In ‘Renewable energy’ Category

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ReNew 143 editorial: not just window shopping

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WHILE ReNew’s focus is normally in the energy arena, once a year we turn our attention to the building fabric, to consider sustainable materials/design and their energy implications. We’ve previously covered roofing and walls, and this time we give the lowdown on both floors and windows. Both of these really matter when it comes to energy efficiency.

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Depending where you live, it seems that different sub-floor structures are in vogue. For example, in Queensland in descending order of prevalence are full concrete slabs, timber floors and waffle pods, whereas in the ACT it’s waffle pods that make up the majority of builds, according to 2016 analysis from CSIRO (www.bit.ly/2Fwzls9). We look at all of these floor designs and consider their sustainability credentials, highlighting some excellent resources along the way.

Your final floor covering might be a concrete or timber finish (look for eco-products) or it might include colourful all-natural linoleum or beautiful bamboo. For all products, the eco-credentials will vary depending on source and the materials used. Our coverage aims to point you in the right direction and introduce you to materials you might not know about already.

Continuing our building materials theme, our buyers guide this issue is on windows. Windows consistently top the list of interest areas in our Sustainable House Day surveys. We’ve updated our guide to help you understand the choices from double glazing, to low-e coatings, to films or other treatments applied to existing windows. We’ve also tracked down nine case studies from readers who’ve upgraded their windows, from full replacement with high-performing windows through to secondary glazing of windows and DIY glass replacement.

As feed-in tariffs paid for solar generation exported to the grid have reduced over time, there’s been a lot of interest in what constitutes a fair rate. The ATA advocates for tariffs that reflect the many benefits of solar generation and has been pleased to see several state governments move in this ‘value-reflective’ direction. One big change on the horizon (in Victoria, at least) is a time-varying feed-in tariff, which rewards generation at the times of the day when the grid needs it most. We help explain the proposed tariff and estimate the benefits over a flat rate.

We also look at Paul Hawken’s Drawdown project, present an ‘almost off-grid’ experiment on the edge of Melbourne, cover how to prepare your home for an electric vehicle, plus much more. Who knows, with the current level of media coverage and new EV announcements, perhaps 2018 will (finally) be the year of the EV in Australia.

Until 6 July, we’re running our biennial reader survey. It’s your chance to let us know what you’d like to see more, or less, of in the magazine. It’s at renew.org.au/readersurvey. We really use the feedback to guide our planning, so we’d love to hear from you

Robyn Deed
ReNew Editor

ATA CEO’s Report

AS WE change seasons, so does the inside temperature of our homes. For the majority of Australians living in energy-leaky 1 or 2 Star homes, it means going from being too hot in summer to too cold in winter, unless a substantial part of energy bills is spent on heating or cooling.

Helping to empower people to make their homes more comfortable to live in, cheaper to run and not cost the earth is what the ATA has been doing for 38 years. The great examples of what people have achieved in their own homes have filled the pages of many issues of ReNew and Sanctuary magazines.

As well as providing practical, independent advice, the ATA advocates for regulatory change to improve home performance. Currently in Australia all new homes and alterations/additions need to achieve a minimum 6 Star energy rating to comply with the National Construction Code. However, it is well-recognised that many homes are not performing at 6 Star once built. There is also an increasing body of evidence that the economically optimal level of new housing should be above the minimum 6 Stars.

According to a recent report from the Australian Sustainable Built Environment Council, 58% of Australia’s buildings in 2050 will be built after 2019, so improvements to the code and optimal performance are critical over the next few years.

The ATA is taking the lead and working with our partners in representing households and advocating for change to the code. We all deserve to live in comfortable, healthy homes that are resilient in a changing environment. You can support our work by making a tax-deductible donation to the ATA at www.ata.org.au/liveable-homes.

CEO, ATA

You can purchase ReNew 143 from the ATA webshop.

News: Small battery uptick

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Recent figures from the Clean Energy Regulator, outlining the uptake in Australia of small-scale battery storage, reveal a 914% increase (693 to 7032 units) from 2014 to 2018. The figures represent voluntary disclosure of new system installations, and don’t account for those not disclosed nor those that may have been retrofitted, so the real figures are likely to be higher. And although battery system uptake only constitutes 2.5% of total PV systems installed in Australia last year, this is still just over double what was installed in 2016 (1.18%).

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On the back of this sort of interest in storage batteries and sales growth, alongside nation-leading renewable energy policy and targets, and incentives promised by both major parties, German battery manufacturer Sonnen will be setting up a manufacturing plant in South Australia and moving its current Sydney headquarters to Adelaide. This will not only create around 400 jobs, but will also provide a cheaper battery storage option for the local market, using locally sourced components (apart from the cells, which are manufactured in Japan) and eliminating the significant cost currently tied up in shipping complete battery units from China or Germany. Sonnen hopes the SA plant will be established and producing its first batteries by the end of this year.
www.cleanenergyregulator.gov.au, www.bit.ly/2Ftj0Uw

Year ACT NSW NT QLD SA TAS VIC WA Total
2014 8 208 3 129 34 5 137 169 693
2015 3 133 1 186 21 6 163 24 537
2016 105 667 6 331 130 18 240 70 1567
2017 183 1742 16 773 445 90 686 204 4139
2018 7 38 0 26 12 0 9 4 96
Total 306 2788 26 1445 642 119 1235 471 7032

New solar PV systems with battery storage by year and state/territory as at 31/1/2018. Note that RET certificates can be created up to 12 months after installation, so 2017+ figures will rise.

