In ‘Electric vehicles’ Category
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.
Electric vehicles: the market in Australia and overseas
Bryce Gaton reports on the evolution of government support and global carmakers’ production plans, which together are driving uptake of electric vehicles.
This year has seen a plane fuelled only by the sun travel around the world, a plethora of home electric storage systems come on the market, Australian households with solar PV systems pass the 1.5 million mark and a Tesla Model S travel from Sydney to Broome. Given 2016 is just past halfway through, what else is to come? Is 2016 to become the year that the hoped-for seismic shift in sustainable transport, energy sourcing and use truly begins?READ MORE »
The power to change things is more in our hands than ever before and I will offer examples from around the world that hopefully we can look back on in 20 to 30 years time to say, “We really did start the sustainable transition then!”
Electric cars around the world
Right now, pure EVs with a 300+km range—the ‘Bolt’—are rolling off the Chevrolet production line to arrive in US showrooms in the last quarter of this year.
Similarly, Mercedes, Volvo, Renault, Nissan, BMW, Kia and many other Chinese makers already offer pure EVs in their lineups, and most of these have announced plans to match the 300+km range of the Bolt and Tesla Model 3. Mercedes is releasing plug-in hybrids (PHEVs) and even Jaguar is rumoured to be well down the track in developing an electric sedan and SUV to match the belatedly perceived threat to their core market from Tesla’s Models S and X.
And VW, as part of its mea culpa for the dieselgate emissions scandal, has recently announced plans to heavily move into electric vehicle design and production.
Overall, the trend towards less polluting vehicles continues, with global uptake of EVs and PHEVs climbing at an increasing rate, growing from 45,000 EVs sold in 2011 to more than 300,000 in 2014 (see Figure 1). EVs represent more than 1% of total new car sales in the Netherlands, Norway, Sweden and the USA (closer to 20% for Norway). And in China, 2014 saw 230 million e-bikes, 83,000 electric cars and 36,500 e-buses hit the road.
Read the full article in ReNew 137.
Off-grid wind and solar
It’s a windy place near Canberra, and Chris Kelman is taking good advantage of that! He describes the evolution of his impressive off-grid wind and solar system — and the avid meter-watching that goes with it.
In a quest to demonstrate the possibility of living a fossil-fuel-free life, I have now made a couple of attempts at setting up my house to run on ‘home-grown’ energy.READ MORE »
My first project, back in 1987, used home-made solar hot water panels, a ‘massive’ 90 watts of PV plus a 1 kW Dunlite wind generator (pictured on the cover of Soft Technology 32–33, October 1989; Soft Technology was the original name of ReNew). At this stage, renewable energy technology was in its infancy and everything was DIY, including building an 18 m tripod tower for the turbine (overcoming a fear of heights was a personal fringe benefit). On this basic system I did manage to run lights, computer, TV and stereo, but there were thin times, of course.
These days, home energy systems are more like Lego — you just plug and play. So with a move back to the bush near Canberra a few years ago, I decided to do it all again, but this time with sufficient capacity to run a standard 230 V AC all-electric house, workshop, water pumps—and an electric vehicle.
The house I purchased had been set up pretty well as a passive-solar home, though it was connected to the grid at the time. It has a north-facing aspect, good insulation and a lot of (double-glazed) windows allowing winter sun to maintain a cosy slate floor. The result is a very stable environment for most of the year.
Energy production—phase 1
In phase one of my new project,in 2012, I installed 3 kW of PV with a Sunny Island off-grid inverter and 40 kWh of VRLA (valve-regulated lead-acid) batteries. Initially, hedging my bets, I configured it as a grid-connected system, with the grid acting as a backup ‘generator’ when required.
After a few months I realised that I rarely needed to use the grid and, as I owned a small antiquated petrol generator from my previous project, I decided it was time to cut the umbilical cord. This turned out to be a rather amusing process. My local energy provider didn’t seem to have an appropriate form for ‘removal of service’ and was bemused about why I would ask them to take the meters away. It was all a bit much for them. Even after the process was completed, I would still occasionally discover lost-looking meter readers around the back of the house!
The weather in this region is well known for its reliable solar insolation, apart from some lean months in mid-winter. Fortunately we are well supplied with wind power as well, as indicated by the Capital wind farm only a few kilometres away.
To confirm the wind resource, I set up a Davis weather station on a 12 m mast at my proposed turbine site and undertook a six-month wind survey. The results from this were compared with historical records from the area and a good correlation was found. This was enough evidence to convince me that wind power backup, particularly to cover the lean winter months, was the best option for my system.
Read the full article about Chris’s impressive off-grid setup in ReNew 134.
Who needs fossil fuels? Tricks and traps of solar car design
In part 3 of our series on the SolarX car design, Swinburne University’s Clint Steele talks to product design engineer Davis Tolley about the challenges and the refinements made so far.READ MORE »
Over the past months, much work has gone into refining the body of the SolarX sports car. In fact, it could be argued that it has been much more than refining. Some dead ends have been encountered and the car now looks very different to what we showed you in previous issues.
So, in this third instalment, we talk with one of the engineers involved in the car’s design. Davis Tolley is a product design engineer, a discipline that combines mechanical engineering with industrial design. Such engineers, with an ability to make products that perform and look good, are ideal for this challenging task.
Davis has been on the team for over a year now and has proven his ability when it comes to designing highly refined engineering systems that still need to capture hearts and minds. I asked Davis about the challenges faced and what he can share with other EV enthusiasts interested in solar.
To read the full article in PDF format, click here.
Top five questions when buying an EV
Kirsten Tanner spoke to Chris Jones from the Australian Electric Vehicle Association for the Ultimate Guide to Buying an Electric Vehicle. Here are her top five things to consider when buying an EV.
Electric cars, motorcycles and scooters are here to stay. Over the next 10 years, Australia’s vehicle fleet will get cleaner and quieter, as plug-in vehicles displace the incumbent internal combustion engine. Once considered a quirky novelty, electric mobility is now a genuine option for motorists. In the last year, the number of plug-in vehicles on the road has literally doubled, and more new models are being released this year.
How do electric cars work?READ MORE »
Electric vehicles (EVs) are cars or motorcycles which use an electric motor and a sizable battery pack to store energy. Pure EVs use only batteries, while plug-in hybrid EVs, or PHEVs, use a small petrol engine to extend the cars range. Most modestly-sized EVs have a 16 to 24kWh battery, while a full sized electric sedan like the Tesla Model S has a 60 or 85kWh battery. The bigger the battery, the further you can drive, but the more expensive it is.
