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ReNew 139

ReNew 139 editorial: Transporting ourselves – driving change at all levels

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IT’S probably fair to say that most of us who are committed to reducing our household greenhouse gas emissions have yet to completely address the area of transport. With transport emissions accounting for some 18% of Australia’s GHG emissions—6% due to urban car travel, according to BZE’s recent report—it is a sizeable problem that we need to consider.


Electric vehicles are part of the answer, with their emissions set to decrease even more as electricity grids get greener. But we also need coordinated public transport and town planning—who wants cities built to accommodate grid-locked cars rather than people? We asked several experts in the transport policy arena to give us their thoughts on where we’re heading transport-wise, and the responses range from a discussion of how our cities are driving a reduction in GHG emissions, to how driverless cars aren’t quite the answer, to a healthy upswing in e-bikes— the fastest growing segment of the transport market it seems.

When it comes to electric vehicles (EVs), there are promising lower-cost, longer-range developments from Tesla and GM, but it may be a while before we see them in Australia—our small market and lack of government incentives are really keeping us stuck in the past. Globally, though, there’s quite a bit of analysis to suggest that we’re on the brink of an electric vehicle revolution.

We look at where the EV market’s heading: which carmakers are leading the way, what’s changing in the world of charging and whether vehicle-to-grid is getting any traction. For EV owners or those thinking about buying one secondhand, we also take a look at EV maintenance and battery health.

We gain insights from several EV owners: one who’s maximising the use of solar PV to charge the car, another who’s got a home charging station on the publicly accessible PlugShare network, and another riding an e-bike into his 70s as a symbol of independence and community. They’re great stories that show ingenuity and a bit of (over)dedication to the cause—one EV owner describes a dash to the garage every time the sun came out or a cloud came over, to turn on/ off the charger, before he found an automated solution to maximise solar charging!

There’s much more, of course. We address a commonly asked question—what about using hydrogen fuel cells to power our vehicles? We also cover a solar + battery system overcoming barriers for apartment buildings, how to choose sustainable plants for your home garden, using thermal imaging to find leaks (so that you, like the article authors, can look forward to your next winter heating bill!) and much more besides.

Our buyers guide is on efficient hot water systems, potentially one of the biggest energy users in the home. We look at hot water heat pumps, solar hot water, PV diversion and instantaneous electric systems, and talk to a range of people with different systems to get some real-world feedback. We look forward to your thoughts!

Robyn Deed
ReNew Editor

ATA CEO’s Report

HERE at the ATA we are just getting our feet back on the ground after the inspirational Community Energy Congress. More than 500 people attended the two days of the congress in Melbourne, hearing international speakers, sharing Australian success stories and learning about the tools and resources available to community groups for their projects. There was time for groups to plan and network so that the congress was an opportunity to make connections and start putting projects into action. It even felt like there were partnerships and deals forming in the morning and afternoon tea breaks!

For me the highlight of the event was the formation of the First Nations Renewable Energy Alliance by the Aboriginal representatives at the congress. Fred Hooper, of the Murrawarri Nation, highlighted the massive change of direction: “This congress has opened our eyes.” The power of people to galvanise and make an immediate impact was clear. “What this congress has given us is a chance to get those people in one place and build something for us, in partnership with all of you in the audience today.”

Ghillar Michael Anderson, of the Euahylia Nation, said the group had already established a steering committee. “Taking ownership of energy security is a huge step forward for our First People. It is a big leap towards tackling poverty and disenchantment. The Alliance is the first step to changing the system.”

The ATA is proud to have helped bring the Australian and Canadian First Nation leaders to the congress and we look forward to working with the Alliance for climate justice.

Donna Luckman

You can purchase ReNew 139 from the ATA webshop.

Battery installation at Stucco

Battery bounty: saving students money

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This innovative project is demonstrating how a solar + battery project can work for both the student tenants and the managing co-op in a low-income apartment complex in Sydney. Robyn Deed talks to the project managers.

GETTING buy-in from all the apartment owners on a solar project in a new apartment building can be hard, but make that a solar + battery project for an existing heritage building used for low-income student housing, and an extra level of energy and commitment is required. But the residents and researchers behind the Stucco Co-operative Housing project in Sydney’s inner-west have achieved just that with a 30 kW solar + 42 kWh Enphase battery installation designed to reduce the 40 student residents’ energy bills and provide a roadmap for other such projects.


Why is solar so tricky for apartments? “The main issue is the ‘split incentive’,” says Bjorn Sturmberg, a former resident of Stucco and one of the project managers. If the apartment owner isn’t the tenant, there’s little incentive for them to pay to install solar when the savings will go to the tenant.

