In ‘Energy efficiency’ Category
ReNew 138 editorial: Looking up – what’s on your roof?
WHEN it comes to sustainable building, there’s a lot of material to cover, so we’re making our way around the building process, bit by bit. Having previously looked at ‘what’s in a wall’ (in ReNew 132), this time we’re hitting the roof.READ MORE »
We delve into the various roofing materials and their sustainability, along with the importance of roof pitch, insulation and colour to a house’s thermal performance. We also look at green roofs, with great resources for finding out more on this home/urban cooling option (with a lovely leafy example featuring on our cover).
With 1.5 million roofs in Australia also housing solar panels, it could be argued that our roofs (and communities) are leading the way in a renewable transition for Australia. But that’s not been without its naysayers and challenges, so ATA expert Andrew Reddaway tackles the issues and solutions needed for a successful shift to 100% renewables. It’s a must-read to correct misconceptions about how renewables work with the grid, particularly given the recent blackout in South Australia and discussions around the closure of Hazelwood.
As well as roofs, we also consider windows—or at least ways to shade them. With a warmer than average summer on the cards, it’s a good time to make sure your home will cope as well as possible in the heat. Keeping the sun off your windows is an important first step, but it’s not always as simple as putting up a blind. In our external shading buyers guide, we look at how to get it right: which windows to shade, how much shade, what materials to use and should shades be fixed, adjustable or even removable to avoid excluding the sun when you need it.
Gardens also provide a cooling benefit, and vertical gardens are a way to get greenery in places where that might not otherwise be feasible. Gardening in pots can be tricky though, so we feature two successful examples, with the message from both being to experiment to get the right plants, and that automatic watering is a must. The other message is that the owners love having herbs and greenery right at the back door!
We hope our article on reusing building materials in the garden will inspire you to find ways to source preloved bricks, concrete tiles or other materials to use for both practical and creative purposes in the garden. The author has been working with high school students to build a permaculture garden from mostly reused materials—and we get to benefit from their ingenuity and enthusiasm with some great examples to copy at home.
Of course, there’s much more besides: an EV owner’s insights into charging, including the knotty issue of kerbside charging for those without driveways, DIY wicking beds using a waste product, an introduction to timber finishes, islands leading the way in sustainability, DIY pressed earth bricks, and much more! We wish you a happy and safe holiday season and look forward to hearing from you in the new year.
ATA CEO’s Report
IT HAS been a whirlwind past few months, with major shifts in global politics like the recent election of Donald Trump as US president and the Brexit vote causing great uncertainty in the area of climate policy.
Thankfully there was a firm commitment from the countries attending the Marrakech Climate Change Conference in November to show the world that the implementation of the Paris Agreement is underway, and the constructive spirit of multilateral cooperation on climate change continues.
While the Australian Government announced ratification of the treaty at Marrakech, it is still unclear how at a federal level we will achieve our carbon reduction commitments. Several states and territories including the ACT, Vic, SA, Qld and NSW are taking the lead, setting more ambitious targets and other mechanisms to combat emissions.
So much uncertainty and change once again highlights the role the community needs to take in not only advocating for effective government policy but getting on with the job. And we need to make sure everyone in the community comes along on the journey.
There is no better example of practical sustainability than community renewable energy. There are now more than 80 community energy groups and 50 projects up and running across Australia. In February 2017, these groups will be gathering in Melbourne for the second Community Energy Congress to share information, develop skills, foster new networks, celebrate success and plan for action. The ATA is proudly one of the organisers of the conference and we look forward to seeing you there. For more information, go to c4ce.net.au/congress.
You can purchase ReNew 138 from the ATA webshop.
Keep your cool: External shading buyers guide
With summers getting hotter in many parts of Australia, keeping the sun off your windows and out of your home is becoming even more important. Anna Cumming looks at the options for external shading, for both new builds and retrofits.
THERE’S been quite a shift from pre-industrial times when glass was an artisan-crafted luxury item, and homeowners were taxed according to the number of panes they had. These days, our houses are getting bigger and so are our windows—often to the point of comprising entire walls. Windows and glazed doors frame views, admit natural light and breezes, and allow a connection with the outdoors. In a well-designed house, they also admit the sun’s warmth in winter to assist passive thermal performance.READ MORE »
However, from a thermal efficiency point of view, windows are the weak link in a home’s building envelope: Your Home notes that up to 40% of a home’s heating energy can be lost and up to 87% of its heat gained through windows. Efficient double-glazed windows with thermally broken frames (preventing heat conduction through the frame) perform considerably better—advanced glazing solutions can exclude up to 60% of heat compared to plain single glazing—but will still allow more heat to enter in summer and escape in winter than the adjacent wall.
Internal thermal blinds or curtains can help a lot in preventing heat loss through windows in winter, but to tackle unwanted radiant heat gain in the hotter months, it’s far more efficient to stop the sun hitting the glass in the first place with appropriate external shading.
Location and orientation
There is a huge variety of options for keeping the sun at bay, from carefully chosen deciduous plantings and simple solutions like a piece of shadecloth on a frame, to awnings, shutters, blinds, and even pergolas with sensor-operated louvre roofs. To choose the best solution, firstly it’s important to consider your location and the orientation of your windows.
In most of Australia, shading is needed on windows on the north, and also the east (to prevent summer sun heating the house from early in the morning) and west (to block hot late afternoon sun). North of the Tropic of Capricorn, thought should also be given to shading windows on the south side of your house, as the sun’s steeply angled path in summer means these windows will also receive direct sun. Helpfully, the Geoscience Australia website (www.ga.gov.au) allows you to find your latitude and calculate the sun angle at any time of the day, on any day of the year.
Find the table of suppliers here.
Read the full article in ReNew 138.
Island of energy: community-owned and renewable
Denmark’s Samso Island went from complete reliance on imported oil and coal to 100% renewable electricity in just a decade. Jayitri Smiles and Nicky Ison explore the community and government partnerships that made it happen.
DURING the global oil crisis in 1973, Denmark began to think creatively about how to supply cheap energy to their population. As they built their first wind turbine, they were unknowingly establishing themselves as future world leaders in renewable energy.READ MORE »
Today, Denmark aims to have renewable energy powering 100% of their country by 2050 and to eliminate coal usage by 2030. These targets build on a track record of success: since the 1990s Denmark has witnessed the quadrupling of renewable energy consumption.
