earth energy

How Will Pumped Hydro Energy Storage Power Our Future?

Pumped storage hydropower has proven to be an ideal solution to the growing list of challenges faced by grid operators.

As the transition to a clean energy future rapidly unfolds, this flexible technology will become even more important for a reliable, affordable and low carbon grid, write IHA analysts Nicholas Troja and Samuel Law.

“Anything that can go wrong will go wrong”. That old adage, Murphy’s law, must seem appropriate for many power grid operators in 2020.

This year has tested the safe running and reliability of grids around the world like few others. Often termed ‘the biggest machine ever built,’ managing a power system, involving the coordination of complex and instantaneous interactions, is a formidable task at the best of times.

With the impacts of the Covid-19 pandemic on top of extreme weather events, greater penetrations of variable renewables and increasingly aged thermal assets, the task has only become more demanding in many markets.

These challenges have brought into sharp focus the growing need for energy storage, such as that offered by pumped storage hydropower.

Recent events highlight the need for pumped storage

Covid-19 continues to have an extraordinary impact on electricity markets. During the height of worldwide lockdowns, with large sections of the economy shutdown or greatly impaired, electricity demand declined by up to 30 per cent in some countries across Europe and in India.

As Fatih Birol, Executive Director of the International Energy Agency (IEA) stated, the demand drop “fast forwarded some power systems 10 years into the future” regarding integrating higher percentages of variable renewable energy (VRE) which receive priority dispatch to the grid. Managing periods of such low demand can create “significant operational risks” for grid operators. In some markets, this has led to curtailing, or shutting down, wind and solar facilities to stabilise the grid.

During such periods, pumped storage hydropower, with its ability to both store and generate large quantities of energy over long periods, was the first port of call for those grid operators lucky enough to have such stations on hand. In Britain, its four pumped storage stations were hailed by the Financial Times newspaper as the “first line of defence in the battle to keep Britain’s lights on”. Able to increase system demand by pumping water back up to their upper reservoir, pumped storage is a more cost-effective way of managing the grid than paying operators to curtail variable supply.

In August, the U.S. state of California experienced rolling blackouts for the first time since 2001 due to a combination of record heatwaves driving up demand, faltering gas-fired stations and a lack of dispatchable generation. As Stephen Berberich, President of the California Independent System Operator (CAISO) said, “we thought there would be adequate power to supply the demand…we were wrong” and the costs to the Californian economy will be significant.

These managed blackouts provide yet another wake-up call for policymakers on the need to appropriately plan for a zero-emissions future. With limited balancing resources such as pumped storage, California’s grid did not have the flexibility to shift sufficient generating capacity to the evenings when the sun had set yet the demand remained high.

Given California’s aim of reaching 100 per cent clean electricity by 2045, mainly from wind and solar power which currently accounts for 20 per cent of generation, significant investment in flexible, low carbon balancing resources will be required.

In response, California is betting big on batteries for short-duration storage, from sub-seconds to up to four hours, to manage intraday variations in net load. However, with those high levels of VRE on the grid, long-duration storage, which can discharge for 10 hours or more at rated power, will be needed to accommodate the seasonal patterns of VREs. It will do so by shifting generation over days, weeks and months of supply and demand imbalance. This is a story that rings true for many countries across the world with ambitious climate targets.

Achieving California’s clean energy target is made even harder by the government’s decision to classify conventional hydropower stations greater than 30 MW as a non-renewable resource under its Renewables Portfolio Standard. This arbitrary classification is at odds with international consensus and penalises the state’s oldest source of affordable, flexible and low-carbon electricity.

Figure 1: Illustration of a closed-loop (off-river) pumped storage station and how it can be used support VRE.

Capabilities of pumped storage

With a total installed capacity of nearly 160 GW, pumped storage currently accounts for over 94 per cent of both storage capacity and stored energy in grid scale applications globally. This has earned pumped storage its name as the world’s “water battery”. It is a mature and reliable technology capable of storing energy for daily or weekly cycles and up to months, as well as seasonal applications, depending on project scale and configurations.

Pumped storage operates by storing electricity in the form of gravitational potential energy through pumping water from a lower to an upper reservoir (see figure 1). The result of this simple solution is a very high round-trip efficiency of 80 per cent, which compares favourably to other storage technologies.

