Linfox is well known for the “You are passing another Fox” sign on the back of its vehicles. But the company has also cut its greenhouse gas emissions by 9% in the last eighteen months, and is on track to cut its emissions by 15% by December 2010.

I had the privilege of interviewing David McInnes, Group Manager Environment and Climate Change yesterday and being inspired about Linfox’s approach to the climate change challenge. It was refreshing not to hear the Carbon Pollution Reduction Scheme mentioned once in the interview. Linfox is reducing its carbon emissions because it wants to, not because its being forced to, and is quietly getting on with it.

So how does a organisation with 15,000 staff, whose carbon emissions mostly come from diesel consumed in trucks, reduce its per km emission by 9% in eighteen months? You can find the interview on our “Good News Interviews” page.

For me a couple of the standouts from the interview were:

• Their staff engagement program. Almost all of their savings have come about by making better use of what they already have, rather than investing in new technology. This has been achieved by getting their staff involved in changing the way things are done and in how trucks and buildings are operated, and making hundreds of small changes.
• Their carbon accounting system – developed in-house. Linfox programmers set up their SAP system such that now monthly carbon reports can be generated, down to the level of individual trucks if necessary. A consistent theme of all organisations cutting their carbon footprints is their focus on accurately and frequently tracking their emissions
• David’s recommendation to any organisation wishing to cut their carbon footprint to undertake an energy audit, which provides the business case for action. Thanks for the plug for my profession David!

After the interview we discussed Linfox’s Greenfox program, and I wish I had left the voice recorder on. This is a fantastic program. Staff can become a Greenfox by passing five training modules. Everyone who completes the training gets a framed certificate, and drivers who complete the training get a Greenfox badge on the shoulder of their uniform. David mentioned that Greenfox’s often become ambassadors, with truck drivers going to their kid’s schools and talking about climate change.

Also not covered in the interview was the great help David got from Linfox’s IT department in modifying SAP. Normally there is a long queue in the organisation for projects requiring SAP changes. The carbon accounting adjustments though were undertaken by the SAP programmers on top of their normal requirements, such was their commitmen to the company reducing its carbon footprint.

Finally David also spoke off the record about the need to focus less on the science and more on the community and the emotional response that when sparked can result in great change.

As one of Australia’s larger businesses Linfox is taking a leadership role by getting on with reducing its corporate carbon footprint. David McInnes is providing inspirational leadership. Take half an hour to listen to David McInnes and I guarantee you’ll come away motivated and hopeful about what is possible if we focus on cutting carbon emission.

Today I had the fortune to see Shai Agassi, founder of Better Place, talk about his vision for the electric car future. Shai calls himself an imaginer – “I imagine the future and engineer towards it”. His vision of an electric car future is elegant, simple, and achievable. Australia is a key part of his strategy to get the world to a tipping point which results in all cars becoming electric.

For electric cars to replace petrol cars they must be cheaper and more convenient. Yet the electric cars available now are more expensive and less convenient because of their short range and limited recharging options.

One of the keys to Shai’s vision is treating the battery – the single most expensive component in an electric vehicle – like gasoline. The battery becomes a consumable, not owned by the car owner. By taking out the battery its possible to make vehicles that are price competitive with gasoline vehicles.

A second key is the electricity grid, which is everywhere, and which he called “the longest extension lead in the world”. By extending the grid to having recharging points where cars are parked, vehicles can be charged whenever they are not in use. Better Place will be buying only wind or solar generated electricity for use in its vehicles.

A third key, for longer trips, is batteries that can be swapped over in a minute. The first prototype has just been built in Japan. So on a long trip (over 200kms) you pull into a battery station, change your battery, then keep going. It will take less time to change your battery than to fill your car for petrol. For a typical suburban vehicle typically there would be around 12 to 15 battery changes per year.

Paying per km you travel – for the electricity and battery amortisation – is still cheaper than the equivalent cost of petrol per km.

The result is:

• Cars that cost less to buy than fossil fuel powered vehicles; and
• Cars that cost less to run than fossil fuel powered vehicles.

Of course a large investment is needed to build the infrastructure – the recharging points and battery change stations. But if cars are cheaper, if they cost less to run, if petrol is only going to keep increasing in price, and if there is going to be continued regulation and incentive to reduce carbon emissions this is not a insurmountable hurdle.