How to get solar onto more apartment buildings is an issue the City of Sydney is currently grappling with, so Stucco “hit the bullseye” says Bjorn, when they put in an application for funding to find an approach that would work for the complex of eight units—with the opportunity to research a significant battery storage installation also in their favour. The result was a grant of $80,000 matched with $50,000 from the Stucco co-op. For City of Sydney, the ‘return’ on their grant is a report on just what the barriers are and guidance on how to overcome them.

Read the full article in ReNew 139.

Greenhouse emissions data

Phasing out fossil fuels

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Professor Peter Newman contends that our cities are driving a change which is reducing greenhouse gas emissions from both coal and oil.

IN 2016 the International Energy Agency announced that the world had changed. For the first time in hundreds of years the world was producing less greenhouse gas (GHG) emissions than the year before without this being caused by an economic crisis1. In 2015 the amount of GHG emitted to the world’s atmosphere decreased by around 0.5% while economic growth continued at more than 3%. A few scientists had predicted this, but mostly the fossil fuel lobby had been in complete denial over its possibility2.


As Figure 1 shows, for the first time the industrial world was producing wealth without this meaning more fossil fuels and more emissions. Despite its huge implications for a world that has faced the global climate issue for decades without much good news, the world’s media were virtually silent.

China is now decoupling their economic growth from GHG very rapidly as shown in Figure 2. This provides great hope that the process will now spread to the whole emerging world. China invested $90 billion in renewables in 2015 (more than 60% of their investment in energy), so much of their continuing growth will be based around solar and wind rather than the fossil fuel-based economic growth of the past 15 years.

Read the full article in ReNew 139.

Waymo self-driving car

Who’s at the wheel: driverless cars

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Will driverless cars transform our cities for the better? Dr John Stone explores what’s driving the development of driverless cars and what they might mean for sustainable urban transport.

THERE IS a lot of talk about emerging transport technologies such as driverless cars. Much is being made of their potential to disrupt urban travel in ways we have not seen since Henry Ford’s black automobiles began rolling off his new assembly lines in 1913 and utterly transformed urban life. What futures— utopian or dystopian—might be unfolding in the boardrooms and laboratories of Google, Tesla and Volkswagen? What alternatives might the new technologies offer us?


An electric future is possible

Alternative propulsion for the standard car or truck is already available. With new battery storage or hydrogen fuel cells, we can begin to imagine a future where electric motors allow us to leave dwindling oil stocks in the ground and stabilise the global climate without disrupting our hyper-mobile urban lives.

I’ll leave to another time the debate on whether we really can generate sufficient extra renewable energy for this sort of transition, but powering well over a billion cars and trucks across the planet is no trivial task (see box). Analysts like Damon Honnery at Monash University say that motorised transport, if made sustainable, will be dramatically constrained whatever our power source.

But better policy is needed

In any case, there are many serious problems in our cities that mass transition to electric power won’t fix: electric vehicles don’t strengthen urban growth boundaries or reduce demand for parking that eats up valuable urban land, they don’t make driving safer, they don’t make the life of the city any more accessible to anyone with few options other than to live on the urban fringe, and they don’t provide the daily exercise that helps prevent heart disease and diabetes.

Read the full article in ReNew 139.

Automatic solar charging

Charging directions: EV owners tell all

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From a plug-in Prius conversion to an electric vehicle charged from the sun to an e-bike as a vehicle for change, EV owners describe how they’ve made an EV work for them.

From plug-in Prius to Leaf on PlugShare


Tim Johnston shares his electric vehicle experiences so far: converting a standard Generation 2 Toyota Prius hybrid into a plug-in hybrid electric vehicle (PHEV), becoming an owner of a 2011 Nissan Leaf in 2014 and registering their home as a charging station on PlugShare.

OUR family of two adults and two kids is very energy conscious and concerned about environmental issues. In 2009 we needed a second car and we wanted that choice to be as carbon-neutral as possible. We also wanted a car that was large enough to carry the kids comfortably, had the latest safety gear and cost less than $20,000.

We’ve always had an interest in electric vehicles; my brother-in-law has had one for a while so I’d seen that electric vehicles were a practical alternative. A test drive of a Nissan Leaf and Mitsubishi i-MiEV at an RACV event in 2009 further piqued my interest. However, a new EV was well beyond our budget, and options were limited at the time. As a compromise, in 2010 we purchased a secondhand 2006 Prius i-tech and so began our electric vehicle journey.

