Carbon Conservation & Energy Efficiency


Bruce Rowse & Team

Archive for the ‘Energy efficiency’ Category

The Venny – a sensible low energy building with an experimental green roof

Thursday, November 11th, 2010

On the weekend I attended the opening of the new Venny, an adventure playground for children from the ages of 5 to 16 in Kensington near the public housing estate.

The new Venny replaces an older building, and from an energy perspective has outstanding, passive-solar design.  I’d encourage other local governments to learn from the Venny with any new community facilities they are building. The key principles being:

  • High levels of insulation, properly installed
  • A well sealed building
  • Lots of thermal mass, and a night purge system, to harness diurnal temperature swings rather than fighting them as is done in conventional building design.
  • Good solar orientation.
  • Solar PV to provide building energy needs.

Project architect Ralph Webster, from the City of Melbourne, summarises the building design

Ralph Weber talks about the Venny (video, 5:40)

Key energy efficient features of the building design are:

  • The green roof.
    Venny green roof

    Venny green roof

    Coupled with the foam “sandwich panel” ceiling, the R rating of the roof is estimated to be around 11 – or nearly 3 times that of most roofs. Foam sandwich panel construction has a key advantage over batts in that its much less likely to be poorly installed, reducing insulation effectiveness.

  • A 5.5 kW solar PV system
  • The 50 mm foam insulation on the inside of the shipping containers around the building, including sandwich panel on the roof to improve its strength and ability to take the load of the green roof.

    insulating board lines the containers

    insulating board lines the containers

  • The high quality windows, with an aluminium weather proof external finish, but the rest timber (so the frame provides a good thermal break). Glazing is double, low-e, with argon fill.
  • High thermal mass in the concrete floor. The floor is spectacular, a key feature of the building, incorporating children’s art, building plans, etc, encapsulated in the floor with a clear resin coating. (I’m not sure how the coating influences the performance of the thermal mass)

    Venny floor

    Venny floor

  • Use of a phase change material (PCM) in the plaster. A 10mm plaster thickness essentially has the same thermal mass as a 90mm brick. The PCM is a BASF product called Micronel, that is encapsulated in the plaster. At 26 degrees it changes phase from a solid to a liquid, absorbing a lot of energy as it does so (just like making ice requires a lot of energy).
  • Sensor controlled lighting, which is a combination of metal halide and T5.
  • Aggressive occupancy sensor timing settings on the toilet lights and fan, with a 5 minute timeout.
  • A night purge. This is used to “recharge” the PCM in the plaster. So for example on a hot summer’s day the PCM may have all melted. By having cool air pass through the building at night it “recharges” (ie solidifies) the PCM. The night purge consists of a couple of windows that open at ground level and a ceiling vent that opens at night. There is provision to install a fan if necessary. The use of a night purge has been the single best feature of Council House 2.

    phase change material (PCM) in plaster ceiling

    phase change material (PCM) in plaster ceiling

  • Ceiling fans to provide cooling via air movement if necessary
  • High efficiency gas wall heater with a balanced flue.
  • Exact due North orientation, minimal use of east and west glazing.
  • Focus on recycling materials (such as shipping containers) for low embodied energy.

CarbonetiX has been involved with the Venny with the provision of a real time monitoring system to track site electricity consumption and solar electricity production, and also to monitor performance of the green roof. Three different substrates have been used in the green roof on a trial basis. We have put temperature sensors in the substrates and are also measuring water use to each section of the roof. This will be used to help evaluate the performance of the different substrates, which is a research project being undertaken by the University  of Melbourne.

The hope is that the building will be a net exporter of energy. What I particularly like about the Venny is its sensible passive solar design, and reliance on simple control (just using the fire panel). Its easier to keep energy use low in a building where the controls are simple and easy to understand.

I would like to install some more sensors to monitor and understand the Venny’s thermal and energy performance in more detail, and Ralph is happy for us to do this, with the University of Melbourne probably available to assist with installation and data analysis. This will help us better understand the effect of the various factors that interact to determine the whole building performance, of use when looking at retrofit options for existing buildings.

If you know of anyone who might have research funding available for this let me know!

And if you are building a new community facility, please get us involved. I have a great personal interest in zero energy buildings, which I believe are possible with today’s technology. With good design believe a zero net energy building can be cost competitive with more conventional, energy inefficient, construction.

LED comments by an early innovator

Friday, November 5th, 2010

Mal Oldis, an earlier innovator with LEDS, contacted me recently with the following comments on our report LED as a fluorescent substitute:

I have read with interest your assessment of LED lighting vs Fluorescent lighting. Well done!!
I have done much work with LEDs and yes, much credibility is lost due to false and exaggerated claims.
Indeed a company for which I was in charge of product development, failed partly due to exaggerated claims.
I probably built the first LED replacement (in Australia)  for a T8 over 10 years ago.
I learn t much from Agilent’s LED division in San Jose and also from the team at Philips in Holland.