The creation of the world’s first fully renewable energy powered island, Samso, is an exemplar of Denmark’s leadership. Not only has Samso become a carbon-negative region, but it has accomplished this world-first using community investment.
In 1997, Denmark’s Minister for Environment Svend Auken was inspired at the Kyoto climate talks. He returned home with a passion to harness the collective efforts of local Danish communities in a way that promoted self-sufficiency in renewable energy. Auken held a competition, which encouraged Danish islands to consider how their clean energy potential could be achieved with government funding and matching local investment.
The most compelling application came from Samso, a small island west of Copenhagen with a population of 4100. This island of 22 villages, at the time run purely on imported oil and coal, was suddenly thrust into the global spotlight and, through a combination of local tenacity, investment and government funding, transitioned to 100% renewable power in just a decade.
At the heart of this energy revolution sit Samso’s community-owned wind turbines. Onshore turbines with a generation capacity of 11 MW offset 100% of the island’s electricity consumption. Another 23 MW of generation capacity from ten offshore turbines offsets Samso’s transport emissions. Most (75%) of the houses on the island use straw-burning boilers via district heating systems to heat water and homes, and the remainder use heat pumps and solar hot water systems.
The extraordinary result is a carbon-negative island and community. The island now has a carbon footprint of negative 12 tonnes per person per year, a reduction of 140% since the 1990s (compare this to Australia’s footprint of 16.3 tonnes per person in 2013 and Denmark’s overall footprint of 6.8). Not only is the island energy self-sufficient, they now export renewable energy to other regions of Denmark, which provides US $8 million in annual revenue to local investors.
And Samso is not slowing down. Highly motivated, knowledgeable and passionate locals are aiming for the island to be completely fossil-fuel free by 2030. They plan to convert their ferry to biogas and, despite already offsetting their vehicle emissions via renewable energy generation, residents of Samso now own the highest number of electric cars per capita in Denmark.
Read about their transition in ReNew 138.
Straight up: vertical garden design
The last thing you want is to spend a lot of money on a vertical garden system and then have it fail. Jenny and Bevan Bates provide advice and inspiration from their own living walls—five years old and growing strong!
THE inspiration to garden vertically is not new. The Hanging Gardens of Babylon, if they are more than legend, may have been an early precursor, built to bring luscious greenery to the ancient city’s terraced buildings. Your grandma’s hanging pots are a more down-to-earth example, as are vines on a trellis.READ MORE »
More recently, the idea of living walls has become a popular trend, in part in response to higher density living and homes with small gardens. For Jenny and Bevan Bates, their move to a new house with a small courtyard— and a stark black brick wall facing their living area windows—was the reason they started experimenting with gardening on a wall.
“You have to be prepared to experiment,” says Jenny. In fact, their first vertical garden was a failure. “We tried a $100 system, but the pots were too small and it dried out too quickly; it was hard to keep anything alive in it,” she says.
However, they persevered and they now have five vertical gardens providing cooling, colour and herbs, which adds interest to their home. The black brick wall in fact sets off one of the vertical gardens nicely—the colour they didn’t like turned out to be complementary to the planting!
That particular garden was their first success, says Jenny. It’s now five years old and thriving. It’s on a south-facing wall overlooked by the north-facing living area windows—a lovely sight.
They created the garden using Woolly Pockets, a product which at the time they needed to get delivered from the USA (though there are now retailers in Australia).
The pockets are composed of long troughs of recycled polyethylene (PET, from milk bottles for example). That recycled aspect was important to them; “You need to think about the full life cycle; for systems made from virgin plastic, there can be a lot to dispose of at end of life,” says Jenny.
Which plants they use has evolved over time; some plants grew bigger than expected, shaded other plants or didn’t like the position.
Read about their vertical garden in ReNew 138.
Reusing building materials in the garden
There are many uses for old building materials in the garden to create quirky but useful structures, with the added advantage that the materials don’t end up in landfill. Permaculture gardener and teacher Drew Barr shares his tips.
BricksREAD MORE »
Bricks are useful objects. Durable and cheap, their regular shape means they can be stacked or laid in patterns. Almost all bricks have the same dimensions, although older handmade bricks may be slightly smaller. The size and shape are designed for easy one-handed handling by an adult.
Bricks are energy-intensive to manufacture and transport, but will last hundreds of years, and can be used over and over again.
When reusing bricks, you’ll need to clean them to remove the mortar. This is dirty and laborious work and seems very slow to begin with, but once you have mastered the knack you will be surprised how fast you can clean bricks. The best tool for this is a scutch hammer, which has replaceable toothed blades called combs. Chip at the mortar where it meets the brick and it will come off in big chunks. Wear gloves and a face shield though as flying mortar chips really hurt.
Broken concrete slabs
Concrete is also a very energy-intensive material to manufacture, and similarly highly durable and strong, and ideal to reuse.
Concrete slabs, sometimes referred to as ‘urbanite’, can be reused to make crazy paving, or stacked without mortar to form low retaining walls. When sourcing slabs make sure you get only non-reinforced slabs such as from council footpaths or old driveways. Reinforcing steel in the concrete is very difficult to cut, and as it rusts it will swell up and split the slab.
Councils often replace footpaths and must dump the slabs of concrete they remove, and they will usually be happy to dump it at your place for free.
Read more on reusing old concrete slabs, clay pavers, roofing tiles, roofing iron, car panels, bathtubs and more in the full article in ReNew 138.
ATA member profile: Ripples in the community
Long-time ATA member Ali Campbell has no qualms about buying secondhand instead of new and looks at all purchases through a “green lens.” She talks to Jodie Lea Martire about how community is critical to sustainability.
