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#Post#: 413--------------------------------------------------
Undersea Turbines
DIR By: AGelbert
Date: November 21, 2013, 2:09 pm
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TidalStream Seeks Partner to Test Ocean Turbines in Deep Waters
HTML http://csmres.co.uk/cs.public.upd/article-images/SeaGen-rotor.jpg
Louise Downing, Bloomberg
November 21, 2013
LONDON -- TidalStream Ltd., a maker of platforms for tidal-power
turbines, is in talks with energy companies and utilities to
test its technology in deeper waters.
TidalStream is seeking to form a partnership next year, John
Armstrong, a director at the London-based company, said in an
interview. It’s talking to turbine makers, marine companies,
shipyards and utilities based in Europe, Asia and Canada.
“We’re open to any deal structure,” Armstrong said by telephone.
“Developing deepwater sites will be expensive, so we want to
engage with companies that have the resources needed to provide
that capital and to provide know-how as well.”
The tidal-energy industry is still in its infancy, with
developers working to market their turbines and bring
commercial-scale projects into operation for the first time.
Tidal energy costs about $440 a megawatt-hour, more five times
the cost of coal-fired power, according to Bloomberg estimates.
TidalStream’s platforms can accommodate groups of turbines at
varying water depths. The technology has the potential to cut
the cost of installing turbines by half, according to Armstrong.
“Turbine makers seem to recognize that this is one way to reduce
costs,” he said. “Most of them have been busy solving the
problem of putting turbines in the water, so they are receptive
to the idea of lowering costs and solving the access and
maintenance and installation problems in one go.”
A future partnership may bring TidalStream together with more
than one company, Armstrong said.
Copyright 2013 Bloomberg
HTML http://www.renewableenergyworld.com/rea/news/article/2013/11/tidalstream-seeks-partner-to-test-ocean-turbines-in-deep-waters?cmpid=rss
My comment:
A. G. Gelbert
November 21, 2013
When they finally get around to it, the obvious fact that
massive and unlimited energy is available from the gulf stream
less than 50 miles from high energy demand population centers on
the Eastern Seaboard of the USA, this source of energy will
become the major input there.
The USA has been building submarines for over 50 years. The
hydrodynamics of undersea large propellers is well understood
and engineered. Pushing a nuclear submarine along is far more
challenging than anchoring a structure on the bottom that does
not have to deal with varying water pressures or large
temperature changes. Also, the lack of oxygen at depth inhibits
metal corrosion and enhances multi-decade MTBF for undersea
turbine metals.
It's time this was embraced worldwide. Undersea currents with
titanic energy potential exist all over the oceans 24/7 and will
be available as long as the planet earth rotates on its axis.
We need fossil and nuclear fuels like a HOLE IN THE HEAD!
HTML http://renewablerevolution.createaforum.com/index.php
#Post#: 628--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: December 27, 2013, 5:23 pm
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Agelbert NOTE: I am posting this here because the very same
cables that are used fro offshore wind can ALSO be shared with
undersea turbines for multiples of the power wind alone can
provide. Plus, undersea current is baseload quality 24/7!
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/>
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Subsea Cables Bring Offshore Wind Power to the People
Cables are increasingly recognized as a crucial aspect of wind
farm construction and operation. Here, we offer a glimpse of a
Norwegian subsea cable manufacturing facility and review the
challenges of this evolving market.
Tildy Bayar, Contributing Editor
December 19, 2013
LONDON -- It might be surprising to learn that Norway’s tallest
building is Nexans’ 120-metre extrusion tower at the company’s
submarine high-voltage direct current (HVDC) cable factory in
Halden. Nexans makes subsea cables that connect offshore wind
farms to the grid, transports them around the world and installs
them underwater so that the cables can bring clean power from
offshore wind farms to onshore substations and from there to our
homes.