Shai believes that the “tipping point” will be reached once three countries have proven the concept. Then the rest of the world is likely to follow – and follow quickly. The first country is Israel, which first supported the idea. Renault are investing one billion dollars in producing a electric vehicle, which will first be sold in Israel; they are aiming to sell 150,000 vehicles in the next few years. The second country is Denmark. And the third country is Australia, with Looksmart founder and former Victorian parliamentarian Evan Thornley heading up Better Place in Australia.  Australia was chosen for a couple of reasons. First its big, unlike Israel and Denmark, and thus provides a demonstration that the technology is suited to big and small countries. Secondly we have large sprawling cities, involving a long suburb to city commute, not dissimilar to many North American cities. A third reason would be that we have a relatively small population of cars, so the net capital cost is relatively low. Shai also said that Australia has lots of Lithium, iron and phosphate, the components used in electric vehicle batteries.

With a country full of electric cars, each with large storage capacity, the intermittent nature of electricity generation from wind and solar can be overcome. When the wind blows and the sun shines batteries in parked cars everywhere will be charged. When its calm and cloudy cars can then feedback into the network. And we move towards the smart grid or distributed network.

The choice of Evan Thornley as Australian CEO is interesting. Clearly Better Place will need tremendous IT and communication infrastructure to communicate with vehicles and the smart grid and monitor battery condition and charge levels. Its hard to go past one of the people who was involved in driving widescale uptake of the internet as a leader.

This future is not that far away. Various governments around the world are now offering subsidies to those who purchase electric vehicles. And in Beijing gasoline cars will be progressively banned from the streets. By 2014 no fossil fuel powered vehicles will be allowed in Beijing.

Shai believes that within 10 years we could have three to four million drivers using electric vehicles in Australia.

Shai Agassi spoke at the inaugural 2009 Alfred Deakin eco-innovation lecture. These lectures will feature optimistic innovation driving a more sustainable world. Shai’s positive vision is a great inspiration and a fantastic way of kicking off the lectures.

If LED lighting continues to develop as fast as it has over the last five years, within ten years it may well be the main form of lighting in use across the world. And lighting in new buildings may look radically different to what it does now.

The major advantage of LEDs is that they are a directional light source. Most other artificial light sources on the market radiate light in all directions. Incandescent light bulbs, compact fluorescent lamps, fluorescent lamps and high intensity discharge lamps such as metal halide all radiate light in all directions.

For example in most fluorescent office light fittings typically only 60% of the light produced by the fluorescent tube is emitted as useful light. A great deal of the light is lost because it goes  upwards or sideways rather than down. Using a reflector may increase the amount of useful light provided up to 80%. But even the most efficient fluorescent light fittings on the market rarely have a light output ratio of above 80%.

LED lights on the other hand produce all their light in a single direction. Light fitting designers can take advantage of this to efficiently direct light exactly where its needed, with very little lost or wasted light.

Go into a progressive hardware or electrical store and you can already see a variety of LED lights being sold.

Fluorescent lamps are the most commonly used lamp in the world. LEDs however are not yet competitive with fluorescents for three main reasons:

1. Energy efficiency is similar but not yet better. A high performance fluorescent tube will produce 100 lumens per watt. Put it in an energy efficient fitting, with a light output ratio of 80%, and the overall lighting efficiency is 80 useful lumens per watt of electricity. The best white LEDs on the market (that we are aware of) produce 75 to 80 lumens per watt. This is good, but not yet better than, fluorescent.
2. Reliability. Unlike fluorescent tubes, which are generally reliable no matter who makes them, LEDs are often unrealiable. We have purchased LEDs from many different manufacturers, and over half have failed within the first year of use.
3. Price. LEDs are still expensive.

This, however, is changing. Energy efficiency is improving, the major lighting manufacturers are increasing their focus on LEDs, and prices are dropping.

Energy efficiency of LEDs has increased markedly in recent years, in 2006 the best LEDs were approaching 60 lumens per watt, by the end of 2008 they were up to 77 lumens per watt. 

Reliability. The three main global light manufacturers - Osram, Philips and Sylvania – are all now selling LED lights. As major global brands they are unlikely to risk the cost and reputational damage of supplying unreliable products. As LED products become more main stream we can expect reliability to improve.

Costs are now starting to decrease as well. Whilst it is difficult to purchase a LED fluorescent substitute light for less than $80, only two years ago the price was $100.