Perhaps the best thing about EVs is their maintenance schedule – check the brakes once a year and rotate the tyres every 20,000 km. That’s about it! With just one moving part – the rotor – electric vehicles are particularly-simple and very robust. PHEVs have a more extensive and expensive service schedule as the onboard petrol engine needs oil and air filter changes.
How do you charge them?
Production electric cars typically come with two charging options – slow and fast. The slow charge option is the most commonly used, as you will no doubt plug in at work or at home. This takes a standard 240 volt AC, 15 amp supply and the vehicle’s on-board charger charges the battery. The rate of charge will depend on the on-board charger – 2.5kW to 7kW is typical. So at 2.5kW, a Nissan Leaf will be fully charged overnight. The fast charge option involves a publicly accessible ‘fast charger’ or ‘Supercharger’ which provides power directly to the battery. Fast chargers may put out anywhere from 25kW to 135kW, and can charge a depleted battery in under 30 minutes. Expect to see more of these around the country, typically located in towns so you can enjoy a coffee break. Converted electric cars typically come with a simple 15 amp plug, however there are now several automotive standard kits out there which allow you to use public charge points.
How far can I drive?
Depending on how you drive and what the conditions are like, your range will vary quite a bit. Long mountain climbs, sustained high speeds, strong headwinds, three passengers and luggage – all of these situations will see a reduction in economy and therefore range (exactly the same as in petrol vehicles). But the upshot is long descents and tailwinds will vastly improve your range. A full charge on a brand new Nissan Leaf will give you about 150km around town and about 110km on the highway. A Tesla Model S with the 85kWh battery can offer an astounding 470km around town, and 300km on the highway, but you will pay for it up front.
The ‘fuel’ economy of a battery electric car is typically quoted in watt-hours per kilometre, or Wh/km. Expect an average of 135Wh/km for a compact EV like the Mitsubishi i-MiEV or Nissan Leaf, and about 185Wh/km for the Tesla Model S. PHEVs will have a modest electric-only range of between 50 and 100km, before the petrol engine kicks in. Due to the added weight and complexity, the electric-only range of a PHEV will generally be worse than a pure EV, but still plenty for most daily needs.
Are they more expensive than a petrol car?
Most automakers are not currently tooled up to manufacture large numbers of electric cars, so the low production runs are more expensive. Also, most automakers rely on finance arrangements and regular service schedules for revenue. With a substantially reduced maintenance regime, you can expect a higher upfront cost. A new Nissan Leaf is about $39,000, and a new Tesla Model S (P85) is about $150,000. But bear in mind you will be driving around at less than 3 cents per kilometre, while a similarly sized petrol car might cost you about 12 or 14 cents per kilometre. If you drive an average of 14,000 km a year for six years, you will have spent as much overall on your electric car as if you’d been driving on petrol. You’ll also break even sooner if you charge off-peak or charge from roof-top solar.
What about converting cars to electric?
Up until very recently, if you wanted an electric car or motorbike, you had to build it yourself. The technical challenge of removing the petrol engine and replacing it with a motor, controller and battery has kept many backyard workshops lit up at night. It’s also a great way of preserving an old or unique car for which replacement parts are hard to find. However it will be difficult to come up with a vehicle as refined as a production model, and certainly not at the same price point. It’s always best to start with a quality donor vehicle you are comfortable with, as it will only ever be this good. Get in touch with your local Australian Electric Vehicle Association (AEVA) branch for more advice on the conversion process, or head along to a branch meeting of the Alternative Technology Association EV groups. The Geelong EV Branch and Melbourne EV Branch meet regularly to discuss EV ownership and conversions.
Find out more about electric vehicles in ReNew 131, the Electric Vehicle Special, or search the ReNew archives for electric car conversion articles.
A tale of two EVs: Blade and Holden Volt
Nearly seven years ago Richard Keech got his first EV. Recently he got his second. This is his experience and reflections on electric cars generally.
EV number 1: Blade Electron
Back in 2007 I became convinced that this society of ours quickly needed to cease using fossil fuels and that electric cars were a necessary part of that change. At the time there were no commercial EVs available in Australia. In late 2007 an audacious start-up called Blade Electric Vehicles set up in Castlemaine, Victoria, and demonstrated a converted Hyundai Getz EV. I had a test drive and was immediately impressed. They called it, initially, the Blade Runner but subsequently changed the name to the Electron.READ MORE »
EV conversions have been around for years. But the Electron wasn’t a custom conversion. Instead it was a standard-order short-run factory conversion. By my reckoning this made it the first commercially available electric car in Australia. Mine was one of the first batch built, what would become known as the Electron Mark 1.
Hopefully, in time, the Blade Electron will achieve the recognition it deserves in Australian motoring history for courageously introducing a commercially available all-electric car alternative well before the major manufacturers. Blade is no longer a going concern but all due credit goes to Ross Blade for his early courage and vision for EV manufacturing in Australia.
I took delivery of my converted Getz in June 2008. Since then it’s given me mostly trouble-free driving for over 36,000 km in suburban Melbourne.
EV number 2: Holden Volt
In December 2014 I bought a second-hand Holden Volt which replaced my 2007 VW Jetta TDI. So now both the family’s cars can be operated around town without the need for any fuel.
GM released the Chevrolet Volt in the USA in late 2010 and in Australia as the Holden Volt in late 2012. It’s a plug-in hybrid, which qualifies as an EV (unlike a Prius) because it’s practical to operate without any petrol. There’s a lot to like about the Volt. As a total package it’s a great all-round car giving the best of both worlds—it works as a pure-electric car around town, and also gives the capacity to drive long distance on petrol when needed.
No going back
Since making the jump to EVs I’ve had a lot of fun and had a fascinating lived experience of the future of private motor vehicles. I think I’ve shown that families can slash their fuel use without seriously affecting their personal transport utility. I know that the next oil shock, when it inevitably comes, will be much less shocking for those of us with EVs. I also think that plug-in hybrids will have an important role to play in the transition to all-electric transportation.
Lastly, I think that once drivers become familiar with the way that EVs drive they won’t want to go back.