ALI Campbell couldn’t bear to see her old piano go to waste, so it stands in the chook shed as a piece of art. It’s a good demonstration of her creative commitment to sustainability, which has led from high eco-living standards at home to diverse community involvement. As Ali says, being part of an active community “helps sustain you and recharges you for staying in the sustainability field.”READ MORE »
Bushwalking and camping gave Ali a connection with nature, but her real evolution towards environmental action came with her first child. She and husband Bruce had been “unwise, unwary consumers until that point”, but they realised that every other parent had also needed clothes, cots and change tables so they could use “secondhand everything.” From there, the Campbells took a good look at their “consumption and stuff.” They reduced purchases, packaging and waste, considered where their food and goods came from, and boosted their home chook-and-vegie garden.
The garden led to conversations about sustainability with others, and builder Duncan Hall put Ali and Bruce on to the ATA. Soon, the family was experimenting with solar stoves, and now “everything we do has that green lens.”
They have worked to reduce their home’s environmental impact, including greywater systems, water tanks, double-glazed windows, reorienting for better lighting and using Australian-made materials. Ali used ATA-sourced information to explain her decisions to both their builder and plumber during renovations, and emphasises that it’s crucial to hire workers who ‘get it’ and aren’t just greenwashing their work.
Ali says, “The community thing is critical. It goes without saying, but it needs to be said.” She spent six or so years volunteering as an organiser with Melbourne’s Sustainable Living Festival (SLF), and gardened with the Stephanie Alexander Kitchen Gardens in Altona Meadows for a time. She is also active on the Inner West Buy Swap Sell and Freecycle Facebook groups.
Ali participates in Transition Hobsons Bay (THB), and she and Virginia Millard run the Give Take Stand: an unstaffed booth where people share quality, unwanted items (like a free op shop). Ali says the autonomous setup has strengthened community involvement without forcing obligation or onus on anyone. It has been hosted in venues around Hobsons Bay and the council is providing funds to boost the work and establish the stand as a waterproof outdoor shed.
Another project Ali organises through SLF and the transitions group is Bunches of Lunches. Now in its third year, Ali and Transitions Hobsons Bay member Tarius McArthur run three-hour sessions which teach participants to cook five healthy, freezable dishes suitable for school lunches—and promote local food, low packaging and low energy use.
Ali and Bruce have also combined their home and community efforts by signing up their new seven-seater VW Caddy to Car Next Door, allowing locals to rent their vehicle. This let the Campbells balance their need for a second car every now and then, while knowing they’re “not just sitting on this asset.”
Reading ReNew gives Ali great ideas, a sense that she’s not alone in her activism, and—most importantly—hope. The magazine’s coverage of policy developments, news analysis and innovations provides “positivity and support, and that’s what keeps her doing this.”
To end with Ali’s own assessment of her environmental contribution: “I can feel frustrated because I’m not creating seismic change, but I hear frequently, most weeks, ‘You’d love this, Ali!’, so I know I’m having a ripple effect around me and I just hope that keeps rippling on and on.”
This member profile is published in ReNew 138. Buy your copy here.
ReNew 137 editorial: Solar and storage, at home and abroad
IT’S a challenging time for consumers sorting out what’s what in the rapidly evolving world of energy storage. New products are coming onto the market every other day, or at least being announced, so what’s true yesterday may not hold true tomorrow.READ MORE »
That being said, we at ReNew are never ones to shy away from a challenge. We aim to get behind the hype and help with the nitty gritty details you need to make a decision. So this issue we take a look at what you need to consider when going off-grid or installing a hybrid system with grid-connected storage. We look at the battery technologies on the market and the inverters that drive the way such systems are installed. Along with new and cheaper battery systems, inverters are evolving at such a rate that the traditional divisions between off-grid and grid-interactive are breaking down—with new hybrid inverters and control software providing many ways to optimise usage and storage of your solar energy.
Three out of four of our case studies combine off-grid or hybrid systems with an electric vehicle, an encouraging trend, which we also put under the spotlight in an EV market update. Our householders’ stories also show that one of the biggest wins from installing solar+storage is that it really focuses attention on how much energy you use, and when.
One of the owners in a mini-grid trial in Mooroolbark is a case in point: being given monitoring tools and energy efficiency information has already changed their behaviour, only a month or so after their system was installed. And they get to share their energy (and knowledge) with their neighbours. Small-scale energy sharing is a bit of a focus this issue too—just what are the benefits of the mini-grids and virtual power plants that are all over the news just now?
Given all the buzz about energy storage, it’s not surprising that course providers are tipping that’s where skills will be needed. Our renewable energy courses guide is a must-read if you’re considering a career in this area.
On another note, our reader challenges always bring home the engaged community that makes ReNew what it is. In our recent photo competition, we were overwhelmed by the responses, both in number and quality, illustrating the many ways that ReNew readers interact with that somewhat overused word ‘sustainability’: from carefully thought-through transport options to renewable energy systems to communities sharing skills, food and more. Unfortunately, we couldn’t include all the entries in the magazine, but we hope to bring you more in the future.
Two decades on, this issue also brings you the 79th Pears Report, an integral part of ReNew—people often note it’s the first thing they read each issue. For the many fans, we’ve now collected 75 columns into an eBook, with support from RMIT’s sustainability fund, and launching in October. Enjoy!
ATA CEO’s Report
WHEN I started at the ATA many years ago, one of the first people I was told to meet was Alan Pears. As many of you know, Alan has been a leading light in energy efficiency and climate change policy over many years.
Currently a Senior Industry Fellow at RMIT University, Alan has been an important contributor to the development of Australia’s sustainable energy and energy efficiency policies, programs and projects since the late 1970s, and a passionate climate response advocate since the late 80s.
His expertise is regularly called upon by governments and agencies, businesses, community organisations and the media; variously as consultant, mentor, award judge, advisor, reviewer and commentator. His achievements in this arena have been acknowledged with numerous industry awards and, in 2009, with his appointment as a Member of the Order of Australia.
We are very excited at the ATA to be launching The Pears Report eCollection: Reflections on Two Decades of Energy and Climate Policy in Australia—75 Articles from ReNew Magazine, 1997–2016 at the All Energy Expo in October. The collection brings together the detailed, accurate and thoughtful insights from The Pears Report columns in ReNew, along with a new and substantial series of articles by Alan discussing the major topics and themes.
Alan has been a great mentor and advisor to many of us, generous with providing his time and expertise especially to not-for-profit organisations like the ATA. We are proud to be able to acknowledge Alan’s invaluable contribution to energy market reform and a better Australia.
