In ‘Off-grid living’ Category
Efficient hot water buyers guide
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.READ MORE »
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.
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.
Still a clever country
Energy efficiency consultant Geoff Andrews admires Australian innovation, but, as has often been noted, finds the next step—commercialisation—is lacking. Collaboration, governments and risk-taking could all improve that, he suggests.
I view innovation as change for good, so change which improves sustainability clearly qualifies. Most readers of ReNew would agree that we have to improve the sustainability of our society, so we must innovate. But, how do we do that, and what lessons can we draw from Australia’s sustainability innovation performance to date?READ MORE »
There is no question that Australia has provided the world with more than its share of innovations, including in sustainability. In renewable energy alone, Australia has led the world in PV efficiency for decades, pioneered many improvements in solar water heaters, and is now developing wave energy. We’ve been first or early implementers of two flow battery technologies (vanadium redox by Maria Skyllas-Kazaco at UNSW in 1980 and zinc bromine by RedFlow). Scottish-born James Harrison built one of the first working refrigerators for making ice in Geelong in 1851 (before that, ice was imported from Canada),and we invented wave-piercing catamarans and the Pritchard steam car. We even had manned (unpowered) flight by heavier-thanair craft a decade before the Wright brothers with Lawrence Hargrave’s box-kite biplane.
Of course, Australian innovations are prevalent in many other sustainability areas including medicine, construction, agriculture and fisheries, but space is limited here. What we could have done a lot better is commercialising those innovations in Australia. Imagine if Australia led the world in the manufacture of solar panels, refrigerators, air conditioners, wi-fi devices and evacuated tube heat exchangers, the way we do with wave-piercing catamarans and bionic ears.
Improving commercialisation would provide funds to improve our budget bottomline and allow us to do even more innovation and more commercialisation. To achieve this, I think we need to do several things.
Read the full article in ReNew 136.
Solar sells: Australian PV research and innovation
From PERCs to heliostats to improving PV quality, Andrew Blakers from the Australian National University describes high-impact innovations that found their way through Australian-led, government-supported research.
Through consistent government grants for innovation over the past 40 years, Australia has punched far above its weight in renewable energy innovation, particularly when it comes to photovoltaics (PV). The potential benefits for the Australian economy are substantial. PV now constitutes about a quarter of new electrical generation capacity installed worldwide each year; wind comprises another quarter; and coal, oil, gas, nuclear, hydro and all other renewables combined constitute the other half. In Australia, PV and wind comprise practically all new generation capacity.READ MORE »
Support for research and innovation lies at the heart of accelerated growth of the renewable energy industry. It supports later-stage commercialisation directly through technology development. Additionally, university research groups underpin undergraduate and postgraduate education and training of engineers and scientists.
High-impact Australian innovations
What are some of the ways Australia has contributed to solar research, and what are some of the commercial successes? Here are eight examples of high-impact innovations that emerged from Australian-led R&D.
1. PERC SOLAR CELLS
The PERC silicon solar cell is an Australian invention which is now used in about half of new solar cell production lines worldwide. It’s set to soon dominate the worldwide solar industry, according to the International Technology Roadmap for Photovoltaics. So far this is the most successful renewable energy technology to emerge from Australia.
BT Imaging’s advanced photo-luminescence characterisation systems for research and industry emerged from the University of NSW. They enable researchers and industrial engineers to visually assess silicon quality in great detail and to modify processes to maximise quality.
Read the full article in ReNew 136.
ATA member profile: Making sinewaves in Australia
Long-time ATA member and software engineer Rod Scott continues to expand the work of Selectronic, his family business which 35 years ago created Australia’s first inverter. He talks to Kulja Coulston.
The success of the renewable energy industry has often tracked along a “sinewave sales curve”, according to Rod Scott, the products and business manager of inverter manufacturer Selectronic. “It’s standing on its own feet more now, but there were times when government program early announcements could dry up business for five months at a time,” he says of the ‘boom and bust’ cycle that has typified the renewable sector in Australia.READ MORE »
Together with his brother Ken, Rod Scott is continuing the work of his pioneering family business which has been part of the local industry from the beginning. Selectronic produced their first inverter in 1981: “It was a 360 watt DC to AC square wave inverter,” explains Rod. “We started small and it grew from there.” In 1990 Selectronic developed one of the earliest model sinewave inverters.