Can I comment on your (very good) report?
I am not suggesting that you do not understand these issues, but there is some technical issues that commonly do not seemed to be explained to potential LED users.

Life time issues. Rated life time for LEDs and Fluorescent lamps is very different but the same term is used.
Rated life time of fluorescent lamps is usually stared time taken (under specified switching cycles) for half the lamps (median life) to fail.
Between 6 to 30 thousand hours are possible.

The rated life under these conditions for most LEDs is around 1.4 million hours. The “life time”  quoted for LEDs of say 50,000 hours (typical for white) is the 50% radiant (photometric) output level. It is interesting to note move to 70% output as noted in your report.

It is common to use the LOR (Light Output Ratio) figure for luminair directly. Also lumen maintenance can vary considerably for a luminair that uses fluorescent lamp due to dust and other contamination on the tube and the reflector, which forms part of the secondary optics.
Any  secondary optics (diffusers etc) using LEDs is simpler and therefore more efficient.

When I talk of the economics of LED lamps, I create an economic model and refer to cost of ownership which includes various maintenance regimes.

Also there is often no mention of the spectral properties, notably the Color Rendering Index which is poor for Fluorescent and even poorer in LEDs.

I did the original engineering for the BP Neon replacement for the service station canopies, and did much work with the City of Port Phillip using LEDs for public lighting.

Mal Oldis.

Government funding for “disruptive and innovative” energy efficiency

Thursday, October 21st, 2010

The US government has set up a special agency within the Department of Energy called the Advanced Research Projects Agency (ARPA) to promote “Disruptive and Innovative Approaches” to clean technology.  ARPA has the following objectives (from the ARPA website):

  1. To bring a freshness, excitement, and sense of mission to energy research that will attract many of the U.S.’s best and brightest minds—those of experienced scientists and engineers, and, especially, those of students and young researchers, including persons in the entrepreneurial world;
  2. To focus on creative “out-of-the-box” transformational energy research that industry by itself cannot or will not support due to its high risk but where success would provide dramatic benefits for the nation;
  3. To utilize an ARPA-like organization that is flat, nimble, and sparse, capable of sustaining for long periods of time those projects whose promise remains real, while phasing out programs that do not prove to be as promising as anticipated; and
  4. To create a new tool to bridge the gap between basic energy research and development/industrial innovation.

ARPA is currently supporting R&D in the following areas:

  • Better batteries
  • Technologies the reduce carbon emissions in coal powered power stations
  • Grid scale energy storage
  • Material advances in magnetic, high voltage switching and charge storage.
  • Electrofuels – microorganisms to harness energy and convert carbon dioxide into liquid fuels
  • Energy efficient building cooling technologies

This is an exciting program, and I particularly like the focus on breakthrough technologies. For example one of the energy efficiency cooling technology projects ARPA is supporting is thermoelastic cooling. This is a space cooling system that could have a a COP (coefficient of performance) up to 175% better than current vapour compression refrigerant systems.

It would be great to have a program similar to ARPA here in Australia.

Wanted – A Leader To Develop Australia’s First Retrofitted Zero Net Energy Building

Tuesday, October 19th, 2010

A zero net energy building is one that produces as much energy as it uses. Yet, to my knowledge, there is not one commercial building in Australia that has been converted to zero net energy use. Its challenging, but not impossible. I’m looking for someone who wants to take up the challenge with us and demonstrate leadership in what can be done with existing buildings.

The imperative for buildings with zero net carbon emissions exists in climate change. It is not practical to tear down all our existing buildings and replace them with new zero net energy buildings. Additionally, the embodied carbon in new buildings is high. There is a strong rationale for taking existing buildings and turning them into buildings that have zero net carbon emissions in their operation. Yet, while I believe this is achievable in many climates (such as Melbourne) with current technology, we are not yet doing it. So I’m looking for someone who wants to demonstrate leadership and start blazing the trail for other building owners to follow.

Globally there is growing support for Zero Net Energy Buildings, and a number of such buildings already exist. The Department of Energy in the US launched it Zero-Net Energy Commercial Building Initiative two years ago in August 2008. It aims to have such buildings marketable by 2025. It  hosts a database ( that features eight buildings that have already achieved this status, ranging in size from 1,530 to 13,600 square meters. One of these is the IDeAs Z Squared Design Facility, a 1960 two storey office in San Jose California that was transformed into a zero net energy building in 2007.

Another example is the Zero Energy Office in Malaysia, built in 2008 and owned by PMT. This building achieves zero net energy in a challenging climate. Singapore also has a 4,500 m2 zero energy building, which was a retrofit, at an academic campus.

