Carbon Conservation & Energy Efficiency


Bruce Rowse & Team

Archive for the ‘Computers and office equipment’ Category

Baw Baw Shire council cuts electricity use by 30% in a rented office.

Tuesday, November 16th, 2010

Last week I caught up with Raj Maniher of Baw Baw shire council in their Smith Street Community Development office that council is renting in Warragul. Raj has implemented a number of measures to cut energy use in the office, and has achieved a 30% electricity saving.

Some of the measures implemented include:

Insulating the ceiling

Double glazing using “magnetite” on some of the windows.

Retrofit Double glazing

Retrofit Double glazing

Getting internal reflective blinds made up by a local blind maker. Very ingeneous!

Internal reflective blinds

Internal reflective blinds

Voltage reduction on the lights

Voltage reduction units on lighting circuits

Voltage reduction units on lighting circuits

Blanking off light fittings with a clear Perspex sheet to prevent air leakage into the ceiling cavity.

Glass panel under light fitting to keep conditioned air out of the ceiling cavity.

glass panel under light fitting to keep conditioned air out of the ceiling cavity.

Disconnecting inefficient lights and replacing with fluorescent

Upgrading to a 5 star fridge

5 star fridge

5 star fridge

Only switching on when needed – for example the airconditioner, and kitchen equipment is turned off at the wall when not in use.

switch off at wall

switch off at wall


How would you save energy in your rented office?

City Switch program launches the City Switch Workbook – showing tenants easy ways to save energy

Tuesday, April 20th, 2010

This morning the City of Melbourne, City of Port Philip and Sustainability Victoria launched the City Switch Workbook. This workbook shows tenants 9 easy steps to reduce greenhouse gas emissions. 

delamping demonstration

delamping demonstration

Brett Muncton (City of Melbourne) and Jake Hallas (Sustainability Victoria) gave a entertaining demonstration of how the workbook can be used. The photos above and below show them demonstrating delamping (step two in the workbook) and setting up power saving settings on a PC (step six).

setting computer power management settings

setting computer power management settings

Written by CarbonetiX, the workbook is based on our successful Greenhouse Gossip program, which was launched in 2008. City Switch signatories in the City of Melbourne and City of Port Philip will also be offered a structured mentoring process, aka the Greenhouse Gossip program.

Presentations by Gadens Lawyers, Telstra and Toyota at the launch showed how its possible to achieve significant energy savings in tenancies. In the case of Gadens Lawyers, a 22% saving was achieved over 12 months at no cost. This was achieved by improving switch off practices, step one of the City Switch Workbook.

city switch work book

city switch work book

Details of the City Switch program can be found here. If you aren’t a tenant in one of the City Switch cities and want to participate in a structured mentored program to achieve guaranteed energy savings please inquire about our Greenhouse Gossip program. Its also suited to those who own their own office building in addition to tenants.

Halve the energy use of your LCD monitor

Thursday, April 15th, 2010

Computing equipment continues to get more efficient, and with LED monitors now available at good prices, there is even more opportunity to save energy.

Good power saving settings should be a given for any computer installation. However as you upgrade your computers there are now many ways to save energy. You can switch to laptops or thin client computers. And a new way is to make sure that your next monitor is backlit with LED lighting.

LCD monitors usually have two cold-cathode fluorescent lights in them, one either side of the screen. These are behind the LCD display, and “back light” the screen to make what is on the screen visible. However monitors are now starting to be readily available on the market that use LEDs for backlighting. As LED lighting is very thin, this can enable more effective positioning of the back lighting – for example a grid of LED lights behind the screen.  The higher lamp efficiency of LED lighting as compared to cold-cathode, combined with more effective positioning equals energy savings.

LCD monitor power use - CCD vs LED

LCD monitor power use - CCD vs LED

For energy efficiency reasons we only run laptops in our office. However we also operate a second screen on each laptop, to improve productivity. We recently purchased a 24” monitor with LED backlighting, and compared with our other 24” monitors this one uses much less – 21 watts vs 39 watts – almost half the energy use.

A monitor with LED backlighting only costs slightly more than a conventional LCD monitor. In our case we paid only around $30 more, and will be saving around $7 a year in energy costs. If we were buying black power, we would also be saving around 46 kg of greenhouse gas annually, equivalent to 900 black balloons.

The payback on the extra money spent on a LED monitor whilst not bad isn’t good either, however for the sake of only $30 I reckon its worth it for the greenhouse savings. And the cost differential will keep on lowering. Additional advantages are a screen with sharper contrast, a slimmer screen, and a product that is easier to recycle as it doesn’t contain cold cathode tubes that contain mercury.

Also LED backlit monitors are not hard to find. Its likely that your computer supplier has one anyway. We purchase all our computers from a shop in down town Frankston, less than one kilometer from our office, and that’s where we got our LED monitor from.

In an earlier blog post I discussed the technical innovation that should make it possible to have a net zero energy building by 2020. This is one of the many innovations that are making that possible.

What will make zero net energy office buildings affordable by 2020?

Wednesday, September 16th, 2009

A zero net energy office building is one which consumes no net energy. Its an office that uses very little energy, then has some form of renewable energy to generate all the power it requires.

With current off the shelf solar technology, presuming little or no shading, its possible to get around 100 kWh  of energy per year per square meter of solar panels at latitudes of around 40 degrees, more in sunny locations at lesser lattitude. For a single storey building, with a roof covered with solar panels, and little shading, keeping office energy consumption to 100 kWh/m2 is easy, and in fact I’ve audited quite a few small offices that are nothing special but only use in the order of 100 to 120 kWh/m2. But a grid connect solar system nowdays costs in the vicinity of  $700 to $1,000 per square meter, which is pretty  expensive, so there are very few zero net energy offices in existence.