Converting a Prius to plug-in

The Prius is a hybrid vehicle that uses the efficiency of an electric motor/generator system to improve fuel economy. The 2006 Prius can be placed into full-electric mode (using an EV mode button on the dash), but the small high-voltage 1.3 kWh nickel-metal-hydride battery means it can only travel short distances in this mode. I researched ways to increase the battery size and settled on a 4 kWh plug-in hybrid electric vehicle (PHEV) conversion kit, produced by a company called Enginer.

The Enginer kit is a rechargeable battery pack that supplements the Prius OEM high-voltage battery. In Australia, the kit was rebranded by NilCO2 as K40 and was suitable for both the Gen 2 and Gen 3 Prius and came in 2, 4 and 6 kWh sizes. In 2011, we purchased the 4 kWh kit for approx $5000. We bought it mainly for environmental reasons and as a bit of a hobby, so we didn’t expect to recoup the cost on savings in petrol.


Towards a fossil fuel free EV: charging from the sun

Based in Canberra, Dave Southgate and his family are aiming to be a ‘fossil fuel free family’. Transport is a big challenge in that arena, but Dave found a smart way to maximise solar charging of their EV. Dave explains the system.

E-vehicle for change

Indigenous elder, actor and educator Uncle Jack Charles is a long-time e-bike rider. He spoke with Eva Matthews about the joys and value of this mode of transport.

Accommodating EVs in strata

How do you charge 15 Teslas in one apartment building that’s not wired for EVs? Resident Gordon Streight spoke with Eva Matthews about this interesting conundrum.

EV stories, two years on

With their stories first shared with us two years ago (‘Best EVer Stories’ in ReNew 131), Eva Matthews caught up with first-time EV owners Linda Hamilton and Ross Ulman to see how they’ve been getting on.

Charging regime and V2G

Consultant at Beyond Zero Emissions and energy expert, Richard Keech takes us through charging the Holden Volt and the potential for backup electricity to the home.


Read the full article in ReNew 139.

VelectriX Ascent Hardtail e-bike

Changing lanes: the emergence of e-bikes

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Worldwide, electric bikes are one of the fastest growing segments of the transport market. Dr Elliot Fishman breaks down the numbers and explains how e-bikes can make transport cleaner and greener.

TRANSPORT systems and behaviours are difficult to change. Although only constituting a fraction of vehicles, there are now many more e-bikes on our roads and bike paths than ever before. In recent years, regulations in Australia have been brought in line with those that exist in the EU, meaning Australian consumers are now afforded greater choice in the types of e-bikes available. The new legislation allows motors with a power output of 250 W and assistance cutting out at 25 km/h.


Electric bicycles (e-bikes) represent one of the fastest growing segments of the transport market. Commercially available e-bikes originated in Japan in the early 1980s1, but technological and cost factors limited market attractiveness until the early 2000s2. Improved battery and motor technology, component modularity and economies of scale have meant e-bikes can now travel longer distances and are more affordable than at any time in history. In the past decade more than 150 million e-bikes have been sold2, the largest and most rapid uptake of alternative powered vehicles in the history of motorisation.

China leads the world in e-bike sales, followed by the Netherlands and Germany. It is estimated that some 95% of the world’s e-bikes are in China, but these are almost entirely of the scooter variety, without functional pedals. The Dutch and German markets are dominated by pedelecs, in which engagement with the pedals is required for the electric motor to function.

Very little is known about Australian e-bike sales, as there are no official databases kept on imports or sales. While we do not know the number of units sold, we do know a little about the demographics of e-bike users (as least those willing to respond to university research projects). Researchers from Monash University found a disproportionately high concentration of respondents within the 41 to 60 age band and almost half earnt more than $100,000 per year, substantially higher than the population average. Almost all (94.4%) of respondents owned a car3.

Read the full article in ReNew 139.

Renault Master ZE

Market acceleration: electric vehicle update

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Around the world, the electric vehicle market has grown phenomenally in both sales figures and vehicle options since our last update barely six months ago— though not so much in Australia. Bryce Gaton outlines what to expect.

IN THIS article, I explore what to expect around the world and in Australia for electric vehicle (EV) and associated equipment releases and updates. I’ve also included some predictions on what we’ll see less of as some of the competing systems start to die away. Sadly, for most of the new releases around the world, I also give the automaker’s reasons for not yet bringing their EVs to Australia.


Cars and vans coming in 2017

Hailed as a game-changing lower-cost, high-range EV, the Chevrolet Bolt (an all-electric 5-seat/4-door hatch, with a real-world 350 km range on the US EPA test cycle and a pre-rebates US price equivalent to AU $48,000) is now rolling out to customers in California and six other US states, and will be available for order across all 50 US states by July this year.

