Archive for the ‘energy’ Category

The huge carbon footprint and massive energy use of online activities and of Bitcoin

May 3, 2021
Graphic courtesy of Alice Eaves on Rehabilitating Earth website

This is a most timely article.    Why is  the world not noticing this?   Elon Musk and other billionaire Bitcoin fans are also fans of space travel –   another energy-gobbling thing.   They are fans of nuclear energy.  The thing that nuclear energy fans have in common with space travel fans and Bitcoin fans is their religious fervour for endless growth and endless energy use.

Unfortunately our entire culture, the Western consumer culture, has swept the world  with a mindless belief in ever more stuff, ever more digital use, with no awareness of the  energy used.   So we tink that our billions of trivial tweets are up ”in the cloud”, – not even realising that they are in dirty great steel data buildings that use massive amounts of energy just to keep cool, This ever- expanding energy and resource gobbling is going to kill us, – and Bitcoin is just one glaring, sorry example of this.

Truth or fiction: Is mining bitcoin a ticking time bomb for the climate?  Rehabilitating Earth   By Jennifer Sizeland 2 May 21

While many of us may consider the carbon footprint of buying a physical item like a jumper or a toaster, it is truly mind boggling to think about the environmental impact of time spent online. This may be why the huge carbon footprints of cryptocurrencies like bitcoin are going largely under the radar for many of us, including investors and climate activists.

Yet the real-world cost of bitcoin cannot be underestimated. A University of Cambridge study found that the network burns through 121 terawatt-hours per year, putting it into a category of a top-30 country in terms of electricity usage. In fact, the carbon cost was largely ignored altogether until 2017 when prices surged and the general population started to take more notice. Aside from the significant carbon footprint of bitcoin, it’s important to understand what bitcoin is and why it’s so popular.

Decoding Cryptocurrencies

Bitcoin is created by mining a 64-digit hexadecimal number (known as a ‘hash’) that is less than or equal to the target hash that the miner is looking for. The miner gets paid in crypto tokens for all the currency they make. The act of solving these computational equations on the bitcoin network makes the payment network trustworthy. It proves the worth of the bitcoin and verifies it at the same time so that it can’t be spent twice. Essentially, an online log makes records of the transactions made and once approved, they’re added to a block on the chain, hence the phrase ‘blockchain’.

What makes it all the more confusing is that not only is cryptocurrency fairly new to the general population, but the way it is created is shrouded in secrecy due to its niche status. This makes it much harder for miners to be held accountable for their intensive carbon usage, in a time when every company needs to consider their impact on the planet.

The secrecy is also what excites investors about bitcoin since it isn’t tied to a certain location or institution and it’s completely decentralised – unlike a bank. Investors trust bitcoin as inflation is controlled algorithmically by cutting the reward rate periodically, rendering the rate of new bitcoin supplies as unalterable by design. The issue remains that there is no government or organisation to hold them to account for their carbon footprint. A footprint which is intrinsically tied to its value as the demand for it increases, using more and more energy. With every market jump, the cost to the planet is greater.

The price of one bitcoin is $57,383 at the time of writing, which takes the market cap value above that of Facebook and Tesla. The wider cryptocurrency market that includes dogecoin, ethereum and litecoin has reached an estimated $1.4 trillion and counting.

From a financial perspective, miners want cheap servers to increase their profit margins which is why much of the bitcoin activity is done in China. As the industry is unregulated there is no reason why activity wouldn’t surge in the place where it costs the least to do it. Currently, China does not have a cost-effective renewable energy supply so two thirds of the grid is fuelled by dirty coal power stations.

Another problematic caveat to the bitcoin story is the amount of so-called green companies and investors that are buying into it. Some of them are not disclosing this element of their portfolio due to the immense carbon footprint but those that are publicly traded have no choice. Perhaps one of the most high-profile companies to reap the rewards from bitcoin is Elon Musk’s Tesla, who have made $1 billion in 10 weeks from their investment. It remains to be seen whether these businesses are doing their due diligence regarding the origins of their bitcoin and if it is mined from a sustainable source. While this may give Tesla more money to invest in green infrastructure, it’s hard to say whether this is the more ethical way to do so……….