Several different types of cable are used in offshore wind
projects. Low (up to 1 kV) and medium-voltage loop cables
transmit the electricity produced in the turbine’s generator to
the transformer, usually located at the tower’s base. Then array
cables connect the turbines on a wind farm to each other and
export cables carry their power to the grid. Finally,
underground and overhead line (OHL) cables that make it all work
on land.
HTML http://www.renewableenergyworld.com/assets/images/story/2013/12/3/body-0-1386110300950.png
Offshore wind export and inter array cable types. Credit:
Nexans.
On a recent tour of the factory, sponsored by Nexans, guides
explained that the high tower at the Nexans factory houses the
vertical extrusion machinery that begins the cable-making
process. From “clean rooms” at the top of the tower, superclean
polyethylene and cross-linkable, super-smooth “semicon” are fed
through a closed system of huge tubes back down to an extruder
at ground level, where the conductive material and insulation
are spit out simultaneously from multiple extruders that feed
into a single head. The tower can produce 15 km of cable in one
week before the workers have to stop the process to change the
enormous receiving baskets.
The height of the tower is important because all of the heat
must be removed from the materials before they enter the tube.
Curing and cooling takes place in a dry atmosphere of
pressurized nitrogen in the building before the materials are
fed from the tower to various stations in other buildings
through “cable ways” which are little wheeled tracks running
across and between buildings.
Using copper, aluminum, lead and wire, the materials are formed
into cable lengths weighing up to 400-500 kg. At the end of the
process the lengths are combined using proprietary joints to
make 60-70 km cables.
After several more processes involving insulation and
strengthening of the cables, they are tested for resilience and
torsion. As a wind turbine’s nacelle rotates, the cables are
severely twisted, so they must be extremely resistant to both
torque and vibration. The torsion tests on cables simulate 20
years of use in a wind installation. Nexans said the exact test
applied to a given cable depends on the customer’s
specifications.
A Challenging Market
The wind industry’s move to deeper waters is challenging,
according to Nexans, because transport vessels can only hold so
much cable. Nexans’ flagship transport and laying boat, the
Skagerrak, holds 50 tons of cable on its built-in turntable. The
Skagerrak can accommodate 65 workers and has travelled all over
the world. Not many vessels can hold its capacity, according to
the company, and there are just one or two others in the world
including the Giulio Verne, belonging to Nexans’ main competitor
Prysmian.
HTML http://www.renewableenergyworld.com/assets/images/story/2013/12/3/body-0-1386110282754.jpg
The Nexans "Capject" can dig trenches in soft or hard sediments,
according to the comany, and is able to operate in depths of up
to 1,000 meters. Credit: Nexans.
With wind farms moving further offshore, said Vincent Dessale,
chief operating officer of the submarine high voltage business
line, Nexans’ customers are seeking increasingly higher
transmission capacity, which means producing larger and longer
cables. The Halden plant ran into problems in 2012, with an
invoice delay in submarine cables leading to a drop in Nexans
stock and an eventual restructuring of the business. The company
has learned some lessons, it said, including that “feeding in
more machines and manpower to match market demand is not
sufficient” and that “coping with growing complexity and
increasing timeline uncertainty requires highly structured
organization, robust processes and the right mindset,” said
Dessale.
Another challenge is that cables are becoming increasingly
important in risk management. “One of the key differences
between offshore and onshore wind farms, at the concept and
design phase is the need to consider cable failure when
designing the electrical architecture,” said David McNaught,
senior engineer at consultancy Frazer-Nash. “If a submarine
cable fails in service the consequences for the operability and
profitability of the wind farm could be dire; especially if
there are delays in securing a suitable repair vessel or if
weather conditions are severe, likely during the winter months.
“It is essential that the electrical cable systems of wind farms
have high reliability – that the system has the ability to
withstand unforeseen circumstances,” McNaught continued. Cable
risk is a relatively new aspect of wind project financial
analyses, he said, but it is increasingly being considered – to
the point where new guidelines from GL Renewables Certification,
published in January, include on-site and power export cables.
