Thermal-Solar Energy

 
 
 

Vocabulary

 

crucial	billboard	demand (2)
peace	store (2)	push up (2)
fossil	look for	fossil fuel
way (2)	generate	unlimited
face (2)	challenge	resource (2)
require	scientist	big/bigger/the biggest
ground	venture	commercial (2)
molten	plant (3)	groundbreaking
slightly	panel (3)	conventional
tower	focus (2)	build/built/built
steam	receiver	concentrate (2)
steel	field (2)	drive/drove/driven
steal	cover (3)	square km
so far	literally	temporary
site	churn out	mirror (2)
churn	floor (2)	get/got/got-gotten
per	headache	mammoth (2)
lift (3)	based on	initialization
reliable	separate	position (3)
curve	matter of	calibration
range	elevation	run/ran/run (3)
provide	imagine	see/saw/seen
weight	intensity	switch (2)
melt	target (2)	hit/hit/hit (2)
precise	thermal	couple (2)
ability	rush (2)	density (2)
utilize	vessel (3)	essentially
pump	diameter	stand/stood/stood (2)
boil	pound (3)	hold/held/held (3)
spin	push (2)	structure (2)
giant	plus (3)	consists of
set (2)	point (3)	potentially
utility	drum (2)	pressure (2)
thick	plate (2)	withstand
destroy	spot (3)	fall/fell/fallen
sit on	set back	sit/sat/sat
retain	prepare	make/made/made
piece	wean (2)	jigsaw puzzle (2)
facility	length (2)	bring/brought/brought
unique	take hold	supply (2)
turbine	mean (3)	meet/met/met (2)
rival	biomass	tremendous
require	pipe (2)	tremendous
	fabulous	come/came/come

 
 
 
 
 
 

Video

 

 
 
 
 

Transcript

Electronic billboards . . . data storage . . . even mobile phones are all pushing up demand for electricity in our cities.

Now an army of engineers is trying to wean these cities off electricity produced from fossil fuels. They are looking for new ways to generate clean power using unlimited natural resources.

In parts of the world with clear skies, that means power from the Sun.

In the Nevada desert, technical director Ryan Paeter and his team face the biggest challenge of their careers.

Brian Painter, Technical Director: “It’s technology that was developed by literally rocket scientists in the middle 80s. And this is the first commercial venture for this technology.”

They are building a groundbreaking, solar-thermal power plant. And it must be finished in less than six months.

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Crescent June’s solar thermal power plant doesn’t use conventional solar panels.

Here over 10,000 mirrors called heliostats are being built around a hundred and ninety five meter tower. The heliostats will focus the sun’s rays onto a special receiver at the top of the tower.

This concentrated solar energy will be used to create steam that will produce electricity.

Brian Painter, Technical Director: “When you’re driving through the heliostat field, it’s like driving through a big mechanical forest. It’s steel. It’s computer-controlled systems. And it’s in its glass.”

So far just 1,400 of the 10,000 heliostats have been installed. Eventually they will cover over five square kilometers of desert.

The project requires so many that a temporary factory has been built on site. It churns out 80 heliostats per day thanks to manufacturing processes lifted straight from an automotive plant.

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Every one is designed for a specific spot on the desert floor. Getting them all to work together creates a mammoth headache for Tim Connor.

Tim Conner, Engineer: “We have to go through this initialization and calibration for each individual heliostat, all ten thousand three hundred and forty-eight (10,348) before they can be operated as a collector field.”

Each heliostat consists of 35 mirrors or facets — every one of which must be perfectly positioned to focus the sun’s rays on the top of the tower.

Tim Connor, Engineer: “Each heliostat has a has a focal length and each individual facet is slightly curved based on the distance it is from the tower and the receiver.

What I’m doing here is running the heliostat through the range of motion for the elevation. And we take it from the plus 90 degrees to the minus 10 position.

Some of the heliostats and more than half a kilometer from the receiver.

Tim Connor, Engineer: “What you see now is the concentrated energy from a single heliostat. You can imagine the intensity, the thermal intensity on the receiver with ten thousand three hundred and forty-eight (10,348) heliostats focused all at one time.

The amount of energy with all the heliostats pointed at the receiver would melt aluminum in a matter of seconds.”

Once the sun’s rays hit the target the precise position is recorded and the calibration is complete.

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What happens once the sun’s rays hit the top of the receiver makes this power station unique. The sun’s energy is used to heat molten salt to over 530 degrees Celsius.