Read detailed reviews of both cars’ performance in ReNew 131.
Resources for electric vehicle enthusiasts
Find out more about electric vehicles with this list of web resources and organisations.READ MORE »
Electric vehicles are evolving at a rapid pace and look set to displace fossil fuel vehicles in the not-too-distant future.
There are a growing number of organisations and websites dedicated to electric vehicles. Check out this list to find out more about EV ownership or building your own EV, and take a look at the many ReNew articles on the EV theme.
The Australian Electric Vehicle Association
The Australian Electric Vehicle Association Inc. (AEVA) is a non-profit organisation founded in 1973, comprising of individuals and organisations with an interest in Electric Vehicles (EVs) and electric vehicle technology.
Our purpose is to provide a forum for social and technical communication in the EV field, to create greater awareness of EVs and encourage their use, to foster further research and development in EV technology, and to be an official source of information on EVs in Australia.
My Electric Car
My Electric Car is a community information resource for electric cars and vehicles in Australia. The website highlights the various developments that are accelerating worldwide in the electric vehicle market. Although Australian oriented, MEC sees value in giving visitors a global perspective in this rapidly evolving space and hopes to stimulate interest, discussion and the uptake of EV transport.
EVWorld is one of the Internet’s longest running publications devoted to electric vehicle technology. Launched in 1998, historically we have covered a board range of EV types from bikes to buses to boats and beyond. Located in Omaha, Nebraska, we now are focusing our resources on promoting a more active mobility lifestyle through both EVWorld and ePEDALER.
EV Obsession is an electric vehicle site for the EV obsessed. Pure EVs, plug-in hybrids and even some hybrids. EV charging stations, apps, market research, policy and more.
For more on conversions:
This is an unofficial photo album for members of the EV Discussion List, an email based forum on electric vehicles. Take a look at all the wonderful EV projects on this website.
EV TV Motor Verks
EV TV Motor Verks is a website with videos dedicated to EV conversions. There are over 272 feature length videos at the site.
ATA EV branches
The ATA has two branches dedicated to electric vehicles:
Geelong EV Branch
The Geelong EV branch provides a forum for anyone interested in Electric Vehicles such as bicycles, cars and other forms of transport in Geelong, the Surfcoast and the Western District.
Meetings are held on the 1st Friday of each month: 7pm at the South Barwon Community Centre, 33 Mt. Pleasant Rd, Belmont VIC. A gold coin donation is collected to cover refreshments.
Melbourne EV branch
This branch provides a forum for anyone interested in Electric Vehicles such as bicycles, cars and other forms of transport.
Meetings are held on the last Wednesday of each month at 7pm in the Engineering Faculty, Swinburne University, Hawthorn campus (entry via the EN building).
ReNew magazine articles
Take a look at Know Your Renewables in ReNew 131 to find out more about electric vehicles including how an EV works, driving an EV, why buy an EV, battery lifespan, cost and materials, charging and more. ReNew 131 contains many more articles on the electric vehicles theme and is available at the ATA Webshop.
ReNew 131 Editorial – Electric avenues to more sustainable transport
Planning this issue started with many conversations about electric vehicles (EVs). “I saw an ad for one the other day,” someone said, “but I can’t remember what it was called.” Someone else said, “Are there any available in Australia?” Several someones asked, “Do you mean the Prius?” Full marks to Toyota for good marketing of the Prius (even though it’s a hybrid rather than an EV), but Australia now has several electric or plug-in hybrid electric vehicles (PHEVs) to choose from.READ MORE »
It is early days, as the sales show (see our article on the EV market in Australia), but perhaps, just maybe, we are at a turning point. It’s happened in the USA, with sales of EVs and PHEVs accelerating since 2011. Our author suggests that perhaps 2015 will be the year things start to change here.
In the USA, and even on a small-scale here, the idea of smart charging (with the timing of EV charging controlled by the grid to avoid peak times) is moving from research to trials. Using your EV as storage is also getting attention, for providing emergency power or grid backup. Read about these in ‘Your EV’s Other Life’.
The latest in our ‘Know your renewables’ series focuses on EVs too, getting under the bonnet to explain how they work, behind the wheel to see how they drive, and discussing the nitty gritty of how to manage charging and maintenance (in answer to the latter—easily, with much less maintenance required than a standard ‘fossil’ car, and many EVs enabled for remote support via their internet connections).
We also talk to owners of electric cars, motorbikes and e-bikes to hear their stories of how they came to the world of EVs. Some have had the ‘EV grin’ forEVer, but others are new to the idea. For all of them, it’s part of a wish to reduce their transport-related emissions; for many, there’s also joy in the new technology (Tesla Model S owners put your hands up); for one, it’s been on his ‘bucket list’ for a while!
Of course, better public transport, better planning and bike-friendly roads can go a long way to reducing our emissions as well. We also look at electrifying some of these options, with electric buses, motorbikes and bikes. We even look at electrifying planes.
We don’t discuss in detail here the question of the difference in emissions between electric vehicles and petrol-powered cars, covered previously in ReNew 120. That equation rests on how dirty the electricity generation is, but the balance can be swung towards the green through solar PV and GreenPower, whereas petrol-power can never be made clean.
It’s not just about EVs this issue. We also cover a household living their off-grid dream with a bike shop, holiday rental and home in WA, examine solar financing, shine a light on the problems commonly found in energy assessments and cover three DIY projects, including the intriguing open-source Open Sprinkler water reticulation controller. Plus our buyers guide this issue is an update of our very popular guide on batteries for household renewable energy systems. Enjoy!
ATA CEO’s Report
One of the most rewarding aspects of working at the ATA is being able to make someone’s day. Like when we give advice to a person who’s doing something sustainable in their home.
Recently we received some lovely feedback from Lauren, an ATA member who was looking to install an off-grid solar system on her property in regional Victoria. She had spent months researching and getting quotes from installers but was unable to make a decision on the best option. After a one-hour consultation with one of our experts, she has gone ahead and bought a system. Lauren said: “You quite quickly helped me to crystallise my needs in just one hour, something I had been chipping away at for over four months. If I had my time again I would have signed up, become a member and made an appointment with you straight away.”
