Shedding some light on Earth Hour and the like.

A couple of weeks ago, Enrico published a post on our Italian blog about an event here in Italy called "M'illumino di meno". It's difficult to literally translate that title (literally it's "I light myself up less" or "I illuminate myself less"), but basically the idea is similar to that of Earth Hour - a massive awareness campaign to turn off the lights for an hour as a way of getting people to think about how much energy they consume. Widespread campaigns like these are essential as far as bringing awareness to people who might no otherwise think of their own environmental footprint. User education - whether it be "users" of light switches or entire houses - is, in fact, the the most important tool in improving our energy reliance.

And as Lord Kelvin so famously said,

If you can not measure it, you can not improve it.

In that spirit, Enrico and I decided to take a look at exactly how much energy we can expect to save on a night like M'illumino di meno or Earth Hour. And then, just for fun (!), we decided to compare that saved energy with how much we'd save by adding one single square meter of insulation to the external wall of our outdated apartment building. (Our dream house is still in design phase!).

Here are our results...


Energy savings from turning off the lights:

We calculated the total primary energy saved by turning off the bulbs, in our apartment Cavriago (RE), for each event:

  • M'illumino di meno: 2.53 kWh/a (kilowatt hours per year)
  • Earth Hour: 1.68 kWh/a.

Energy saved by thermally insulating 1 square meter of our outer wall:

We calculated the total primary energy saved by insulting 1 square meter of our outer wall with 10 cm of insulating material:

  • 41.18 kWh/a

Insulating one square meter on outer wall saves 16 times more energy than switching off the bulbs for one hour once or twice a year.

Obviously, the difference here is that turning off a light does't cost anything and it's an easy way to get people involved on a large scale. Once millions of people start turning off their lights all at the same time, it's a very powerful statistic to see how much energy is saved worldwide. And that has a great and indisputable value.

But why stop at turning off the lights for one hour? Imagine what would happen if everyone knew as much about insulation as they do about energy saving bulbs.

It is now 2015. We are 3 years away from the Near Zero Energy EU Directive requiring all member countries to set energy efficiency requirements in all new constructions, with the goal of reaching "Near Zero Energy" by 2020. Changing the bulbs or turning off the lights isn't going to cut it.

We need to use the momentum of great events like M'illumino di meno and Earth Hour to push for education in other parts of home use.

The light bulbs in our homes have changed drastically in the past ten years. The walls, however are the same. This is the real problem.

Mariana Pickering

Emu Systems, 6145 Broadway, Denver, CO, 80216