Neoen Hornsdale Battery 08 600px

SA renewables post-election?

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ReNew magazine was just about to go to print with the following story about SA renewables, but uncertainty about support for these projects from the new South Australian state government elected on Saturday 17 March meant we pulled the story. But we thought it worth recapping the projects here, even though we’re not sure that all of them will still proceed.

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At least one of the projects, the Housing Trust virtual power plant trial, is already in train, with contracts signed. The incoming government has said it will honour any contracted projects so it seems clear that will continue. With the others, we hope the new state government will see the value in them, both for increasing stability in the grid and reducing prices for a range of SA households—and cementing SA’s position as the nation’s leader in renewable energy. The Guardian has written this article about the prospects, and here is Renew Economy’s initial reading of the situation.

These projects were financed by the previous government’s $150 m Renewable Energy Technology Fund (RETF).

The first cab off the rank from SA’s RETF rose to the challenge posed by Tesla’s Elon Musk in mid-2017 in response to the state’s much-publicised ‘energy crisis.

A 100 MW lithium ion battery—the world’s largest—was installed at French renewable energy company Neoen’s Hornsdale Wind Farm in Jamestown, in partnership with Tesla, who agreed to deliver the battery system ‘within 100 days of signing a grid interconnection agreement with the government or it’s free’.

It was delivered within 63 days. On 7 July, Hornsdale was selected to host the battery; the connection agreement was signed in October; the battery was installed, and charged and discharged into the grid for the first time on 28 November; the community was invited to celebrate on 9 December. The wind/battery facility operates 24/7 providing stability services and emergency backup power.

The RETF more recently awarded $3m to Perth-based Carnegie Clean Energy to build a 2 MW/500 kWh battery storage installation that will create a renewables-based microgrid on the old General Motors Holden site in Elizabeth, on the northern outskirts of Adelaide. The battery storage system combined with a 3 MW rooftop solar system—possibly Australia’s largest at a single site—could also be expanded to 10–15 MW if all the available roofspace was used.

A microgrid for the produce markets was to be realised with $10.5 m from the fund, to combine 2.5 MW solar PV, 4.2 MWh of Tesla battery packs and a 2.5 MW diesel generator that is expected to save stall holders around $500,000 a year.

And a $2 m grant plus $30 m loan from the RETF was to see the rollout of the world’s largest (250 MW/650 MWh) virtual power plant (VPP), comprising a network of at least 50,000 homes with solar and battery systems, over the next 4.5 years. A trial has already commenced, in which 1100 Housing Trust properties will receive a 5 kW PV system and 13.5 kWh Tesla Powerwall 2 battery—installed for free and paid for through the sale of electricity. A further 24,000 Housing Trust properties were to follow, and then a similar deal offered to all SA households and businesses from June 2019.

The VPP was expected to lower the energy bills of participating households by 30%, as well as helping stabilise power supply for the whole state through provision of around 20% of its average daily energy requirements.

www.bit.ly/2tkNweg, ourenergyplan.sa.gov.au, www.hornsdalepowerreserve.com.au

142 Front cover 150dpi full size

ReNew 142 editorial: to boldy solve the split incentive

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THERE are some great landlords out there, providing comfortable, energy-efficient housing for the 31% of Australians who rent. But there are also many cases of poorly maintained and poorly performing rental properties. With New Zealand bringing in minimum standards for energy efficiency measures such as insulation, it’s time for Australia to step up. The states have some schemes in place, but much more is needed, including incentives and regulations.

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We look at what’s happening in Australia, what landlords can do (and what some are doing already), and the energy efficiency scorecard currently being trialled in Victoria that may help push the market in the right direction.

Another area where renters often miss out is the savings that come from solar. The same goes for apartments, where it can be difficult to install solar for many reasons, including technical. But both markets can and are being catered for. We look at what’s possible to solve the solar ‘split incentive’ and look at case studies of solar panels making their way on to this under-used rooftop resource: a win for landlords, renters and the environment.

Our buyers guide this issue is on solar panels. Although many ReNew readers may already have systems, there are still many rooftops without solar (including rental ones), and many readers may be looking to add a larger system to their existing one. We also follow one person’s story of their recent solar install: how they did their research and sizing, and the process from accepting the quote through to receiving a feed-in tariff for their homegrown clean energy.

Over the past year, the ATA has been advocating for a transition to a 100% renewable grid for Australia. Andrew Reddaway’s report from last year asked if it was possible (answer: yes, and by 2030). This time he investigates how Australia is progressing. It seems that a clear transition is underway, with many projects in the pipeline, all renewable. But it requires proper planning, which has been lacking to date. Andrew’s work shows just what a plan might look like. It’s inspiring, and maddening at the same time: it’s affordable and possible to do this within 13 years, yet we are sitting around debating whether we should allow Liddell to close or not.

There’s much more in the issue besides. We look at PV recycling, present an induction cooktop mini guide and give an update on the growing (at least elsewhere) EV market. Beyond solar PV, Tim Forcey argues that we all need to become familiar with the term ‘renewable heat’. As he says, in his home, just 20% of his home’s renewable energy comes from solar—the other 80% comes from heat from the air, used by his hot water heat pump and air conditioner.

We hope you enjoy the issue. The ReNew team wishes everyone a relaxing and safe holiday period and we look forward to hearing from you in the new year.

Robyn Deed
ReNew Editor

ATA CEO’s Report

In Australia, renewable energy and carbon emission targets are again being used as a political football, in which there are no winners. In fact, it’s hard not to feel that each time we take two steps forward with action on climate change, we also take three steps back.