You can purchase ReNew 137 from the ATA webshop.
Tassie off-grid home
Given their distance from the nearest power pole, it made sense financially as well as philosophically for this Sydney couple to go off-grid in their new home in Tasmania. Peter Tuft describes how they went about it.
As we approached retirement my wife Robyn and I knew we did not want to spend the rest of our lives in Sydney. Sydney’s natural environment is glorious but it is also much too busy, too hot and humid in summer, and our house was too cold and hard to heat in winter. We had loved Tasmania since bushwalking there extensively in the 1970s and it has a lovely cool climate, so it was an obvious choice.READ MORE »
We narrowed the selection to somewhere within one hour‘s drive of Hobart, then on a reconnaissance trip narrowed it further to the Channel region to the south. It has lush forests and scattered pasture with the sheltered d’Entrecasteaux Channel on one side and tall hills behind—just beautiful. And we were extraordinarily lucky to quickly find an 80 hectare lot which had all those elements plus extensive views over the Channel and Bruny Island to the Tasman Peninsula. It was a fraction of the cost of a Sydney suburban lot.
The decision to buy was in 2008 but building did not start until 2014 so we had plenty of time to think about what and how to build. We have always been interested in sustainability, and renewable energy in particular, even before they became so obviously necessary: my engineering undergraduate thesis in 1975 was on a solar heater and Robyn worked for many years on wastewater treatment and stream water quality. There was never any doubt that we would make maximum use of renewable energy and alternative waste disposal methods.
From the beginning we knew the house would be of passive solar thermal design. The house sits high on a hill (for the views!) and faces north-east. The main living room is entirely glass-fronted, about 11m long and up to 4m high with wide eaves. That allows huge solar input to the floor of polished concrete. A slight downside is that there is potential for it to be too warm in summer, but we’ve managed that with shade blinds and ventilation and so far it has not been a problem. All walls, floor and roof are well insulated, even the garage door, and all windows are double-glazed. Supplementary heating is via a wood heater set in a massive stone fireplace chosen partly for thermal mass and partly because it just looks awesome. Warm air from above the wood heater convects via ducts to the bathroom immediately behind the chimney, making it very cosy indeed.
Read the full article in ReNew 137.
ReNew 136 editorial: Aussie, Aussie, Aussie! Homegrown design and tech
Cheering on Australian-made research and production in this issue has proved something of a conversation starter. Everyone has a favourite product or company, or an opinion on what we’re doing well or not so well. But the ‘we’ has stumped me at times: against a backdrop of stalled climate policy and the way the on-again, off-again support for renewables has affected the industry, it can be hard to speak proudly of that ‘we’.READ MORE »
Yet there is a story to be told of innovation (an overused word perhaps!) in Australia that is slightly different from the one we often hear. The stories of lost commercialisation opportunities and industry heading overseas are certainly one strand, but there’s also a (very ReNew) story of DIY activists getting a renewables industry started in Australia, of researchers leading the world in solar cell design—with the Australian-invented PERC cell now featuring on about half of new solar cell production lines—and of a fast-growing community energy sector taking on the unique challenges of the Australian energy market, making projects work, then advocating for change to make them work better. And, of course, of architects slowly, slowly bringing sustainability into the mainstream of building design. Sustainability is another overused word, but it’s been exciting finding these stories of research, investment, production and development.
It’s not all about energy or household systems. One of the best stories comes from Bruce Pascoe, based on the research for his book Dark Emu. The oldest grain grinding stone in the world has been found in Australia, evidence of breadmaking 12,000 years before the Egyptians. As Bruce asks, why don’t “our hearts fill with wonder and pride” in such innovation?
There’s much beyond our Australian-made theme. Building with strawbales is one, with guidance on the workshops that can help, and case studies on people who love their houses ‘built of straw’. We look at the important issue of keeping textiles out of landfill, and we also cover ways to reconnect with nature in the city. A reader tests whether battery-powered leaf blowers can compete with petrol ones (many may think that the job could be done with a broom, but the author suggests otherwise), and we look at what to consider to ensure you buy or build the most efficient computer possible. With gaming PCs using up to 350 watts just for the graphics card(s), it’s particularly important information for parents of young gamers!
Many households are about to lose their higher feed-in tariffs, so we (via the ATA, ReNew’s publisher) look at what solar customers should do. Finally, our buyers guide this issue is on eco-paints. It’s a good news story with many sustainable changes in the industry since our last buyers guide in ReNew 107, including a new scheme for recycling paints. It’s a packed issue, enjoy!
ATA CEO’s Report
THE Australian-made green innovations in this issue of ReNew are a great testament to home-grown ingenuity. The ATA has been fostering sustainable technology since 1980, when a group of enthusiasts concerned about fossil fuels and pollution came together to form our organisation. Their can-do, practical approach has been at the heart of the ATA ever since.
The ATA has had many Australian firsts including owning a community wind turbine at Breamlea in Victoria, national sustainability education tours with our energy-mobile and Australia’s first trial of greywater systems in response to growing interest in water saving during the millennium drought. We also led the way in making it easier for home solar systems to be connected to the grid by actively lobbying for consistent agreements and financial incentives. The now 1.5 million households in Australia with rooftop solar have benefitted from the ATA’s pioneering work.
And the innovations continue: we played a key role in the installation of a 36 kilowatt solar system at the Kurrawang Aboriginal Christian Community near Kalgoorlie in WA. The project showed how you can be creative with community energy and impact investment for community and environmental benefits. Thanks go to ATA member Robin Gardner, who was instrumental in the success of the project.
ATA members were also instrumental in developing and assembling the new Village Lighting Scheme solar system that will be installed this year on hundreds of homes in East Timor as part of the Google Impact Challenge grant. Special thanks to Alan Hutchinson and Patrick Eijsvogel for their huge effort on the new system design, and the many volunteers involved. In recognition of our work in East Timor, the ATA recently won a United Nations Association of Australia World Environment Day Award!
You can purchase ReNew 136 from the ATA webshop.