Empowering people with quality information so they can make informed choices is the ATA’s mission. We achieve it in a variety of ways including the ATA member and consultancy advice service, information in ReNew and Sanctuary magazines, e-books and other online resources such as the Tankulator (tankulator.ata.org.au) and Sunulator (www.ata.org.au/ata-research/sunulator). There are also the face-to-face services we provide at our Speed Date a Sustainable Expert events, and our presence at home shows and other community events.
As existing sustainable technologies and solutions evolve and new ones emerge, the ATA will continue to play a key role as an independent voice helping people make sustainable choices.
The Australian electric vehicle market
Bryce Gaton explores what’s available now and what may be added soon to the Australian electric vehicle offerings.
Around the world, electric vehicles are moving beyond the realm of frustrated early adopters building their own to showroom doorstoppers providing viable alternatives to the fossil (fuelled) vehicle. With products coming out of most of the major manufacturers’ factories, there are now almost too many options for the would-be electric vehicle buyer to select from!READ MORE »
Unless, that is, you live in Australia…so why are we waiting?
What’s available overseas
There are so many electric vehicle options available overseas that it’s necessary to list them by vehicle segment rather than by manufacturer. Table 1 (in ReNew 131) shows a selection of electric vehicle (EV) and plug-in hybrid electric vehicle (PHEV) models that are currently available around the world (with the exception of the Tesla Model X which is expected to be released this year). They’re grouped by Euro NCAP segment, a designation that defines the type of vehicle, such as mini, compact, mid-size, etc.
Australian EV/PHEV offerings
The bold vehicle names in Table 1 are those currently on offer, or able to be bought secondhand, here in Australia in 2015. It’s a bit sad really, given the plethora of offerings elsewhere. However, combining this data with Table 2, we can see that five of the world’s six top-selling EV/PHEVs are available here, with the sixth offering in Australia (the i-MiEV) still in the world top 20. So at least it can be said that Australia does get the top EV/PHEV offerings. On the other hand, the EV/PHEV sales figures for Australia (in Table 3) are far less encouraging.
With such low EV and PHEV sales in 2014 in Australia, it is not at all surprising that the major vehicle manufacturers are seemingly uninterested in bringing additional models to split the market further.
It could also be argued that the manufacturers have done very little to promote EVs in Australia; however, that appears to be changing in 2015. With recent advertising campaigns for the Leaf, Outlander PHEV and BMW i3, as well as some canny marketing by Tesla, this year may see a surprising result for EV sales in Australia.
Read the full article in ReNew 131.
Know your renewables: All about EVs
Electric vehicles are evolving at a rapid pace and look set to displace fossil fuel vehicles in the not-too-distant future. Lance Turner looks at some of the basic concepts and terms you might come across when discussing EVs.
For almost 100 years, the personal automotive industry has been dominated by internal combustion engine (ICE) vehicles, burning either petrol, diesel or LPG. As an alternative to ICE-powered vehicles, electric vehicles (EVs) have been nothing but a novelty to most people, purported to lack range and power, making them unsuitable for most people’s uses.READ MORE »
However, all that is changing, with EVs making steady inroads into the global car market, and even (slowly) here in Australia. The shift in thinking started with the introduction of hybrid electric vehicles (HEVs), such as the Toyota Prius and the Honda Insight. With these vehicles, especially the Prius as it can run in all-electric mode at lower speeds, the general public started to experience some of the advantages of HEVs, such as reduced exhaust pipe emissions, almost silent driving and greatly increased efficiency.
But hybrids have a number of drawbacks. Firstly, as they have both an electric drivetrain and an internal combustion engine, they are more complex than either straight ICE vehicles or EVs. Secondly, although there is an electric drive component to their drivetrains, hybrids still gain all their motive power from fossil fuels (conventional hybrids can’t be charged from the mains grid, and they usually have quite small battery packs), so they are still an unsustainable form of transport, despite having lower emissions than equivalently sized ICE vehicles. The world’s oil reserves will last longer with hybrid vehicles, but will still eventually be exhausted.
As the public’s acceptance of hybrids grew, there was the desire for vehicles that had the advantages of EVs, without the limitations. Hence, the plug-in hybrid electric vehicle (PHEV) was born. These are similar to a hybrid but they differ in two important ways—they have larger battery packs that can be charged directly from mains power, rather than from the on-board ICE, and their electric motor is designed as the primary motor. This means that they can be driven as an EV until the battery is almost flat (or another battery level setpoint), at which time the ICE starts up and provides electricity to charge the battery and power the electric motor.
For owners who do many short trips, PHEVs can run purely on electric power and may never need to use the petrol backup at all. The Holden Volt is an example of such a vehicle, and the most recent incarnation of the Volt has an electric-only range of around 80 km, making it suitable for all-electric use most of the time.
However, there is a need to uncouple personal transport from fossil fuels completely to reduce emissions from this sector, and given that alternative fuels such as ethanol and hydrogen often produce as much CO2 in their production as they save, the only realistic way to achieve this currently is to make cars completely electric, removing the internal combustion engine option altogether.
Read the full article in ReNew 131, covering how an EV works, energy recovery from braking, driving an EV, why buy an EV, battery lifespan, cost and materials, charging and more!
Everything’s going electric: Planes, buses and bikes
It’s not just cars that are going electric. Lance Turner takes a look at other transport options that are ditching fossil fuels, including electric bikes.
While electric cars seem to get all of the publicity, there’s a lot more happening regarding the electrification of transport than just cars.
Personal transport—motorbikes and bicyclesREAD MORE »
On the personal transport side of things, motorbikes are set to become the next big EV thing, and we have already started to see the move to electric two-wheelers here in Australia. Quite a few low-powered commuter type electric scooters have been on the market for a while, but for anyone looking for a replacement for their fume spewing motorbike, there haven’t been many options—until now.
Vehicles such as the Australian-made Catavolt S6 and Zero SR from Zero Motorcycles in the USA have shown that electric motorbikes are now viable replacements for all but long-distance touring bikes. For example, the Zero SR with Power Tank long-range battery has city/ highway/combined ranges of 298/151/201 km respectively, a top speed of 164 km/h and a zero to 100 km/h time of under four seconds. Note that with electric vehicles, city range is often better than highway range due to the lower air friction losses and the opportunity for energy recovery with regen braking. This is the opposite of ICE vehicles, which are very inefficient in stop-start travel and reach much greater efficiency at a fixed speed.
