All over the world, people discuss sustainability. Mainly in holistic terms and using open theories facts and figures are not the centre of discourse. And when mentioned numbers are often used in an way only those numbers are used which fits the ideas of the speaker. One scientist proclaims a disastrous transition already in ten or twenty years, due to the fact that oil extraction can't meet demand, another sceptics denies these 'facts' with the idea that there is plenty of energy.
What we have to do is getting informed, according to Prof. MacKay. People should know facts and figures. We should be aware what our demand for energy is, where it comes from, and where it could come from in the future. Therefore, the book offers a quantified analysis of almost all options when talking about renewable and sustainable energy. Furthermore, everything we use and consume nowadays is analysed. Hereby important is to relate different units mutually. Let's talk about cars: how much kWh is needed to drive 50 kilometres with a car? 40 kWh, according to MacKay. When we know this, it becomes possible to have an idea about the effectiveness of renewable sorts of energy like windmills. For Britain, a 10 % coverage with windmills would result in the generation of 20 kWh /d for one person, while a 50 km drive with the car uses already 40 kWh.
Only when people are aware of such quantifications and their interrelations, it becomes useful to speak out on effectiveness or to give advice about which investment. But, moreover, people become able to have a rational discussion 'without any hot air' about their energetic behaviour and useful new techniques.
Sustainable energy - without the hot air; David JC MacKaypage index