How to save your wallet (and the world) by reducing electricity use

Shut_it_offNot everyone accepts that man made changes to our environment is a direct cause of global warming.  I blame our education system.

Fortunately, we do tend to agree that paying less in electricity bills is a good thing and for the most part leaving our wallets a little heavier also results in less environmental damage.

Lets consider how our use of computing systems can save us a few dollars, and perhaps also reduce the chance of our grandkids surfing lessons being relocated to Ayres Rock.


Running Costs of Computing Equipment

Computer systems consume varying amounts of electricity based on the type of components they use and the workload they are under.

On average, older systems use more power than modern computers.  Modern computers are better at throttling back their power consumption when they are not doing heavy work.

Most desktop computers will consume 80-300W when turned on.  Power consumption when off is usually a few watts.  Working on 100W, if left on 24/7 that’s 100x24x365/1000 = 876kWh or about $236 of electricity per year at 27c per kWh.

It pays not to leave your PC on!

Related peripherals can use a surprising amount of power.  A typical home modem/router with wireless may use 15W and are usually left on 24/7.  That’s about $35 a year.

The running cost of computers and related equipment can add up to more than their purchase price over their lifetime!

So what can we do to reduce running costs?

A story of Parked Cars and Global Warming

Sitting in a parked car on a Brisbane summer day is a test of survival.

Sunlight enters and heats surfaces and the air inside the car. If the windows are open, inside air does not have to get very hot before it will move and take heat away. Additionally, heated surfaces will radiate heat out of the car. The air temperature inside the car will settle a little above the outside temperature, once energy out equals energy in.

Now try closing up the windows so it is harder for the air to escape. Surfaces will need to get very hot, so they can radiate more energy, and air will get very hot, with much less escaping. The temperature inside will settle at a higher point where the hot surfaces and hot air allows the rate of energy leaving to again equal the energy entering.

No, it is not a perfect comparison to global warming, but the basic idea is related. The concept of dynamic equilibrium.

We know that some gases, like carbon dioxide, trap heat more than other gases. We know there is a lot more of such gases in our atmosphere than used to be. We can measure this. The reason seems to be that we are pumping more into the atmosphere faster than other processes are pulling it out (another example of dynamic equilibrium in process of rebalancing).

The basic effect is not debatable, its high school science and understood for hundreds of years. Global temperatures are increasing and will continue to do so as we move to a new equilibrium point. These changes will cost us.

The uncertainty inherent in predicting how and when this change will impact our biosphere is where the confusion comes in. The magnitude, timescale, and localised changes that will result are difficult to nail down. Disagreement over details are interpreted by the media as disagreement over the underlying phenomenon. The earth is complex, and the outcome is not as simple as everything heating up evenly. For example, a warmer arctic may destabilise the gulf stream and cause major blizzards in the northern US more often than before (happening as I write this). How about predicting explosions to form vast sinkholes in Siberia as the permafrost melts? Some of what will happen we will only see when its too late to prevent.

Journalists and politicians are guilty of drawing conclusions without the education to understand the issues, and will cherry pick the “expert” following the view they want to believe in. They confuse the uncertainty inherent in local and transitional predictions with the surety of the overall effect and inevitable net negative for the human race. But this isn’t the politicians issue to solve, its ours, they are simply our employees who need better instruction and need to be reminded of this fact from time to time. While that message forms and global action accelerates, simply turning off when not needed is a small but useful contribution.


Turn it off

When you are not using a computer for any significant period of time, turn it off!

You may also want to turn off your PC at the wall overnight to avoid the standby power consumption, particularly if it is attached to the same power point as other standby hungry devices.

Remember to turn off your router overnight.  If you happen to have your router plugged in to the same point as perhaps your PC, TV, Foxtel, Hi-Fi gear, and so forth, then turning them all off can save significant cost.