Still a clever country
Energy efficiency consultant Geoff Andrews admires Australian innovation, but, as has often been noted, finds the next step—commercialisation—is lacking. Collaboration, governments and risk-taking could all improve that, he suggests.
I view innovation as change for good, so change which improves sustainability clearly qualifies. Most readers of ReNew would agree that we have to improve the sustainability of our society, so we must innovate. But, how do we do that, and what lessons can we draw from Australia’s sustainability innovation performance to date?READ MORE »
There is no question that Australia has provided the world with more than its share of innovations, including in sustainability. In renewable energy alone, Australia has led the world in PV efficiency for decades, pioneered many improvements in solar water heaters, and is now developing wave energy. We’ve been first or early implementers of two flow battery technologies (vanadium redox by Maria Skyllas-Kazaco at UNSW in 1980 and zinc bromine by RedFlow). Scottish-born James Harrison built one of the first working refrigerators for making ice in Geelong in 1851 (before that, ice was imported from Canada),and we invented wave-piercing catamarans and the Pritchard steam car. We even had manned (unpowered) flight by heavier-thanair craft a decade before the Wright brothers with Lawrence Hargrave’s box-kite biplane.
Of course, Australian innovations are prevalent in many other sustainability areas including medicine, construction, agriculture and fisheries, but space is limited here. What we could have done a lot better is commercialising those innovations in Australia. Imagine if Australia led the world in the manufacture of solar panels, refrigerators, air conditioners, wi-fi devices and evacuated tube heat exchangers, the way we do with wave-piercing catamarans and bionic ears.
Improving commercialisation would provide funds to improve our budget bottomline and allow us to do even more innovation and more commercialisation. To achieve this, I think we need to do several things.
Read the full article in ReNew 136.
The world’s first baker
Why don’t we know about the oldest grinding stones in the world, found in Australia, or the crops cultivated by Aboriginal Australians? Bruce Pascoe is helping change that.
If you were asked who the world’s first bakers were, what would your answer be? Most would think first of ancient Egypt where it is believed bread was first baked around 17,000 BCE. And yet there is evidence to show that grindstones in Australia were used to turn seeds to flour 30,000 years ago. Archaeologists found the evidence for this at Cuddie Springs in New South Wales in the shape of an ancient grinding stone which had been used to reduce grass seeds to flour. These were the bakers of antiquity. It took Egypt 12,000 years to repeat this baking experiment. Why don’t our hearts fill with wonder and pride?READ MORE »
Australian sovereign nations cultivated domesticated plants, sewed clothes, engineered streams for aquacultural and agricultural purposes, and forged spiritual codes for the use of seed in trade, agricultural enterprises, marriage and ceremony.
This was and is an incredible human response to the difficulties of fostering economic, cultural and social policies. It may be unique in its longevity but also in its ability to flourish without resort to war. Australia’s reluctance to acknowledge what was lost can be witnessed in our ignorance of the birth of baking, the gold standard of economic achievement.
Why is this? Is it a malicious refusal to recognise the economic triumphs of the people from whom the land was taken or a simple culture of forgetting fostered by the bedazzlement of Australian resources and opportunities?
If we could rid ourselves of the myth of low Aboriginal achievement and nomadic habits, we might move toward a greater appreciation of our land. We might begin to wonder about the grains that explorer Thomas Mitchell saw being harvested in the 1830s, and the yam daisy monoculture he saw stretching to the horizon of his ‘Australia Felix’, the early name given to western Victoria. These crops must have been grown without pesticides and chemical fertilisers and in harmony with the climate; surely they are worthy of our investigation.
Read the full article in ReNew 136.
Less noise, no fumes – testing cordless leaf blowers
ReNew reader Colin Dedman puts the latest generation of lithium-ion cordless leaf blowers to the test and is blown away by how far they’ve come, though price and run time can be an issue.
Why would you buy a cordless leaf blower? Why would you buy a leaf blower at all? For the most sustainable living, shouldn’t we rake up all our leaves and debris by hand, and clean out our gutters by crawling around on the roof?READ MORE »
For those of us with rainwater tanks, cleaning the gutters frequently is a necessity rather than a luxury, to ensure that precious rainwater ends up in the tanks rather than spilling out of a blocked gutter. For many years I cleaned up the leaves by hand, while cursing the weekly scream of my neighbour’s two-stroke leaf blower. Then my aging back convinced me that if you can’t beat them, join them, so I purchased my own screaming $88 petrol blower, that does clean the gutters and patio well. But I hate using it on account of the noise, fumes, hard starting and mixing/storing of two-stroke fuel. There must be a better way.
Corded electric leaf blowers are quieter, always start first time and can potentially use renewable electricity, but the inconvenience of a long extension cord rules them out for me. What about the electric cordless blowers then—are they just ‘toys’ as many people think?
Here I blow away the myths, by subjecting a variety of cordless blowers to a series of standard tests so you can judge which blower, if any, is suitable for your needs. I’ve included two mid-range petrol blowers and a corded blower in the tests for comparison.
Measuring blower performance
Some manufacturers would have us believe that the all-important parameter is the air flow rate in cubic metres per hour, while others boast of their impressive discharge velocity in kilometres per hour or metres per second. In reality, both are important.
The most useful single parameter to measure a blower’s effectiveness is the blowing power in watts (W), being the power of the moving airstream, as this relates directly to the ability to shift stubborn debris and move a lot of leaves and debris in a short time. The blowing power is less than the input power, due to inefficiencies in the motor and fan.
Manufacturer published values of air flow and velocity have not been included, because they are sometimes incomplete or inconsistent. In one case the specifications printed on the box were different to in the user manual—both can’t be right! Other issues include quoting the peak rather than average velocity at the discharge nozzle, and quoting the higher flow rate without the nozzle attached. Therefore, to enable meaningful comparison of competing blowers, I’ve measured the air flow rate, velocity and blowing power according to ANSI Standard B175.2, using calibrated equipment, and tabulated this for all the blowers tested, providing a resource for comparison of blower performance.
To read the extended version of this article in its entirety, click here to download it in PDF format.