Pumped storage tends to have high energy-to-power ratios and is well suited to provide long discharge durations at very low energy storage costs. Across different timescales, pumped storage can serve multiple functions (see figure 2). For example, at shorter discharge durations, it is suitable for ancillary services such as frequency balancing and back-up reserve.

With four to eight hours of discharge, it can provide daily shifting for day-night energy arbitrage. For longer durations over 10 hours, it can accommodate multi-day supply profile changes, reduce energy curtailment, replace peak generation capacity and provide transmission benefits.

Figure 2: The plot above visualises (logarithmic scale used) the estimated discharge durations relative to installed capacity and energy storage capacity for some 250 pumped storage stations currently in operation, based on information from IHA’s Pumped Storage Tracking Tool. The vast majority of pumped storage stations have a discharge duration longer than 6 hours, and some are capable of seasonal storage.

The majority of today’s pumped storage stations were built some forty years ago. Yet, they are still providing vital services to our power systems today. With occasional refurbishment, these long-term assets can last for many decades to come.

Despite being a mature technology, the resurgence of interest in pumped storage has brought forth numerous new R&D initiatives. One prominent example is the European Commission’s four-year XFLEX HYDRO project, which aims to develop new technological solutions to enhance hydropower’s flexibility. Latest innovations, such as variable speed turbines and smart digital operating systems, will be tested on a range of pumped storage demonstration sites.

While often thought of as geographically constrained, recent studies have identified vast technical potential for pumped storage development worldwide. Research by the Australian National University highlighted over 600,000 potential sites for low-impact off-river pumped storage development, including locations in California. There is also growing interest in retrofitting pumped storage at disused mines, underground caverns, non-powered dams and reservoir hydropower stations.

Seeking a path toward a clean, affordable and secure transition

California is a pioneer in the energy transition. Though many opponents of wind and solar have unfortunately used the blackouts as an example of why their rapid roll-out is a threat to a secure, reliable grid. As noted earlier, the blackouts were not due to too much VRE capacity being on the grid, but a lack of integrated planning to support an evolving electricity mix with sufficient dispatchable generation and storage.

The IEA recently stated that, dispatchable pumped storage, along with conventional hydropower, is the often overlooked workhorse of flexibility. However, its development, like many energy storage technologies, is currently being hampered by the lack of appropriate regulatory frameworks and market signals to reward its contribution to the grid. Outside China, year-on-year installed capacity growth has been anaemic at just 1.5 per cent since 2014 (see figure 3).

Figure 3: Global pumped storage installed capacity by region. Note that 2019 recorded the lowest growth in pumped storage capacity for over a decade, with only 304 MW added. Source: IHA’s database.

Given the technology’s long lead times, investment decisions are needed urgently to ensure that pumped storage, in conjunction with other low-carbon flexibility options, are available to grid operators without needing to rely on carbon-intensive gas-fired generation as a backup. This is especially important as VRE penetration reaches increasingly high levels not yet experienced on a regular basis.

IHA is continuing to work across the hydropower sector and is seeking to learn lessons from other sectors to support the development and deployment of pumped storage. Together with national authorities and multilateral development banks, we are developing a new global initiative to shape and enhance the role of the technology in future power systems.

Further information

Join our Hydropower Pro online community or sign-up to our email newsletter via our website homepage for latest developments.

To learn more about IHA and our work on pumped storage, please visit: www.hydropower.org/pumped-storage

To contact the authors please email nicholas.troja@hydropower.org and samuel.law@hydropower.org

Nick Troja is a Senior Hydropower Sector Analyst. His work focuses on building and sharing knowledge on global hydropower, including identifying trends in project financing, policies and market dynamics.

Before joining IHA, Nick worked for the UK’s steel industry focusing on the EU Emissions Trading System and the impact of other EU level climate change and energy policies on the sector. Prior to this he worked for the UK’s department of energy and climate change, covering a wide range of policy areas and as an adviser to the shadow minister for emissions trading and climate change in Canberra. He holds a bachelor’s degree in international business and master’s degree in public policy.

Samuel Law is Hydropower Sector Analyst. His work focuses on building and sharing knowledge on sustainable hydropower development, working on topics such as clean energy systems, green financing mechanisms and regional hydropower development.