If physically turning off a switch is a practically difficult, you can look for devices that can do it automatically for you.  I’m not a fan of this method, but they can be useful in rare circumstances – timers, power boards that automatically turn off passive power, and wireless devices that let you turn off multiple wall points with a remote control can all be effective.  The best method is to arrange a simple physical switch to be accessible.  Where a wall point is hidden, then a power board with a physical switch moved to an accessible point will often do the trick.


Use Wake on LAN

But what if you leave your computer or NAS on so you can access it remotely whenever you need to?

The answer is wake on LAN.  This is a technology where the machine is essentially off and uses a little standby power, but it will listen for a certain type of network traffic.  When it receives a special type of network packet, it will wake up without you needing to hit the power button.

It is possible to send this type of wake up call from anywhere, so you can wake up your PC remotely, and then log in like usual.  Trying googling “Wake on Lan setup”


Make smart buying decisions

Some years ago monitors with LED backlights were introduced and slowly replaced LCD backlights.  In theory they provided better image quality, though differences were often small and when introduced they often cost a premium over the LCD panels.  We had customers who insisted in buying LCD panels to “save” a few dollars.

I recall measuring the power use of two similar monitors at about 20” size. The LCD consumed 50W and the LED 20W.  The LED cost slightly more.

Assume the screen is on 8 hours a day, every day, then we have 30W x 8 hours x 365 days = over a year 87.6kWH of more electricity being used by the LCD unit.  Over say a 5 year lifetime of the monitor, that’s 438kWh more power consumed by the LCD.  At a cost of 27c a kWh, that’s an extra cost to run of about $118.   It makes a buying decision easy, the LED that nominally costs $20 more works out much cheaper than the LCD when we factor in running costs.  And yet we even had businesses buying LCDs over LEDs because running costs was simply not considered!  That’s just bad business.

The same idea applies across a range of technology.  Building a media centre machine?  Maybe look at a NUC computer, maybe a low power Atom processor, a SSD HDD, and so forth.

80_PlusBuying a new desktop?  Maybe upgrade the power supply to give you better reliability but also better efficiency.  Look at power supplies rated at high efficiency, say gold over bronze and save perhaps 10% of the PCs power consumption while enjoying a quieter machine (more efficiency means less heat and so less fan noise)


Use your PCs power plan — never use a screen saver!

Screen savers were designed in the days of cathode ray based monitors, where displaying a static picture for a long period could “burn” the image into the screen.  It was not possible to power down these screens automatically so screensavers were devised to ensure the image displayed would change, even when no one was using the computer.

The modern equivalent are a computers power settings.  You can use this feature to turn off the signal to the monitor when there has been no activity on the computer for some time.  The monitor will go into standby mode and save power.

There are additional settings which may help reduce a PCs power consumption such as putting the whole computer into a standby mode when no activity has been detected.  You can also tweak power setting for various components such as automatically power down internal hard disk drives when they are not needed.


Technology to manage your power use

The Internet of Things is a concept where appliances and devices across your home are interconnected and can be managed with software.  The control points tend to be your computing systems, traditional PCs as well as smartphone and tablets.  There will be many uses, some which are possible today and others not yet conceived, but what is inevitable is that these systems will allow us to better measure and manage our power consumption.

As a relatively simple example that is used today, sensors can be used through the house which automatically control lighting, turning lights off after you leave a room and back on automatically as you approach.

Heating and cooling solutions for your house can be setup into zones and smart systems can vary the level of cooling and heating automatically based on occupancy, perhaps using the same sensors that the lights use.  A more advanced function would be to use sensor and control data to predict your usual patterns and automatically operate systems to account for that.  The system might know you go to bed around 11PM and like to have the fan on if the temperature is above say 25 degrees, but the smart system could also slow the fan during the night and turn it off entirely if the temperature drops to say 20 degrees, saving power and giving you a better sleep.


Further Reading

Green Computing – Wikipedia

GREEN COMPUTING Way to reduce Global Warming – ASM

What is Wake-on-LAN and How Do I Enable It? – How-To Geek

Typical Family Home Could Contain More Than 500 Smart Devices by 2022 – Gartner

Smart Lighting – Wikipedia

Climate News – Science Daily

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