One important lesson we can take from this is that it demonstrates how the digital world has a very real impact on planet Earth. Whether we’re buying cryptocurrency or simply scrolling the internet, we are impacting the planet in one way or another

Solar sails for space voyages

February 18, 2021

Nuclear Rockets to Mars?, BY KARL GROSSMAN– CounterPunch, 16 Feb 21,”………. As for rocket propulsion in the vacuum of space, it doesn’t take much conventional chemical propulsion to move a spacecraft—and fast.

And there was a comprehensive story in New Scientist magazine this past October on “The new age of sail,” as it was headlined. The subhead: “We are on the cusp of a new type of space travel that can take us to places no rocket could ever visit.”

The article began by relating 17th Century astronomer Johanne Kepler observing comets and seeing “that their tails always pointed away from the sun, no matter which direction they were traveling. To Kepler, it meant only one thing: the comet tails were being blown from the sun.”

Indeed, “the sun produces a wind in space” and “it can be harnessed,” said the piece. “First, there are particles of light streaming from the sun constantly, each carrying a tiny bit of momentum. Second, there is a flow of charged particles, mostly protons and electrons, also moving outwards from the sun. We call the charged particles the solar wind, but both streams are blowing a gale”—that’s in the vacuum of space.

Japan launched its Ikaros spacecraft in 2010—sailing in space using the energy from the sun. The LightSail 2 mission of The Planetary Society was launched in 2019—and it’s still up in space, flying with the sun’s energy.

New systems using solar power are being developed – past the current use of thin-film such as Mylar for solar sails.

The New Scientist article spoke of scientists “who want to use these new techniques to set a course for worlds currently far beyond our reach—namely the planets orbiting our nearest star, Alpha Centauri.”……. more

India’s nuclear power programme unlikely to progress. Ocean energy is a better way.

August 18, 2019

The problem is apparently nervousness about handling liquid Sodium, used as a coolant. If Sodium comes in contact with water it will explode; and the PFBR is being built on the humid coast of Tamil Nadu. The PFBR has always been a project that would go on stream “next year”. The PFBR has to come online, then more FBRs would need to be built, they should then operate for 30-40 years, and only then would begin the coveted ‘Thorium cycle’!

Why nuclear when India has an ‘ocean’ of energy,

M. Ramesh – 30 June 19 Though the ‘highly harmful’ source is regarded as saviour on certain counts, the country has a better option under the seas

If it is right that nothing can stop an idea whose time has come, it must be true the other way too — nothing can hold back an idea whose time has passed.

Just blow the dust off, you’ll see the writing on the wall: nuclear energy is fast running out of sand, at least in India. And there is something that is waiting to take its place.

India’s 6,780 MW of nuclear power plants contributed to less than 3% of the country’s electricity generation, which will come down as other sources will generate more.

Perhaps India lost its nuclear game in 1970, when it refused to sign – even if with the best of reasons – the Non Proliferation Treaty, which left the country to bootstrap itself into nuclear energy. Only there never was enough strap in the boot to do so.

In the 1950s, the legendary physicist Dr. Homi Bhabha gave the country a roadmap for the development of nuclear energy.

Three-stage programme

In the now-famous ‘three-stage nuclear programme’, the roadmap laid out what needs to be done to eventually use the country’s almost inexhaustible Thorium resources. The first stage would see the creation of a fleet of ‘pressurised heavy water reactors’, which use scarce Uranium to produce some Plutonium. The second stage would see the setting up of several ‘fast breeder reactors’ (FBRs). These FBRs would use a mixture of Plutonium and the reprocessed ‘spent Uranium from the first stage, to produce energy and more Plutonium (hence ‘breeder’), because the Uranium would transmute into Plutonium. Alongside, the reactors would convert some of the Thorium into Uranium-233, which can also be used to produce energy. After 3-4 decades of operation, the FBRs would have produced enough Plutonium for use in the ‘third stage’. In this stage, Uranium-233 would be used in specially-designed reactors to produce energy and convert more Thorium into Uranium-233 —you can keep adding Thorium endlessly.