However, despite community frustration with political leadership in this area, there are positive stories to tell. The momentum for a low-emissions future grows apace with the price of renewable energy continuing to fall—it is now cheaper to develop solar and wind energy than new coal-fired power stations in most countries. And we have industry leaders calling for certainty on energy policy so that they can get on with the job.

The good news is that the knowledge, technology and solutions to enable households and communities to reduce their carbon emissions and save money are available.
With electricity prices continuing to rise, new technologies such as batteries and heat pumps coming on to the market and more Australians wanting to take control of their energy future by producing their own renewable energy, there is a need more than ever for quality, independent information for households. That’s where the ATA and our commitment to providing quality independent advice comes in, most recently with our free online solar & battery sizing tool. Find it at www.ata.org.au/ata-solar-advice.

At the ATA every year we are helping hundreds of thousands of people make a practical difference and we’ll keep doing this through 2018. Thank you to all our members, partners and supporters who are part of our community of change.

Donna Luckman
CEO, ATA

You can purchase ReNew 142 from the ATA webshop.

DSC_0757

Solar panel buyers guide 2018

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We’ve contacted photovoltaics manufacturers for details on warranties, cell types, size and price to help you decide which solar panels are best for you.

Solar photovoltaic (PV) panels have become a common sight in the Australian urban landscape. From powering domestic dwellings to providing power for camping or even hot water, PV panels are everywhere. In Australia there are around 1.7 million rooftop solar installations, totalling over 5.6 GW of installed capacity.

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However, there are still many homes without solar. This article aims to provide guidance for those looking at purchasing a solar installation, whether a new system or an upgrade. It includes types of solar panels and factors to consider when buying them. The guide focuses on PV panels only. For information on other components that may be used in a solar installation (e.g. inverters), system sizing and economic returns, see ‘More info’ at the end of the article.

Solar panel types: monocrystalline, polycrystalline and thin film
Solar panels are made from many solar cells connected together, with each solar cell producing DC (direct current) electricity when sunlight hits it. There are three common types of solar cell: monocrystalline, polycrystalline and thin film. There are very few thin-film panels on the residential PV market—most panels are of the crystalline type.

Both monocrystalline and polycrystalline cells are made from slices, or wafers, cut from blocks of silicon (one of the most common elements on Earth). Monocrystalline cells start life as a single large crystal known as a boule, which is ‘grown’ in a slow and energy-intensive process. Polycrystalline cells are cut from blocks of cast silicon rather than single large crystals.

Thin-film technology uses a different technique that involves the deposit of layers of semiconducting and conducting materials directly onto metal, glass or even plastic. The most common thin-film panels use amorphous (non-crystalline) silicon and are found everywhere from watches and calculators right through to large grid-connected PV arrays. Other types of thin-film materials include CIGS (copper indium gallium di-selenide) and CdTe (cadmium telluride). These tend to have higher efficiencies than amorphous silicon cells, with CIGS cells rivalling crystalline cells for efficiency. However, the materials used in some of these alternatives are more toxic than silicon—cadmium, particularly, is a quite toxic metal.

Each cell type has some advantages and disadvantages, but all in all, modern solar panels do pretty much what they are designed to do. There are no moving parts to wear out, just solid state cells that have very long lifespans.

Crystalline cells are a very mature technology and have a long history of reliability, so a good quality crystalline PV panel will very likely perform close to specifications for its rated lifespan, which is 25 years or more for most panels. Crystalline panels are usually cheaper than thin-film types, with the cheapest being polycrystalline panels, although the pricing gap between cell types has diminished in recent years.

Read the full article in ReNew 142

Click here to download the full buyers guide tables in PDF format.

Sheep roam seven hectares on the UQ Gatton solar farm

100% renewable by 2030

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In late 2016, we reported on ATA analysis that showed a 100% renewable grid is feasible and economic in the long-term. Here, Andrew Reddaway follows up to see how we’re progressing towards that goal.

The last year has seen much action in the electricity grid, both announced and commenced. It’s become clear that the electricity grid’s transition is well underway, as coal-fired power stations are being replaced by renewables. However, poor planning and coordination has caused problems such as curtailment of wind generation in SA.

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Transition planning needed
As the grid transitions to a high level of renewables, good long-term planning is required. If the grid’s current planning arrangements continue unchanged, decisions and investments will be uncoordinated. They may make sense for the short-term profits of individual companies, but may not lead to a well-designed overall system. The Chief Scientist considered this, and recommended an “integrated grid plan” by the Australian Energy Market Operator (AEMO).

In the current system, generators compete against each other, may close without notice and have a business incentive to conceal their future intentions.

There is no guarantee that new power stations will be built—the system expects that investors will foresee a shortfall, identify a profit and construct the needed infrastructure. To assist investors, AEMO annually produces the Electricity Statement Of Opportunities report attempting to identify future shortfalls. This document only looks ahead 10 years, and doesn’t consider scenarios such as 100% renewables. AEMO also produces a transmission report, which looks ahead 20 years but has a relatively narrow focus on transmission lines and related assets.

In hindsight this system has a clear flaw. If investors fail to act in time, generating capacity may be insufficient to meet demand. It takes several years to build a new power station, but an old one can be closed very quickly—Hazelwood’s owners provided only five months notice. Individual asset owners have no responsibility for overall system reliability.

This is why interventions in the market have been required in 2017, including the SA government’s Energy Plan.

The current system also relies heavily on clear, long-term government policy to guide investors. Without such policy, investors face the risk that their newly-built asset might have to contend with unexpected new incentives, rules and regulations.