Even international deliveries have commenced with the first Bolt delivery in Canada happening in January this year. It was also exhibited at the 2016 Paris motor show last September as the Opel Ampera-e, to go on sale in Europe sometime in 2017. Unfortunately, this first-generation Bolt will not be built in right-hand drive, so we will have to wait for the next generation Bolt before we might, possibly, see it in Australia.

Also at the 2016 Paris motor show, Renault announced a doubling of the range of its all-electric Zoe. Based on the Nissan Leaf and developed as part of the Renault–Nissan alliance, the Zoe was launched in 2013 with a real-world range of around 140 km. The Zoe has been the biggest selling EV in Europe since 2015, outselling its cousin the (now ageing) Leaf with its attractive styling and modern interior. With the doubling of the Zoe’s range to around 280 km, it should sell even more.

On our side of the world, the Zoe has even reached the shores of New Zealand. In August 2016 it was released there, but with an eye-watering driveaway price of around AU $71,500 (compared to AU $30,000 to $45,000 in England), I doubt they’ll sell many. Sadly for Australia, Renault still maintains they will not do much about selling EVs here until the government introduces incentives for them. Given the current Australian government’s approach to the auto industry, we are likely to be waiting a while.

On the topic of Renault, at the Brussels motor show in January this year, Renault made two major announcements. The first was an addition to their EV line-up with a 200 km (European test cycle, see box on EV ranges) battery range Master ZE. The Master is a 1.5 to 2 tonne van (a common-sized van used for local deliveries in Europe), so an EV Master makes a lot of sense there. The other announcement from Renault was an increase to the battery range of the smaller Kangoo ZE electric van to around 270 km (European test cycle). The Kangoo ZE is also listed as “will soon be available in Australia” on the Renault Australia website—as it has been now for well over a year.

Meanwhile Tesla (arguably the initiator of the other automakers’ recent rush to EVs!) has started deliveries of the Model X in Australia, with several seen on the roads here recently. And just around the corner is the production of the Model 3, slated to start production in July this year (and pre-production in February), with the first US deliveries planned for later in 2017.

Read the full article in ReNew 139.

Nissan Leaf battery

Keeping your EV battery healthy

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In the first of a series, Bryce Gaton looks at the core part of the EV, its battery pack, and how to give it the longest possible life. In later articles, he will explain the options for testing and monitoring the battery pack in your EV.

WE ARE all familiar with the ways to prolong the life of an internal combustion engine (ICE) vehicle—regular service, monitor the oil, etc—but EVs are a whole new ball game. What do they need to maintain them in tip-top working order? And how can we test them to know if things are going wrong?


While in general EVs need less maintenance than conventional cars, there are some considerations which will help keep the car performing well for longer and reduce maintenance costs. The battery pack is the component that is both the costliest to replace and the most within our control to keep healthy.

For example, for an ICE vehicle converted to battery electric, replacing the battery pack can cost from $110 to $300 per lithium cell with the battery pack size ranging from 30 to 100 cells—at a cost of $3300 to $33,000. For a Nissan Leaf, replacing the 24 kWh battery is around $6500 fitted (AU$ equivalent to US$ replacement cost—Leaf replacement batteries are not necessarily available here).

What is an EV battery pack made of?

All the pure EVs and hybrids on the market now use variations of a lithium ion chemistry. A common one is lithium iron phosphate, commonly written as LiFePO4. Lithium offers many advantages over previous battery technologies. In particular, it allows for much lighter batteries than lead-acid, which is what EV batteries used to be made from.

Lithium batteries can also be more deeply discharged, down to 20% capacity, giving more available energy to take you further; they hold a stable voltage through most of their discharge range (see graph); they can take high charge and discharge rates, allowing for hard acceleration and fast charging; and they are largely maintenance-free.

They should also have a long life, if looked after, with 70% to 80% capacity remaining in the battery after eight to ten years. And even after that, lithium EV battery packs are still usable in less demanding applications, such as home storage

Lithium cells have some features that need to be taken into account in the design of the car and charging systems. If they are overcharged or discharged (below 2.5V or above 4V), they will likely be destroyed (although LiFePO4 are more abuse resistant and may be recoverable). And, in some formulations, they can catch fire. This is particularly a problem for the super light, very energy dense ones in phones and the like: think Samsung Note 7. EV batteries are now made with formulations that are more resistant to starting or maintaining a fire.

To allow for these issues, modern EVs and hybrids include a battery management system (BMS). The BMS is a complex set of electronics that manages the charging of each cell, as well as controlling the current available to drive as the battery discharges.

