[Graeme]

Cheap Solar Power—at Night

$this->bbcode_second_pass_quote('', 'W')hen the world’s largest solar thermal power plant—in Ivanpah, California—opened earlier this year, it was greeted with skepticism. The power plant is undeniably impressive. A collection of 300,000 mirrors, each the size of a garage door, focus sunlight on three 140-meter towers, generating high temperatures. That heat produces steam that drives the same kind of turbines used in fossil-fuel power plants. That heat can be stored (such as by heating up molten salts) and used when the sun goes down far more cheaply than it costs to store electricity in batteries (see “World’s Largest Solar Thermal Power Delivers Power for the First Time”).

But many experts—even some who invested in the plant—say it might be the last of its kind. David Crane, CEO of NRG Energy, one of three companies, including BrightSource Energy and Google, that funded the plant, says the economics looked good when the plant was first proposed six years ago. Since then, the price of conventional photovoltaic solar panels has plummeted. “Now we’re banking on solar photovoltaics,” he told a crowd of researchers and entrepreneurs at a conference earlier this year.

The allure of solar thermal technology is simple. Unlike conventional solar panels, it can generate power even when the sun isn’t shining. But in practice, it’s far more expensive than both fossil fuel power and electricity from solar panels. And that reality has sent researchers scrambling to find ways to make the technology more competitive.

One big challenge, says Philip Gleckman, chief technology officer of Areva Solar, is that the arrays of mirrors, as well as the motors and gearboxes used to aim them at the sun, are expensive. One potential fix, he says, comes from a San Francisco startup, Otherlab, which replaces the motors with pneumatics and actuators that can be made cheaply using the manufacturing equipment that’s currently used to make plastic water bottles.

The head of Otherlab’s solar efforts, Leila Madrone, says the technology could cut the cost of mirror fields for concentrating sunlight by 70 percent. But even this cost reduction, she says, won’t be enough to make the technology competitive with solar panels—even though the mirrors account for a third to a half of the overall cost of a solar thermal plant.

Getting overall costs down will require increasing the amount of power a solar thermal plant can generate, so it can sell more power for the same amount of investment. One approach to increasing power output is to increase the temperatures at which solar thermal power plants can operate, which would make them more efficient. They currently operate at 650 °C or less, but some researchers are developing ways to increase this to anywhere from 800 °C to 1,200 °C. That approach is being pursued by another startup, Halotechnics, which uses high-throughput screening processes to develop new materials—including new kinds of salt and glass—that can store heat at these high temperatures (see “Cheap Solar Power at Night”).

Another option, being funded by a new program at the U.S. Advanced Research Projects Agency for Energy, is to make power plants that add solar panels to solar thermal power plants. The basic idea is that solar panels can only efficiently convert certain wavelengths of light into electricity. Much of the energy in infrared and ultraviolet light, for example, doesn’t get converted, and is instead emitted as heat. The new projects look for ways to harness that heat.

[Oilguy]

There is growing evidence that birds flying in the vicinity of a solar thermal power project in California’s Mojave Desert are being injured and even killed either by the solar heat that’s focused with mirrors on its three energy-collecting towers, or by colliding with the mirrors themselves.

Yet a task force set up to investigate the problem at the Ivanpah Solar Electric Generating System (ISEGS) has brushed aside several recommendations by the forensics laboratory of the U.S. Fish and Wildlife Service (FWS), according to the minutes of a meeting on the subject obtained by the Los Angeles public television station KCET.

Full article at: https://oilprice.com/Latest-Energy-News/World-News/800-Degree-Heat-From-Solar-Mirrors-Frying-Birds-Mid-Air.html

[efarmer]

I predict the birds will eventually form an insurgency and unable to assail the mirror array / power tower installations, will instead begin pooping on all the photovoltaic panels they can find in small tactical units, most probably after they have consumed all the berries they can obtain.

On a more serious note, it shows how hard it is for us to scale even solar energy technology and avoid inadvertent damage to nature. Come on engineers, how about a steam whistle that makes a really low note and spooks them before they get cooked?

[AgentR11]

The question is....

do they taste good on a sesame seed bun?

[dinopello]

I may need this bird death ray at some point. This year, I planted all sorts of blueberry, blackberry and flowers of various kinds. I've always had a lot of birds but now they are taking over and getting territorial. Birds get very protective - I even had a Cardinal male and female harassing me as I worked in the garden. Must of had a nest nearby. Anyway in future seasons I plan to cover the fruit with a bird proof netting and they may get quite upset. I don't want to kill anything but maybe a few shots across the bow, as it were.

[diemos]

Outstanding.

We should build public housing beneath the towers. Then the poor can just sit outside and wait for the free pre-cooked chickens to fall from the sky.

[MD]

These type solar installations are well suited for the remotest of arid desert. Not so many birds out there.

Even so it would make sense for the engineers to figure a way to repel the birds. They have to clean up the mess, after all. If it gets messy enough they will fix it.