The Catavolt S6 is available online at www. customevperformance.com while the Zero range is available from a number of dealers here in Australia (see www.zeromotorcycles. com/au/locator and www.motoelectro.com.au).
While on the subject of two wheels, electric bicycles have been a popular choice for many years, and there is a wide range available. Indeed, most bike shops have at least some models, but it’s important not to cut corners and buy the cheapest bike you find. There’s a price to pay if you want a robust bike with a reliable battery and motor—buying a cheapie might leave you stuck with a failed battery in only a year or two, meaning an expensive unscheduled replacement. There are numerous good quality e-bikes available, so talk to your local bike shop and see what they recommend. For more information, see the Electric Bike Buyers Guide in ReNew 123.
Read the full article in ReNew 131, including more on buses and planes.
Not just transport: Your EV’s other life
Electric vehicle by day, powering your home by night? Kristian Handberg explains how EVs could help in the energy storage equation.
For those with solar PV systems getting paid next to nothing for their surplus generation, the day is fast approaching when they might store this energy for later use. But should they use a stationary battery or an electric vehicle?READ MORE »
The situation for stationary batteries is changing rapidly. Battery costs are coming down and electricity market rules are changing to accommodate new business models for energy sellers who use storage1. Solar homeowners may soon be offered energy supply agreements that include a battery located on their property but owned and operated by their electricity retailer2. Homeowners will see the benefits via reduced electricity costs and supply agreements that avoid the complexity and risk of owning and operating a grid-connected energy storage system.
Right now, however, solar homeowners must deal with these challenges themselves. High upfront costs and long paybacks, risks associated with new technology and warranty commitments, and complicated energy management strategies are all reasons to delay on battery investment or look for alternatives.
One of these alternatives may be to use an electric vehicle as storage—if an electric car works for your transport needs, why not also use it to get better value from your solar investment.
While vehicle charging can be managed in line with solar production, at present there are no electric cars in the Australian market that allow charge to be extracted for other uses. Equipment is sold in Japan that allows emergency backup power to be obtained directly from the vehicle (see box on this page), along with vehicle-to-home (V2H) charging solutions that can provide backup and solar PV optimisation. Combining a standard charger with a bi-directional inverter (supporting both the vehicle charging and discharging) and an energy management controller, these V2H systems currently cost around $1000/kW (or around $4000 for a 16A V2H unit, as compared to $500–$1000 for a standard 16 A charger).
These costs can be expected to decrease as the technology improves and the plug-in vehicle market grows. Driven by these changes and the results of trials currently underway, the analysts Navigant are forecasting that V2X-enabled vehicles (vehicles which support discharging activities) will be launched internationally in 2016 alongside improved V2H systems3.
As the technology evolves, there will be opportunities for householders, within the context of wider considerations.
Read the full article in ReNew 131.
EV charging infrastructure in Australia
Is the lack of EV charging stations in Australia really holding back EV sales? Tim Washington considers the question in light of the US experience.
It’s almost impossible to talk about electric cars without talking about public charging infrastructure—understandable, given the prevalence of petrol stations to make our cars ‘go’. But when it comes to electric vehicles (EVs), is this infrastructure something we really need?READ MORE »
A wide distribution of petrol stations is required because 100% of our petrol car refuelling is done in public. For EVs, the situation is quite different: public EV charging infrastructure is needed to service just 5% to 10% of an EV driver’s fuelling needs.
Indeed, one of the selling points of EVs is the ability to plug in at home and start every day with a ‘full tank’.
On top of that, the average driving distance in Australia is around 40 km a day, well below the standard range of most EVs.
Nevertheless, range anxiety is real— averages are just that, after all, so there will be times people need to travel further than the EV’s range. One way this anxiety can be (partially) resolved is with readily accessible public charging stations.
But do public EV charging stations make business sense? What is the government’s role, if any? A good way to examine these questions is to look at overseas experience.
Dots on a map
“Dots on a map, Tim, that’s what they want— dots on a map.” This is what a major US EV charging station operator said to me when I asked about their car charging operations.
At last count, there were around 9500 ‘dots on a map’—public EV charging stations—in the USA. Compared to around 200 in Australia, that would seem like a lot. But key lessons can’t be learnt based on headline stats alone, so in this article I’ll attempt to look at the experience for charging station operators in the US and what lessons can be learnt from this to help expand charging infrastructure in Australia.
Read the full article in ReNew 131.
Off-grid EV charging
From off-grid electric vehicle (EV) charging to a desire for more sustainable transport, EV owners share the stories behind their choices with Robyn Deed.
Until recently, number one on Ross Ulman’s ‘bucket list’ was owning an EV and charging it from the sun (a ReNew kind of bucket list!). He got to tick off that item late last year after buying a secondhand Nissan Leaf, with 10,000 km on the clock, around the same time as he and his wife Vivienne moved to their new energy-efficient off-grid home near Daylesford.READ MORE »
He bought the Leaf from a friend who was upgrading to a larger EV, a Mitsubishi Outlander, which, with its ‘range extending’ petrol engine meant the friend could do without a second fossil-fuelled car. Pure EVs are probably uncommon in the country, says Ross, because of the longer distances travelled and the resulting ‘range anxiety’. Range doesn’t cause Ross problems, however. He plans ahead for his longest trip, about 90 km return to Ballarat for work, which is well within the 120 km range of his fully charged Leaf (the quoted range is 170 km, but he finds he only gets about 120 km with the hilly driving around Daylesford). His main driving is into and around Daylesford, about 15 km, all easily doable without mid-trip recharging.
He doesn’t drive the Leaf for his occasional trips to Melbourne, though driving there from Daylesford would be no problem, and charging in Melbourne would be no problem also, as there are charging stations in the city. However, the trip back to Daylesford would be problematic as, even if leaving Melbourne with full charge, the Leaf would need a further charge, albeit a short one, on the journey home—the increase in altitude uses more power than the downhill run into Melbourne. Ross is planning to upgrade in a couple of years, when a Leaf with double the range is slated to become available. He hopes that affordable EVs with double or triple the range of the current Leaf will make them more mainstream. And leadership from government is also needed. “EVs are the future of the car industry,” he says, “but we really need strong public policy with incentives and infrastructure investment.”