To address this growing concern, Nexans said it has scaled up
risk analysis at the tendering stage and the company is working
to develop and implement risk mitigation before beginning
production.
Another challenge is transport for larger and longer cables.
The current Skagerrak, the third in its line and 130 km, was
built in 1993; the Skagerrak 4, which is expected to be complete
in 2014, will be 140 km.
HTML http://www.renewableenergyworld.com/assets/images/story/2013/12/3/feature-1-1386110300950.jpg
Coils of cable at the base of the Nexans' 120-meter extrusion
tower at the company's submarine high voltage direct-current
(HVDC) cable factory in Halden, Norway. Credit: Nexans.
The market is growing in complexity, too, said Dirk Steinbrink,
executive vice president for high voltage and underwater cables.
The project scope of Nexans’ work has expanded to offer not just
cables but turnkey interconnection solutions, he said.
On the Northwind project, which is expected to be completed
before the end of 2013, Nexans is contracted to supply cables to
connect the Belwind 2 offshore wind farm to Northwind, and
Northwind to the shore. The project’s scope includes cable
design, testing, supply, jointing termination work and on-site
testing (called cable witnessing). The company said that it
would use the largest cable ever manufactured at the project
site, a 1-meter wide, 30-kg behemoth.
Offshore wind farm developers must also consider the social
impact of the installation process. “The acceptance level from
people living [near a site] is quite low,” ??? >:( Steinbrink
said. “They like green energy but don’t want to see us doing the
work. So we do micro-tunneling, especially in places with
tourism.”
HTML http://www.clker.com/cliparts/c/8/f/8/11949865511933397169thumbs_up_nathan_eady_01.svg.hi.png<br
/> ;D
Frédéric Michelland, senior executive vice president for high
voltage and underwater cables, North and South America, does not
expect the market for wind turbine cables to evolve dramatically
over time. Today, he said, Nexans covers 80 percent of the
European market, while “tomorrow that will move to North America
and China – but we expect our market to remain largely
European.” In Europe there are “still plenty of projects where
most of the action will take place,” he said.
HTML http://www.renewableenergyworld.com/rea/news/article/2013/12/subsea-cables-bring-offshore-wind-power-to-the-people
HTML http://www.createaforum.com/gallery/renewablerevolution/3-191213230928.jpeg
Within a 130 km of every major coastal city in the world is
enough undersea current to power them many times over, at
baseload quality 24/7, immune to ocean surface storms, and with
very low transmission losses due to the short distance from the
harvesting point to the user.
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/>
#Post#: 1313--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: June 6, 2014, 9:59 pm
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HTML http://2.bp.blogspot.com/-GL5j1HJXNGE/U5HAcjeP3KI/AAAAAAABEGY/ZBbqo0mVQi0/s1600/06-06-2014c.gif
Friday, June 06, 2014
TIDAL POWER’S FORCE RISING IN SCOTLAND
Tidal Power — GE & Others Looking To Harness The Power Of The
Moon ;D
James Ayre, May 25, 2014 (Clean Technica)
“…[Tapping the energy of] tidal fluctuations caused by the
movement of the [moon] has remained somewhat elusive…though, a
number of interesting projects/approaches are being
pursued…Scotland has been noted as possessing significant tidal
resources that could meet up to 50% of its energy needs…GE Power
Conversion is currently in the process of testing out new tidal
turbine generators [on the sea floor near the Orkneys in
Scotland]…[Turbines planned for the bottom of the Pentland
Firth, a narrow channel that separates the Orkneys from the
northern tip of Scotland… resemble large aircraft propellers
submerged in 180 to 240 feet of water…[at strategic] ‘pinch
points’ of the firth, where the tides rush in and out at the
highest speeds…[T]idal power generation arrays will become much
more common in the coming years, as the benefits of the
technology are realized on a larger scale…The $1.2 billion [320
MW Swansea Bay Tidal Lagoon Project] is currently set to begin