Read the full article in ReNew 139.

Shanghai maglev train

The future of long-distance travel

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We regularly look at the future of shorter range personal transport options, but what about long-range and public transport options? Lance Turner takes a look at where long-distance and public travel is headed.

TRAVELLING locally is already becoming more environmentally friendly, with the introduction of electric cars and public transport running from renewables. But what about long-range transport: what’s happening there? There is a global push towards reducing emissions in long-range transport options, be they rail, air transport or shipping, but there are significant challenges. Let’s look at what’s happening around the world, and how we may be getting around in the not too distant future.



According to the European Environment Agency (, emissions from all passenger rail (with an average of 156 passengers per train) in Europe are around 14 g of CO2 per passenger kilometre. Compare that to a large car (four passengers) of 55 g, a regular bus (12.7 passengers) of 68 g and aircraft (88 passengers) of 285 g. These figures will vary depending on the type of trains, cars and buses, as well as the source of generation for the electricity used (Europe has lots of renewables and nuclear compared to other regions such as the USA and Australia), but the indicators are clear—we need fewer planes and more trains.


High speed rail (HSR), where trains run at speeds above 200 km/h (for existing lines, or 250 km/h for new lines) between major population centres without stopping, is common in countries such as China (which has some 22,000 km of HSR network) and Japan, and throughout much of Europe. However, Australia has never managed to get a high speed rail network off the ground, despite many concepts and plans being put forward. One problem here has been a lack of political will for such long-term projects. Another problem, specific to Australia, is the huge distances between cities and our smaller population. In short, the cost per taxpayer for a high speed rail network is much higher in Australia than in most other countries, making it a difficult sell (see

Central to the lower environmental cost in HSR systems is the use of electric trains. Being able to derive power from renewable energy sources rather than on-board diesel engines means that high speed rail becomes an even cleaner transport option as the percentage of renewables in the grid mix increases—just like any EV. Further, the cost of transport is no longer tied to that of fossil fuels so, as renewables become cheaper, the cost per kilometre travelled can fall.

The majority of high speed rail networks still use steel wheels on steel rails, but some of the fastest HSR projects use a more recent technology—maglev, or magnetic levitation, where strong magnets are used to lift the train just above the track, eliminating most sources of friction and allowing for higher speeds. Indeed, the fastest HSR train in regular service is the Shanghai Maglev Train, which runs on a 30.5 km track from Shanghai Pudong International Airport to the outskirts of central Pudong.

Read the full article in ReNew 139.

Hydrogen fuel cell powered train

Hydrogen as a fuel – is it viable?

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Is the hydrogen economy ever going to happen and are fuel cell vehicles really a viable alternative? Lance Turner cuts through the hype and takes a realistic look at using hydrogen for transport and energy storage.

ANYONE interested in renewable energy will have come across numerous articles on hydrogen fuel cells, and in particular, their use in cars and other transport as a potentially greener replacement for conventional internal combustion engine (ICE) drivetrains. However, to date there are very few fuel cell vehicles on the roads, apart from a few in demonstrator fleets, all subsidised by either the government or vehicle manufacturers.


So why haven’t we seen the fuel cell revolution as promised? There are a number of reasons, but let’s first look at the basics of fuel cells.


What is a hydrogen fuel cell vehicle?

In its simplest form a hydrogen fuel cell consists of two electrodes (an anode and a cathode) separated by an electrolyte. Hydrogen gas is introduced at the anode and oxygen from the air at the cathode. The two combine to produce electricity, heat and water.

In a fuel cell vehicle, hydrogen is stored in high-pressure tanks and delivered to the fuel cell at a reduced pressure, while air is passed through the fuel cell stack (the common term for a number of fuel cells in a single unit) courtesy of an electrically driven compressor system. By varying the rate of gas flow through the stack, the electrical output of the fuel cell system can be controlled.

The electricity then normally passes through a DC to DC converter to produce a voltage suitable for the vehicle’s drive motor and battery bank (or ultracapacitor bank).

The resulting electricity powers one or more electric motors, which propel the car— exactly like a battery-based electric vehicle.

As mentioned, fuel cell vehicles include a battery or large ultracapacitor for temporary energy storage. This is required as a fuel cell takes a small amount of time to respond to gas flow rate changes. In a vehicle this would be an unacceptable delay—imagine putting your foot down only to have the car do very little for a couple of seconds. The battery and/or ultracapacitor store a relatively small amount of energy but they can deliver it immediately as a large amount of power. They also provide extra power when the total demand exceeds that available from the fuel cell stack (which usually has a lower maximum power output than the motors are rated for) such as when overtaking and hill climbing.

