The Elithis Tower in Dijon, France, consumes just 20 kWh/m2 and was designed to cost no more than a conventional office buildings. The February issue of Ecolibirum, the magazine of AIRAH (Australian Institute of Refrigeration, Air Conditioning and Heating) reported on this building.

It is a 10 storey building of around 5,000 m2, with solar panels covering the rooftop. A “light shield” allows light but not radiant energy into the building. Low environmental impact materials have been used in its construction.

This is an extraordinary achievement, and is an example of human ingenuity rising to the climate change challenge. Most office buildings of that size would consume over 200 kWh/m2, and a very efficient building around 60 kWh/m2.

The Elithis Tower is the first building that I am aware of that beats the 30 kWh/m2 we achieved in the CarbonetiX office in 2008. In 2009 our emissions crept up to 33 kWh/m2, probably due to the introduction of additional computer monitors and staff countering the savings from skylights we installed at the end of 2008.

The Elithis Tower sets a great standard which I hope inspires further great engineering and design to make low or no energy use buildings the norm rather than the exception.

In October 2008 we started an independent evaluation of LED lights as a substitute for fluorescent lighting. The evaluation was undertaken in partnership with the Sustainability Fund, managed by Sustainability Victoria, and with the support of Frankston City Council. We chose to focus on fluorescent lighting because this is by far the most common form of lighting used in commercial buildings.

The trial has involved firstly a desk-top evaluation of LED products, then selection of lamps from those six manufacturers who appeared to have the best products. These were then tested by CarbonetiX for light output and power consumption. The best performing lamp was then sent to a NATA certified laboratory for photometric testing.

The useful light provided by the best lamp in a standard office fluorescent fitting was similar to that of a used halo-phosphor fluoro tube – a surprising result as earlier testing we had undertaken indicated the LEDs were just not bright enough to be used as a fluorescent substitute.”

We then replaced 176 fluorescent tubes with the lamp that had performed best in our testing  in the Mahogany Neighbourhood Community Centre in the City of Frankston.  Users of the facility were surveyed before and after the upgrade and noted either no change or an improvement in the lighting. An illumination assessment showed that illumination levels after the upgrade were around the same as before. Yet power consumption has dropped from over 40 watts per lamp down to 18 watts.

In October we undertook another check up of the lamps, eight months after they were installed. Illumination levels were similar to when they were installed, and none of the LED lights had failed.  Eight months of operation is not nearly long enough to establish whether or not the lamps will operate for 50,000 hours or not as claimed by the manufacturer. But it is a good start.

LEDs as a fluorescent substitute are still expensive, with roughly a ten year return on investment in an office environment. But this trial indicates that if the technology continues to evolve and prices drop that LEDs could help halve the use the energy used by lighting in commercial buildings.

In June the US Department of Energy launched the $10 million “L Prize” for the development of a 21st century lamp that produces more than 150 lumens per watt (current lighting technology is around 100 lumens per watt).  It also challenged the industry to develop a 10 watt LED replacement for the 60 watt incandescent light bulb. Philips have already submitted an entry in the 10 watt incandescent replacement.

With stimulation like this LED technology can only improve.

Not withstanding this good news, a strong word of caution for the here and now is necessary. After our testing we had a lot of LEDs from a number of manufacturers lying around our office. So of course we took out our fluoro tubes and put them in. All of these LED tubes, from five different manufacturers, have now failed. My advice would be for anyone contemplating the use of LEDs – firstly make sure you are happy with the level of illumination provided, then secondly ask the supplier to provide a minimum 3 year or 15,000 hour guarantee, with lumen depreciation (loss of light output) to be no more than 10% over the 15,000 hours.

In my previously post, I was expecting any smart grid pilot project roll-out in Australia.

Two days later, Victoria gives me one immediately. On 23th Oct 2009, Electricity distributor SP AusNet announced its partners to facilitate the roll-out of more than 680,000 ‘smart meters’ to homes and small businesses across eastern and north eastern Victoria by December 2013.

Partnering with SP AusNet in the AMI (Advanced Metering Infrastructure) program are: Landis+Gyr, GE and GridNet, UXC Limited, Electrix, Motorola, Unwired, eMeter, Logica, Accenture, Enterprise Business Services, and Geomatic Technologies.

SP AusNet adopts WiMAX technology which is a high-speed, high-bandwidth wireless communication technology would be utilized in any future 4G broadband. I reckon this is a great choice for Australia with low population density.

“GE is providing the meter communications technology for the utility’s network and delivering half of the smart meters, with Landis+Gyr providing the other half. Motorola will provide the communications infrastructure.”

“SP AusNet is on track to roll out its 680,000 meters, with roughly 40,000 meters to be installed by the end of June next year.”

Victorian please do not be surprised when you receive an introductory letter from SP AusNet, because you will get a smart meter soon.

Image from www.sp-ausnet.com.au

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.

Most commercial buildings in Australia have moved away from incandescent bulbs to compact fluorescents, which are much more energy efficient and last longer. The limitations of CFLs are slow warm up time, early failure if frequently switched, and high cost for dimmable CFLs. Additionally some speciality bulbs, such as chandelier bulbs, don’t have readily available CFL equivalents. But as CFLs are four or five times more efficient than incandescent in our energy audits we always try to build a strong case for switching to CFLs.

But incandescent may be getting a second life. Australia enacted the first legislation banning  sales of low efficiency lamps (incandescent) and the US followed. With a much larger market than ours this has sparked some innovation in the design of incandescent lamps.

Philips now has a incandescent that is 30% more efficient than a standard incandescent. Osram is shortly coming out with one 25% more efficient.

These sort of efficiency gains still leave CFLs as clearly the superior option, but as there is more research undertaken the incandescent could get even better yet.

If incandescent efficiency can be improved by 20% a year, it will take six or seven years to catch up with where CFLs are now. Which is a long time, unless there is an innovation that provides a quantum improvement in efficiency.

LED lights on the other hand are now getting close to CFL efficiency.

Its great to see all this lighting innovation happening, and hopefully we will soon see screw in and plug in bulbs that are more efficient than CFLs