ReNew 135 editorial: Water inside and out
In Sophie Thomson’s Adelaide Hills garden, indigenous plants that survived under a ‘no watering’ scheme for several years have struggled this year, with some dying. In Victoria, we’re seeing reservoir levels dropping, street trees struggling and many gardeners dismayed over just how dry the soil is. It’s a similar story in many parts of Australia, with the tinder-dry bush causing devastating fires such as those in the Tassie wilderness.READ MORE »
If we don’t want to abandon our gardens, critical as they are in providing shelter, cooling and habitat, as well as food, what do we do? In this issue, we explore some of the approaches that can help gardens thrive with efficient and effective use of water.
Sophie Thomson issues a challenge to rethink our gardens into watering zones, with most of the garden given to ‘no water’ and ‘low water’ plants — think local indigenous planting and choosing plants appropriate to the site and conditions. But that doesn’t mean abandoning the higher water usage plants altogether, such as vegies; instead, we look at more efficient ways to water, including drip irrigation — potentially regulated according to temperature and rainfall — and wicking beds, where the water is delivered to the plant roots and wicks up to where it’s needed. We’ve previously covered rainwater and greywater use in detail (see ReNew 125 and 130) so this time we shift attention to using stormwater via rain gardens, a way to reduce polluted runoff into our rivers and water the vegies at the same time. We also visit Melliodora, the Australian permaculture co-founder’s property in Victoria, and find out how permaculture principles meld with water efficiency.
In the tropics and subtropics, the problem is slightly different — coping with deluges in summer and relatively dry winters. Two northern Australian gardening experts give advice on what to plant and ways to use water effectively in these regions.
It’s not all about gardens. We also look at where households can save water, inside and out, and compare water usage around Australia. Our mini guide is on waterless toilets, definitely worth considering as a water- and pollution-saving measure.
Our main buyers guide is on heating. We often get queries about hydronic heating, so we’ve updated our guide to include both reverse-cycle air conditioners and hydronic.
And amidst all the talk about batteries and going off-grid, we take a look at what’s available in all-in-one battery systems, and where the market is heading. We also examine the sustainability benefits of solar and solar + battery systems. If you’ve ever wondered just how much effect your solar system can have on the grid—can it really affect the output of a coal-fired power station?—this article is for you.
Plus there’s lots more: a DIY on double glazing, a mini hydronic system, reviews of 10 water-saving books, where wind farms are heading and the Pears Report on how different the approaches to energy policy can be.
As we head into a disturbingly hot start to autumn, an election year and post the Paris climate talks, we welcome your feedback and input. We hope this year we can see action on climate change rather than just words.
ATA CEO’s Report
The year 2015 ended with an historic agreement at the United Nations Climate Change Conference in Paris to limit global warming below 2°C. As a signatory to the agreement, Australia is now part of the push for a net zero emissions world.
At the ATA we are at the forefront of advocating for, encouraging and advising on sustainable technology and practices in Australian homes and communities to make a big impact on reducing carbon emissions. We are continuously researching and investigating new and emerging technology for a more sustainable future.
As an example of putting knowledge into action, we were very excited to team up with the Centre for Appropriate Technology (CAT) to install an off-grid solar system at the Oriners ranger base in far north Queensland. We have been admirers of CAT’s work installing solar systems in remote Indigenous communities for many years and have profiled some of their work in ReNew previously. After funding cuts to their Bushlight program, the ATA was more than happy to work with CAT to trial a project reducing the costs of installing a system, with ATA members volunteering skills and labour.
A big thankyou to David Tolliday, John Dickie, Olivia Laskowski and CAT’s Andre Grant for their work and dedication on a successful first project. We look forward to collaborating again in our goal for a net zero-emissions world.
You can purchase ReNew 135 from the ATA webshop.
Heating buyers guide 2016
Heating can be a large proportion of energy use in the home. Lance Turner looks at what efficient options are available, including hydronic and reverse-cycle air conditioners.
OUR previous heating buyers guide looked at heat pumps (commonly called reverse-cycle air conditioners) due to their high efficiency, low cost and simple installation. Later in this guide we take another look at reverse-cycle air conditioners and their advantages, and list the most efficient units currently available.READ MORE »
However, there is another form of heating that not only lets you choose a heat pump as the heat source, but other energy sources as well if they are more appropriate. That system is hydronics.
Hydronic systems consist of a heat source (commonly called the boiler) to heat water, and one or more pipe circuits which have the heated water flowing through them. Each circuit incorporates one or more radiators, which emit warmth into the room.
Most hydronic systems have multiple circuits, so you can heat all or only part of a home, allowing you to leave unused, closed- off rooms unheated to reduce energy use.
Water is circulated through the system using low-pressure pumps, and circuits are turned on/off by electrically operated valves, usually controlled by an electronic controller. The controller enables a system to be programmed to heat certain parts of a home at particular times—for example, heating the living areas during the evening and the bedrooms just before bedtime.
Hydronic systems are recognised to have a number of advantages over other forms of heating. The heat being either underfoot or close to it (through the use of skirting radiators or panel radiators mounted at floor level) means that you get the feeling of warmth with lower ambient room temperatures than with space heating. Also, there is generally very little air movement with hydronic heating, reducing the potential cooling effect of airflows produced by convective heating such as reverse-cycle air conditioners or ducted gas systems.
Read the full article in ReNew 135
Click here to download the full buyers guide tables in PDF format.
Double glazing on a budget
Double glazing can be very expensive, but with a bit of care and patience you can add double glazing to existing windows without breaking the bank. Alan Cotterill shows us how.
Built in 2002, my four-bedroom brick veneer house has stock standard powder-coated aluminium windows and doors. With my previous efforts to retrofit for energy savings and thermal comfort (see ‘Efficiency on a budget’ in ReNew 130), I had already fitted effective shading for my windows in the warmer weather. As I understand it, this is a prerequisite if double glazing is not going to be counterproductive in summer. But for winter, double-glazed windows insulate and thus hold in the heat much better than a single-glazed pane. Thus, I embarked on a project to retrofit my windows with a second (acrylic) pane.READ MORE »
For the additional panes, I used 3 mm cast acrylic sheet accurately cut to size commercially by The Plastics Factory. They cut 34 panels within a tolerance of 1 mm to my requested dimensions. Accurate measuring by myself was of paramount importance for this! Buying direct from a wholesaler meant a good saving; in fact, the cost was around half that of uncut sheets from local retail outlets.