construction in 2015, with a completion date likely to be
sometime in 2018…If the project is deemed successful, current
plans are for the development of four more projects in other
lagoons — which when all taken together would provide up to 10%
of the UK’s domestic electricity needs…”
HTML http://newenergynews.blogspot.com/2014/06/tidal-powers-force-rising-in-scotland.html
#Post#: 2332--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: December 5, 2014, 2:28 pm
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HTML http://www.freesmileys.org/emoticons/emoticon-object-106.gif
HTML https://youtu.be/o8nezU0M7mI
Air and Ocean Currents
HTML http://www.createaforum.com/gallery/renewablerevolution/3-301014182902.gif<br
/>( to me! ;D)
HTML https://youtu.be/5tRiZG-yR24
[move]Ocean Currents 1994 -2002 [/move]
#Post#: 3726--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: September 7, 2015, 4:24 pm
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Water, Energy and Waste Sustainable Development in Large Cities
HTML http://public.wsu.edu/~mreed/380American%20Consumption_files/image002.jpg
There is no doubt that humans in general, and those concentrated
in cities in particular, are responsible for much of the massive
demand for potable of water and energy. There is also agreement
that this demand is, at present not healthy for the biosphere in
general and humans in particular. There is too much waste,
inefficient energy use, lack of renewable energy infrastructure,
pollution from fossil fuels and inefficient water use as well.
In summary, there is a consensus among knowledgeable and
observant people in the reality based community that our present
trajectory in the above issues is unsustainable.
The solution requires the phasing out of all fossil fuels and
nuclear fission power plants and replace them with Renewable
energy. This energy needs to be harvested within 100 miles or
less from the highest energy users on the planet, the large
cities, in order to have lower transmission and infrastructure
costs.
The energy must be baseload quality 24 hours a day with wind and
solar to supplement demand spikes along with pumped water
storage energy, fuel cell or battery storage technologies.
The renewable energy source that is best suited on a global
scale because it is constant, powerful and close to the major
cities is the energy from ocean currents.
Observe the two maps below.
HTML http://1.bp.blogspot.com/-H6e11TQ_hvE/UO5qL-oVmSI/AAAAAAABN90/ag5rEdPU6p8/s1600/youtube_logo.gif
World population concentration
Now let us overlay the Hydrosphere. ;D
Please observe the result of the merging of the hydrosphere
graphic and the population concentration graphic below:
HTML http://www.createaforum.com/gallery/renewablerevolution/3-191213230928.jpeg
The energy is renewable, does not disturb the biosphere or
hydrosphere and can completely replace the polluting energy we
now suffer from. The densely populated areas have this powerful
source nearby.
Ocean currents have far more energy potential than ocean tides.
The tides alone are estimated to have a potential tidal stream
energy capacity of over 120GW globally. Using both plus wind and
PV would make a 100% Renewable Energy transition to the 18TW the
planet required feasible with technology we now have.
Just in the UK alone, the marine power resource is estimated to
be more than 10GW, representing about 50% of Europe’s tidal
energy capacity.
In the USA a project is now in the works to provide wind turbine
power to the East Coast for up to 1.9 million households. When
built out, the Atlantic Wind Connection (AWC) backbone will
stretch 350 miles off the coast from New Jersey to Virginia and
will be able to connect 6,000MW of offshore wind turbines.
HTML http://4.bp.blogspot.com/_7ZYqYi4xigk/TLPB6bft9VI/AAAAAAAAG5o/lnS4tAR8QT0/s1600/transmission.png
Now look at where those wind turbines will be and realize that
undersea turbines can be placed close by and save on cabling the
energy to the shore. Much more energy can be harvested 24 hours
a day from the ocean current. Sharing energy transmission cables
from wind and ocean current turbines will save millions of
dollars and hasten the transition to 100% clean energy.