Seventy years down the line, India is still stuck in the first stage. For the second stage, you need the fast breeder reactors. A Prototype Fast Breeder Reactor (PFBR) of 500 MW capacity, construction of which began way back in 2004, is yet to come on stream.

The problem is apparently nervousness about handling liquid Sodium, used as a coolant. If Sodium comes in contact with water it will explode; and the PFBR is being built on the humid coast of Tamil Nadu. The PFBR has always been a project that would go on stream “next year”. The PFBR has to come online, then more FBRs would need to be built, they should then operate for 30-40 years, and only then would begin the coveted ‘Thorium cycle’! Nor is much capacity coming under the current, ‘first stage’. The 6,700 MW of plants under construction would, some day, add to the existing nuclear capacity of 6,780 MW. The government has sanctioned another 9,000 MW and there is no knowing when work on them will begin. These are the home-grown plants. Of course, thanks to the famous 2005 ‘Indo-U.S. nuclear deal’, there are plans for more projects with imported reactors, but a 2010 Indian ‘nuclear liability’ legislation has scared the foreigners away. With all this, it is difficult to see India’s nuclear capacity going beyond 20,000 MW over the next two decades.

Now, the question is, is nuclear energy worth it all?

There have been three arguments in favour of nuclear enFor Fergy: clean, cheap and can provide electricity 24×7 (base load). Clean it is, assuming that you could take care of the ticklish issue of putting away the highly harmful spent fuel.

But cheap, it no longer is. The average cost of electricity produced by the existing 22 reactors in the country is around ₹2.80 a kWhr, but the new plants, which cost ₹15-20 crore per MW to set up, will produce energy that cannot be sold commercially below at least ₹7 a unit. Nuclear power is pricing itself out of the market. A nuclear power plant takes a decade to come up, who knows where the cost will end up when it begins generation of electricity?

Nuclear plants can provide the ‘base load’ — they give a steady stream of electricity day and night, just like coal or gas plants. Wind and solar power plants produce energy much cheaper, but their power supply is irregular. With gas not available and coal on its way out due to reasons of cost and global warming concerns, nuclear is sometimes regarded as the saviour. But we don’t need that saviour any more; there is a now a better option.

Ocean energy

The seas are literally throbbing with energy. There are at least several sources of energy in the seas. One is the bobbing motion of the waters, or ocean swells — you can place a flat surface on the waters, with a mechanical arm attached to it, and it becomes a pump that can be used to drive water or compressed air through a turbine to produce electricity. Another is by tapping into tides, which flow during one part of the day and ebb in another. You can generate electricity by channelling the tide and place a series of turbines in its path. One more way is to keep turbines on the sea bed at places where there is a current — a river within the sea. Yet another way is to get the waves dash against pistons in, say, a pipe, so as to compress air at the other end. Sea water is dense and heavy, when it moves it can punch hard — and, it never stops moving.

All these methods have been tried in pilot plants in several parts of the world—Brazil, Denmark, U.K., Korea. There are only two commercial plants in the world—in France and Korea—but then ocean energy has engaged the world’s attention.

For sure, ocean energy is costly today.

India’s Gujarat State Power Corporation had a tie-up with U.K.’s Atlantic Resources for a 50 MW tidal project in the Gulf of Kutch, but the project was given up after they discovered they could sell the electricity only at ₹13 a kWhr. But then, even solar cost ₹18 a unit in 2009! When technology improves and scale-effect kicks-in, ocean energy will look real friendly.

Initially, ocean energy would need to be incentivised, as solar was. Where do you find the money for the incentives? By paring allocations to the Department of Atomic Energy, which got ₹13,971 crore for 2019-20.

Also, wind and solar now stand on their own legs and those subsidies could now be given to ocean energy.

How our electricity system of the future could be powered by sun, wind and waves

April 7, 2019

Our electricity system of the future could be powered by sun, wind and waves @nickymison

Response to ‘Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems’

November 3, 2018

Science Direct 18 May 18 

Scientists refute Ben Heard’s paper opposing reneweable energy

November 3, 2018

Can we get 100 percent of our energy from renewable sources? New article gathers the evidence to address the sceptics LAPPEENRANTA UNIVERSITY OF TECHNOLOGY 

Is there enough space for all the wind turbines and solar panels to provide all our energy needs? What happens when the sun doesn’t shine and the wind doesn’t blow? Won’t renewables destabilise the grid and cause blackouts?

