When your IT equipment is due for upgrade it’s the perfect time to greatly reduce your computing energy use. But how do you know what products to use?

The US EPA Energy Star standard is now the defacto standard for energy use computing equipment. This certifies products as either being energy star compliant or not.

This is now a quite stringent standard, with version 5.0, the latest version, coming into force on 1 July 2009. The standard takes into account the power used by computers when off, in standby mode, and when in idle mode (that is when on, the operating system has loaded, and activity is limited to basic system applications).  Each mode is weighted according to an estimate of the hours per year the computer will be in each mode.

For example to be energy star compliant a category A desktop computer (your typical office computer with a single core processor) would need to use say less than 2 watts when off and in standby mode, and 39 watts or less in idle mode. Most desktops we measure when undertaking audits consume more than these threshold limits. A similar category A notebook would need to use say less than 1 watt in off and standby modes, and 13 watts or less in idle mode.

Thin client requirements are similar to laptop/notebook requirements.

The Energy Star (5.0) standard covers five categories:

1. Desktops, Integrated Desktops and Notebooks
2. Workstations
3. Game Consoles (under development)
4. Small Scale Servers
5. Thin Clients

So a simple way to maximise the energy savings from your next computer upgrade is to specify that ALL equipment (desktops, notebooks, thin clients, servers) be Energy Star (5.0) compliant. Or if your upgrade isn’t happening for a year or so, to the most recent Energy Star version at that time. You can see full details of the standard at the Energy Star website.

And of course if you are currently operating desktop computers seriously consider thin clients (which will cost no more, but greatly reduce your energy use) or notebook computers.

The Energy Star site includes a list of products that are available internationally, and not just in the US.

In conjunction with the Energy Star site you can also use the EPEAT website, which assesses products against a range of sustainability criteria including:

• Materials selection
• Design for end of life
• Product longevity/life cycle extension
• Energy conservation
• End of life management
• Corporate performance
• Packaging

The EPEAT site lists products available in 40 countries, including Australia. It is a program of the Green Electronics Council, a charitable not for profit organisation. EPEAT is a green electronics certification system. The list of EPEAT certified computers in Australia is pretty small, so if you have a preferred vendor who isn’t on this list I’d encourage you to ask your vendor to get their product EPEAT certified.

Computers continue to get more powerful, but are they using less power? This afternoon I interviewed Stuart King from Dell Australia/New Zealand. Stuart talks about how computer power use is coming down, discusses the Intel vPro technology for power management, thin client computing, and how you can greatly reduce computer power use at no cost. Click here to listen to this interview which looks at how computer technology is advancing. This interview is particularly recommended for anyone in the process of upgrading their computers - the perfect time to achieve some big energy savings for your organisation.

The Climate Savers Computing initiative aims to reduce computer energy consumption by 50% by 2010. Organisations on its board of directors include Dell, Google, Intel, HP, Microsoft, CSC and WWF. It has hundreds of members, all committed to purchasing energy-efficient PCs and servers for new IT purchases, and to broadly deploying power management.

The CSC website includes case studies on deployment of aggressive power management across entire organisations, and a range of guides for activating power management settings. It has a large FAQ section, and if you want to learn about power management the chances are you will find an answer on this site.

Use this site to help you promote and roll out effective power management of your existing computers.

If upgrading your computers seriously consider a thin client or virtual desktop solution for maximum power savings, unfortunately the Climate Savers Computing Initiative doesn’t yet have much information on these solutions.

Virtual desktops provides large computer energy savings and are becoming easier to deploy. Great for schools, universities and offices!

Most of the time only a small fraction of a computer’s power is being used. If you took a office or school with say 100 PCs, with an average load of say 15%, in effect 85 of the PCs would be redundant if it was possible to take advantage of the full power of 15 PCs across 100 work stations.

By employing “thin client” or “virtual desktops” this is made possible. With virtual desktops one PC “box” can then be used to power multiple workstations. This leads to very large energy savings. Additionally by reducing the number of “boxes” there is a resource saving. Maintenance costs are reduced and total lifecycle cost is lower.

There are some impressive examples of where this technology is now being used. Ncomputing is a vendor of virtual desktops, with 180,000 units deployed in schools in Macedonia. Canon in Thailand are using virtual PCs, as is DHL in Peru. In the USA virtual desktops are being used in schools in California and Wisconsin. In Australia its customers include schools such as Wondonga South Primary (Vic), Brighton Public School (SA), MacGregor State High (Qld).

In Australia Gold Creek and Parlmerston district schools in the ACT are using thing client computers supplied by Dycom. RMIT University in Melbourne is also using thin clients.

Take up of thin clients could however be much stronger. Victoria’s Department of Education and Early Childhood Development has reported weak demand from schools inquiring about the National Secondary School Computer Fund which is part of the Commonwealth Government’s Digital Education Revolution.

The flexibility of notebook computers is certainly an advantage over thin clients. However for total minimum power use and minimum life cycle cost and resource use its hard to beat a thin client or virtual desktop system. Thin clients should certainly be seriously considered by anyone involved in computer purchasing and network administration.

A few months ago I wrote a blog posting about how tighter regulation of electricity supply voltages could save Australia 15 million tonnes of greenhouse gas a year.

However a comment on that posting suggested that voltage reduction may not result in any useful savings.

Below I report on the results of an experiment we undertook to identify how much power can be saved, if any, by operating equipment at a lower voltage.

We measured a variety of single phase loads at different voltages. A variable transformer was used to vary the voltage. A German made Power Tech plus plug in power meter was used to measure voltage, current, power and power factor at the different loads. Loads experimented with included typical single phase lights, computer equipment and a fan.

The experimental set up is shown above. Below is a graph showing the results of the testing.

This graph clearly shows that for common lighting loads power consumption decreases with decreased voltage

• Incandescent lamp (resistive load)
• T8 fluorescent (inductive load)
• T5 fluorescent (electronic ballast)

The reduction in power consumption with the T5 fluorescent (with an electronic ballast) was unexpected.

The fan, with a single phase (shaded pole?) motor, also used less power with lower voltage, interestingly the power factor improved as voltage was lowered, with the power factor the highest at 220 volts.

The PC computer and monitor both showed lowest power consumption at 230 and 240 volts, but power consumption generally did not decrease with voltage. Power factor improved a little at lower voltages.

This experiment shows that for a variety of loads power consumption is in fact less at lower voltage.

For heating or cooling loads equipment may need to run longer when at lowered voltage to reduce the same amount of heating or cooling, with no net energy savings.

Three phase synchronous motors are unlikely to use any more or less power (a theoretical assertion, we don’t have the equipment to test), having the motors run at 230 volts rather than 240 or 250 volts however is unlikely to cause motor damage due to excess current as the voltage difference is only small.

But with lighting and many single phase motors power consumption drops with lowered voltage.

My back of the envelope calculations still come up with a saving of around 15 million tonnes of greenhouse gas if voltages were closer to the 230 volt standard rather than being at 240 to 250 volts.

If high voltage drops in distribution were a problem additional network infrastructure could be used to deliver a more consistent voltage across the network. 2009 is the year of the “smart grid.” A smart grid could mean multitap transformers that can be changed on the fly to deliver a more consistent 230 volts across the whole electrical network.