Indeed, the main difference between a purely battery electric vehicle (EV) and a fuel cell vehicle (FCV) is that the FCV has a combination of fuel cell system and small battery rather than a single large traction battery—in most other respects they are quite similar.

To store a usable amount of hydrogen in a small space, such as required for a vehicle drive system, you need to compress it enormously. How much does it have to be compressed? To gain acceptable ranges comparable to a typical petrol car or current long range EV (400 km or more), the level of compression is many hundreds of times atmospheric pressure.

Both Honda with their Clarity FCV and Hyundai with their ix35 vehicle use a maximum tank pressure of 700 Bar, or around 700 times normal atmospheric pressure, 70 megapascals, or over 10,000 psi in the old of pressure per square centimetre of tank surface area. terms. In more common terms, that’s 700 kg

Read the full article in ReNew 139.

Hot water savings

Efficient hot water buyers guide

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If your old hot water system has seen better days, maybe it’s time for an efficient replacement. We show you how solar and heat pump hot water systems work, what’s available and how to choose one to best suit your needs.

ONE of the biggest energy users in any home is water heating—it can account for around 21% of total energy use (on average, according to YourHome), at a considerable financial cost each year. Water-efficient appliances are one way you can reduce energy use—for example, you could replace an inefficient showerhead (e.g. some use 20 litres per minute) with the most efficient, which uses less than 5 litres per minute, saving water and water heating energy each time you shower. But far greater energy reductions are possible if you replace a conventional water heater with a heat pump, solar thermal or solar electric system.


Such systems have the added advantage of reducing your greenhouse gas emissions. For example, for an average family the reduction can be as much as four tonnes of CO2 per year—the equivalent of taking a car off the road!


What we do and don’t cover

From an efficiency and environmental point of view the future of household energy is electric. The rise of rooftop solar and the availability of GreenPower means that households can use 100% renewable energy to run their appliances, including hot water systems.

This means we don’t cover efficient gas hot water options such as gas instantaneous in this guide, although the solar thermal hot water systems listed do have gas boost options. Gas used to be seen as the cleaner energy choice, at least when compared with burning coal, but there are better non-gas appliances available to households now. And changes in the gas market mean gas prices are on the rise. Replacing a hot water system with a modern solar thermal or electric one is often the first step in disconnecting from the gas grid, and the associated costs and greenhouse gas emissions.

We cover systems designed for household hot water that can run from renewable energy, including electricity, and ambient and solar thermal heat. These include heat pump, solar thermal, electric instantaneous and the newer kids on the block, PV diversion and direct PV water heating systems. Heat pump systems can be designed for other purposes in the home such as pool heating or hydronic heating, but these are out of the scope of this guide.


Read the full article in ReNew 139.

Download the full tables from the guide here.

See an energy use comparison between heat pump water heaters and resistive element water heaters here.

Read a list of questions to ask your hot water system installer before giving them the job here.

Water heating ways

Getting into hot water

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Five reader stories and five different systems that illustrate there’s more than one way to get into hot water!

A tale of two solar hot water systems


Jen Gow has tried out both flat plate and evacuated tube solar hot water systems, and discusses the differences.


Don’t dismiss resistive element hot water

For Dave Southgate, converting to an all-electric house did not involve using a heat pump for hot water. Here’s what he did instead.


How to save money with a hot water heat pump

Jonathan Prendergast shares his quest to reduce his hot water bills by switching to a heat pump.


Troubleshooting issues with solar hot water

Ewan Regazzo’s electrical engineering background was put to good use troubleshooting a faulty solar hot water installation. It’s now working well, but there were several issues along the way.


Resistive versus gas

Linda and Mike Dahm were surprised when the energy costs for their dual occupancy homes, one with solar PV and an electric resistive hot water and one with gas hot water, worked out about the same. Here’s what happened.

Read the full article in ReNew 139.

Thermal imaging camera

Energy detectives

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Knowing that double glazing can be compromised by incorrectly sealed window frames, Jean and Barry Lambert used affordable thermal imaging technology to check and rectify the installation—and find other sources of house heat losses.

LIVING in Canberra’s cold climate you need to think carefully about heat loss. We’ve done work on our house to improve its insulation, glazing and heating system efficiency. But that doesn’t necessarily translate to the best possible thermal performance if there are gaps or weak spots in the insulation—and that’s where we found a thermal imaging camera came in handy.