The best plan so far
In the absence of long-range planning by authorities for a high-renewable grid, the best studies have come from universities. In February 2017, the ANU published a clear vision for our future grid. Its researchers found the most economic combination for a fully renewable grid comprises:

  • wind farms (45,000 MW)
  • solar farms (23,000 MW)
  • rooftop solar (17,000 MW)
  • existing hydroelectric and biomass generators (10,800 MW)
  • pumped hydro energy storage
  • extra transmission lines.

Read the full article in ReNew 142 or you can find the paper on which the article is based at www.ata.org.au/news/100-renewable-energy-by-2030.

Heat pumps harvest renewable heat

Beyond solar PV

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There’s more to renewable energy than just electricity. Renewable heat is an important alternative to gas for Australian homes and industry, writes Tim Forcey.

MANY Australians just love renewable energy. The deployment of rooftop solar photovoltaic (PV) panels continues to grow. Large wind farms are becoming more common in every state. Even the energy storage potential of the Snowy Mountains is in the news, as is Tesla with their big batteries. With these technologies and resources, we can aim to avoid the worst effects of climate change and quit burning coal and gas to generate electricity.

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But there is more to renewable energy than just generating electricity. Australia also has massive opportunities for deploying technologies that harvest or create ‘renewable heat’.

It may be because Australia’s climate is not as cold as elsewhere that the term ‘renewable heat’ is rarely used here. Contrast this to Europe where, because of its key role in reducing greenhouse gas emissions, entire conferences are devoted to renewable heat. In Japan, research since the 1970s has made that country a global leader in renewable heat harvesting technologies such as heat pumps. For decades in New Zealand and Tasmania, places poorly endowed with fossil fuels, renewable heat has played an important role both in homes and more widely across their island economies.

Beyond the environmental benefits, there is a new economic reason why Australians should be interested in using renewable heat: the rapidly rising price of gas.

Read the full article in ReNew 142.

Grid voltage corrected infographic

Renewables improving the grid

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An innovative trial is using smart solar inverters on homes, both on their own and combined with batteries, to improve grid stability. By Lance Turner.

Many Australians are all too aware how unstable the electricity grid can be at times, especially under large loads, such as when everyone gets home and cranks up the air conditioner on a hot day. Other factors that can affect local grid stability can include large numbers of distributed generation sources (such as home PV systems) in a small area, long grid distribution lines, and old, poorly maintained or undersized grid equipment such as transformers and cables.

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The result can be a number of problems (see Figure 1), including low or excessive grid voltage, low or high grid frequency or poor power factor (a mismatch of the voltage and current waveforms).

While upgrading grid equipment is one possible solution, it’s not the only answer. Long feeder lines experience both increases and decreases in voltage along the line due to the natural impedance (like resistance) of the cables—homes a long way down the feeder can see an ohm or more of impedance between the substation and the home.

At times of light load (energy consumption) but high PV generation, such as the middle of a sunny weekday, the feeder may see a steadily increasing grid voltage along its length; for each ohm of impedance along the feeder line, every amp flowing into the grid raises the voltage on the grid by 1 volt. For example, each 5 kW solar system can be adding 20 amps into the grid, or an increase of up to 20 volts above the other end of the feeder line. In the evening when solar generation is almost zero but demand is high, this same grid impedance causes the voltage to sag. Thus, the voltages along the feeder, especially towards the far end, can vary widely (see Figure 2).

A good example of how extensive the problem can be is in Figure 3, which shows the high and low grid excursion events (where the grid voltage tends towards the allowable limits) for a selected substation over a two-year period.
Although this can be mitigated by an increase in cable size to lower resistance and installing transformers with a higher capacity, such upgrades are expensive and can never eliminate voltage variation caused by system impedances. So, other, smarter options are now being considered.

Read the full article in ReNew 142.

monitoring_guide_phone

Knowledge is power – Energy monitoring guide

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Need help getting the upper hand on your electricity bills or checking that your solar system is working? You should consider an energy monitoring system, says James Martin from Solar Choice.

DO YOU have a clear picture of what’s drawing electricity in your home right now? If you’re like most Australians, you probably don’t.

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Historically, this hasn’t been an issue because electricity bills weren’t a major concern for most households and, in any case, the number of devices was probably small. But these days electricity prices are high and there are likely to be more electricity-consuming devices plugged into the walls of any given home than the occupants can think of off the top of their heads.

Many Australians have turned to solar panels to help them fight rising prices. Rooftop solar is now affordable and commonplace — the Hills Hoist of the 21st century.

However, comparatively low solar feed-in tariffs in most places mean that solar homes have less incentive to send solar electricity into the grid and more incentive to use it directly. Despite this fact, many (if not most) solar system owners would be at a loss if you asked them how much energy their system produced yesterday, never mind the proportion that they managed to self-consume.

Solar systems have even failed without the homeowner realising until they received their next bill. So monitoring is important!

Types of energy monitoring and management systems
Thankfully, there’s a growing number of products on the market that shed light on household energy consumption and solar generation. These devices take a range of approaches and offer a range of functions, but can generally be classed as either monitoring systems or management systems.

As the name implies, a monitoring system enables the user to ‘see’ what’s happening with their electricity, usually via an app or web-based portal, whereas a management system lets them not only observe but also ‘reach in’ and control which devices switch on at what times.

In reality, the line between the two is becoming increasingly blurred as platforms that once offered only monitoring get upgraded to let them do more.

Monitoring and management systems can be lumped into roughly five categories based on how they are physically installed in the home.