Samuel holds a master’s degree in environmental technology from Imperial College London and has a technical background in environmental engineering. Prior to joining IHA, he completed an internship with the United Nations in Bangkok. At the UN, he conducted research on Sustainable Development Goals, integrated resource management and collaborative governance, as well as supported project implementation and organised international conferences. He also has experience as a business intelligence analyst in London, where he conducted research on market dynamics and investment trends across industries.

Australian Renewable Energy Agency

Like the hydroelectric power stations that have powered Tasmania for a century, a new generation of pumped hydro plants will play an important role in Australia’s future energy mix. With the Australian Energy Market Operator forecasting that 15 GW of large-scale storage will be needed by the early 2040s, pumped hydro is expected to operate alongside large-scale batteries and other energy storage technologies. Learn more about pumped hydro here – https://arena.gov.au/blog/how-could-p

Advances In Solar Power Exploration Into Technology

Solar power is in a constant state of innovation in 2019, with new advances in solar panel technology announced constantly. In the past year alone, there have been milestones in solar efficiency, solar energy storage, wearable solar tech, and solar design tech. Read on to get the complete update on all the breakthroughs you should know about in the world of new solar panel technology. The cost of solar is dropping across the nation. See prices in your area and get free solar quotes on the EnergySage Marketplace.

Solar technology: what’s new in 2019?

There are two main types of solar technology: photovoltaics (PV) and concentrated solar power (CSP). Solar PV technology captures sunlight to generate electric power, and CSP harnesses the sun’s heat and uses it to generate thermal energy that powers heaters or turbines. With these two forms of solar energy comes a wide range of opportunities for technical innovation. Here are some of the latest emerging/further developing solar panel technologies for 2019:

Solar skin design

One major barrier for the solar industry is the fact that a high percentage of homeowners consider solar panels to be an unsightly home addition. Luckily, one new venture has a solution. Sistine Solar, a Boston-based design firm, is making major strides with the concept of aesthetic enhancement that allow solar panels to have a customized look. The MIT startup has created a “solar skin” product that makes it possible for solar panels to match the appearance of a roof without interfering with panel efficiency or production.

Solar powered roads

Last summer paved the way for tests of an exciting new PV technology – solar powered roads. The sidewalks along Route 66, America’s historic interstate highway, were chosen as the testing location for solar-powered pavement tech. These roadways are heralded for their ability to generate clean energy, but they also include LED bulbs that can light roads at night and have the thermal heating capacity to melt snow during winter weather. The next stop following sidewalk tests is to install these roadways on designated segments of Route 66.

Wearable solar

Though wearable solar devices are nothing new (solar-powered watches and other gadgets have been on the market for several years), the past few years saw an innovation in solar textiles: tiny solar panels can now be stitched into the fabric of clothing. The wearable solar products of the past, like solar-powered watches, have typically been made with hard plastic material. This new textile concept makes it possible for solar to expand into home products like window curtains and dynamic consumer clean tech like heated car seats. This emerging solar technology is credited to textile designer Marianne Fairbanks and chemist Trisha Andrew.

Solar batteries: innovation in solar storage

The concepts of off-grid solar and solar plus storage have gained popularity in U.S. markets, and solar manufacturers have taken notice. The industry-famous Tesla Powerwall, a rechargeable lithium-ion ion battery product launched in 2015, continues to lead the pack with regard to market share and brand recognition for solar batteries. Tesla offers two storage products, the Powerwall 2.0 for residential use and the Powerpack for commercial use. Solar storage is still a fairly expensive product in 2019, but a surge in demand from solar shoppers is expected to bring significantly more efficient and affordable batteries to market in 2019.

Solar tracking mounts

As solar starts to reach mainstream status, more and more homeowners are considering solar – even those who have roofs that are less than ideal for panels. Because of this expansion, ground mounted solar is becoming a viable clean energy option, thanks in part to tracking mount technology. Trackers allow solar panels to maximize electricity production by following the sun as it moves across the sky. PV tracking systems tilt and shift the angle of a solar array as the day goes by to best match the location of the sun.

Though this panel add-on has been available for some time, solar manufacturers are truly embracing the technology. GTM Research recently unveiled a recent report that shows a major upward trend in the popularity of tracking systems. GTM projects a 254 percent year-over-year increase for the PV tracking market this year. The report stated that by 2021, almost half of all ground mount arrays will include solar tracking capability.