Some background on our house

Located in an inner suburb of Canberra, our four-bedroom brick house was built in the 1970s. The major axis runs north–south, with the living area to the west (giving views to the Brindabella mountains) and the bedrooms facing east.

Canberra of course has quite a wide temperature range (it’s in climate zone 7). Outside temperatures on winter mornings can fall below zero, while summers are usually dry and warm.

Canberra’s cold winters dictate that insulation is a priority to reduce heat loss. We insulated the walls with R3 rockwool and we topped up the existing ceiling insulation to an R5 rating. We replaced the original oil heating with ducted gas, and added deflectors on the floor vents to direct hot air away from windows. By varying the airflow rate using the outlet dampers in the floor vents, around a 50 °C outlet temperature is maintained, giving a comfortable 18 °C to 20 °C temperature inside the house.

Read the full article in ReNew 139.

Bringing nature back

Sub-tropical build – Bringing nature back

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Richard Proudfoot and his partner have brought nature in to their suburban block, at the same time as reducing energy and water use. He describes their house and garden build, and the satisfying birdsong-filled results.

IN 2008 we sold our small cottage in inner-city Balmain, in Sydney, and moved to Bribie Island, just off the Queensland coast between Brisbane and the Sunshine Coast.


Why a life on Bribie Island? My partner Fiona was born and raised near Royal National Park, just south of Sydney. I was born and raised in the Australian outback. We both appreciate the bush and as we neared retirement, we looked for a simple, sustainable life in a leafy setting. While we loved the inner Sydney vibe, it could never be called simple, and true sustainability was always going to be difficult to achieve.

Bribie also has arguably Australia’s best climate. In summer, the temperature rarely exceeds 29 °C, while in winter the temperature range is 15 °C to 25 °C, and annual rainfall is 1.2 metres. It is a great environment to use passive solar design techniques to build a sustainable, more self-sufficient house.

We bought an ordinary suburban (650 m2) block (of sand!), 200 metres from the beach, bordered by neighbours on three sides. Much of the time, a cool sea breeze from the Coral Sea blows across our block. The block runs east-west and has many mature trees on the back boundary.


So what kind of house to build?

Working closely with the builder, we came up with a design based on their classic Queenslander kit home. The house is elevated to catch the sea breeze and there is always cool air flow under the floor. It has verandahs on all four sides. It has high ceilings with a fan in every room, essential for sub-tropical days and nights. Most of the windows are north facing. There is very little glazing on the south and west sides, to provide maximum protection from the many storms which come in from the south-west. Every room opens onto a verandah, including the bathroom.

We wondered about building on sand, but our builder allayed our concerns. He used about one metre (depth) of concrete per footing. He couldn’t go much deeper because the water table starts about two metres below the surface. To date we have not observed any cracks in the walls, so our initial concerns appear to have been unwarranted.

Read the full article in ReNew 139.

Plants for home garden

Selecting sustainable plants for the home garden

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Indigenous, non-indigenous native, or exotic: which plants will grow best in your home garden and which are the most sustainable? Well, it depends whether you’re considering bushland threats, water usage or other factors, says Warren Worboys from the Australia Garden.

ONE OF the roles of the Australia Garden in Cranbourne, Victoria, is to research and promote the growing of Australian native plants in home gardens as well as in public gardens and parklands. The strict selection process we follow in selecting plants for the Australia Garden may help if you’re trying to find the most sustainable plants to use in your own garden at home.


The gardens include a diverse range of natives to cater for the equally diverse tastes and needs of home gardeners. But the selection process is not just a matter of going to the local nursery and buying plants with the prettiest flowers.

Bushland threats

One of the biggest issues for the Australia Garden is the threat to adjacent bushland if plants escape and become weeds or hybridise with the indigenous flora. This is something to consider for home gardens as well.

At the gardens, we’ve established a database which records all Australian plants which have become weedy (anywhere) and all plant species which have shown capacity to hybridise with any plant species indigenous to our site. A new plant species being introduced to the Australia Garden is compared with this list and if there are any known threats which cannot be managed then the plant species is rejected for use in the gardens.

Read the full article in ReNew 139.

The Pears Report

The Pears Report – don’t mention the war

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Tony’s war on renewables may be ongoing, but what has been the effect? It’s not such an easy war to win, writes Alan Pears.

TONY Abbott did his best to kill off renewable energy when he was PM—and he’s still trying it seems. But it is interesting to look back at the consequences of his efforts. The war on renewables was meant to reduce electricity prices. But it has done the opposite—and a lot more.


The big negative for renewables has been that the uncertainty created by the war led to a collapse in investment in large renewable energy projects. And the compromise 2020 large-scale renewable energy target (LRET), reduced from 41,000 GWh to 33,000 GWh, is now driving much less renewable energy development.