In a review paper last year in the high-ranking journal Renewable and Sustainable Energy Reviews, Master of Science Benjamin Heard (at left) and colleagues presented their case against 100% renewable electricity systems. They doubted the feasibility of many of the recent scenarios for high shares of renewable energy, questioning everything from whether renewables-based systems can survive extreme weather events with low sun and low wind, to the ability to keep the grid stable with so much variable generation.

Now scientists have hit back with their response to the points raised by Heard and colleagues.The researchers from the Karlsruhe Institute of Technology, the South African Council for Scientific and Industrial Research, Lappeenranta University of Technology, Delft University of Technology and Aalborg University have analysed hundreds of studies from across the scientific literature to answer each of the apparent issues. They demonstrate that there are no roadblocks on the way to a 100% renewable future.

“While several of the issues raised by the Heard paper are important, you have to realise that there are technical solutions to all the points they raised, using today’s technology,” says the lead author of the response, Dr. Tom Brown of the Karlsruhe Institute of Technology.

“Furthermore, these solutions are absolutely affordable, especially given the sinking costs of wind and solar power,” says Professor Christian Breyer of Lappeenranta University of Technology, who co-authored the response.

Brown cites the worst-case solution of hydrogen or synthetic gas produced with renewable electricity for times when imports, hydroelectricity, batteries, and other storage fail to bridge the gap during low wind and solar periods during the winter. For maintaining stability there is a series of technical solutions, from rotating grid stabilisers to newer electronics-based solutions. The scientists have collected examples of best practice by grid operators from across the world, from Denmark to Tasmania.

The response by the scientists has now appeared in the same journal as the original article by Heard and colleagues.

“There are some persistent myths that 100% renewable systems are not possible,” says Professor Brian Vad Mathiesen of Aalborg University, who is a co-author of the response.

“Our contribution deals with these myths one-by-one, using all the latest research. Now let’s get back to the business of modelling low-cost scenarios to eliminate fossil fuels from our energy system, so we can tackle the climate and health challenges they pose.”

For more information, please contact:

Tom Brown, Young Investigator Group Leader, Karlsruhe Institute of Technology |

Kornelis Blok, Professor, Delft University of Technology |

Christian Breyer, Professor, Lappeenranta University of Technology |

Brian Vad Mathiesen, Professor, Aalborg University |

The research papers for further information:

T.W. Brown, T. Bischof-Niemz, K. Blok, C. Breyer, H. Lund, B.V. Mathiesen, “Response to ‘Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems’,” Renewable and Sustainable Energy Reviews, DOI:10.1016/j.rser.2018.04.113, 2018.

B.P. Heard, B.W. Brook, T.M.L. Wigley, C.J.A. Bradshaw, “Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems,” Renewable and Sustainable Energy Reviews, DOI:10.1016/j.rser.2017.03.114, 2017.

Response to ‘Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems’

October 9, 2018

Science Direct 18 May 18 

Energy Hogs: Can World’s Huge Data Centers Be Made More Efficient?

June 2, 2018

Energy Hogs: Can World’s Huge Data Centers Be Made More Efficient?
The gigantic data centers that power the internet consume vast amounts of electricity and emit 3 percent of global CO2 emissions. To change that, data companies need to turn to clean energy sources and dramatically improve energy efficiency.
 Yale  Environment 360   

The cloud is coming back to Earth with a bump. That ethereal place where we store our data, stream our movies, and email the world has a physical presence – in hundreds of giant data centers that are taking a growing toll on the planet.

Data centers are the factories of the digital age. These mostly windowless, featureless boxes are scattered across the globe – from Las Vegas to Bangalore, and Des Moines to Reykjavik. They run the planet’s digital services. Their construction alone costs around $20 billion a year worldwide.