When LED lights are achieving energy efficiencies in excess of 120 lumens per watt, lamp costs of less than $2 a watt, and low failure rates (less than say 1%) lighting as we now know it will be superseded. It will be possible to retrofit LEDs and cut lighting energy use by 50% or more in almost any building. New buildings, with lighting designs built around LEDs, may well be providing office – standard illumination for 2 watts of electricity use per square meter or less (current best practice is around 5 watts per square meter).

These new lights may look very different. Light fittings may become panels with hundreds of LEDs on them. Or ceilings may end up with stripes of LEDs across the ceiling. Or ceilings will end up with sockets into which panels of LEDs can be plugged in, so that its easy to move LEDs around in response to the lighting needs of a room (more above a desk, less in the corridors).

If control and sensing technologies can become sufficiently low cost buildings may well be set up to provide lighting whose intensity varies with occupancy and usage.

The rapid development of LEDs is exciting. It gives me hope that, when it comes to lighting, humanity will be able to greatly reduce its carbon footprint in the not too distant future.

Earlier today I interviewed Cameron Schuster, Sustainability Manager of Wesfarmers Limited. Wesfarmers owns Coles, Bunnings, Kmart, Officeworks, Target and a large number of other businesses.

Cameron’s says the following three things are critical to any organisation wishing to cut their carbon emissions.

1. Measure. Wesfarmers is putting in an internet based measurement and reporting system in place. This will provide store managers and others easy access to information about how they are performing.
2. Win senior management commitment
3. Entrust and empower people throughout the organisation to initiate activities to reduce their carbon emissions. Lots of small initiatives can add up to large carbon savings.

As with my interview with Toyota the theme of continuous improvement comes through in this interview. Wesfarmer’s carbon reduction strategy also has a strong emphasis on energy efficiency.

Click here to go to the interview with Cameron, or here to view Wesfarmer’s most recent sustainability report.

(Part Two) The first part of this topic was published on the 8th of May.

Flat Plate Solar Collectors

Flat panel (aka flat plate) collectors work on the principle of copper pipes running through a glass covered collector, often connected to a water storage tank on the roof. The hot water can then thermosiphon itself in and out of the tank, thus heating the water. Finally the hot water is gravity fed into the house from the roof. This is an extremely efficient way of gaining and storing hot water and can be over 90% efficient in the right climate. The simplest combination is the close-coupled system (see photo below).

However, the water tank may be located in the roof space or on the ground as a separate unit in which case a pump is necessary to circulate the water. This is known as a split system. Flat panel collectors are still the most commonly used collectors in domestic hot water applications in warmer climates due to their affordability and reasonably easy installation. The collectors should last well over 20 years and can handle an operating temperature up to 80 degrees.

Evacuated Tube Solar Collectors

Evacuated tube collectors consist of glass tubes with a layer of heat absorbent coating inside them. As the tubes encasing the water pipes are a vacuum it greatly reduces heat loss. The thermal energy retention can be up to 97%. Copper pipes run through the centre of these evacuated glass tubes in a U-shape. These are all connected to a common manifold which is then connected to a slow flow circulation pump which pumps water to a storage tank below. The hot water can be used at night or the next day due to the insulation of the tank. Evacuated tubes are often used in commercial applications or in applications where hotter water is needed, since they are capable of generating temperatures above the boiling point of water (for example on dairy farms). While evacuated tubes have a long life similar to flat plate collectors, they are composed of fragile glass tubes which may occasionally need replacement.

Comparisons

As pointed out in Part One of this blog it is not a simple matter of using evacuated tubes or flat panels as each circumstance is different. Each collector design has its own merits. Both systems can save over 3 tonnes of GHG emissions per year and can reduce heating energy consumption in a home between 50%  to 80% especially when electric hot water storage systems are being replaced. In addition both systems can be up to 70% efficient when heating water and heat losses in the system are taken into account. So instead we should look at the benefits and the short comings of each system.

Evacuated Tubes

Advantages

• No heat losses due to convection and conduction because glass collectors are hermetically sealed.
• No change of performance during the service life of the collectors as there is no corrosion.
• Thermal diode operation principle, the hot water flows one way only from the collector to the tank and never the other way around.
• It is able to harness sunshine from all directions due to its cylinder-shaped glass tubes.
• Well-suited for colder climates with reduced hours of sunshine, where frost may be a problem or where the roof is prone to overcast from clouds.
• Freeze free so can be used in sub-zero temperatures and in the presence of snow.
• Easy installation due to light weight and no maintenance needed afterwards.
• Requires smaller roof area for installation.
• It is less apparent on roof because of the absence of a water tank coupled to it.
• Each glass tube is independent from each other so in case of breakage it can be replaced.
• Minimum greenhouse emissions when combined with gas boosting.
• Saves about 3 tonnes of CO2 annually when compared to electric storage.
• Very low running cost when used with gas or off peak electricity.
• On average it is about 5 years payback on investment.
• Suited for commercial and industrial applications.