“It was then that our bigger models started to come out with energy-management functionality. It was all off-grid back then,with Australia being such a sparse country—storage for on-grid systems would have been a very strange concept!” It was in the early 2000s when they developed their first grid-interactive inverter, as that side of the market started to take off.
Rod’s parents established Selectronic in 1964 as a contract manufacturing business and ran it out of the Scotts’ backyard bungalow in Boronia, Victoria, before moving into a factory. The company cut its teeth custom-making transformers and inductors for the local electronics industry before launching its own electronics products division. Decades later, Selectronic continues to manufacture products locally, when most manufacturing has moved offshore.
“We were one of the first to make inverters in Australia, and we might also be one of the last.” Employing around 35 to 40 staff at its Chirnside Park factory in Victoria, Selectronic indirectly employs another 100 people in Australia through its supply chain, and will soon open an international office in Johannesburg. “We can’t get everything made here, particularly the specialist electronics, but we support local if we can, as it gives us flexibility and control over the quality of the product.”
Research and development has underpinned the company’s success for half a century, explains Rod: “Our future products look like what our customers demand, and it’s always been that way. When we developed the SP PRO in 2008, we already had 28 years of off-grid experience.” Selectronic’s continued commitment to the traditional offgrid market is also paying off, as the flexibility and reliability of those systems is relevant to the growing solar hybrid market. A few years ago a German company, KACO New Energy, rebadged Selectronic’s 5 kW SP PRO under their own label.
Rod has been an active ATA member and committed advertiser in ReNew. He is also personally committed to renewable technology at home, and is running off a 5 kW SP PRO with about 2.5 kW of solar photovoltaic panels. At a recent party none of his guests noticed the suburb-wide power outage: “I had to take everyone out onto the street before they believed me that we were the only ones still with power.”
This member profile is published in ReNew 136. Buy your copy here.
A light in the bush
A pilot project at an Indigenous ranger station in northern Queensland has shown how collaboration can help bring low-cost sustainable power to remote bush locations—and turn off the polluting generators. By David Tolliday.
For many years now, volunteers with the Alternative Technology Association (ATA, ReNew’s publisher) have been working with other organisations to provide solar lighting and improve quality of life in East Timor. Last year, ATA’s volunteers were called on to similarly help power up Oriners Ranger Base in Cape York, northern Queensland.READ MORE »
A seed is sown
In 2014, the Kowanyama Shire Council’s Land Office invited the Centre for Appropriate Technology (CAT) to visit their Oriners Ranger Base (160 km west of Laura, on the Cape York Peninsula) to look into the power and water situation there. In particular, the base was in need of a new, reliable stand-alone solar energy system to replace the old 12 V system that had, sadly, been stolen from the site a couple of years earlier.
The land office hoped CAT’s experience and design knowledge would help them find the best way to set up a system, maximising the use of very limited funds (from their own income sources) to achieve a high-quality, durable remote-area solar power system. Looking at the challenge, CAT considered a collaborative model that would incorporate pro-bono installation by experienced solar industry professionals combined with ‘sweat equity’ from the community. This model would use key elements of their highly successful Bushlight Program (see box), along with the pro-bono partnerships.
A project is born
In early 2015, after discussions with the ATA (whom CAT considered a natural partner for the project), CAT’s pilot proposal was accepted. The ATA had agreed to support the pilot by sourcing two volunteers with the appropriate technical expertise and experience to take care of the installations.
The ATA put out a national call for suitable volunteers and, after a selection process, I was chosen to be the lead installer, with John Dickie assisting. I’m from Melbourne and John’s from Canberra, and we are both electricians and Clean Energy Council (CEC) accredited solar installers.
After months of planning, we arrived in Cairns to meet CAT’s Project Manager, Andre Grant. We then spent two days checking and loading equipment, and purchasing last-minute supplies before heading off for the seven-hour 4WD trip to Oriners Ranger Base.
After meeting the Indigenous rangers—’Brolga’ (Philip Yam), Garry Hudson and John Clark—along with land and sea manager Chris Hannocks and local Kowanyama Shire electrician Jared Warren, we surveyed the existing power setup. It consisted of an array of petrol generators, extension leads, portable lights and power boards, mostly laying across the ground. In anticipation of the arrival of the truck and container the next day, we headed to bed early.