One interesting aspect of Ross’s EV is that it’s charged off-grid. He only charges the EV during the day when the sun is shining, a bit different from the usual overnight charging regime. The off-grid system, designed by Off-Grid Energy Australia, is AC-coupled, which Ross says has been fantastic, enabling him to charge the EV at the same time as the house batteries are charged: any draw from the house or car comes direct from the solar panels (when they’re producing energy), rather than from the house battery, reducing battery cycling.
The solar PV system is oversized (10.5 kW solar and 40 kWh batteries), which the system designers say should be sufficient to charge both the house batteries and the car even on cloudy days. So far (they’ve had the system since November 2014) there have been a couple of runs of four or five cloudy days and sufficient energy has indeed been generated.
Ross plans to work around his solar system production to avoid over-discharge of the batteries. If there’s a run of rainy days, he won’t charge the Leaf: if it has enough remaining charge he’ll drive it short distances; and, if it hasn’t, then he’ll make alternative transport arrangements, such as using their petrol vehicle or public transport. So what’s next for Ross’s bucket list? Well, there’s that Leaf upgrade in a couple of years. Or perhaps it’s just time to settle back and enjoy demonstrating that off-grid and EV can go together.
Read more stories about EV ownership in Best EVer stories: Electric vehicle owners share the love in ReNew 131.
Melbourne EV Expo 2015
Here’s the latest news about the EV Expo in Melbourne this April. Find out how you can get involved.
We’re doing it again! The Melbourne EV Expo 2015 will be held on Sunday April 19th in the Atrium at Swinburne University in Hawthorn. Please put this date in your diary!READ MORE »
This years event is shaping up to be bigger and better than last time. Still with all the same great stuff, some new bits, and much more advertising planned.
We are calling for all enthusiasts with electric cars, bikes, motorbikes, scooters, skateboards, outboards, or any other vehicles propelled by electric motors. Bring your vehicle along for the chance to be admired, and even judged in the Show ‘N’ Shine for prizes and cred if you want (registrations MUST be made prior to the event this year).
We are really keen to get a vintage electric car if possible, who knows someone with one? Please put us in touch with them if you can.
We are also keen to hear from anyone who can donate a couple of hours on the day to help with the running of the event. You will be rewarded with a free Expo t-shirt, and will feel great about helping bring EV’s to the masses!
Please get in touch if you’d like to assist with the pre-event planning too, we could always use a couple more people.
Please email email@example.com if you can help out in any way.
We look forward to seeing you there, and please say you’ll attend on our Facebook event page here to receive updates about the event.
Kael Rail: Ultralight solar bike rail project
Being involved with the ATA (ReNew’s publisher) is something that brings great variety and enjoyment. A great example of this was a chance phone call with Danielle and her seven-year-old daughter Kael. Doug Rolfe explains.READ MORE »
Seven-year old Kael had an idea for her local school science competition, but working out if the idea was realistic was proving a problem. After all, where do you go to ask about solar-powered trains for transporting kids with bikes to school?
Queensland Rail did their best to help with information about their electric rolling stock, but the scale of the average locomotive and standard carriages was well beyond what Kael was thinking of.
Happily, someone put Danielle, Kael’s mum, onto the ATA. We quickly saw that Kael’s idea had merit and pooled our office expertise to help find existing projects worldwide. Our local experience with Melbourne trams and custom electric vehicles also proved helpful.
After some help in understanding the rough energy requirements, Kael was able to finish her research and complete her project.
A few weeks later, we got the exciting news— after receiving a highly commended award at Mudgeeraba Creek State School, Kael had won first place in the Year 2 and 3 division of the Griffith University Gold Coast Schools Science Competition in the Environmental Action Project section. Of course, Kael was most excited by the prize of an iTunes voucher:”You can download games!”
This success also meant that Kael’s project was automatically entered in the science competition run by the Science Teachers Association of Queensland. After some nervous days, Danielle received word that Kael had to attend as she had won a prize.
In the end, Kael’s project won her first prize in her division in the Queensland event. Mudgeeraba Creek State School won the prize for best overall school—they received 21 prizes from their 31 entries, including the Queensland Science Student of the Year!
What gave Kael the idea?
Kael says: “We love our school, which is why we travel the extra distance. I have always wanted to ride my bike to school. But Mum and Dad say it’s too dangerous and there are places without bike paths. We do have electric trains, but not near us. I like riding my bike and I’m getting really fast. At school, we were looking at how we use energy in our lives. So then I thought of a solar-powered bike rail. Solar is free energy from the sun and no pollution.”
Danielle, Kael’s mum, says that the local roads are a big traffic area during school times. Some mornings it can take 40 minutes to do what’s usually a seven-minute drive. The high concentration of schools in the area means that a local public transport option would be quite desirable.
Kael says, “We wanted it [the railway] along the road, but it would make the road more crowded. Then we decided to have it away from the traffic.”
Kael worked out a very practical 5 km route for the ultralight train that would collect students on bikes from a number of schools along the way, using existing power and water easements behind the local community.
Kael spoke to Nick Abroms, Gold Coast Council’s Active Travel Project Officer who thought the idea made real sense. He said it was clear that people would use it, because it would cut down travelling time and be safe
Read more in ReNew 130.
Food vs fuel: Ethics and sustainability
Does biofuel production contribute to global food shortage and hunger, or not? Dr Seona Candy steps us through the pros, cons and complexities of using food crops for biofuels.READ MORE »
In a recent edition of ReNew (ReNew 127), an article describing the use of grain as fuel for wood pellet stoves was published. It inspired some opposing comments regarding the use of food for fuel. Although I can’t comment directly on this particular case of burning grain for space heating, I can perhaps provide some insight into the complexity, ethics and sustainability of the wider debate.
The ‘food vs fuel’ debate, as it is commonly known, is mainly concerned with first-generation liquid biofuels. These biofuels are derived from various agricultural crops that can also be used for food and feed, and have been developed primarily for transport uses. This is the case because there are already considered to be sufficient renewable energy options available to provide stationary energy.
The central argument in the ‘food vs fuel’ ethical debate is about whether the development (or not) of biofuels will cause people to go hungry. Critics of biofuels argue that diverting food crops to biofuel production will increase food prices and cause hunger, particularly among the global poor. Advocates of biofuels argue that their development will help mitigate climate change, and its potential future impacts on agriculture and food production, thus avoiding hunger for everyone (the global poor included) in the longer term.