The biggest, covering a million square feet or more, consume as much power as a city of a million people. In total, they eat up more than 2 percent of the world’s electricity and produce 3 percent of CO2 emissions, as much as the airline industry. And with global data traffic more than doubling every four years, they are growing fast.

Yet if there is a data center near you, the chances are you don’t know about it. And you still have no way of knowing which center delivers your Netflix download, nor whether it runs on renewable energy using processors cooled by Arctic air, or runs on coal power and sits in desert heat, cooled by gigantically inefficient banks of refrigerators.

We are often told that the world’s economy is dematerializing – that physical analog stuff is being replaced by digital data, and that this data has minimal ecological footprint. But not so fast. If the global IT industry were a country, only China and the United States would contribute more to climate change, according to a Greenpeace report investigating “the race to build a green internet,” published last year.

Storing, moving, processing, and analyzing data all require energy. Lots of it. The processors in the biggest data centers hum with as much energy as can be delivered by a large power station, 1,000 megawatts or more. And it can take as much energy again to keep the servers and surrounding buildings from overheating.

Almost every keystroke adds to this. Google estimates that a typical searchusing its services requires as much energy as illuminating a 60-watt light bulb for 17 seconds and typically is responsible for emitting 0.2 grams of CO2. Which doesn’t sound a lot until you begin to think about how many searches you might make in a year.

And these days, Google is data-lite. Streaming video through the internet is what really racks up the data count. IT company Cisco, which tracks these things, reckons video will make up 82 percent of internet traffic by 2021, up from 73 percent in 2016. Around a third of internet traffic in North America is already dedicated to streaming Netflix services alone.

Two things matter if we are to tame these runaway beasts: One is making them use renewable or other low-carbon energy sources; the other is ramping up their energy efficiency. On both fronts, there is some good news to report. Even Greenpeace says so. “We are seeing a significant increase in the prioritization of renewables among some of the largest internet companies,” last year’s report concluded.

More and more IT companies are boasting of their commitment to achieving 100 percent reliance on renewable energy. To fulfil such pledges, some of the biggest are building their own energy campuses. In February, cloud giant Switch, which runs three of the world’s top 10 data centers, announced plansfor a solar-powered hub in central Nevada that will be the largest anywhere outside China.

More often, the data titans sign contracts to receive dedicated supply from existing wind and solar farms. In the U.S., those can still be hard to come by. The availability of renewable energy is one reason Google and Microsoft have recently built hubs in Finland, and Facebook in Denmark and Sweden. Google last year also signed a deal to buy all the energy from the Netherlands’ largest solar energy park, to power one of its four European data centers.

Of the mainstream data crunchers for consumers, Greenpeace singled out Netflix for criticism. It does not have its own data centers. Instead, it uses contractors such as Amazon Web Services, the world’s largest cloud-computing company, which Greenpeace charged with being “almost completely non-transparent about the energy footprint of its massive operations.” Amazon Web Services contested

this. A spokesperson told Yale Environment 360 that the company had a “long-term commitment to 100 percent renewable energy” and had launched a series of wind and solar farm projects now able to deliver around 40 percent of its energy. Netflix did not respond to requests for comment.

Amazon Web Services has some of its largest operations in Northern Virginia, an area just over the Potomac River from Washington D.C. that has the largest concentration of data centers in the world. Virginia gets less than 3 percent of its electricity from renewable sources, plus 33 percent from nuclear, according to Greenpeace.

Some industry insiders detect an element of smoke and mirrors in the green claims of the internet giants. “When most data center companies talk about renewable energy, they are referring to renewable energy certificates,” Phillip Sandino, vice-president of data centers at RagingWire, which has centers in Virginia, California, and Texas, claimed in an online trade journal recently. In the U.S. and some other countries, renewable energy certificates are issued to companies generating renewable energy for a grid, according to the amount generated. The certificates can then be traded and used by purchasers to claim their electricity is from a renewable source, regardless of exactly where their electricity comes from. “In fact,” Sandino said, “the energy [the data centers] buy from the power utility is not renewable.”

Others, including Microsoft, help sustain their claims to carbon neutrality through carbon offsetting projects, such as investing in forests to soak up the CO2 from their continued emissions.