I adhered the acrylic sheet to the aluminium surrounds of each panel of glass using highly flexible silicone sealant. The reasons for this choice were two-fold.
Firstly, the linear expansion rate from a change in temperature is significantly different between the acrylic sheet and the aluminium frame, with the acrylic expanding at three times the rate of the aluminium. With a 1200 mm edge and a temperature change from 0 to 40 °C, the acrylic would expand nearly 4 mm more than the aluminium frame. Flexibility of the sealant would cater for this to some extent.
Secondly, if a glass panel needs replacing down the track or a return to single glazing is desired, the silicone sealant could be scraped off (although still a tedious, fiddly job!)
Read the full article in ReNew 135.
A tropical take: smart cooling in the tropics
A Northern Territory program that works with low-income residents to reduce their energy bills and improve their comfort is starting to see results. Robyn Deed talks to one of the energy assessors about his approach and how the project is progressing.
ReNew first reported on COOLmob’s Smart Cooling in the Tropics project in December 2014, when the project was just starting. Since then, 480 households have had initial home visits and many have had upgrades applied to their homes.READ MORE »
Data is also being collected. This is the first large-scale project to identify and measure the best approaches to cooling, comfort and energy efficiency in tropical Australia. The outcomes will be used to inform national energy policy, and to influence building codes and rating systems to make them appropriate for the tropics.
The research findings will consider a range of factors including which treatments produced the biggest energy cost savings, which households achieved improvements in comfort levels, and which participants gained better awareness of energy consumption issues and opportunities.
While the evaluation phase is only just starting some early anecdotal observations are giving a flavour of the evidence to come, says Project Manager Jessica Steinborner: “The two primary issues identified through the home visits are heat gain and air flow.”
- Many homes have no or inadequate shading and a number have dark roofs.
- A high proportion of homes assessed have outside walls of high thermal mass.
By the end of the project, nearly a quarter of participating homes will have had a heat prevention solution such as shading or reflective roof paint.
“Shading has been a really popular treatment. In addition to preventing heat gain, shading creates a protected outdoor living space away from the hot concrete interiors of their homes,” says Jessica.
- Ventilation is often restricted either as a result of the orientation or because of the design, with windows and doors poorly located to capture a prevailing breeze.
- Many homes have fly screens in disrepair and consequently not in use, leading to houses being shut up with the air conditioner on.
Half of the households will have received a treatment addressing air flow including upgrades to their doors and windows to facilitate passive cooling and upgrades to their fans (ceiling, wall and floor).
Other observations and some surprises
- The majority of participants are home during the day and, despite reporting the highest discomfort in the afternoon, they were opting to not use the air conditioner until the evening.
- Average number of air conditioners was three and average temperature setting was 24 °C.
- On average, participants were using 26 kWh/day, the average usage for Darwin.
Until more data is available, it’s great to hear comments like this: “I have lived in Darwin for 15 years and this is the first time I’ve felt cool and comfortable during the wet season,” says Mieme, one of the participants.
Read the interview with one of the energy assessors in ReNew 134.
A focus on thermal efficiency
Energy efficiency is perhaps the most critical aspect of sustainable living, yet it’s oft-ignored and subject to changing government policies. Robyn Deed talks to Lyn Beinat from ecoMaster about the changes she’s seen in the energy efficiency industry and her top tips for householders.
Energy assessment business ecoMaster has seen many government policy introductions and exits over the 11 years they’ve been in business. They’ve had to constantly adapt. “Even changes to solar panel rebates and the RET have affected us, although we don’t deal with solar products,” says ecoMaster CEO Lyn Beinat. Government support is crucial to confidence. Lyn comments, “Perhaps people decide it’s all too hard or likely to be too costly when the government support isn’t there.”READ MORE »
The biggest shift in ecoMaster’s approach has been that they now look at the whole house right from the start. Lyn says, “It’s not that we want people to do everything all at once, but we’ve found that people are often focusing on just one aspect, like secondary glazing, when that may not be the most important thing to look at. The biggest problem is often draughts.”
Another change they didn’t expect at all has been a move into product development. Their research and work on their own home, and with clients, has led them in that direction. Maurice Beinat (Lyn’s husband and ecoMaster’s Chief Technical Officer) has done a lot of energy efficiency assessments (“more than anyone on the planet!” claims Lyn) and through that they identified problems that needed better solutions.
For example, for draughtproofing, Lyn says there are many products available, but it’s hard to find ones that are going to last: “many of the stick-on draught excluders will only last a year or so before they start peeling off, or they’ll cause problems for door closing,” notes Lyn.
Read the full article, including approximate costs for thermal efficiency changes, and Lyn’s top tips in ReNew 134.
On the rebound: countering the sceptics
Does energy efficiency lead to energy use that offsets some of the savings, via a ‘rebound effect’? It’s not that simple, says Alan Pears, and in fact, the opposite can happen.
MANY ‘energy efficiency sceptics’ argue that saving energy simply leads to increased energy use that offsets the savings. Some go as far as suggesting energy efficiency is a waste of time and a sham.READ MORE »
Indeed, there is a large body of literature that documents the existence of a ‘rebound effect’. But there is wide disagreement about how large it is—estimates range from a 10% to 70% reduction in net savings. Studies find that the extent of this rebound varies across sectors and activities.
On the other hand, other studies have shown that estimates of potential savings from energy efficiency policies have often been conservative, and costs have been over-estimated. For example, recent analysis of the effectiveness of Australia’s appliance efficiency programs, using improved field data and analytical methods, increased the estimated benefits by a factor of two (as measured by cost per tonne of avoided carbon).
The International Energy Agency has shown that, if the multiple benefits of business energy efficiency measures are considered, total savings can be up to 2.5 times the value of the actual energy saved. These benefits can include productivity improvement, health benefits, reductions in costs in infrastructure and more.
Like many issues, the rebound effect has an element of truth underpinning it. But, overall, it is not a game changer. Indeed, with the right policy settings and in many situations, investment in saving energy can amplify overall energy savings. This article aims to unravel the story.