[BobInget]

Quick reminder, these are NOT PV panels but reflective mirrors all sunlight focused on a central tower.

Until this serious problem is solved there may not be more such power plants.
Around airports many bird scaring strategies have been attempted with limited success.
Since birds at high altitudes aren't a problem for solar steam. Loud sounds might work.

Motion sensors could set off propane or CO/2 powered noise maker cannons.

[MD]

$this->bbcode_second_pass_quote('BobInget', 'Q')uick reminder, these are NOT PV panels but reflective mirrors all sunlight focused on a central tower.

Until this serious problem is solved there may not be more such power plants.
Around airports many bird scaring strategies have been attempted with limited success.
Since birds at high altitudes aren't a problem for solar steam. Loud sounds might work.

Motion sensors could set off propane or CO/2 powered noise maker cannons.

[AgentR11]

I'm tellin ya...

BBQ Stand

[Surf]

According to this article:
http://www.kcet.org/news/rewire/solar/concentrating-solar/bird-deaths-continue-through-may-at-ivanpah-solar.html
$this->bbcode_second_pass_quote('', 'O')f the 80 bird carcasses recorded in May, 55 were found during carcass surveys while the remaining 25 were "incidental" finds made by plant workers during normal work operations. As only about 20 percent of the facility is covered by the carcass surveys, it's reasonable to assume the actual month's death toll is upward of 300 or so.

[Pops]

wow, 300 birds. I wonder how many salmon they killed damming the Columbia?

[Logic]

Cats kill tons of birds as do glass covered office buildings.
It is not possible to build anything and not have any impact on nature.

These studies need to provide context. In isolation those numbers are meaningless.

[Surf]

$this->bbcode_second_pass_quote('', 'C')ats kill tons of birds as do glass covered office buildings.
It is not possible to build anything and not have any impact on nature.

These studies need to provide context. In isolation those numbers are meaningless.

[Graeme]

Why You Should Be Paying Attention To The ‘Other’ Form Of Solar Power

$this->bbcode_second_pass_quote('', 'o')lar photovoltaic (PV) systems have seen explosive growth because of their stunning 99 percent price drop in the past quarter century. As a result, the other form of solar power — concentrating solar thermal power (CSP) — is a small fraction of the solar market.

But the International Energy Agency (IEA) says CSP has a very bright future too because it enables cheap, efficient storage, which allows CSP plants to provide electricity long after the sun has set. According to the IEA’s 2014 CSP Technology Roadmap, 11 percent of global electricity will be generated by concentrating solar thermal power in 2050. In this post, I review the basics of CSP and look at how its recent resurgence portends a big future.

CSP is the use of mirrors to focus sunlight to heat a fluid that runs an engine to make electricity. One of the basic CSP designs used today is the power tower (above photo of the Crescent Dunes Solar Energy Project), which uses many mirrors moving in two dimensions to focus sunlight on a central tower that holds the engine. Another key design is the parabolic trough, which uses mirrors to focus the light on a long tube filled with a heat-storing fluid (right).
The key attribute of CSP is that it generates primary energy in the form of heat, which can be stored 20 to 100 times more cheaply than electricity — and with far greater efficiency. Commercial projects have already demonstrated that CSP systems can store energy by heating oil or molten salt, which can retain the heat for hours.

[vox_mundi]

Sponge creates steam using ambient sunlight

$this->bbcode_second_pass_quote('', '[')img]http://news.mit.edu/sites/mit.edu.newsoffice/files/styles/news_article_image_top_slideshow/public/images/2016/MIT-Sun-Steam-2.jpg[/img]

How do you boil water? Eschewing the traditional kettle and flame, MIT engineers have invented a bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam through its pores.

The design, which the researchers call a “solar vapor generator,” requires no expensive mirrors or lenses to concentrate the sunlight, but instead relies on a combination of relatively low-tech materials to capture ambient sunlight and concentrate it as heat. The heat is then directed toward the pores of the sponge, which draw water up and release it as steam.

From their experiments — including one in which they simply placed the solar sponge on the roof of MIT’s Building 3 — the researchers found the structure heated water to its boiling temperature of 100 degrees Celsius, even on relatively cool, overcast days. The sponge also converted 20 percent of the incoming sunlight to steam.

In their new design, the researchers settled on a spectrally-selective absorber — a thin, blue, metallic-like film that is commonly used in solar water heaters and possesses unique absorptive properties. The material absorbs radiation in the visible range of the electromagnetic spectrum, but it does not radiate in the infrared range, meaning that it both absorbs sunlight and traps heat, minimizing heat loss.

The researchers obtained a thin sheet of copper, chosen for its heat-conducting abilities and coated with the spectrally-selective absorber. They then mounted the structure on a thermally-insulating piece of floating foam. However, they found that even though the structure did not radiate much heat back out to the environment, heat was still escaping through convection, in which moving air molecules such as wind would naturally cool the surface.

A solution to this problem came from an unlikely source: Chen’s 16-year-old daughter, who at the time was working on a science fair project in which she constructed a makeshift greenhouse from simple materials, including bubble wrap.