Brian Painter, Technical Director: “The salt that we’re using in this system is not your regular, ordinary table salt; it’s only found in a couple places in the world.

And its value is in its density and the ability to store energy.”

Salt is heated by the focused power of the Sun. It is then piped into a storage tank where it retains heat for up to 10 hours.

When power is needed, the molten salt is pumped to a generator where it boils water, producing steam. This steam spins a turbine generating electricity.

As the salt cools, it is pumped back to the top of the receiver to be heated again.

Brian Painter, Technical Director: “Right now we’re standing in the middle of the hot salt tank. It’s a very large tank: 140 feet (42.7 meters) diameter 40 feet (12.2 meters) tall and it’ll hold 70 million pounds (3.18 million kg) of salt that is a thousand 50 degrees Fahrenheit (566.6 degrees Celsius).”

The tank acts like a giant battery, storing the sun’s energy until needed. Crucially for a power station fueled by the sun, this means it can produce electricity long after the sun has set.

And even when the sky is cloudy, it can generate electricity, reliably day-in day-out.

Brian Painter, Technical Director: “We can actually collect the energy during the day and then we can operate whenever we want. So essentially electricity collection and electricity generation are two separate processes. So the utility here in Nevada is looking for us to generate reliable electricity well into the evening hours twelve o’clock noon to 12 o’clock midnight.”

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Today a key piece of the steam generating plant is being lifted into place. The drum weighs in 95 tons (86.2 tons) making the lift a difficult and potentially dangerous task.

To withstand high pressure steam, the drum is made of five centimeter thick steel plate. If it falls, it will destroy the structure it sits on, and set Brian and the team back by several months.

Brian Painter, Technical Director: “Right now we’re rigging up a steam drum this is pretty well the last heavy lift we have on the site. We’re gonna set it up on top of the steel structure on top there.

We don’t want anybody hurt we don’t want any equipment damaged. And so there’s a lot going into this lift. There’s a lot of planning and preparation to make this happen.”

Installing the drum is an important milestone.

Brian Painter, Technical Director: “This vessel right here is the last part of the process of making steam. The steam travels through the piping from here to the steam turbine.”

Another piece of this complex jigsaw puzzle is lowered safely into place, bringing Crescent June solar thermal facility step closer to producing the electricity Las Vegas can’t live without.

Brian Painter, Technical Director: “When the switch finally goes on, it would be a tremendous rush for everybody. I mean we’ve been been building for years to have this technology really take hold and see the facility coming together is great but once we once we turn that switch on it’ll be fabulous.

When complete the plant will provide 110 megawatts of power, enough for 75,000 homes. It might not rival the 1.4 million homes powered by London’s biomass burner, but in theory this technology could supply all the electricity Las Vegas needs

Brian Painter, Technical Director: “When you’re looking into the future cities like Las Vegas and Los Angeles are going to be utilizing a tremendous amount of solar energy for their power needs and this project can help meet those future requirements.”

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Questions

Electricity, Electric Power. Is electricity vital to the modern world? Is it a double-edged sword?

Water Supply, Running Water. Thermal-solar power functions best in Canada, Norway and Russia. True or false

Telephone Lines. Is thermal-solar power a recent innovation? Was it developed after 2000? Does it rely on solar panels?

Internet Access. How does thermal-solar power it work?

Roads, Highways, Freeways. The Crescent June thermal-solar project in Nevada receives the reflectors from factories in Ohio, Michigan and Pennsylvania. Is this right or wrong? Why are the reflectors produced on-site?

Bridges and Tunnels. Do the reflectors remain in a fixed position? Do their movements follow a single pattern?

Airport. The reflectors generate just enough heat to boil water. Is this correct or incorrect?

Harbor, Port. Can the thermal-solar plant only produce electric power during the day?

Railway, Rail line. What was the most difficult and challenging part of the thermal-solar plant construction?
 
 
 
TV Station. What are the main sources of power in your region or country?

Radio Station. Have there been changes or shifts to “greener” or sustainable or renewable sources of energy?

Sewage Treatment Plant. Is there much debate and discussion by the media, government, scientists and businesses about renewable energy?

School, University. Has there been a greater sense of urgency in light of extreme weather conditions?

Coal Powered Plant, Oil Powered Plant. What might happen in the future?

Clinic, Hospital. What can or should people, business and governments do?