Read the full article in ReNew 141.

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Towards grid independence

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What happens when a home with very low electricity use adds a battery? Terry Teoh describes his home’s interesting results.

OUR house is an Edwardian three-bedroom brick home renovated in 2010 along sustainable design lines. With two occupants, our house achieves a very low average electricity consumption of 2.4 kWh/day, though note that gas is (currently) used for space heating, cooking and boosting of solar hot water.

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We installed a 5 kW solar PV system in December 2016. With the array oriented east and west, the seasonal difference in energy production is accentuated compared to a north-facing array: our system produces on average 26 kWh/day in summer and 7 kWh/day in winter.

In April 2017, we added a 4 kWh Sonnen eco8 battery to our system to provide solar load shifting—storing solar energy produced during the day for use at night.

In the first two months of operation (to June 2017), our house has moved from 30% to 70% grid independence—i.e. 70% of our energy is now generated by our solar system.

Interestingly, that 70% is lower than we expected given a substantially oversized solar array and battery. It turns out that our standby energy usage is too low to be served by our inverter!

However, it’s still a good result and the battery has lifted solar self-consumption from 5% to 50% and paved the way for us to disconnect from the gas network and move to an all-electric, renewably powered household.

Motivations
Our motivations for installing a battery system included a desire to maximise solar self-consumption and grid independence. The latter is not out of antipathy for energy companies or the grid. We want to stay connected to the grid.

The grid is good; it will just be used in a different way in the future to support a decentralised energy system where consumers will have more control over how they make, use, store and share energy.

Read the full article in ReNew 141.

Relectrify

Second life for EV batteries

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We’ve looked at recycling end-of-life batteries before, but what if they could be reused instead? A startup in Melbourne is making that happen for electric vehicle batteries.

In Australia, with just 4000 or so electric vehicles on the road, you’d be forgiven for thinking we can defer dealing with ‘end of life’ EV batteries for a good while yet. However, the global view is quite different.

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Some two million EVs are on the road world-wide (up from around 400,000 in 2013) and, with warranted battery life ranging from five to eight years, a large number of batteries are approaching end of life. Whether that’s a problem or an opportunity depends on your perspective.

Getting value from a second-life battery
Relectrify, a Melbourne-based technology startup, is a company that sees the upside.

At the end of its usable life in an EV, says Relectrify’s Valentin Muenzel, a battery generally has around 2000 charge–discharge cycles left—or about half its life. It may not be suitable for continued use in a car, but there are other uses, in household systems, for example, where the lighter loads can mean it’s still got a useful future.

It’s not quite as simple as plugging a used EV battery in to your home energy system, of course.

One issue is that cells may have degraded differently across the battery pack. A standard battery management system (BMS) will prevent the entire battery from discharging below the fully discharged point of the weakest cell (a passive BMS) or take from those cells with more energy capacity to make up for those with less (an active BMS). The latter can improve the energy output, but the degree of improvement depends on the difference in capacity between the cells.

To maximise the energy output from the battery, the team of engineers at Relectrify has instead designed what they term a “BMS on steroids”.

This outputs full capacity for all cells that are functioning, rather than balancing the current between cells, in effect draining each cell completely to its safe end point voltage each cycle.
It’s a neat ‘plug and play’ system—a circuit board screwed atop the battery screw terminals (or welded if needed) that optimises at the cell level to use all the energy in the cell. It can work with lithium ion batteries as well as other types, including nickel-metal hydride—any that have a ‘contained’ battery chemistry, so not flow batteries, for example.

Firmware updates to the algorithm can be delivered via the cloud, so as they improve the technology, existing systems can benefit.

Read the full article in ReNew 141.

Desert Rose render

A net zero energy home

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A net zero energy home for desert conditions is the mission of the next international Solar Decathlon, but the University of Wollongong’s entry could have applicability far beyond the competition.

The University of Wollongong’s entry in the next international Solar Decathlon is perhaps aptly named. It’s called the Desert Rose, after a plant that can cope with the tough conditions the team will encounter when they build and operate their sustainable house design in the host city, Dubai, in November next year.

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With temperatures of 35+°C every day, less than 2 mm of rain for the month and desert sands that present problems for both greenery and solar panels alike, there are certainly challenges ahead.

Student-led sustainable innovation
What is the Solar Decathlon? Sometimes called the Energy Olympics, the decathlon was started in 2000 by the US Department of Energy to encourage innovation in sustainable, renewably-powered residential buildings.

The contest challenges university student teams to not only design, but also build and operate a home that produces more energy than it consumes—a net zero energy home.

The University of Wollongong (and Australia) first competed in 2013. Amazingly, that entry, the Illawarra Flame (www.illawarraflame.com.au/house.php), won with the “highest score ever recorded,” says a suitably proud Brendan Banfield, building services manager for the 2018 team.

It’s a crash course in construction for the student competitors. The houses they design get built, dismantled and rebuilt, perhaps many times over the course of the competition.

In 2013, the Illawarra Flame was built and dismantled twice before its journey in seven 40-foot containers to that year’s Chinese host city. It took 12 weeks to build the first time (in a warehouse in Wollongong), but then just five days to dismantle and ten to re-assemble on site in China.

It’s an undertaking that gives the student competitors—from diverse fields including engineering, architecture, health, arts, business and communications—incredible hands-on experience in design, construction and problem-solving.

In fact, a US Department of Energy survey (covering four solar decathlons from 2002 to 2009; see www.bit.ly/2jgguaf) found some 76% of past competitors went on to jobs in the sustainable building and clean energy sector, compared to just 16% of non-competing fellow students (and 92% found the competition critical to their job-seeking).