Advances in solar panel efficiency

The past few years in the solar industry have been a race to the top in terms of solar cell efficiency, and recent times have been no different. A number of achievements by various panel manufacturers have brought us to higher and higher maximum efficiencies each year. The solar cell types used in mainstream markets could also see major improvements in cost per watt – a metric that compares relative affordability of solar panels. Thanks to Swiss and American researchers, Perovskite solar cells (as compared to the silicon cells that are used predominantly today) have seen some major breakthroughs in the past two years.

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The result will be a solar panel that can generate 20+ percent efficiency while still being one of the lowest cost options on the market. Of course, the work doesn’t stop there, as MIT researchers reminded us in May when they announced new technology that could double the efficiency of solar cells overall. The MIT lab team revealed a new tech concept that captures and utilizes the waste heat that is usually emitted by solar panels. This typically released and non-harnessed thermal energy is a setback and opportunity for improvement for solar technology, which means this innovation could help the cost of solar to plummet even further.

Solar thermal fuel (STF)

There is little debate when it comes to solar power’s ultimate drawback as an energy source: storage. While the past decade has seen incredible growth of the PV industry, the path forward for solar involves an affordable storage solution that will make solar a truly sustainable energy source 24 hours a day. Though solar batteries (mentioned above) are a storage option, they are still not economically viable for the mainstream. Luckily, MIT Professor Jeffrey Grossman and his team of researchers have spent much of the past few years developing alternative storage solutions for solar, the best one appears to be solar thermal fuels (STFs).

The technology and process behind STFs is comparable to a typical battery. The STF can harness sunlight energy, store it as a charge and then release it when prompted. The issue with storing solar as heat, according to the team’s findings, is that heat will always dissipate over time, which is why it is crucial that solar storage tech can charge energy rather than capture heat. For Grossman’s team, the latest STF prototype is simply an improvement of a prior design that allowed solar power to be stored as a liquid substance. Recent years saw the invention of a solid state STF application that could be implemented in windows, windshields, car tops, and other surfaces exposed to sunlight.

Solar water purifiers

Stanford University researchers collaborated with the Department of Energy this year to develop a new solar device that can purify water when exposed to sunlight. The minuscule tablet (roughly half the size of a postage stamp) is not the first solar device to filter water, but it has made major strides in efficiency compared to past inventions. Prior purifier designs needed to harness UV rays and required hours of sun exposure to fully purify water. By contrast, Stanford’s new product can access visible light and only requires a few minutes to produce reliable drinking water. As the technology behind solar purifiers continues to improve, expect these chiclet-sized devices to come to market with hikers and campers in mind as an ideal consumer audience.

What new solar technology means for homeowners

For those considering solar panels systems, this long list of solar panel technology innovations from recent years is nothing but good news. Efficiency upgrades, storage improvements and equipment capabilities all contribute to more efficient power output for solar panels and lower costs for systems. Many of the products mentioned in this article, such as tracking mounts and solar batteries, are available in the EnergySage Solar Marketplace – all you have to do is indicate your preference for particular equipment options when you register your property. To get an instant estimate for your home’s potential solar costs and savings, try our free Solar Calculator.

By: Luke Richardson

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This Is How We’d All Die Instantly If The Sun Suddenly Went Supernova

As far as raw explosive power goes, no other cataclysm in the Universe is both as common and as destructive as a core-collapse supernova. In one brief event lasting only seconds, a runaway reaction causes a star to give off as much energy as our Sun will emit over its entire 10-12 billion year lifetime. While many supernovae have been observed both historically and since the invention of the telescope, humanity has never witnessed one up close.

Recently, the nearby red supergiant star, Betelgeuse, has started exhibiting interesting signs of dimming, leading some to suspect that it might be on the verge of going supernova. While our Sun isn’t massive enough to experience that same fate, it’s a fun and macabre thought experiment to imagine what would happen if it did. Yes, we’d all die in short order, but not from either the blast wave or from radiation. Instead, the neutrinos would get us first. Here’s how.