HTML http://marinebio.org/i/currents/Ocean_currents_1943.jpg
HTML http://static.ddmcdn.com/gif/storymaker-five-ocean-power-plants-1112010-515x388.jpg
As the new, clean energy replaces dirty energy, full
electrification of the economies to eliminate the internal
combustion engine for power plants, vehicles and factories will
clean the air in large cities.
With plenty of renewable energy to electrify the planet and
eliminate the internal combustion engine pollution, the
worldwide potable water problem can be solved anywhere on the
planet that the relative humidity is above 23% (any place it is
not a desert climate) by extracting water from the ambient air.
The waste water can, given all the ocean current energy, be
processed for agricultural fertilizer (eliminating petrochemical
fertilizers).
In this way, we will imitate the biosphere in turning our waste
into a nutrient that benefits all life on earth, not just
humans.
HTML https://youtu.be/WEe1bVjORN4
A. G. Gelbert
#Post#: 3727--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: September 7, 2015, 4:40 pm
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Rising sea levels will not affect our ability to harvest energy
from Ocean Currents.
So, if we harvest a lot of our energy from the oceans, at least
we won't be making things worse as the earth heats up. I always
say that when you are in hole, it is prudent to stop digging.
The ocean currents are available near most of the populated
areas 24/7. We have the technology to tap that energy. This is
not hard.
Here is some info on the physics of Ocean Currents. They leave
out the rotation of the earth, which is behind MOST of the
physics of ocean currents. But we would all be dead without
rotation for many other reasons so I can understand why it such
a given that it is not mentioned (i. e. assumed).
HTML http://www.freesmileys.org/emoticons/emoticon-object-106.gif
HTML https://youtu.be/o8nezU0M7mI
Air and Ocean Currents
HTML https://youtu.be/5tRiZG-yR24
[move]Ocean Currents 1994 -2002 [/move]
#Post#: 4017--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: October 18, 2015, 1:47 pm
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Ocean Tides to Power More Than 150,000 Homes
Amanda Froelich, True Activist | October 18, 2015 12:09 pm
While the power plant below looks more like a gorgeous get-away
than a solution to man’s energy needs, its benefits extend far
beyond its beauty. As Reconstruct reports, the Swansea Bay Tidal
Lagoon will use the rise and fall of ocean tides to generate
enough renewable electricity to power 155,000 homes for 120
years.
[center]
HTML http://ecowatch.com/wp-content/uploads/2015/10/tidalplant750.jpg[/center]
[center]The Swansea Bay Tidal Lagoon will use the rise and fall
of ocean tides to generate enough renewable electricity to power
155,000 homes for 120 years. Photo credit: Preconstruct[/center]
Though not completed at present, when the structure is finished,
it will produce enough electricity to displace more than a
quarter million barrels of oil each year—while leaving virtually
no carbon footprint.
Power plants have been generating electricity from the oceans’
tides since 1966, but the Swansea Lagoon is the first to employ
a radically new method.
[center]How Does It Work? ??? [/center]
It’s nearly six-mile-long barrier wall will enclose a huge
amount of water in an artificial “tidal lagoon.” This lagoon
captures and holds seawater at high tide. As the tide goes out,
water in the 4.5 square mile lagoon will be as much as 27 feet
higher than the water outside its walls. This immense pressure
will be routed through 26 turbines, flooding out to sea until
the water level equalizes on both sides of the lagoon.
The flow is reversed at high tide, keeping the sea out of the
lagoon until it reaches maximum height. Then water is let go, so
it may rush through the turbines until it again fills up the
lagoon.
To put it into perspective, the amount of water rushing through
the turbines would fill 100,000 Olympic swimming pools each day.
The Swansea Bay Tidal Lagoon will crank out clean energy as well
as be used as a sports arena, aquaculture farm and seaside
sculpture garden, reports GoodNewsNetwork. Its aquaculture farm
will grow oysters, kelp and other local sea crops.