As with all good plans, things didn’t go quite right—the truck had to turn back because of a leaking radiator; two days later, it arrived. The days were very hot and the humidity high, so work was limited to early morning and late afternoon. (You know it’s hot when not even the Indigenous rangers will work in the midday heat!) At one point we realised we had miscalculated the required quantity of array cable. Some frantic telephone calls later, we had the parts on a plane to the local town—a three-hour round trip away.
We had a time limit of two weeks, which sounds plenty; however, wiring the ranger station made our job more involved, and we also installed the container we shipped up with our solar equipment as a new secure kitchen/storage area, to help prevent thefts when the rangers were away.
Early in the second week, we were finally able to test and commission the stand-alone power system, and so turn off the noisy, polluting generators. Oriners Ranger Base now had a reliable, sustainable 240 V power supply—for light, power and, importantly, refrigeration, for maintaining food for the rangers over the wet season, when access is severely restricted.
We finally broke camp on the Tuesday to head back to Cairns. Taking two days, we checked out the next possible project at a ’nearby’ Indigenous-owned cattle station. Back in Cairns, we had a night out to celebrate a successful project before boarding our planes home the next day.
Highlights (and challenges!)
It was challenging, not only because we were miles from any suppliers, but also because it was hot: very, very hot. It was a great experience, however, and the team worked well together. Having the opportunity to share my solar knowledge with John, Jared and Andre was very rewarding. The Indigenous rangers really appreciated our efforts, and they were also great—sharing their knowledge and stories, and taking us ‘red claw’ (freshwater crayfish) hunting for our dinner. I can highly recommend volunteering.
For John: “As well as a fantastic experience working in a remote location and meeting some sensational people, it was great to be able to contribute, albeit in a small way, to the installation of sustainable, clean, quiet technology that provides more reliable power for essential items such as refrigeration, lighting and communications, and which should have a long lifespan. This, in turn, allows the traditional owners and rangers to more effectively look after and manage their country.”
The project was to design and install a reliable and robust stand-alone power system that would provide at least 10 kWh per day of 240 V supply to the ranger’s house and shed, to replace aging generators that were not only noisy and unreliable, but also produced considerable pollution.
The design was based on a DC-coupled PV array stand-alone configuration; however, with changes in industry practices and thinking, we would consider an AC-coupled system for future installations.
One issue that became apparent in designing this system was the change in the requirement of power conversion equipment (inverters and charge controllers) in AS/NZS 5033, which came into effect in July 2015. Many of the tried-and-true charge controllers used in stand-alone power systems for years no longer complied, and the newer, approved models were not readily available.
Finally, reliability and redundancy were major considerations in this design. In line with CAT’s experience, the system was robustly designed to ensure the realities of remoteness and poor access to service and support would not lead to system breakdown or failure.
- PV modules: 24 x BenQ model PM060P00-255 (total 6.12 kW)
- PV mounting frame: Clenergy PV-ezRack® SolarTerrace II-A
- Inverter: Selectronics SP-Pro SPMC481-AU 5 kW
- Charge controller: 2 x Studer Vario Track VT80 MPPT charge controllers
- Batteries: 24 x Hoppecke 8 OPzV Solar 1000Ah VRLA (50 kWh)
- Surge protection: 2 x MidNite MNSPD DC Type 1 devices
- Capacity: Minimum 10 kWh per day from 50 kWh battery bank
Governed by a majority Indigenous Board, the Centre for Appropriate Technology is a not-for-profit technology innovation company that works with remote Indigenous communities to design, build and manage technologies that support self-reliance and economic independence.
CAT is well known for its Bushlight Program, which designed and installed 130 solar systems (stand-alone and hybrid) to provide reliable, affordable 24-hour power to small communities across Australia. Bushlight systems near Kowanyama include Fish Hole, Scrubby Bore and Baas Yard.
The Bushlight approach ensures that system design is based on community planning processes that benchmark current and future energy needs, and provides community-based training in monitoring and managing the systems to maintain optimal loads and performance. This project provided the opportunity to develop a new model for delivering solar power with limited funding, while incorporating the sustainability and reliability delivered by the Bushlight approach. It hopefully benchmarks a process that will be of benefit to other remote ranger bases and homelands.