Brendan says, “The technology used or invented is typically five years ahead of the market and 10 years ahead of the building code, giving competitors an ‘edge’ when seeking work or starting a business”—some 16% of those surveyed had started their own sustainability business as a result.

Read the full article in ReNew 141.

Read more about the Desert Rose team and their entry here.

Saltwater_Batteries

Saltwater batteries in use

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When the old battery bank gave out, it was back to diesel for a time at this significant conservation site in the Mallee. But an innovative off-grid upgrade has changed that and led to a significant improvement over the old system, as Trust for Nature’s Chris Lindorff and Tiffany Inglis explain.

UP IN the Mallee, along the River Murray in far north-west Victoria, lies Neds Corner Station, a former sheep property now being restored as a significant natural habitat by the not-for-profit Trust for Nature.

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With an extreme climate—temperatures soar close to 50 °C in summer and frosts occur in winter—and no grid connection, this 30,000 hectare (300 km2) property presents challenges not only for habitat restoration, but also for the off-grid energy system needed to support the on-site rangers and visitors.

Purchased by conservation organisation Trust for Nature in 2002, the site is now home to two rangers and up to 30 visitors at a time: researchers and students studying the flora and fauna; bird groups conducting site surveys; works crews working on neighbouring public land; volunteers assisting with site restoration tasks such as reducing rabbit numbers, replanting local species and installing fences to keep out foxes; and the occasional corporate days and camping trips.

The site includes a homestead, shearer’s huts (used as accommodation), kitchens and conference/workshop rooms, with associated energy needs for heating/cooling, lighting, water pumping, refrigeration and gas cooking.

Energy system, take 1
When the property was first bought by Trust for Nature, the site ran solely on a diesel generator. Then, in 2012, philanthropic donations enabled the installation of a solar power system with a lead-acid battery bank. The system was designed to cater for an average of 25 kWh/day energy use, with a 25 kVA diesel generator as backup.

Over the following years, however, more people came to Neds Corner and energy demand increased, which led to the generator running more often than not.

Frequent, heavy cycling of the flooded lead-acid battery bank meant it performed poorly and reduced its lifespan. Following the failure of multiple battery cells in 2016, the battery bank was disconnected and the diesel generator again became the sole source of electricity.

Read the full article in ReNew 141.

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ATA member profile: Spreading the word on sustainability

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Long-time convenor of the ATA’s Perth branch, Travis Hargreaves tells Anna Cumming about his experiences in the retail solar sector and his real passion—educating people on sustainability and equipping them with the knowledge to continue the conversation.

ORIGINALLY from Melbourne, Travis Hargreaves took off around Australia on his motorbike when he was 20. “I went here, there and everywhere, then I ended up in Perth and met my partner, and the rest is history.” Travis has been in Perth ever since and is a stalwart of the sustainability movement there.

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“I always had an interest in sustainability and the environment,” says Travis.

Ten years ago he decided to get proactive and do some study in renewable energy; the TAFE in Perth didn’t offer a dedicated course, so instead, Travis was one of just two students that year who undertook a Diploma in Electrotechnology, which covered renewable energy as one of its four subject areas.

At the same time, he started up his first solar business: “The market was small at the time. I provided solar system design, sales and installation services for three solar retailers,” he explains. In 2010 he set up a solar retailer that services Perth and southern WA with solar and battery storage system design and installation.

Travis has far more on his plate than simply running his business though. When the ATA’s Perth branch was set up, Travis got involved and was swiftly asked to become the convenor, a role he’s held since 2009.

Through the activities of the ATA branch, Travis has become a sought-after speaker on sustainability and it’s this educational role that inspires him the most.

“Consumers are wanting to get past the talking and have the information to take action,” he says. “I started talking about energy efficiency and the importance of making those changes before investing in solar. Then I developed presentations on the basics of solar panels and battery storage, then about three years ago I started promoting electric vehicles, and now vehicle-to-grid technology.”

“I like my audience to leave inspired but also frustrated and wanting to push for change; I try to give them the knowledge to continue the conversation. Rather than bombarding them with technical information, I provide them with arguments for why we should be heading down this path so they can have conversations with their neighbours and explain the benefits—to living costs, local job creation and, of course, the environment.”



Lobbying for renewables and the jobs that go with it at the Rally for Renewables in Perth in 2014.


Travis has been involved with several other environmental advocacy groups. He was the WA branch president of the Australian Solar Council in 2014 and 2015, and instrumental in the 2014 Rally for Renewables campaign in Perth which brought together a host of organisations to lobby for legislation favouring renewable energy.

He’s also proud of a successful joint campaign to protest and reverse the WA state government’s decision to remove the solar feed-in tariff in 2013.

While Tony Abbott was prime minister, local representatives from both the Australian Solar Council and Clean Energy Council met with Liberal senators in WA to discuss local renewable energy and the potential benefits to the community.

It was useful education for Travis. “I think we were successful to a certain extent, but I also became aware of how the politics around renewable energy worked. They understood, but were toeing the party line.”

Travis is quietly keen to keep on pushing for change. “I got involved with the ATA because of its independent voice and its mission to provide information to the community. That’s what I continue to do today—use my knowledge to educate and influence people and inspire them to take action.”

This member profile is published in Renew 141. Buy your copy here.

