Professor David MacKay, University of Cambridge, wrote a brilliant book last year about Sustainable Energy to get more numbers and less adjectives into the public discourse.
It is the best book I have read in a decade.
The contents are described in exquisite detail on the book’s website www.withouthotair.com. (Indeed, the whole book is available for free as a .pdf download!) However, it is worth mentioning the elegant buildup of the book: MacKay shows how much energy we use today, broken down into the ten major categories. This is compared with the possible power output of the possible sustainable energy sources like wind, solar, wave, tide, biomass,…
The buildup is very pedagogical and it is at once easy to understand the relative importance of various energy sources and sinks.
The book is written from a UK perspective, but the same calculations can be done for a country of your choice. MacKay has even setup a public wiki where people already started to do this for countries over the world.
I got inspired by the visualization techniques and the tools to get all numbers into a comparable format. It is not trivial how to compare a laptop computer with a bicycle commute, but MacKay has chosen a device that works all the way, see the columns to the right.
Since I read the book I have monitored our home energy consumption (gas and electricity) to better understand the energy impact of our family (kWh/day):
Goran Christiansson's Blog 