An animation sequence of the 17th century supernova in the constellation of Cassiopeia. This… [+]

NASA, ESA, and the Hubble Heritage STScI/AURA)-ESA/Hubble Collaboration. Acknowledgement: Robert A. Fesen (Dartmouth College, USA) and James Long (ESA/Hubble)

A supernova — specifically, a core-collapse supernova — can only occur when a star many times more massive than our Sun runs out of nuclear fuel to burn in its core. All stars start off doing what our Sun does: fusing the most common element in the Universe, hydrogen, into helium through a series of chain reactions. During this part of a star’s life, it’s the radiation pressure from these nuclear fusion reactions that prevent the star’s interior from collapsing due to the enormous force of gravitation.

So what happens, then, when the star burns through all the hydrogen in its core? The radiation pressure drops and gravity starts to win in this titanic struggle, causing the core to contract. As it contracts, it heats up, and if the temperature can pass a certain critical threshold, the star will start fusing the next-lightest element in line, helium, to produce carbon.

This cutaway showcases the various regions of the surface and interior of the Sun, including the… [+]

Wikimedia Commons user Kelvinsong

This will occur in our own Sun some 5-to-7 billion years in the future, causing it to swell into a red giant. Our parent star will expand so much that Mercury, Venus, and possibly even Earth will be engulfed, but let’s instead imagine that we come up some clever plan to migrate our planet to a safe orbit, while mitigating the increased luminosity to prevent our planet from getting fried. This helium burning will last for hundreds of millions of years before our Sun runs out of helium and the core contracts and heats up once again.

For our Sun, that’s the end of the line, as we don’t have enough mass to move to the next stage and begin carbon fusion. In a star far more massive than our Sun, however, hydrogen-burning only takes millions of years to complete, and the helium-burning phase lasts merely hundreds of thousands of years. After that, the core’s contraction will enable carbon fusion to proceed, and things will move very quickly after that.

As it nears the end of its evolution, heavy elements produced by nuclear fusion inside the star are... [+] concentrated toward the center of the star. When the star explodes, the vast majority of the outer layers absorb neutrons rapidly, climbing the periodic table, and also get expelled back into the Universe where they participate in the next generation of star and planet formation.

As it nears the end of its evolution, heavy elements produced by nuclear fusion inside the star are… [+]

NASA / CXC / S. Lee

Carbon fusion can produce elements such as oxygen, neon, and magnesium, but only takes hundreds of years to complete. When carbon becomes scarce in the core, it again contracts and heats up, leading to neon fusion (which lasts about a year), followed by oxygen fusion (lasting for a few months), and then silicon fusion (which lasts less than a day). In that final phase of silicon-burning, core temperatures can reach ~3 billion K, some 200 times the hottest temperatures currently found at the center of the Sun.

And then the critical moment occurs: the core runs out of silicon. Again, the pressure drops, but this time there’s nowhere to go. The elements that are produced from silicon fusion — elements like cobalt, nickel and iron — are more stable than the heavier elements that they’d conceivably fuse into. Instead, nothing there is capable of resisting gravitational collapse, and the core implodes.

Artist’s illustration (left) of the interior of a massive star in the final stages, pre-supernova,… [+]

NASA/CXC/M.Weiss; X-ray: NASA/CXC/GSFC/U.Hwang & J.Laming

This Is Why We Don’t Shoot Earth’s Garbage Into The Sun

Imagine our planet as it was for the first 4.55 billion years of its existence. Fires, volcanoes, earthquakes, tsunamis, asteroid strikes, hurricanes and many other natural disasters were ubiquitous, as was biological activity throughout our entire measured history. Most of the environmental changes that occurred were gradual and isolated; only in a few instances — often correlated with mass extinctions — were the changes global, immediate, and catastrophic.

But with the arrival of human beings, Earth’s natural environment has another element to contend with: the changes wrought upon it by our species. For tens of thousands of years, the largest wars were merely regional skermishes; the largest problems with waste led only to isolated disease outbreaks. But our numbers and technological capabilities have grown, and with it, a waste management problem. You might think a great solution would be to send our worst garbage into the Sun, but we’ll never make it happen. Here’s why.

The very first launch of the Falcon Heavy, on February 6, 2018, was a tremendous success. The rocket… [+]

Jim Watson/AFP/Getty Images

Today In: Innovation

At present, there are a little more than 7 billion humans on the planet, and the previous century saw us at last become a spacefaring civilization, where we’ve broken the gravitational bonds that have kept us shackled to Earth. We’ve extracted valuable and rare minerals and elements, synthesized new chemical compounds, developed nuclear technologies, and produced new technologies that far exceed even the wildest dreams of our distant ancestors.