MaxBoegl_windwater

News: Innovative water battery

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Pumped hydroelectric storage to help maintain grid stability is not a new approach for the energy industry—indeed, it was first used in the USA in 1930. However, German wind turbine manufacturer Max Bögl Wind AG has introduced an innovative twist, which they showcased at the Energy Storage North America (ESNA) fair in San Diego in August. The ‘water battery’ combines renewable power generation with a modern pumped-storage power plant to be used in periods of high demand. The pumped-storage power plant is available in three performance classes (16, 24 or 32 MW) and can switch between production and storage within 30 seconds.

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The first project to use the technology is being developed in Stuttgart, Germany. It comprises a windfarm of four turbines, each of which have tower bases with in-built water storage capacity of 70 MWh. These are connected to a hydroelectric power station with 16 MW installed capacity and a lower reservoir in the valley 200 m below.
www.bit.ly/MBWAGWB

Feature image: This windfarm in Stuttgart, Germany, is using wind turbines combined with pumped hydro for energy storage, with water stored at the base of the turbines! Image: courtesy Solar Consulting

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Energy justice for First Nations communities

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Aboriginal representatives at the Community Energy Congress have formed an alliance to achieve affordable renewable energy for First Nations communities. Kate Greenwood writes that the ATA is honoured to be part of this process.

ONE OF the highlights of the second Community Energy Congress, held in Melbourne in February this year, was hearing the voices of 13 Aboriginal leaders sharing their personal and powerful stories of what energy justice means to their communities. For some, it is literally a matter of whether they can remain on their ancestral land.

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The Aboriginal leaders took to the stage alongside Melina Laboucan-Massimo and Chief Gordon Planes from Canada. In contrast to the enormous energy security challenges faced by Australia’s First Nations communities, in Canada 50% of community energy is owned by First Nations people. Having delegates from Canada inspired everybody and enabled participants to realise the transformational possibilities of community energy.

In special breakout sessions of the congress, those communities negatively affected by resource extraction, dependence on fossil fuels and climate change met to talk about how renewable energy can be part of a story of hope and a catalyst for change, renewing and regenerating their communities. While the bigger goal for Aboriginal communities is self-determination and sustainable nationhood, renewable energy is a means to get there.

One of the most exciting moments of the congress, on day two, was the launch of the First Nations Renewable Energy Alliance, formed by Aboriginal representatives in attendance.

Fred Hooper of the Murriwarri Nation highlighted the massive change of direction. “We go to government all the time,” he said. “And yet for 200 years the government has been putting us down. This congress has opened our eyes.” He said the power of people to galvanise and make an immediate impact was clear. “What this congress has given us is a chance to get people in one place and build something for us, in partnership with all of you in the audience today.”

Read the full article in ReNew 140.

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Capital improvements: The path to all-electric

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Switching to electric appliances wasn’t really thought of as economically or environmentally beneficial 10 years ago when Ben Elliston’s household started their efficiency improvements, so theirs has been a gradual path to all-electric. By Robyn Deed.

You could call Ben Elliston’s household a ‘poster child’ for getting off gas, but that’s not how it began. Rather, when they started the process to improve the efficiency of their Canberra home 10 years ago, the family’s mindset was aligned with the message at that time that gas was a cheaper and relatively clean fuel, compared to grid electricity. Ten years on and several ‘face-palm-why-did-we do-that’ moments later, they are now enthusiastically all-electric, with their energy use, operating costs and greenhouse gas emissions all pleasingly reduced—and with some added advantages of their new electric appliances that they didn’t expect.

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Looking back, Ben says one of the biggest shifts has been in what a state-of-the-art electric appliance looks like. From the simple electric element appliances of the 80s (the coil cooktop, electric blow heaters and electric element tanks), many of the newer appliances offer not only lower running costs—over both gas and older electric units—but also safety and other benefits. Ben says, “There were lots of advantages we hadn’t anticipated when we shifted to electric appliances. For example, our induction cooktop has smarts to switch off if it senses that a pot is too hot and has run dry; our heat pump air conditioner is also much quieter than our old gas wall heater.”

The other major factor for Ben’s family is environmental. With the ACT now well on the way to 100% renewable electricity by 2020, Ben says, “In 2020, our household will be net zero emissions, which would not be possible if we were still using any gas appliances.”

Read the full article in ReNew 140This article is based on a talk given by Ben Elliston at the ATA’s Canberra branch meeting in April 2017 and an interview with Ben. Click here for slides from the talk.

Capture

Solar sizing: big returns

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Why it’s now advisable to ‘go big’ when installing a solar system, even if you don’t use much electricity: Andrew Reddaway presents the latest ATA modelling.

Many people ask us what size grid-connected solar system they should get. Traditionally, the ATA (ReNew’s publisher), has advised people to consider this carefully. If you primarily want to help the environment and cost is of little concern, it has always made sense to install as many panels as possible, as all their generation displaces electricity from dirty, centralised power plants. But most people have budgetary constraints, so their solar system needs to make economic sense as well as help the environment. To achieve this, we’ve previously recommended that people size a solar system based on their electricity consumption and maximise their other opportunities, such as energy efficiency. However, things have changed.

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Two big changes

1. Solar system prices

The last five years have seen significant price reductions, especially for larger solar systems. Prices vary with component quality and location, but on average a 5 kW solar system now costs around $6200 according to Solar Choice’s residential price benchmark data.

Let’s compare a 5 kW system to its smaller 2 kW cousin. To compare two different system sizes, the cost is presented in dollars per watt. Figure 1 reveals that since August 2012, the larger systems have halved in price, while the smaller ones have dropped by only a quarter.