The first of these two arguments seems fairly straightforward. Indeed, biofuel development in the early 2000s did precede significant rises in the prices of staple crops, causing the 2007/08 global food crisis and food riots in many countries. But it is not safe to assume that biofuels alone caused food prices to rise or that the impacts of rising food prices were negative for all groups who make up the global poor.
According to a report from the International Food Policy Research Institute, the 2007/08 food crisis was primarily driven by a combination of rising oil prices, a greater demand for biofuels and trade shocks in the food market.
Rising oil prices led to increased costs of cereal production, as conventional agriculture is an energy-intensive enterprise. Higher energy prices increased the demand for biofuels, which became more competitively priced when compared with oil. At the same time, cereal demand increased from oil-producing countries and weather shocks reduced the supply of some grains, increasing prices further. This led to a ban on exports by producers and panic buying by importers, which only increased prices yet again.
These increased prices led to food riots in developing countries. As Thompson2 argues, though, increased food prices negatively impact mainly the urban poor, who must purchase their food. For the rural poor, however, who produce and sell their food, rising food prices could be an advantage. It would increase their income and ability to buy food that they don’t grow themselves. Since the rural poor make up around 80% of the global poor, fewer people may in fact go hungry due to rising food prices.
Read the full article in ReNew 130.
Electric vehicles and the grid
Increased EV uptake means challenges for the grid, but the good news is that demand-side management could help. Marcus Brazil and Julian de Hoog explain.
The last few years have seen a rapid increase across the globe in the uptake of electric vehicles (EVs). A recent report by the US Department of Energy points out that sales of EVs are increasing faster than those of hybrids, if you compare the same stages of the technology life cycle. One of the leading manufacturers of EVs, Tesla, is now valued at more than $30 billion and has been projected to be a major disrupter of the automotive industry. Many major car makers are planning to introduce electric and hybrid models into the Australian market in the near future.READ MORE »
An important question that is often overlooked in discussions on electric vehicles is: what will be their impact on the electricity grid? An EV with a typical daily commute of 40 km requires roughly 6–8 kWh of energy to recharge; this is equivalent to the daily needs of a small household. In other words, if you buy an electric vehicle, the impact on the local electricity network is about the same as adding a small house to the neighbourhood. Furthermore, in an unregulated environment, most EV owners are likely to plug in when they arrive home, around 6 pm, at exactly the time that residential electricity networks experience peak demand.
The impact of EVs on the electricity grid
The main challenges to the grid arising from the increased uptake of electric vehicles fall into three categories.
Perhaps the most well known of the problems, peak load occurs at the time of day when the highest demand for electricity occurs. Our networks are sized to withstand peak demand, but if electric vehicles are added to the network, then the additional demand may be too much for the local lines and transformer to handle. New infrastructure may need to be installed, the cost of which is inevitably borne by the consumer.
The lines in a local distribution network have an impedance of their own. As current travels from the transformer to your house, this impedance leads to a decrease in voltage. The more current you draw, the more the voltage drops. An electric vehicle can draw a lot of current for long periods of time, and therefore cause a significant, sustained drop in your voltage. Low voltage can mean that some appliances may not run properly, or may run inefficiently (reducing their lifetimes). What’s more, the drop in voltage caused by an EV does not affect only its owner; it can affect other houses in the network too, particularly those furthest from the transformer.
Phase unbalance and power quality
Most distribution networks in Australia are 3-phase, and most houses connect to only one of these phases. If several people in a neighbourhood buy EVs, and by chance these are connected to the same phase, then there can be significant losses in efficiency in the network due to the resulting unbalance. There is also the potential that an EV and its charge point could affect the overall quality of the power in the network, for example by distorting the 50 Hz grid waveform.
When are these problems likely to arise? A study of two networks in Australia suggests that there can already be problems at fairly low vehicle uptake rates—for example at only 10% in a network based in Melbourne. While even a 10% uptake of EVs is some years away, now is a good time to start thinking about how to prepare for these problems.
The solution: shifting of demand
The good news is that many of these problems can be prevented. Electric vehicles are among the most ‘flexible’ loads in the grid: they can be shifted to other times of the day, such as overnight, when there is more capacity in the network.
Read the full article in ReNew 129.
The world record breaking eVe
Doug Rolfe meets team Sunswift as they embark on their record breaking race with the very sleek eVe.
In the chill and deep morning fog north of Anglesea, the University of New South Wales Sunswift team is preparing eVe for a big day. This amazing car is a sleek, black vehicle that has the look of a high end sports car, yet it uses only around 3HP at 100km/hr.READ MORE »
With the solar panels carefully taped over and sealed against light leakage, the arrays disconnected and the solar power controller removed from the car, it has become a pure battery electric vehicle for an attempt at the world record for the average speed over 500km for a vehicle under 500kg. The previous record was 73km/hr set in 1988 by the GM Sunracer. The team are expecting to easily beat that record. “We didn’t come here to do 75km/hr.” says 2013 team project director, Sam. The race will consist of 120 laps of the 4.2km track at the Australian Automotive Research Centre proving ground.
Project Director, Hayden Smith, says the UNSW project began in 1995 with a team from a range of disciplines including mechanical, electrical, software, renewable and photovoltaic engineering. “Furthermore, we have students from other faculties contributing to the team – arts, media, design, business, science – the list is endless. It’s by far one of the most academically diverse undergraduate student groups at UNSW,” says Hayden.
The committed team of engineering students swarm over the car, changing tyres, adjusting tyre pressures, checking connections, and mounting their ‘piece de resistance’, a short aerodynamic tail designed to improve the already impressive aerodynamic by another 5%. Finally the aerodynamic wheel covers are taped on.
There’s a large Confederation of Australian Motor Sport (CAMS) team scrutinising the vehicle, locking off the solar panel connections and mounting the lap transponder. After they go over the vehicle with a thorough series of safety checks, Garth Walden, driver for the ELMOFO EV race vehicle, climbs in and mounts the removable steering wheel. After getting strapped in to the race harness and completing radio checks, the door gets taped shut for aerodynamic advantage.
Finally, with CAMS approval, eVe heads out with a quiet whir for a shakedown lap. As it flys past the pits, the team cheer it on as the radar gun clocks it at 110 km/hr. It’s quietness is a true sign of the efficiency of this vehicle at these speeds.
With all set and a nod from the timekeeper, eVe sets out on her goal: 120 laps of the 4.2km track in the shortest time possible.