Although these new technologies have transformed our world and improved our quality of life, there are negative side-effects that have come along for the ride. We now have the capacity to cause widespread damage and destruction to our environment in a variety of ways, from deforestation to atmospheric pollution to ocean acidification and more. With time and care, the Earth will begin self-regulating as soon as we stop exacerbating these problems. But other problems just aren’t going to get better on their own on any reasonable timescale.

Nuclear weapon test Mike (yield 10.4 Mt) on Enewetak Atoll. The test was part of the Operation Ivy.… [+]

National Nuclear Security Administration / Nevada Site Office

Some of what we’ve produced here on Earth isn’t merely a problem to be reckoned with over the short-term, but poses a danger that will not significantly lessen with time. Our most dangerous, long-term pollutants include nuclear by-products and waste, hazardous chemicals and biohazards, plastics that off-gas and don’t biodegrade, and could wreak havoc on a significant fraction of the living beings on Earth if they got into the environment in the wrong way.

You might think that the “worst of the worst” of these offenders should be packed onto a rocket, launched into space, and sent on a collision course with the Sun, where at last they won’t plague Earth anymore. (Yes, that was similar to the plot of Superman IV.) From a physics point of view, it’s possible to do so.

But should we do it? That’s another story entirely, and it begins with considering how gravitation works on Earth and in our Solar System.

The Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity… [+]

NASA / Messenger mission

Human beings evolved on Earth, grew to prominence on this world, and developed extraordinary technologies that our corner of the cosmos had never seen before. We all have long dreamed of exploring the Universe beyond our home, but only in the past few decades have we managed to escape the gravitational bonds of Earth. The gravitational pull exerted by our massive planet is only dependent on our distance from Earth’s center, which causes spacetime to curve and causes all objects on or near it — including humans — to constantly accelerate “downwards.”

There’s a certain amount of energy keeping any massive object bound to Earth: gravitational potential energy. However, if we move fast enough (i.e., impart enough kinetic energy) to an object, it can cross two important thresholds.

The threshold of a stable orbital speed to never collide with Earth: about 7.9 km/s (17,700 mph).
The threshold of escaping from Earth’s gravity entirely: 11.2 km/s (25,000 mph).

It takes a speed of 7.9 km/s to achieve "C" (stable orbit), while it takes a speed of 11.2 km/s for... [+] "E" to escape Earth's gravity. Speeds less than "C" will fall back to Earth; speeds between "C" and "E" will remain bound to Earth in a stable orbit.

It takes a speed of 7.9 km/s to achieve “C” (stable orbit), while it takes a speed of 11.2 km/s for… [+]

Brian Brondel under a c.c.a.-s.a.-3.0 license

For comparison, a human at the equator of our planet, where Earth’s rotation is maximized, is moving only at about 0.47 km/s (1,000 mph), leading to the conclusion that we’re in no danger of escaping unless there’s some tremendous intervention that changes the situation.

Luckily, we’ve developed just such an intervention: rocketry. To get a rocket into Earth’s orbit, we require at least the amount of energy it would take to accelerate that rocket to the necessary threshold speed we mentioned earlier. Humanity has been doing this since the 1950s, and once we’ve escaped from Earth, there was so much more to see occurring on larger scales.

Earth isn’t stationary, but orbits the Sun at approximately 30 km/s (67,000 mph), meaning that even if you escape from Earth, you’ll still find yourself not only gravitationally bound to the Sun, but in a stable elliptical orbit around it.

The Dove satellites, launched from the ISS, are designed for Earth imaging and have numbered… [+]

NASA

This is a key point: you might think that here on Earth, we’re bound by Earth’s gravity and that’s the dominant factor as far as gravitation is concerned. Quite to the contrary, the gravitational pull of the Sun far exceeds the gravitational pull of Earth! The only reason we don’t notice it is because you, me, and the entire planet Earth are in free-fall with respect to the Sun, and so we’re all accelerated by it at the same relative rate.