Larger systems have always enjoyed economies of scale compared to smaller systems, because while the installer is on the roof it’s relatively easy for them to add more panels. One difference now is that the price of solar panels has fallen faster than other components. The industry has also become more familiar with larger systems, as they are now more frequently installed than small ones.

2. Feed-in tariffs

The Victorian government recently announced that solar feed-in tariffs will rise to 11.3 c/kWh from 1 July 2017, roughly double their previous level, and IPART has recently recommended a similar change in NSW. These changes are primarily due to wholesale electricity prices in the eastern states roughly doubling over the past year to around 10 c/kWh. We expect other states to follow suit, as feed-in tariffs below the wholesale electricity price are clearly unfair to people with solar. (In WA, a similar rise in wholesale rates hasn’t occurred, but prices might still rise due to the state government winding back its subsidy of electricity prices.)

What this means for solar system sizing

Given these changes, if you’re planning a solar system, is it worth it to upsize from, say, 2 kW to 5 kW?

The extra panels will be relatively cheap but more of their generation will be exported, which doesn’t help the economics.For example, depending on household consumption, a solar system rated at 5 kW might export 80% of its generation. Electricity exported to the grid only earns the feed-in tariff, ranging from 5 c to 14 c per kWh, depending on your location and electricity plan. Solar electricity used on-site, rather than exported, saves you paying the grid tariff, typically around 20 c to 35 c per kWh.

Surprisingly, our modelling of the economics found that a 5 kW system now has a shorter or equivalent payback time to the 2 kW system. We studied the economics by simulating a large number of scenarios in half-hour intervals for a whole year using Sunulator, ATA’s free solar feasibility calculator.

Our primary economic measure is payback time, the number of years until bill savings recoup the installation cost—the fewer years the better. Payback times shorter than 10 years are generally considered attractive to solar customers, as the system is likely to pay for itself before any significant expenses, such as replacing the inverter. The panels should last at least 20 years, so cumulative bill savings are large, especially for a larger system.

To do the modelling, we assumed a feed-in tariff of 11.3 c/kWh in Victoria and in other states a doubling of feed-in tariffs from current levels, phased in over the next five years. We considered common grid tariffs in each capital city, for a variety of household consumption profiles, along with likely tariff increases (we used AEMO’s retail tariff forecasts, but since they were based on Hazelwood closing in 2020, which happened this year, we pulled them forward by three years; this allows for annual tariff rises between 1.5% for Queensland and 3.4% for Tasmania). Panels are assumed to be north-facing with a 20-degree tilt. Our analysis also includes panel degradation over time.

Read the full article in ReNew 140The full report on solar sizing, including references, is available at www.ata.org.au/news/bigger-solar-is-better-ata-report

 

Pomona

Battery storage gets competitive

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It seems the convergence of environmental realities and the economics of renewables is finally escalating apace. While large-scale wind and solar farms have been the big focus of the last few years (and continue to be), large-scale battery storage has become ‘the next big thing’.

Globally and domestically, governments and corporations are rolling out big storage projects that will provide the missing link between renewable energy generation and grid stabilisation/meeting peak demand.

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In a few months, Germany will accept delivery of Europe’s biggest battery—a 48 MW/50 MWh lithium-ion unit—that will help provide grid stability in the Jardelund region near the border with Denmark, which currently relies on intermittent wind power. In the USA, its largest battery storage facility, the 20 MW/80 MWh Pomona Energy Storage Facility in Southern California, opened in January this year. India’s first (10 MW) grid-scale battery storage system was also launched in January, and Bloomberg New Energy Finance is slating that 800 MW of storage could be commissioned by 2020.

In Australia, in the wake of South Australia’s recent ‘crisis’ of energy supply, a key response from the SA Government has been to support the construction (by winning tender, before year’s end) of a 100 MW battery —Australia’s largest to date—with $150 m from a renewable technology fund. There have been 90 expressions of interest from 10 countries. [Update: this tender has now been awarded.]

One of the companies competing, Australia’s Lyon Group, has said that, regardless of the outcome of the tender process, it will build a $1 b battery and solar farm—believed to be the world’s biggest—by the end of this year, in SA’s Riverland region: 3.4 million solar panels and 1.1 million batteries will generate 330 MW of electricity and provide 100 MW/400 MWh of battery storage (depending on configuration). The project is fully financed, with grid connection already well progressed. The company’s 120 MW solar/100 MW/200 MWh battery Kingfisher project in SA’s Roxby Downs is also due to start construction in September 2017, to be running by June 2018. A third smaller storage project of 20MW/80MWh is also being developed on Cape York.

The Victorian Government recently announced a $20 m tender, as part of its $25 m Storage Initiative, which calls for proposals detailing the construction of large-scale storage facilities in the state’s west. Applications close mid-June and, from the process, the government aims to deploy up to two projects that will provide at least 100 MWh of battery storage by January 2018.

The ACT’s Next Generation Storage Program is committed to providing around 36 MW of distributed battery storage, through subsidised residential batteries, which plans to see 5000 homes signed up by 2020. And in the Northern Territory, results of a tender for 5 MW of battery storage (the nation’s largest, until the SA and Vic announcements, above) are about to be released.

Feature image: A peek into the Pomona Energy Storage Facility; at 20 MW/80 MWh, currently the largest in the USA. Image: Pomona Energy Storage, courtesy AltaGas Ltd

Hydrogen fuel cell powered train

Hydrogen as a fuel – is it viable?

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

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

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

 

What is a hydrogen fuel cell vehicle?

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

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

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

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

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

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

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

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

Read the full article in ReNew 139.