In all the clamour about saving energy, what energy systems and savings in fact make a difference on a scale that matters?

Fascinating analysis here:

Our conclusion: if we covered the windiest 10 per cent of the country with windmills, we might be able to generate half of the energy used by driving a car 50 km per day each. Britain’s onshore wind energy resource may be “huge,” but it’s not as huge as our huge consumption. I should emphasize how audacious an assumption I’m making. … The windmills required … are fifty times the entire wind hardware of Denmark; seven times all the windfarms of Germany; and double the entire fleet of all wind turbines in the world. This conclusion – that the greatest that onshore wind could add up to, albeit ‘huge’, is much less than our consumption – is important …

And what about this:

... solar photovoltaic (PV) electricity is viciously expensive in the cloudy UK, and just sticking panels on roofs won’t do much — it seldom yields any large proportion of the energy used in the building it’s on top of. You need to cover a big portion of the country in cells.

All in all, according to MacKay, if you like solar it probably makes more sense to put the panels in North Africa and bring the power to the UK over efficient high-voltage DC lines. As an engineering matter the desert-solar idea is quite feasible — not very different in scale from piping in gas across continents and beneath seas, as people already do.

Or this:

There’s also a thing called a thorium energy amplifier reactor which would be a lot more efficient. If it works as its Nobel prize-winning designers predict, known thorium reserves would run six billion people at American luxury for sixty thousand years.

Read. And Think.