“She was able to heat it to 160 degrees Fahrenheit, in winter!” Chen says. “It was very effective.”
Chen proposed the packing material to Ni, as a cost-effective way to prevent heat loss by convection. This approach would let sunlight in through the material’s transparent wrapping, while trapping air in its insulating bubbles.

The bubble wrap, combined with the selective absorber, kept heat from escaping the surface of the sponge. Once the heat was trapped, the copper layer conducted the heat toward a single hole, or channel, that the researchers had drilled through the structure. When they placed the sponge in water, they found that water crept up the channel, where it was heated to 100 C, then turned to steam.

Steam generation under one sun enabled by a floating structure with thermal concentration, Nature Energy http://www.nature.com/articles/nenergy2016126 (2016)

[Tanada]

$this->bbcode_second_pass_quote('', 'A')urora solar energy project is a 150MW solar thermal power plant being developed near Port Augusta in South Australia.

SolarReserve, a renewable energy company, is developing the project with an estimated investment of $650m under a contract from the South Australian government.

Construction of the project is expected to commence in 2018 and is scheduled for completion in 2020.

The Aurora solar power plant will produce 500GWh of electricity a year and have a lifespan of approximately 40 years without any degradation. It is expected to meet 5% of South Australia’s power demand.
Aurora power plant location

The Aurora power plant is to be located on a vast pastoral area adjacent to the Stuart highway, approximately 30km north of the town of Port Augusta.

Proximity to the highway makes it highly accessible during construction as well as operation.
Aurora solar power plant make-up

The Aurora plant will comprise more than 12,000 automatic, dual-axis tracking heliostats measuring 96m² in size each. The heliostats will cover an area of 1.2 million metres squared (120ha) and will be equipped with a control unit and software to enable precise tracking of the sun.

The plant will also include a 240m-tall tower with a receiver located on top, a cold and hot salt storage tank, steam turbine, and steam generator. The heliostats will be arranged circularly around the tower to increase the solar harvest.

Aurora will also be equipped with a dry cooling system, which reduces the water usage and will save one million litres of water annually.
Power generation at Aurora

The new plant will use concentrating solar power technology (CSP) to produce electricity. The heliostats will move according to the position of the sun and concentrate the sunlight on to the receiver, which will act as a heat exchanger and create extremely high temperatures.

Liquid salt from the cold storage tank will be pumped into the receiver where it will be heated to 566°C. The heated salt will then flow into the hot salt tank and onto the steam generator to produce steam, which will drive the steam turbine to generate electricity.

The plant will be connected to a 275kV transmission network located nearby. Aurora will be able to store 1,100MWh of energy for up to eight hours.
Molten salt technology

The Aurora solar power plant will use molten salt as a heat transfer medium as it retains heat and allows for uninterruptable electricity generation. Salt will be circulated through the receiver during the daytime and stored in tanks during night time, enabling 24/7 operation of the plant.

The molten salt need not be replaced for the entire lifespan of the plant as it can be recirculated and reused with no expected loss. The molten salt storage technology is also cost-effective, reliable and efficient.
Financing

The South Australian Federal Government is providing an equity loan of up to $110m for the project.
Agreements made

SolarReserve has signed a Generation Project Agreement (GPA) with the South Australian Government in August 2017, under which the government will pay $78 per MWh to the company.
Aurora solar project benefits

Aurora solar project will generate sufficient electricity for 90,000 homes and will offset 200,000t of carbon dioxide emissions a year. The project will also support federal and state renewable energy targets.

The power plant is expected to create 4,000 direct, indirect and induced jobs during the construction phase and 50 long-term and permanent jobs during the operational phase.

The project will also source 60% of the equipment and services from South Australia, contributing to the industrial and economic growth of the region.

[AdamB]

$this->bbcode_second_pass_quote('', ' ')
Egypt has the natural potential to become one of the world’s strongest energy players as it contains the three main natural elements to develop an abundance of energy: sunlight, wind and hydro-energy. Despite that, Egypt has been failing to provide a stable source of electricity to its ever-growing population. The country imports oil despite having the largest oil refinery in Africa, according to an American Security Project background report from 2015.However, a recently announced project promises to provide the needed amount of clean, renewable solar energy to transform Egypt into a clean energy producer. The Benben SolarPark near the southern city of Aswan promises to transform Egypt into a major solar energy player in the world. The ambitious project, set to be the largest solar park in the world, aspires to provide somewhere between 1.6-2GW of solar power by mid-2019. Egyptian officials believe

[Tanada]

$this->bbcode_second_pass_quote('AdamB', '')$this->bbcode_second_pass_quote('', ' ') The country imports oil despite having the largest oil refinery in Africa, according to an American Security Project background report from 2015.

[theluckycountry]

$this->bbcode_second_pass_quote('Cyrus', 'W')ell, although this is great technology, I don't think it is feisable for mass energy production. I think we are a little too far down the line to make this scalable. Trust me, we will run to coal way before this...