My last post spawned an interesting discussion on how we should be focussing our energy saving efforts – should we be worrying about saving a few watts in one area, while there are other areas which are wasting kilowatts?
How we each approach this depends a lot on our personalities. Some people think big and need to see huge value resulting from their actions. Others find joy in fine tuning all the details and making sure that everything is just right.
I feel that the two go hand in hand. Each on its own lacks substance. If all you can see are the fine details it is difficult to work towards a bigger goal. If all you can see is the big goal, it is hard to see the small steps that need to be taken to achieve it. It is a bit like that saying: how do you eat and elephant? One bite at a time.
Setting big goals is important, and so is sweating the small stuff. We still come back to that question though: where should we focus our energy to have the largest impact?
There are two important areas to focus on,
- The biggest point of pain, and,
- The easiest thing we can do.
I am currently working on a warehouse floor application and one of the issues is power consumption. Power consumption affects how many units can be powered from a single power supply, and what type of cabling is used. When I made some measurements I found that the system was consuming way more energy while idle than I was happy with. The easiest (and in this case only) way to address that was to do some investigation into the power saving options of the microprocessor. I managed to cut the idle power consumption to 20% of what it was. In this case the amount of power saved per unit is not much (100mW) but the number of units is high. It helps me to increase the number of units I can drive, as well as saves a reasonable amount of energy overall. That small saving per unit will save around 350kWh/month in this application – the monthly energy consumption of my home.
So sweat the small stuff, and sweat the big stuff. Build momentum and keep moving forward.
To the engineers: what you do matters – keep making good choices.
Photo, courtesy of Mandy Goldberg, licensed under a Creative Commons license.
A quick guide to computer energy saving
- Set your monitor/display to turn off after 15 minutes or less (don't use a screen saver).
- Set your hard drives to turn off after 15 minutes or less.
- Set your system to sleep after 30 minutes or less.
- Choose "Minimal Power Management" as a power scheme in XP (this makes sure the processor can go into low power modes while it is not busy). In Vista make sure your "Minimum processor state" is set to a low value under the advanced power options and "Processor power management."