Disadvantages

• Expensive to purchase due to more components, such as pump, separate water tank and associated plumbing and electrical work.
• Less cost effective than flat panels based on initial investment.
• Glass tubes could break easily in a hail storm or from falling branches.
• In higher ambient temperatures it is less efficient than flat panels.
• In direct summer sun it could be too efficient making the water too hot which results in wastage.
• Evacuated tube collector’s aperture area is typically between 60 and 70% of the gross collector area (meaning that’s how much of the total area exposed to sun is doing useful work).
• Some heat pipes are prone to cracking rendering the system useless especially at the braising points. These don’t like repeated heating and cooling down especially if it is very sudden.
• The welding should be done with silver alloys to prevent this from happening.
• Mainly made in China, thus not supporting Australia.

Flat Panels

Advantages

• Operates extremely efficiently in warmer climates and in higher ambient temperatures especially when water tank is horizontal and adjacent to the collectors.
• It can be between 44% to 76% more cost effective in warm climates than evacuated tubes.
• Losses are minimised because of water tank being located next to collectors.
• Thermosiphon operation minimises maintenance - no moving parts or distant pipes.
• Simple to install as system can be purchased as one unit with collectors and tank together.
• Affordable to purchase for the above reasons and because of less plumbing involved.
• No electrical installation required in most cases where stand alone system is used (ie the tank is not separate from the collectors).
• Space saving as water tank is located on roof and not in or around the house.
• Robust construction.
• Large collector area.
• Flat plate collector’s aperture area is typically between 90 and 95% of the gross collector area.
• Mostly made in Australia for Australian conditions, which supports the local industry and economy.

Disadvantages

• Can corrode.
• The air gap between the absorber and cover pane could result in heat losses during cold and windy days.
• It can rob the water of built up heat if the collector becomes colder than the water temperature.
• No internal method of limiting heat build up and have to use outside tempering devices.
• In colder climates it may need extra protecting devices from frost or freezing.
• It is more reliant on accurate northern exposure in order to operate efficiently.
• Installation could be difficult due to weight and size.
• Circulates water inside insulated areas. Prone to leakage, corrosion and restriction of flow due to possible airlock.

The graph below compares the three main types of solar hot water systems and their efficiency.

Explanation: Solar collector efficiency is plotted as a straight line against the parameter (Tc-Ta)/I, where Tc is the collector inlet temperature (in °C), Ta is the ambient air temperature (in °C), and I is the intensity of the solar radiation (W/sq. m.). Notice that inexpensive, unglazed collectors are very efficient at low ambient temperatures, but efficiency drops off very quickly as temperature increases. They offer the best performance for low temperature applications, but glazed collectors are required to efficiently achieve higher temperatures.

Summary

From the above descriptions and considering the merits and drawbacks of each system the following conclusion can be drawn. In warmer climates and most temperate zones, where there is good exposure to sunshine throughout the year, and the ambient temperature is fairly stable the flat panel collectors are recommended to be used. Also, if there is good uninterrupted northern exposure available the flat panel is more economic. The flat panel is extremely efficient and the systems can produce sufficient hot water for most households. The use of a flat panel system will result in up to 80% reduction of hot water cost when compared to electric storage units. These are also more affordable with a faster payback period on investment. They are designed and made in Australia for Australian conditions.

On the other hand the evacuated tube systems have an advantage of being able to operate in colder climates or where there isn’t enough sun light (ie. some alpine or mountain areas, prone to overcast or where there are more trees). These systems also work well in the presence of snow or sub-zero temperatures. The unique design of the glass tubes allows it to capture sunlight from various angles thus heating the water for longer periods. In some cases where very high water temperatures are required - even in warmer climates- the evacuated tubes have the ability to produce water at higher temperatures than flat panels. Being smaller in surface area these units could be more suitable where there is a lack of space. Again 80% reduction in hot water cost and GHG emissions are quite achievable from such a system.

Please take note of the references for the graphs and information in this article. Where possible we have used information stemming from government websites, academic resources, and manufacturers data. If you need more information or actual references please contact us.