Aggressive energy conservation and use of off the shelf technology (like skylights) can mean that office energy consumption is kept down to somewhere between 30 to 50 kWh/m2, meaning only half the roof needs to covered with solar panels, or allowing for some shading. For example our office uses only 30 kWh/m2/year, but is shaded in winter, we could make it energy neutral now just by covering around 2/3rds of the roof in solar panels.

So it is possible now, in 2009, to have a zero net energy office, but its not easily affordable, yet. And if your office is 3 storeys or higher, its becomes very hard to achieve no matter what your budget.

Technological advances however, are happening rapidly and I believe that by 2020 a zero net energy low-rise office may be affordable. And importantly this should be achievable by retrofitting an existing office building, with no need to especially construct a new building. Some of these technological changes are:

  • The emergence of LED lighting. Assuming by 2020 we have LED lighting of around 200 lumens per watt. Allowing for some daylighting, and good use of task lighting, it may be possible to have annual lighting use less than 8 kWh/m2/year.
  • Computer efficiency improvements. Assuming that with thin client architecture and high efficiency monitors by 2020 an office PC uses 15 watts, and that a 200 watt server can then serve 30 clients, computer energy use would be around 3 to 4 kWh/m2/year.
  • There are many likely pathways for HVAC, which will depend on climate. A likely pathway for temperate climates is 100% fresh air HVAC systems, with air to air heat exchangers, but also using legacy internal ducting to allow high flow full economy cycles. Fans will be highly efficient, and heat pumps will have high efficiencies at a range of loading conditions, with the conditioning of air separated from ventilation to lower fan energy use. Couple this with light weight retrofit phase change materials (PCM) to provide thermal mass (eg plasterboard with encapsulated PCM), white roofs (where there are no solar panels), glazing treatments and new insulating membrane technologies to improve the thermal performance of the building. Seal the building well, and combine with good use of sensors and intelligent control all of which limits HVAC energy use to say 15 kWh/m2/year.
  • Miscellaneous loads: high efficiency fridge at say 150 kWh/year; near zero standby loss hot water system; high efficiency multi function devices, totalling say 4 kWh/m2/year.

This will result in total office energy use of around 30 kWh/m2/year.

With aggressive energy conservation occupants should be able to to get down to say 15 to 20 kWh/m2/year.

Assume solar panel efficiency is more than double current efficiency and the installed price per watt of a grid connect system is one third of the current cost. This will provide 260 kWh/m2/year at a cost of say $500 per square meter.

A single story unshaded office where aggressive energy conservation is practiced will then need only 8% of its roof covered with solar panels, at a cost per square meter of building area of only $40.

A three storey half shaded office building would need most of its roof covered.

It should be possible to have a 7 storey building energy neutral if unshaded and the roof is covered with solar panels. Of course if additional solar panels can be added to walls it should be possible to get even taller energy neutral buildings.

By 2020 the net zero energy low-rise office building should be easily affordable, and in fact it may well be standard good financial practice to convert existing office buildings to energy neutral ones. So even building owners with no interest in acting to slow climate change will have energy neutral buildings. And most low rise office buildings then – whether they are 100, 50, or 1 year old –  could be energy neutral.

I say “should” and “may” because I still have some doubt as to whether a couple of the technologies that modify the thermal performance of a building –  particularly PCMs, and retrofit membrane’s that improve its insulation properties – will be affordable. But then again with focus a lot can change in 11 years, and as more of us demand better energy performance from our buildings I believe that this will spark the innovation needed to make zero net energy office buildings common place.

You can help make this a reality by acting now to make your building more efficient. Do what is affordable now. Then repeat regularly - technology is now advancing quickly. You’ll create the demand that will drive the innovation that will create the technology that will make energy neutral buildings common place.

You have SPAM with a huge carbon footprint

Thursday, September 3rd, 2009

You may have come across this news item a couple of months ago but it is worth taking another look. Although, the study was conducted by a major spam-ware corporation, it is clear that junk e-mails have a huge carbon footprint.


Anything powered by electricity emits greenhouse gases. Recently research was conducted in the US to find out the amount of energy needed to transmit, process and filter spam globally. The results were startling. According to the ‘Carbon Footprint of Spam’ report the average greenhouse gas emission of a single spam message is 0.3 grams of CO2. Is this a lot? Well, if you multiply this by the number of spam sent annually it translates into a huge figure.

It is estimated that there are 62 trillion junk e-mails sent each year. In terms of energy this equals to the energy needed to drive a car around the planet 1.6 million times. If looking at the electricity needed to power these spam it equals to 33 billion kWh. This amount of electricity could power 2.4 million homes for a year! Spam-related emissions for all e-mail users around the world in 2008 totalled 17 million tons of CO2 or about the same as the emissions produced by 3.1 million passenger cars. That’s 0.2% of the total global emissions.

The report found that about 85 to 91% of all e-mails globally is spam. Nearly 80% of the spam-related GHG emissions came from the energy used by the PC users viewing, deleting and searching for legitimate e-mails amongst the junk e-mails. But spam filtering itself accounts for about 16% of spam-related energy use. To view and trash a piece of spam takes about 3 seconds.

If every inbox were protected by spam filters, organisations and individuals could reduce today’s spam energy by 75% or by 25 billion kWh per year. This would save the same amount of greenhouse emissions as produced by 2.3 million cars. In late 2008 a major source of online spam was taken off line and global spam volumes dropped by 70%. However, there are always new ones to take its place.