We have helped several of our clients achieve energy savings of 50% or close to 50%. I’m itching for the opportunity to go all the way and get a year round 100% reduction in energy imported from the grid, whilst delivering a workplace that is comfortable and healthy. This is extremely challenging, as energy use needs to be reduced to around 30kWh/m2/year for a single storey building – and even less than this for multi-storey – and then the roof covered with solar panels to generate all the energy the building uses year round. But I’m confident it can be achieved. In our existing leased premises we are using just over 30 kWh/m2/year. I know it’s possible to get energy use this low on the top storey of a building (which we are) or in a single storey building. A relatively narrow multi storey building, would also be suitable, but even more challenging.

And the economics? I think that zero net energy use could be achieved at little extra cost with an existing building that was in poor condition and due for a major refurbishment, including a complete changeover of the existing HVAC system.  It won’t be cheap, as zero net energy in Melbourne means a building that is very well insulated and sealed, has a good amount of thermal mass, and has good control over how the sun gets into the building. But if the building is in a bad state anyway, a fair bit of money will need to be spent in any case. The aim would be that anything extra spent on the refurbishment to achieve zero net energy would pay for itself in less than ten years in the energy savings.

Prerequisites are:

  • Single storey, or reasonably narrow multi-storey building no more than 4 storeys high.
  • Building must be a commercial building – for example, an office, library, etc – cannot be residential or industrial.
  • At least 1,000m2, but preferably in the range of 2,000 to 5,000m2 in area.
  • Building must be structurally sound.
  • Owner who:
    • Wants to have the first, or one of the first, existing commercial buildings in Australia to be retrofitted for zero net energy,
    • Is willing to really engage actively in the process,
    • Wants to stand up, be seen as a leader, and promote the concept of zero net energy building refurbishments.
    • Is ready to start now.

Please get in touch with me if you own such a building and are interested, or know of someone who is, or, if you are an investor and are willing to buy an existing building and turn it into a showcase.

Bruce Rowse

Raising the profile of energy efficiency

Wednesday, October 13th, 2010

Last week  I attended the All Energy conference in Melbourne. Running over 2 days, with over 30 conference sessions, just one was dedicated to energy efficiency.  Rob Murray Leach, head of the Energy Efficiency Council who chaired the session, kicked it off by saying that this was the most important session of the conference, as 65% of the world’s carbon reduction by 2020 to come from energy efficiency according to the International Energy Agency.

But is energy efficiency getting 65% of the press coverage, is it 65% of the conversation around 2020 carbon abatement targets? Clearly it isn’t.

There is a massive vacuum when it comes to awareness and understanding of the most cost effective way by far of reducing carbon emissions – energy efficiency. Have a conversation about reducing your carbon footprint, and the first thing to come up will be solar panels, not building controls.

Yet from an economic perspective energy efficiency is extraordinarily interesting in comparison with solar. At commercial electricity tariffs, without subsidies, even the cheapest solar PV system has a payback of over 25 years.

Cover the entire roof of a typical two or three storey office building with solar panels and you’ll reduce electricity usage at the site by around 15%, whilst spending about four times your annual electricity costs to buy the solar system. Yet energy efficiency could probably deliver that same 15% saving with a 2 to 3 year return on investment.

So why isn’t energy efficiency getting the attention it deserves?

As an industry we haven’t been effective in promoting energy efficiency. The recently formed Energy Efficiency Council, of which CarbonetiX is a member, is now taking up this challenge, but there is a long way to go.
Energy efficiency is not visible. The results of changes to the lights and the way the air conditioning is controlled are only visible to the person paying the much lower energy bills, and the person who championed the changes. Solar panels are visible to everyone.

The invisibility of energy efficiency is compounded by the fact that the good news stories aren’t told. They may not even be told to people in the building where the savings have been achieved, let alone to the wider public.
And energy efficiency, whilst it gets good savings, is not that easy to do, but there is a perception that it is easy. So organisations may undertake a DIY approach, with no training and no experience, and not achieve any noticeable savings. A classic DIY approach would be to spend $2,000 to get occupancy sensors fitted to control the lights in the toilets – I’m sorry but the savings from this simply won’t show up in your energy bills.

The problem arising from failed DIY efforts is that this then creates the perception that energy efficiency doesn’t work. And nothing could be further from the truth. Yes, energy efficiency does work, but you need to know what you are doing. Businesses don’t get the receptionist to do their tax return. A qualified, experienced accountant who  is normally contracted to do so. But when it comes to saving energy, all too often its assumed that an environmental officer or a facility maintenance officer can effectively do energy efficiency.

So, to raise the profile of energy efficiency, celebrate and promote the savings you achieve. Put up a plaque above reception showing how much you have saved, or a graph of how your energy use has gone down. Get a high NABERS rating and put the certificate in reception as well. Talk about what was done to use the savings. Get a case study done and circulate it amongst your staff. Then send the case study off to your local paper and get them to do a profile on what you have achieved.

And to get those savings, to make energy efficiency really work for you, get expert advice and guidance.