Here’s a great piece by David MacKay, author of Sustainable Energy — Without the Hot Air. An excerpt:
(CNN) — We need to introduce simple arithmetic into our discussions of energy.
We need to understand how much energy our chosen lifestyles consume, we need to decide where we want that energy to come from, and we need to get on with building energy systems of sufficient size to match our desired consumption.
Our failure to talk straight about the numbers is allowing people to persist in wishful thinking, inspired by inane sayings such as “every little bit helps.”[…]
Take, for example, the idea that one of the top 10 things you should do to make a difference to your energy consumption is to unplug your cell-phone charger when you are not using it. The truth is that leaving a phone charger plugged in uses about 0.01 kWh per day, 1/100th of the power consumed by a lightbulb.
This means that switching the phone charger off for a whole day saves the same energy as is used in driving an average car for one second. Switching off phone chargers is like bailing the Titanic with a teaspoon. I’m not saying you shouldn’t unplug it, but please realize, when you do so, what a tiny fraction it is of your total energy footprint.
In total, the European lifestyle uses 125 kWh per day per person for transport, heating, manufacturing, and electricity. That’s equivalent to every person having 125 light bulbs switched on all the time. The average American uses 250 kWh per day: 250 light bulbs.
And most of this energy today comes from fossil fuels. What are our post-fossil-fuel options?
Among the energy-saving options, two promising technology switches are the electrification of transportation (electric vehicles can be about four times as energy-efficient as standard fossil-fuel vehicles) and the use of electric-powered heat pumps to deliver winter heating and hot water (heat pumps can be four times as energy-efficient as standard heaters).
Among all the energy-supply technologies, the three with the biggest potential today are solar power, wind power and nuclear power.
As a thought-experiment, let’s imagine that technology switches and lifestyle changes manage to halve American energy consumption to 125 kWh per day per person. How big would the solar, wind and nuclear facilities need to be to supply this halved consumption? For simplicity, let’s imagine getting one-third of the energy supply from each.
To supply 42 kWh per day per person from solar power requires roughly 80 square meters per person of solar panels.
To deliver 42 kWh per day per person from wind for everyone in the United States would require wind farms with a total area roughly equal to the area of California, a 200-fold increase in United States wind power.
To get 42 kWh per day per person from nuclear power would require 525 one-gigawatt nuclear power stations, a roughly five-fold increase over today’s levels.
I hope these numbers convey the scale of action required to put in place a sustainable energy solution.