David Tolliday is a senior instructor in renewable energy training at Holmesglen Institute in Melbourne. He holds CEC accreditation in grid-connected PV and stand-alone (off-grid), small wind and hybrid power systems.
Read more articles in ReNew 135.
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.
Farming Renewably: Reaping the benefits
One person/farm can make a difference: David Hamilton describes how his farm’s sustainable conversion cut carbon, benefited the landscape and turned a profit.READ MORE »
I’ve read many inspiring articles in ReNew from individuals trying to live more sustainably and lessen their impact on the planet. This article takes a slightly different approach–a rural perspective–to demonstrate that it can be commercially viable to run a farming enterprise using systems that are truly renewable, whether that’s for water, electricity, housing, food, livestock, pasture or wildlife.
Our journey to sustainable farming began in 1993, when my wife Roberta and I purchased a 60-acre property in the south-west of WA with the twin objectives of restoring the degraded land and becoming as self-reliant as possible. The land included pasture that was totally lifeless and neglected, along with a dam, two winter streams, old gravel pits and two areas of magnificent remnant native forest. We wanted to be independent for water, electricity and as much of our food as was practical. Withe fewer bills to pay, we could work fewer hours off the farm–which was very appealing.
As a registered nurse with no farming experience, I was on a vertical learnign curve. Luckily, Roberta has a dairy farming background and, with her accounting experience, is a wizard at making a dollar go a long way.
When we began, we were both working full-time. We spent the first two years establishing a gravity-fed water supply, preparing the hosue and shed sites, and fencing the property, including to protect remnant bush from planned livestock. We also planted over a thousand native trees and shrubs, plus a few ‘feral’ trees for their air conditioning and fire-retardant properties.
Read the full article in ReNew 132.
A micro-hydro buyers guide
A micro-hydro turbine can be one of the cheapest sources of reliable electricity—if you have the right site. Lance Turner looks at what’s available.
Solar panels are the energy generators of choice for most domestic renewable energy systems, but there are other forms of renewable energy generation that can provide supplementary or even primary power generation if you have the right site.READ MORE »
One possibility is a micro-hydro system: the production of energy from water, with domestic-scale systems sized up to 100 kW. If you have a rural property with a suitable water source, then micro-hydro may be a good option, particularly if a high tree canopy precludes the use of solar panels or wind turbines.
The kinetic energy stored in flowing water can be considerable. You just need to look at the deep pools often found below large waterfalls or how the rocks in a creek are worn smooth by the flow of water. To get an idea of the forces involved, try aiming the jet from an ordinary garden hose at your hand. You will feel the force of the water striking your hand and being deflected. This is basically how many hydro turbines work.
Run-of-river versus dammed
Hydro systems fall into two broad designs—run-of-river and dammed systems.
Run-of-river systems simply take water from a high point of the river or creek, pass it through the hydro turbine and return it to the river or creek at a lower point. Only a portion of the water in the water source is diverted through the system.
In a dammed system, the water source is dammed, producing a water reservoir. The height of the water behind the dam produces the required head for the hydro turbine (the head is the term commonly used to describe the vertical height of the water column that is producing the pressure to run the turbine).
Most domestic systems are run-of-river types, as these produce the least environmental impact and are the cheapest to install. They are also the type your council and/or water authority is most likely to approve. After all, damming a water source can cause considerable environmental disruption and should be avoided.
Some run-of-river systems do use a small dam, known as pondage, to ensure an adequate flow into the intake pipe. The amount of pondage can be small or may be increased to provide more reliable energy output from the turbine during times of lower water flows in the water source. It is possible to use pondage that is separated from the water source completely, to prevent any negative effects on the water source.
Read the full article in ReNew 132.
Building a solar reticulation system
Martin Chape explains how he replaced a power-hungry bore pump with a low-cost solar unit and automated his watering system at the same time.
For some time I’d wanted to get rid of my power-hungry three-phase mains-operated bore pump, used to water my garden from the aquifer beneath my house. This forms part of a bigger plan to move all my 240 volt appliances off-grid. The large power drain of the three-phase bore pump would almost double the size of the inverter I’d need to go off-grid, even though it only gets used in summer, and then for just 15 minutes, three times a week.READ MORE »
So, I decided to replace it with a 24 volt DC bore pump run from solar PV. This pump fills a rainwater tank from the bore, using a float switch to turn the pump off when the tank is full. The resulting system can be completely automated and independent of utility-supplied water and electricity.
