What's "A Lot"?

My friend Monkey and I've been chatting in the comments section of my September Quote of the Day about what the "a lot" in the quote means. The quote comes from a forthcoming book Sustainable Energy Without Hot Air, by David J.C. MacKay as noted in this post.

MacKay is a Professor of Natural Philosophy in the Physics Department at the University of Cambridge and the gist of his book is to take known sources of sustainable energy, estimate their production at full implementation, and to compare that to current energy use. The result is that for Britons there is some cutting back on electrical consumption to be done before they get under the sustainable threshold (no carbon-emitting sources of electricity). There's a much bigger change required if they are also to avoid nuclear sources.

The quote I lifted was MacKay's justification for setting a threshold of a 10% reduction in energy consumption for the efficiency measure to make his list of things Great Britain needs to focus their political will on. His contrasting point was that there's a massive marketing campaign focused on getting people to unplug wall chargers when they're not being used. Here he compares the power draw of all the chargers he could find in his house -- 0.5 Watts -- to the total average power consumption of the average Brit -- 5000 Watts. So the action of unplugging chargers is focused on 1/10000th of the average power consumption of a Briton. If the world cut it's total power consumption by 1/100000th, we'd hardly notice the difference.

So, if we're going to advertise, if the politicians and greens are going to bloviate, let's do it about things that cut at least 1/10th of our individual and national use.

In terms of looking at what changes I can make as a home-owner and what to focus my time and money on, this yard stick bumps certain projects to the top of the list and other projects lower down. Two things that make the above 10% list are replacing my current fridge with a smaller and efficient model, and replacing my water heater with a tankless water heater. Things that are much lower on the list are hanging a wash line and unplugging the microwave when I'm not using it. These are good things, but they have much less pay back.

Perhaps Monkey is looking for an action point. If you were to go through your life and make a list of all the ways you could save energy or gas or heating oil, and one of those items turned up a 10% savings, focus on getting that done. A list of things to consider:

• Share a ride to work once a week.
• Hibernate or shut off your computer rather than leaving it on.
• If your fridge is nearly empty or contains only compost and condiments, consider unplugging it.
• Change your bulbs to CFLs. Don't use halogen lamps unless they're also working as a space heater.