If we were in space and managed to escape from Earth’s gravity, we’d still find ourselves moving at approximately 30 km/s with respect to the Sun, and at an approximate distance of 150 million km (93 million miles) from our parent star. If we wanted to escape from the Solar System, we’d have to gain about another 12 km/s of speed to reach escape velocity, something that a few of our spacecraft (Pioneer 10 and 11, Voyager 1 and 2, and New Horizons) have already achieved.

The escape speed from the Sun at Earth's distance is 42 km/s, and we already move at 30 km/s just by... [+] orbiting the Sun. Once Voyager 2 flew by Jupiter, which gravitationally 'slingshotted' it, it was destined to leave the Solar System.

The escape speed from the Sun at Earth’s distance is 42 km/s, and we already move at 30 km/s just by… [+]

Wikimedia Commons user Cmglee

But if we wanted to go in the opposite direction, and launch a spacecraft payload into the Sun, we’d have a big challenge at hand: we’d have to lose enough kinetic energy that a stable elliptical orbit around our Sun would transition to an orbit that came close enough to the Sun to collide with it. There are only two ways to accomplish this:

Bring enough fuel with you so that you can decelerate your payload sufficiently (i.e., have it lose as much of its relative speed with respect to the Sun as possible), and then watch your payload gravitationally free-fall into the Sun.
Configure enough fly-bys with the innermost planets of our Solar System — Earth, Venus and/or Mercury — so that the orbiting payload gets de-boosted (as opposed to the positive boosts that spacecraft like Pioneer, Voyager, and New Horizons received from gravitationally interacting with the outer planets) and eventually comes close enough to the Sun that it gets devoured.

The idea of a gravitational slingshot, or gravity assist, is to have a spacecraft approach a planet... [+] orbiting the Sun that it is not bound to. Depending on the orientation of the spacecraft's relative trajectory, it will either receive a speed boost or a de-boost with respect to the Sun, compensated for by the energy lost or gained (respectively) by the planet orbiting the Sun.

The idea of a gravitational slingshot, or gravity assist, is to have a spacecraft approach a planet… [+]

Wikimedia Commons user Zeimusu

The first option, in reality, requires so much fuel that it’s practically impossible with current (chemical rocket) technology. If you loaded up a rocket with a massive payload, like you might expect for all the hazardous waste you want to fire into the Sun, you’d have to load it up with a lot of rocket fuel, in orbit, to decelerate it sufficiently so that it’d fall into the Sun. To launch both that payload and the additional fuel requires a rocket that’s larger, more powerful and more massive than any we’ve ever built on Earth by a large margin.

Instead, we can use the gravity assist technique to either add or remove kinetic energy from a payload. If you approach a large mass (like a planet) from behind, fly in front of it, and get gravitationally slingshotted behind the planet, the spacecraft loses energy while the planet gains energy. If you go the opposite way, though, approaching the planet from ahead, flying behind it and getting gravitationally slingshotted back in front again, your spacecraft gains energy while removing it from the orbiting planet.

The Messenger mission took seven years and a total of six gravity assists and five deep-space… [+]

NASA/JPL

Two decades ago, we successfully used this gravitational slingshot method to successfully send an orbiter to rendezvous and continuously image the planet Mercury: the Messenger mission. It enabled us to construct the first all-planet mosaic of our Solar System’s innermost world. More recently, we’ve used the same technique to launch the Parker Solar Probe into a highly elliptical orbit that will take it to within just a few solar radii of the Sun.

A carefully calculated set of future trajectories is all that’s required to reach the Sun, so long as you orient your payload with the correct initial velocity. It’s difficult to do, but not impossible, and the Parker Solar Probe is perhaps the poster child for how we would, from Earth, successfully launch a rocket payload into the Sun.

Keeping all this in mind, then, you might conclude that it’s technologically feasible to launch our garbage — including hazardous waste like poisonous chemicals, biohazards, and even radioactive waste — but it’s something we’ll almost certainly never do.

Why not? There are currently three barriers to the idea:

The possibility of a launch failure. If your payload is radioactive or hazardous and you have an explosion on launch or during a fly-by with Earth, all of that waste will be uncontrollably distributed across Earth.
Energetically, it costs less to shoot your payload out of the Solar System (from a positive gravity assist with planets like Jupiter) than it does to shoot your payload into the Sun.
And finally, even if we chose to do it, the cost to send our garbage into the Sun is prohibitively expensive at present.