The pumps and tank
I ordered a 24 volt DC multistage submersible bore pump (a Kerry M243T-20) from a dealer on AliExpress, for US $178. This pump is class IP68 (fully dust and water tight; see en.wikipedia.org/wiki/IP_Code), has a 25 mm outlet pipe, can pump to a head of 20 metres at 3000 litres per hour and draws 384 watts (at 24 volts that’s about 16 amps).
While waiting for the solar pump to arrive I removed the existing bore pump and sold it for $500. Using that as my starting capital, I hunted down a 2500 litre poly rainwater tank through Gumtree and, with the help of my neighbour, installed it on a brick and concrete foundation. I had first considered building an elevated tank stand, to provide water pressure from the height, but decided against this after reading a story of a home-built stand collapsing on someone. I also would have needed local government approval.
So the tank ended up on the ground and I purchased a second pump to move the water out of the tank to the garden. It’s a 24 volt DC submersible pump (US$35 from another AliExpress seller) with a single impeller (the spinning rotor that pushes the water), a 25 mm outlet pipe, 12 metre head capacity and it draws 120 watts. Oddly, it claims a flow rate of 8000 litres per hour compared to the 3000 litres of the bore pump.
[Ed note: Cheap devices bought directly from China can vary in quality; checking the seller’s feedback score and comments can assist, but as Martin’s experiences show, there can still be issues.]
When this pump arrived from China it had been damaged in transit so I ordered a second one and then contacted the supplier. The supplier was very good and supplied parts which I used to repair the first pump, which is now in my shed as a spare.
The solar bore pump then arrived and with the help of a friend I soon had it installed in the bore. It seemed to work initially, but then stopped after just 10 minutes.
I contacted the supplier in China but they claimed their pumps don’t fail. After many tests and emails, I removed the pump from the bore and made a video of it running in a container of water. The video clearly showed that it didn’t pump water but rather blew out smoke. Only then did the manufacturer agree to replace the pump—if I paid the shipping from China for the new one.
When the replacement bore pump arrived, I installed it in the bore and wired it through the float switch (a boat bilge switch) mounted upside down in the top of the rainwater tank. This switch turns the pump off when the tank is full.
Read the full article in ReNew 131.
Going off-grid slowly: a DIY project
Stan Baker dreams of ditching his energy company and going off-grid. He explains how he aims to achieve this, one step at a time.
The well-documented ‘gold plating’ of the poles and wires networks has meant rising service fees for consumers despite falling demand for delivered energy. My own electricity bills reflected this and caused me to seriously consider leaving the grid altogether. A further consideration was the increasingly disruptive weather being experienced around the country resulting in power outages caused by high winds and electrical storms. When attempting to be energy independent, however, the problem is the high cost of the batteries and other equipment necessary to generate and deliver electricity.READ MORE »
Being something of a DIY type, I considered what bits I had sitting around in my garage and what expertise I might have that could be relevant. A passion over the years for converting hybrid cars to plug-in hybrids meant I had a reasonable understanding of lithium batteries, including the management electronics needed to ensure their longevity. I also had a 1.5 kW, 12 VDC Latronics inverter acquired years earlier for some long-forgotten project. Naturally, I had the usual nerdy stuff such as miscellaneous electronic parts as well as some understanding of microcontrollers.
In effect, I had much of what was needed to deliver 240 VAC off-grid, but with one question unanswered: where was the input energy to come from?
My house has a flexible pricing plan from Origin that provides cheaper electricity between 11 pm and 7am. This meant I had a lower cost source of electricity for charging the batteries, at least for initial trialling. So, about six months ago I put together a simple system using lithium iron phosphate (LiFePO4) batteries from an electric vehicle conversion that were down to around 50% of their original capacity and therefore unsuited for vehicular use.
The battery charger was a simple linear unit that used toroidal transformers. I had my fuse box modified so that the lights in the house could be powered either from the inverter or directly from the mains.
The original system was not particularly efficient and I estimated I was losing around 50% of the incoming energy, mainly due to the battery charger. However, it did keep my lights going during most nights and encouraged me to consider a more sophisticated battery storage system.
