Sky-High Radiation Found in Fukushima Fish

[kristopher]

55. McKay's presentation can be very misleading

This blog link is worth reading fully:
http://energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences

...The numbers in the first third of Professor MacKay’s book all lead to the conclusion on page 103 that even if we used all of our renewable resource to its technical maximum, ignoring economic, social and environmental constraints, then it is not enough to meet our energy demand. And that (as he writes later in the book) this applies to Europe too — he writes: “Europe, like Britain, cannot live off its own renewables”.

And yet the figures on 103 are wrong — we all agree on that — you, me, David, the official statistics. So any conclusion based on them must be in doubt.

Indeed, there are plenty of reasons for doubt — because in addition to the inflated demand, the first third of the book also contains economic, social, and environmental constraints on supply, despite the statement to the contrary (I’ll write a bit more about the supply side in a new article, later). So those are not about the physics of the thing at all — they’re opinions. So, we have an inflated demand, and a set of political opinions on supply. That’s not (in Professor MacKay’s words) “what the laws of physics say about the limits of sustainable energy”.

As it turns out, Britain’s renewable resource is an order of magnitude higher than our energy demand.

And so Britain, (just like Europe and the whole world) can get 100% of its energy from renewable resources.

A much better approach is demonstrated by work such as this:
Cost-minimized combinations of wind power, solar power and electrochemical storage, powering the grid up to 99.9% of the time

Abstract
We model many combinations of renewable electricity sources (inland wind, offshore wind, and photovoltaics) with electrochemical storage (batteries and fuel cells), incorporated into a large grid system (72 GW). The purpose is twofold: 1) although a single renewable generator at one site produces intermittent power, we seek combinations of diverse renewables at diverse sites, with storage, that are not intermittent and satisfy need a given fraction of hours. And 2) we seek minimal cost, calculating true cost of electricity without subsidies and with inclusion of external costs. Our model evaluated over 28 billion combinations of renewables and storage, each tested over 35,040 h (four years) of load and weather data. We find that the least cost solutions yield seemingly-excessive generation capacity—at times, almost three times the electricity needed to meet electrical load. This is because diverse renewable generation and the excess capacity together meet electric load with less storage, lowering total system cost. At 2030 technology costs and with excess electricity displacing natural gas, we find that the electric system can be powered 90%–99.9% of hours entirely on renewable electricity, at costs comparable to today's—but only if we optimize the mix of generation and storage technologies.

http://www.sciencedirect.com/science/article/pii/S0378775312014759