This time-series photograph of the uncrewed Antares rocket launch in 2014 shows a catastrophic... [+] explosion-on-launch, which is an unavoidable possibility for any and all rockets. Even if we could achieve a much improved success rate, the risk of contaminating our planet with hazardous waste is prohibitive for launching our garbage into the Sun (or out of the Solar System) at present.

This time-series photograph of the uncrewed Antares rocket launch in 2014 shows a catastrophic… [+]

NASA/Joel Kowsky

The most successful and reliable space launch system of all time is the Soyuz rocket, which has a 97% success rate after more than 1,000 launches. Yet a 2% or 3% failure rate, when you apply that to a rocket loaded up with all the dangerous waste you want launched off of your planet, leads to the catastrophic possibility of having that waste spread into the oceans, atmosphere, into populated areas, drinking water, etc. This scenario doesn’t end well for humanity; the risk is too high.

Considering that the United States alone is storing about 60,000 tons of high-level nuclear waste, it would take approximately 8,600 Soyuz rockets to remove this waste from the Earth. Even if we could reduce the launch failure rate to an unprecedented 0.1%, it would cost approximately a trillion dollars and, with an estimated 9 launch failures to look forward to, would lead to over 60,000 pounds of hazardous waste being randomly redistributed across the Earth.

Unless we’re willing to pay an unprecedented cost and accept the near-certainty of catastrophic environmental pollution, we have to leave the idea of shooting our garbage into the Sun to the realm of science fiction and future hopeful technologies like space elevators. It’s undeniable that we’ve made quite the mess on planet Earth. Now, it’s up to us to figure out our own way out of it.

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Ethan Siegel

I am a Ph.D. astrophysicist, author, and science communicator, who professes physics and astronomy at various colleges. I have won numerous awards for science writing since 2008 for my blog, Starts With A Bang, including the award for best science blog by the Institute of Physics. My two books, Treknology: The Science of Star Trek from Tricorders to Warp Drive, Beyond the Galaxy: How humanity looked beyond our Milky Way and discovered the entire Universe, are available for purchase at Amazon. Follow me on Twitter @startswithabang.

Source: This Is Why We Don’t Shoot Earth’s Garbage Into The Sun

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How to Stop Water Polution. In case you’re wondering what water polution has to do with a new continent discoevered in the Pacific Ocean, here’s the answer to this mystery. This new continent is an island that consists solely of garbage and plastic waste. Some countries are ready to announce an ecological disaster. Let’s see if there’s something we can all do to save the planet. TIMESTAMPS The popularity of plastic 0:26 Garbage islands 1:47 The Great Pacific Garbage Patch 2:30 Problems connected with the plastic pollution of the ocean 4:39 Bali ecological disaster 7:31 Several ways to solve problem 8:26 #newcontinent #garbageisland #ecologicalproblem Music: Butchers – Silent Partner https://www.youtube.com/audiolibrary/… SUMMARY -2 million plastic bags a minute are thrown away. As for bubble wrap, the amount produced in just one year would be enough to cover our planet around the equator. 500 billion plastic cups are used and disposed of annually. -There are 3 huge garbage islands in the world: in the central North Pacific Ocean, in the Indian Ocean, and in the Atlantic Ocean. -The size of the Great Pacific Garbage Patch is currently more than 600,000 square miles. According to the journal Scientific Reports, there are more than 1.8 trillion pieces of plastic that have accumulated in this area. -Plastic objects in the ocean kill animals or get stuck in their bodies. Some types of plastic are toxic. In addition, plastic has the ability to absorb such poisonous substances as mercury. Birds often choke to death after trying to swallow a bright object that has caught their eye. -Indonesian authorities have recently declared a “garbage emergency.” More than 100 tons of waste brought ashore every day to beaches from Seminyak and Jimbaran to Kuta. -To solve the problem, people can find a way to remove the garbage that is already in the ocean. Another way out is to decrease pollution or stop it completely. Subscribe to Bright Side : https://goo.gl/rQTJZz —————————————————————————————- Our Social Media: Facebook: https://www.facebook.com/brightside/ Instagram: https://www.instagram.com/brightgram/ 5-Minute Crafts Youtube: https://www.goo.gl/8JVmuC —————————————————————————————- For more videos and articles visit: http://www.brightside.me/

Tag: earth energy

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