It looks like it ought to be the square of the wind speed, because kinetic energy is one half m v squared. But what is the mass here? It is the mass of air passing the wind turbine, so that is proportional to the wind speed.

This makes intermittency a huge problem. When the when is blowing at half speed, you only get one eighth of the energy. Imagine planning for low winds by over provisioning by a factor of two. You have built twice as many wind turbines as you need for a day with the designed for wind strength, expecting that you will make it through low wind days without black outs. But when the wind strength dips to 79% of design nominal, you are already down to half power, taking up the entire margin provided by over provisioning. The wind drops to 78% and you have to start shedding load :-( Or at least drawing on storage.

I keep seeing critics of wind power asking "what do you do on calm days?". That is a bad question. It leads to boosters and critics both worrying about the occasional calm day when the air is still. But we need to worry about the half strength days. And those are common place days when the wind is still blowing and we expect the turbines to turn and the electricity to stay on.

A credible wind power system would have eight fold over provision, and weeks of storage. The occasional day when the wind is above design strength all day would be a cause for celebration: we have captured a weeks worth of energy in a day! And we could start feeling that we had a secure energy supply. We are nowhere near facing the challenge of intermittency nor the expense of intermittency.

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felis-parenthesis 11mo ago

That is a destructive question. The tradeoff between profit and treatment is discussed ad nauseam. The gradual accumulation of treatments that extend life, without restoring its quality, and are expensive, is painful to think about. So we don't. But we need to, and the profit question helps us procrastinate and never get round to the uncomfortable issue :-(

I frame it with an equation life-span = health-span + grim-span. Modern medicine is extending the health-span. But for every extra year of health-span, we get three or four years more grim-span. (3? 4? I'll admit that I'm guessing wildly. I just don't want to follow my grand-mother and my parents down the care-home, dementia-unit, nursing-home, route.) Expensive grim-span.

We are well down the road of nibbling away at the quality of the health-span with taxes (or insurance premiums) to pay for expensive medical treatments. When do we say: there is a cash limit. That is a scary thing to say. Perhaps I will fall ill, find out that there is a treatment to save my life, find out the cost is over the cash limit, and get told "sorry, you'll have to die". Maybe the cash limit will be low because I decide to opt out of insurance for expensive treatments, enjoy spending the money I save, and die when my luck runs out.

There are two battles. One is around opting out. If I opt out of paying for the more expensive treatments for others, and therefore (by fairness) for myself, can I change my mind when I fall ill? Obviously not. Can I still whine about it, or must I die quietly? The other battle is about the future. More expensive treatments are coming. When is the breaking point when the money runs out?

Returning to the profit question, the British National Health Service (the NHS) is funded out of general taxation and free at the point of use. Do we Britbongs escape the profit issue? We should, because the NHS is a non-profit. But it doesn't work out like that. At constant funding there is a tradeoff between the wages of doctors and nurses and treatment. At constant funding, higher pay means fewer doctors means less treatment. Alternatively there is a tradeoff between funding and taxes. The politicians in charge need to keep in touch with fluctuating public sentiment. What will get them re-elected? More taxes and more health care? Lower taxes and scandals about people dying waiting for treatment? Perhaps the warning sign of the impending breaking point is no-one can get re-elected. The low tax politicians cannot get re-elected because of the deaths. The health care spenders cannot get re-elected because of the taxes.

We need to learn to memento mori least we build a world in which we spend our lives working long hours in health care, before eventually falling ill and taking a very long time dying, kept alive by the strenuous efforts of many younger people.