The design of the 2-seater car is impressive. With such high aerodynamic performance (a CdA under 0.2) and a lightweight carbon fibre body, its energy requirements are more on the scale of household appliance rather than a road-going vehicle.
Eventually the fog lifts, and so do the spirits of the team as, lap after lap, eVe performs faultlessly. There’s a scheduled pit stop planned for lap 60, but on lap 53 the car blows a front right tyre. The car travels a few more kilometres to complete the lap and return to the pit area, running only on the rim of the carbon fibre wheel. The team was fully prepared and after a quick and smooth seven minute pit stop to change drivers and both front wheels, CAMS driver Karl Reindler heads out for the second half of the day. Seeing the chase/support car being refuelled during the pit stop provided an interesting contrast to the zero emission eVe.
The post-mortem on the blown tyre shows it was heavily worn, but had failed when an object had pierced the sidewall. Even so, the team is focused on their goal and plan for a second pit stop. On lap 97, in only four minutes, they change the front right wheel (taking the cornering load) and Garth heads out again to finish off. Karl clearly enjoyed himself: “I could do that all day; it’s comfortable, relaxing, but the racing seat is hard on the lower back!”
Egged on with cheers and waves, eVe crosses the line, completing the 120 laps in just over four and a half hours giving an average speed of well over 105km/hr (the actual record confirmation is an International FIA process that takes up to a month). The sense of relief and celebration is obvious, but also interesting is the team’s confidence in their vehicle during the day. They clearly had no doubt that they we’re going to comfortably break the existing record. We look forward to a friendly rivalry of teams with stunning designs like this attempting to break the new record.
The following puts eVe’s effort in context.
Vehicle Energy used to travel 500km*
UNSW Sunswift eVe 20 kWh @ 107 km/h 
Nissan LEAF 86 kWh @ 89 km/h 
Tesla Model S 67 kWh @ 89 km/h 
2013 Toyota Corolla 238 kWh @ 62.6 km/h 
 20 kWh approximate – it’s still a race vehicle so there are secrets
 highway cycle, 24kWh pack @ 80%DOD, 4.5 charges
 85 kWh pack @ 80%DOD (510 km range = 0.98 charge)
 E170/2013 model, ADR 81/02 126.96.36.199 ‘extra urban’ = 5.4lt/100km, 8.8 kWh/lt for 91 octane fuel.
It’s pretty hard to compare these test conditions and vehicles, but it’s still possible to say that eVe uses roughly one-quarter to one-third of the energy of a ‘normal’ electric car and maybe one-tenth of that of a petrol vehicle.
To become road legal eVe will need lights, a higher running height, a safety glass windscreen some latches and stronger hinges for the doors and possibly side impact protection. That will add some weight, but would still come under 500-600kg and be capable of travelling 400+km at highway speeds. If current EVs with that capability are high-end sports vehicles using up to four times as much energy, storing all that energy means larger battery capacity and therefore cost. Through great design the UNSW Sunswift team have demonstrated a way to break the price/range problem.
The spaghetti wiring and raw internal look clearly shows that this isn’t a production vehicle, but those are relatively trivial things to change. The basic vehicle is a true candidate to become a road going hypercar. Exciting times!
Controller: 2x Tritium Wave Sculptor 22
Motors: Two rear wheel motors based on the winning CSIRO design, bought in and then re-engineered. These motors have a peak power output of 10kW, 20kg weight per wheel, 97% nominal efficiency and normally run at 1-2kW.
Solar array: The 4 m2 array is considered to be a range extender. The Sunpower monocrystalline solar cells have 22% efficiency (after encapsulation) which equates to about 880W for the array.
Battery: The lithium ion battery used for the record run weighs 100kg and has
20kwh useable capacity (12 hours to charge). The nominal system voltage is 140 volts
Battery Monitoring System: Custom system that monitors individual cell voltage and temperatures and also the total energy used from the battery pack.
Tyres: Michelin special order low rolling resistance (LRR) tyres.
UNSW Sunswift www.sunswift.com
The SolarX solar car: part 2
Energy will flow from the sun, the brakes and even the shock absorbers in the SolarX solar car. Clint Steele describes the power train in part 2 of our series on the car’s design.
The main function of a solar car is, not surprisingly, to convert solar energy to torque at the driving wheels so that the car can travel at speeds that make it a practical driving option.
Power flowREAD MORE »
The biggest difference in a solar car’s power system, compared to a conventional car, is in the flow of energy and the recapture of that energy. In a standard petrol car, the power flow is pretty much one way: fuel engine transmission.
In this solar car, however, there’s an additional flow, with power reclaimed via regenerative braking. This is common to most electric vehicles.
There’s also one more power flow in the SolarX. In most cars (electric or non-electric), energy is lost in the suspension system as it dampens the car vibrations. Shock absorbers can reach up to 180 °C as they dispel this energy as heat. This sounds high, but the actual amount of energy is usually not enough to warrant the effort of regenerative shock
absorbers. This is not the case here—the power used by the car is so small that the suspension units will make a significant difference. Thus, the team working on the suspension are also developing a regenerative shock absorber.
In a standard car, the power is delivered as needed: fuel is delivered to the engine or the current is drawn from the batteries when required.
However, the sun is an energy source that can’t be controlled in such a way. If the batteries are fully charged and the vehicle is at a speed that needs a relatively small amount of power, any excess energy falling on the solar cells is lost. And, in fact, this extra energy needs to be managed, to avoid damaging the batteries. This is another unusual aspect of managing the energy flow in this solar car.
Figure 1 shows the major components and the layout of the power system that ultimately converts sunshine to tractive effort. The subsystems are discussed below.
Most electric vehicles on the market today rely on lithium battery technology. For the SolarX car, the design team is investigating a hybrid energy storage system consisting of traditional lithium ion batteries coupled with supercapacitors.
Supercapacitors have superior power density, much higher than that of chemical batteries, which means they can be lighter for the same peak output power capacity.
A series of high-power car stops and starts will cycle a battery enough to shorten its life. By using supercapacitors to take these peaks, the life of the battery can be extended considerably.
This is not a concern in solar car racing, which is the pedigree of this car, but it is in road cars.
One of the challenges of this project will be managing the flow of electricity to each of the batteries and capacitors as desired.Read the full article in ReNew 127. Read Part 1 of the article here.