All this matters because the differences in carbon emissions between data centers with different energy sources can be dramatic, says Geoff Fox, innovation chief at DigiPlex, which builds and operates centers in Scandinavia. Using data compiled by Swedish state-owned energy giant Vattenfall, he claims that in Norway, where most of the energy comes from hydroelectricity, generating a kilowatt-hour of electricity emits only 3 grams of CO2. By comparison, in France it is 100 grams, in California 300 grams, in Virginia almost 600 grams, in New Mexico more than 800 grams.

Meanwhile, there is growing concern about the carbon footprint of centers being built for Asian internet giants such as Tencent, Baidu, and Alibaba in China; Naver in South Korea; and Tulip Telecom in India. Asia is where the fastest global growth in data traffic is now taking place. These corporations have been tight-lipped about their energy performance, claims Greenpeace. But with most of the region’s energy coming from coal-fired power stations, their carbon footprint cannot be anything but large.

Vattenfall estimates the carbon emissions in Bangalore, home of Tulip’s giant Indian data center, at 900 grams per kilowatt-hour. Even more troubling, the world’s largest center is currently the Range International Information Hub, a cloud-data store at Langfang near the megacity of Tianjin in northeast China, where it takes more than 1,000 grams of CO2 for every kilowatt-hour.

Almost as important as switching data centers to low-carbon energy sources is improving their energy efficiency. Much of this comes down to the energy needed to keep the processors cool. Insanely, most of the world’s largest centers are in hot or temperate climates, where vast amounts of energy are used to keep them from overheating. Of the world’s 10 largest, two are in the desert heat of Nevada, and others are in Georgia, Virginia, and Bangalore.

Most would dramatically reduce their energy requirements if they relocated to a cool climate like Scandinavia or Iceland. One fast-emerging data hub is Iceland, where Verne Global, a London company, set up its main operation.

…….. Greenpeace says the very size of the internet business, and its exposure to criticism for its contribution to climate change, has the potential to turn it from being part of the problem to part of the solution. Data centers have the resources to change rapidly. And pressure is growing for them to do so.The hope is that they will bring many other giant corporations with them. “The leadership by major internet companies has been an important catalyst among a much broader range of corporations to adopt 100 percent renewable goals,” says Gary Cook, the lead author of the Greenpeace report. “Their actions send an important market signal.”

But the biggest signal, says Fox, will come from us, the digital consumers. Increasingly, he says, “they understand that every cloud lives inside a data center. And each has a different footprint.” We will, he believes, soon all demand to know the carbon footprint of our video streams and internet searches. The more far-sighted of the big data companies are gearing up for that day. “I fully expect we may see green labelling for digital sources as routine within five years.”

Solar energy: greenhouse emissions becoming lower – will be very low by 2018

February 1, 2017

How clean is solar power?

A new paper may have the answer

Dec 10th 2016 THAT solar panels do not emit greenhouse gases such as carbon dioxide when they are generating electricity is without question. This is why they are beloved of many who worry about the climate-altering potential of such gases. Sceptics, though, observe that a lot of energy is needed to make a solar panel in the first place. In particular, melting and purifying the silicon that these panels employ to capture and transduce sunlight needs a lot of heat. Silicon’s melting point, 1,414°C, is only 124°C less than that of iron.

Silicon is melted in electric furnaces and, at the moment, most electricity is produced by burning fossil fuels. That does emit carbon dioxide. So, when a new solar panel is put to work it starts with a “carbon debt” that, from a greenhouse-gas-saving point of view, has to be paid back before that panel becomes part of the solution, rather than part of the problem. Observing this, some sceptics have gone so far as to suggest that if the motive for installing solar panels is environmental (which is often, though not always, the case), they are pretty-much useless.

 Wilfried van Sark, of Utrecht University in the Netherlands, and his colleagues have therefore tried to put some numbers into the argument. As they report in Nature Communications, they have calculated the energy required to make all of the solar panels installed around the world between 1975 and 2015, and the carbon-dioxide emissions associated with producing that energy. They also looked at the energy these panels have produced since their installation and the corresponding amount of carbon dioxide they have prevented from being spewed into the atmosphere. Others have done life-cycle assessments for solar power in the past. None, though, has accounted for the fact that the process of making the panels has become more efficient over the course of time. Dr Van Sark’s study factors this in.