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.
Victorian primary school’s mission to go off-grid
A school with a social conscience has taken a leading role reconnecting with its community and helping the planet. Sydenham-Hillside Primary School teacher Lisa Crossley writes about student work promoting renewable energy, and the end of year sustainability party!
Sydenham-Hillside primary want to empower their students and bring about a change that starts with their local community. As part of the Grade 6 Science curriculum, students have been engaged in understanding the benefits of living sustainably.READ MORE »
Students have developed their understanding of the long term benefits of renewable energy, consequences connected to the greenhouse effect and the importance of maintaining the delicate balance of the Earth’s ability to continue being a self-sustaining ecosystem.
To conclude the unit, students were given the challenge of designing and creating a 3D model of a product/building/structure which uses renewable energy and sustainable components. Each student developed models to represent sustainable schools, caravans, homes, kitchens, farms and transport vehicles just to name a few. They also developed a marketing campaign to promote their product to the school community which included a poster/billboard and a television commercial.
To celebrate the students’ endeavors the school hosted the first ‘Sustainability Party’ which showcased real life examples of products such as electric cars, biofuel generator, wind turbines and a solar heated water system. Students experienced first-hand how sustainable practices can be realistically applied to products we use and benefit from every day. During this day, students were able to speak to engineers, architects and environmental groups about a range of community projects.
It is the school’s mission to become the next 5 Star rated sustainable school. We now have a sustainability officer who is working toward an impressive goal of implementing as many sustainable strategies as possible with the ideal aim to be self sustainably ‘off the grid’. We are welcoming any support from businesses, government departments or individuals within the community who can help us with our goal of becoming the next 5 Star rated school. We are eager to develop a ‘sister’ relationship with any other primary, secondary or tertiary schools which have first-hand experience in the implementation of sustainable practices.
Anyone who would like to get on board with Sydenham-Hillside Primary School’s mission can contact Lynne Comben: Sustainability Officer on (03) 9361 5400 or alternatively email Comben.Lynne.K1@edumail.vic.gov.au.
Off-grid in the suburbs
One ReNew reader has used his electric vehicle to take most of his energy consumption off-grid. He explains how he did it.READ MORE »
I was keen to increase the size of my PV system as my house was using more energy than the system produced in winter. This meant I was importing energy from the grid at 29 c/kWh (100% GreenPower, I hasten to add!).
I was also keen to experiment with going off-grid. I considered going completely off-grid, but that would mean losing the perceived reliability of supply from the grid, requiring a leap of faith for a suburban consumer like me.
My solution, instead, was to install a separate off-grid PV system. I now have two PV arrays with separate inverters, one connected to the grid and one off-grid, with the house running (mainly) on the off-grid system.
The idea of going off-grid with battery systems was featured in ReNew 128. One article suggested that price parity with a grid connection is yet to arrive, particularly in metropolitan areas, as PV may now be cheap but batteries are still expensive.
However, I already had a good-sized (8 kWh) lithium ion battery in my plug-in Prius conversion. I was able to use this battery for my off-grid system, with it providing around 6 kWh storage at 75% depth of discharge. So, even though I live in metro Melbourne, the economics worked out well for me.
My system required some technology: I purchased a 4 kVA Ecotronics unit from Commodore Australia that does it all. It is a MPPT (maximum power point tracking) PV controller, battery charger, AC inverter and grid UPS all in one (see Products, this issue).
It is designed to run off a 48 volt battery, the same as my Prius PHEV conversion system battery. The conversion system, from Enginer in the USA, uses a 48 volt battery and a DC–DC converter to step the voltage up for the Prius’s drive system.
The Ecotronics unit can also automatically revert to grid power if there is not enough sun or the battery is low. It can even be set up for load levelling—i.e. charging the battery bank on night-rate mains power then supplying power during the day. However, with a relatively high night-rate tariff (19 c/kWh), the economics for this are marginal for me—a 10 c/kWh saving over the day rate of 29 c/kWh.
The Ecotronics unit simply connects to the Prius conversion’s 48 volt battery via a large Anderson connector (a high current rated two-pole connector popular in DC systems). When not running the house loads, the Prius battery can either be charged from the Ecotronics unit’s built-in battery charger or the charger that came with the Prius conversion kit.
Read the full article in ReNew 130