However, even the reduced LRET still means a lot of renewable generation capacity has to be built fast, from a near standing start, to generate 55% more renewable electricity than was produced in 2016, by 2020.

A report for the Clean Energy Regulator ( estimates an additional 6000 MW of generation capacity will be needed to meet the reduced 2020 target—a doubling of the renewable generation capacity installed since 2001. This has driven up the price of large-scale generation certificates (LGCs) from a long-term price of $30–$40 to $80–$90 (see box).

So it is now very profitable to build new renewable generation capacity under the LRET, and we are seeing a boom. Of course, Mr Abbott can now complain about the high price of renewables—that he caused by frightening investors which, in turn, has led to a shortage of new renewable capacity and LGCs. As in all markets, a shortage has driven up prices.

But Australian media have noticed that renewable energy prices for new generation everywhere else, and in bids for ACT government auctions (which are outside and additional to the LRET), are falling. Without the LRET uncertainty, LGC prices should have been stable or even falling as more new, cheaper generation was built.

Read the full article in ReNew 139.

ATA member

ATA member profile: Ten years in a (non-)leaky boat

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Get the building envelope as good as you can before focusing on the bling, says long-term ATA member Dr Wendy Miller. She talks to the ATA’s Richard Finn about what she’s gained at home and at work in her two decades in the sustainability arena.

DR WENDY Miller and her husband Ray have been part of the ATA family since 1997 when a renewable energy subject at the local TAFE made them keenly aware that what they were doing now impacted on their children’s future. As a family of five, they decided to try to get their all-electric house’s stationary energy consumption down to one kilowatt-hour (kWh) per person per day. This meant renovating their hot 1970s house as finances allowed: installing ceiling insulation, changing roof colour, adding external window shading, purchasing energy-efficient appliances when replacements were needed and installing solar hot water and solar PV.


Over time (about eight years) this resulted in a reduction in electricity consumption from 22 kWh per day to 5.7 (with four adults): about 1.4 kWh per person per day. For a short time their solar PV system (installed in 2000) was even an officially registered power station on Australia’s energy network! Wendy remembers: “That was an interesting time at the start of the rooftop solar revolution. I remember, perhaps not so fondly, the robust discussions with government and the network to get ‘permission’ for our system to be connected. But it did lead, a number of years later, to being invited to Queensland’s feed-in tariff discussions as a consumer advocate.”

In 2008, as ‘empty nesters’, Ray and Wendy took advantage of a move to the Gold Coast to take their sustainability drive to the next level and construct their 9 Star ‘eBay House’— so called because much of the construction and fitout (including the kitchen sink!) was purchased secondhand.

Wendy talks proudly of the rainwater collection, water and waste recycling system, the rooftop solar system and revegetation of the once bare block to not only produce food, but to support indigenous native plants and encourage bird, marsupial and reptile life. Energy-wise their total daily consumption is about 4 kWh per day—and all of that is well and truly met with their 1.7 kW PV system. “I’m really pleasantly surprised at how the price of solar has decreased: in 2000, a 1.5 kW system cost in the vicinity of $16,000. Now you can buy a system three times as big for a quarter of the price!”

However, she is quick to state: “The more you do, the more you realise what needs to be done.” In terms of the built environment she says that we need to think differently, and question just why Australia has settled on the standard “two adults, two kids, granite benches and air conditioning” type house. “I’ve got nothing against granite benchtops,” Wendy says, “but ideally we should focus first on getting the building envelope as good as we can, rather than focusing on bling and gadgets. If your house is designed and constructed well, it (like a boat) should not be leaky. Like a bilge pump, the air conditioner should be considered a ‘safety mechanism’ for extreme events, not an everyday item to make up for poor quality design and construction.”

Her career as a senior research fellow in energy efficiency and housing at the Queensland University of Technology has meant exposure to the world. In Europe, she’s seen new approaches to designing housing for non-traditional groupings, such as communities of single people all buying together, or collectives of families leading their own residential development. In the USA there is the Tiny House Movement.

Wendy believes the ATA and its publications provide essential services. Apart from the chance to share an idea or ask a question, the ATA is a voice for the people, a chance to be heard at governmental level, she says. Wendy was a long-time Brisbane branch member and convenor, before shifting down the coast.

As the weather heats up, and other houses’ ‘bilge pumps’ get switched on, in eBay House Wendy and Ray are walking the talk, now sailing their ‘boat’ into their grandchildren’s future.

This member profile is published in Renew 139. Buy your copy here.