Panel games  To estimate the number of solar panels installed around the world, Dr Van Sark and his team used data from the International Energy Agency, an autonomous intergovernmental body. They gleaned information on the amount of energy required to make panels from dozens of published studies. Exactly how much carbon dioxide was emitted during the manufacture of a panel will depend on where it was made, as well as when. How much emitted gas it has saved will depend on where it is installed. A panel made in China, for example, costs nearly double the greenhouse-gas emissions of one made in Europe. That is because China relies more on fossil fuels for generating power. Conversely, the environmental benefits of installing solar panels will be greater in China than in Europe, as the clean power they produce replaces electricity that would otherwise be generated largely by burning coal or gas.

Once the team accounted for all this, they found that solar panels made today are responsible, on average, for around 20 grams of carbon dioxide per kilowatt-hour of energy they produce over their lifetime (estimated as 30 years, regardless of when a panel was manufactured). That is down from 400-500 grams in 1975. Likewise, the amount of time needed for a solar panel to produce as much energy as was involved in its creation has fallen from about 20 years to two years or less. As more panels are made, the manufacturing process becomes more efficient. The team found that for every doubling of the world’s solar capacity, the energy required to make a panel fell by around 12% and associated carbon-dioxide emissions by 17-24%.

The consequence of all this number-crunching is not as clear-cut as environmentalists might hope. Depending on the numbers fed into the model, global break-even could have come as early as 1997, or might still not have arrived. But if it has not, then under even the most pessimistic assumptions possible it will do so in 2018. After that, solar energy’s environmental credentials really will be spotless.

Solar energy powers South Australia’s desert Sundrop Farms

November 21, 2016

Desert farm grows 180,000 tomato plants using only sun and seawater

Farms that grow food in arid deserts, without groundwater or fossil fuels, could be the future of agriculture. BRYAN NELSON October 10, 2016, No soil, no pesticides, no fossil fuels, and no groundwater. And yet, a thriving farm in the heart of the arid Australian desert. How is this possible?

An international team of scientists has spent the last six years fine-tuning a system that pipes seawater in from the ocean and desalinates it using a state-of-the-art concentrated solar energy plant. The water is then used to irrigate 180,000 tomato plants grown in coconut husks instead of soil, kept in a network of greenhouses.

The result is Sundrop Farms, a commercial-scale facility located just off the Spencer Gulf in South Australia that began construction in 2014. Today it’s producing an estimated 17,000 tons of tomatoes per year to be sold in Australian supermarkets.

Given the increasing demand for fresh water around the world — a problem that’s particularly apparent in the sunburned landscape of South Australia — this might just represent future of large-scale farming, especially in coastal desert regions that have previously been non-arable.

The heart of the farm is the 23,000 mirrors that reflect sunlight towards a 115-meter high receiver tower. All of that concentrated sunlight produces an immense amount of power, up to 39 megawatts. That’s more than enough to cover the desalination needs of the farm and supply all the electricity needs of the greenhouses.

The seawater, too, has other purposes besides just irrigation. During scorching hot summers, seawater-soaked cardboard lines the greenhouses to help keep the plants at optimal temperature. Seawater also has the remarkable effect of sterilizing the air, meaning that chemical pesticides are unnecessary.

All in all, the facility cost around 200 million dollars to get up and running. That might sound excessive, but in the long run the facility should save money compared to the costs of conventional greenhouses that require fossil fuels for power. It’s a self-sustaining, cost-efficient design so long as the initial investment can be provided. Facilities similar to the Australian one are already being planned for Portugal and the U.S., as well as another in Australia. Desert areas like those seen in Oman, Qatar and the United Arab Emirates could be next in line.

“These closed production systems are very clever,” said Robert Park of the University of Sydney, Australia, to New Scientist. “I believe that systems using renewable energy sources will become better and better and increase in the future, contributing even more of some of our foods.”