What is rebound?
The term ‘rebound effect’ itself reflects a bias against valuing energy efficiency. It implies that some or all of the claimed savings from energy efficiency are inevitably taken back through increased energy use. This can certainly occur, but the opposite, amplification of savings, can also occur. The outcome depends on the policies, the behaviour of decision-makers, and the technical detail.
Broadly, the critical factors influencing the size and direction of the overall change in energy use due to energy efficiency improvement are how big the financial savings are, how they are spent, the overall impact of that spending as it flows through the economy, and technical system effects.
A more balanced term might be ‘flow-on effect’.
Consider an extreme example. If I use the money I save through energy saving actions to buy a block of energy-intensive aluminium, overall energy use may increase, as more energy will have been used to produce the aluminium than I am likely to have saved. But if I invest my savings in more energy saving actions, or to support the growth of an energy saving industry, I will amplify the energy savings.
In practice, the overall outcome is difficult to estimate: if the aluminium I buy is used to reduce the weight of a car, the fuel savings may exceed the lifetime energy ‘cost’ of the aluminium—if I believe the aluminium industry’s research! And, if the aluminium is eventually recycled, up to 90% of the energy ‘invested’ in its production will be recovered, reducing future energy consumption.
Read the full article in ReNew 134.
Energy out west: A second life in sustainability
How do you get into energy auditing as a career? And how do you run an audit? Alan Benn’s experiences provide insights helpful to those looking to get into the field, and those wanting to audit themselves, or friends and family—or even their local school! By Robyn Deed.
As a semi-retired electronics engineer with a keen interest in sustainability (perhaps a common ReNew reader profile!), Alan Benn’s move into energy assessment work allowed him to combine his technical skills with his sustainable self.READ MORE »
Based in Perth, Alan’s career change began with a six-month energy auditing course in 2010/11, via a federally funded Green Skills course run by the WA Council of Social Services. Starting with the two-week Home Sustainability Assessment course, it moved to auditing of workplaces in the not-for-profit community sector. As well as hands-on training doing assessments, he learnt technical info, across energy, water and buildings—”that’s where I first learnt about window U-values,” he says.
Although the course was excellent, of 75 trainees (most retraining to start a new career), only three or four are now working in the field. He notes: “Running a business like this can be hard, and there’s little work in energy assessments, particularly residential assessments.” Alan has been a volunteer with Perth-based community association Environment House for over 10 years and most of his paid auditing work is on their auditing contracts with local councils. Some programs are targeted at low-income residents, but most are open to any ratepayers. He’s done assessments from “little retirement units to mansions using 80 kWh/ day of electricity”.
An exercise in understanding
A big part of an assessment, he’s found, is explaining energy and water bills: helping the resident to understand their usage, what the units charged for mean, how usage changes over the seasons, and what’s a reasonable level of usage for gas, electricity and water, depending on the appliances installed.
“So few people know about energy costs,” Alan says. He often asks how much petrol costs, which most people know, and then he asks: how much do electricity, gas and water cost? A few know electricity costs, but he’s never had anyone know the cost of gas or water.
Read the full article in ReNew 134.
New choices in lighting: An LED buyers guide
The move to LED lighting has become mainstream, with more options appearing constantly. Lance Turner takes a look at what’s available.
For many homes, lighting is one of the most overlooked aspects. Incorrect lighting can make a room unpleasant to be in, or make it more difficult to perform tasks such as reading or cooking. Getting it right can take a bit of effort, and though this guide won’t answer all your questions about lighting design, hopefully it will give you a headstart when thinking about the types of lighting to use and the questions to ask.READ MORE »
With almost all lighting technology moving towards LEDs, this guide focuses on LED bulbs. Even the reasonably efficient technologies such as fluorescent tubes and compact fluorescent lamps are rapidly being replaced by LED lighting. It’s likely that within 10 years, most other light sources will have disappeared in favour of the robustness, longevity and energy efficiency of LEDs.
What is an LED?
LEDs (light emitting diodes) are unlike any other lighting system. They contain no glass tubes or heating filaments, instead using a small piece of semiconductor material (as used in computer chips) that emits light directly when a current is passed through it.
LEDs produce light in a range of colours, without the need for coloured filters; thus, to get white light, a phosphor is used over a blue or UV LED chip, similar to what’s used in a fluorescent tube.
Note that the LED is actually the small light producing element(s) in a light bulb or fitting, but most people now erroneously refer to LEDs as the entire bulb or fitting.
There are a number of specifications that are useful to consider when buying LED lights.
All light bulbs have a wattage rating, which measures how much power they consume. This is where LEDs have a shining advantage over older, more inefficient technologies. For domestic LED lights, the rating is usually between one and 20 watts, compared to a typical incandescent rating of 25 to 100 watts.
Light output: lumens, LUX and beam angle
Many LED bulbs include an ‘equivalent-to’ wattage rating, showing the wattage of the incandescent bulb that the LED bulb is equivalent to in terms of light output. For example, a six watt LED bulb might be rated as putting out the same amount of light as a 50 watt incandescent.
This ‘equivalent-to’ rating is based on the light output in lumens. The lumen rating of an LED bulb, usually included on the packaging, measures the total light output, relative to the response of the human eye.
For bulbs that are suitable for general room lighting—those with wide beam angles, above 60 degrees, but preferably 90 degrees or more—matching lumens for lumens should give you the result you need. Thus, for these types of lights (these are generally found in the common Edison screw, bayonet or ‘oyster’ fittings), the ‘equivalent-to’ rating should be all you need to determine if the bulb is a suitable replacement.
For directional lights, often known as spot lights, it’s a bit different. These are lights with a smaller beam angle, up to around 60 degrees. Such lights are generally used for task lighting, directed onto a desk or work area. Halogen downlights are an example of these—it’s because of their small beam angle that so many of them were needed to light a room! For these spot lights, small differences in the beam angle can make a big difference in how bright the light appears. Many people have had the experience of buying an LED bulb which was meant to be equivalent to a 50 watt halogen, but found that it appears much less bright. The lumens may have been lower, but more likely the beam angle was narrower, creating a bright light directly under the light but darker patches around it.
Read the full article in ReNew 133.