In addition, the lagoon can be used as a giant arena for sailing
and cycling sports.
The designers of the fabulous structure plan to implement
sculptures that appear to disappear into the water or rise out
of it as the tides roll in and out.
[center][center]
HTML http://ecowatch.com/wp-content/uploads/2015/10/tidalplant2750.jpg[/center][/center]
[center]Photo credit: Preconstruct[/center]
Its location at Swansea, Wales was chosen because it has some of
the highest tide differences in the U.K. This will maximize the
amount of water that can be used to turn turbines and generate
the 420-gigawatt hours per year.
Plans for the structure were approved by the UK Energy Ministry
in June, and construction is expected to begin sometime in 2017.
The builders are presently bargaining to exchange the $1.5
billion price tag (subsidized by the government for 35 years)
for approval on two more tidal lagoon plants at Cardiff and
Newport.
HTML http://ecowatch.com/2015/10/18/ocean-tidal-lagoon/
#Post#: 4018--------------------------------------------------
Re: Undersea Turbines
DIR By: AGelbert
Date: October 18, 2015, 3:07 pm
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--- Quote from: RE link ---
>
> [quote author=Eddie link=topic=559.msg88610#msg88610
date=1445194448]
> I like that. While such extreme tides are pretty rare, there
are some other places this could work out. Such an elegant
design, the very antithesis of a nuke plant, don't you think?
>
--- End Quote ---
The mean tidal range in Prince William Sound is 3m. You might
get a decent amount of electricity out of that.
However, how would all the Salmon get to their spawning grounds
if you put one of those across the sound?
RE
[/quote]
RE,
Eddie is right and you are wrong. I know you will not accept
that, but your premise that large tidal differentials are
required for a "decent" amount of electricity is incorrect. A
TINY difference, on a daily basis, is FAR more cost effective
for electrical generation, and a LOT of it, than generating the
SAME amount of power from fossil fuels. It hasn't been done
BECAUSE the fossil fuel industry DID NOT WANT IT to be done.
Thermodynamic efficiency and total required output had NOTHING
to do with it.
But you can keep believing Gail Tverberg's BALONEY until the
cows come home if you wish. You aren't known for altering your
position on anything. You retreat into large fonts and
repetition. You are a nice guy, RE. but you are as stubborn as
they come.
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[center]
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[/center]
Yes, I'm stubborn too. ;D But I was a cornucopian three years
ago, according to you. Now I'm too pessimistic, according to
you. So tell me, old chum, who has failed to alter their
position with new data, you or me? ;)
There is only one thing to be said about the whole "fossil fuels
are the best thing since toasted bread" BALONEY:
[center]
HTML http://40.media.tumblr.com/tumblr_lwx7wy0tIK1qd9a66o1_500.jpg[/center]
Dream on, fossil fuelers. The writing is on the wall for your
CRAP. and it ain't gonna take 50 years for humanity to read it
so you can keep trashing the planet and stuffing your empathy
deficit disordered pockets. Have a nice day.
[center]
HTML http://www.createaforum.com/gallery/renewablerevolution/3-281014151757.png[/center]
[center]
HTML http://graysondemocrats.org/wp-content/uploads/2011/05/end-oil.jpg[/center]
[center]
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[center]
HTML http://www.createaforum.com/gallery/renewablerevolution/3-190915212112.png[/center]
Here are the thermodynamic FACTS about Fossil Fuels versus PV
Renewable energy (for those who can read them objectively):
--- Quote ---
> Renewables have higher ERoEI than fossil fuels
HTML http://www.smile-day.net/wp-content/uploads/2011/12/Smiley-Thumbs-Up2.jpg<br
/>
>
> One the central claims of the peak oil/energy decline
movement, is that renewable sources of power have extremely low
ERoEI. Therefore, it is claimed, renewables are no substitute
for fossil fuels, because they cannot provide enough “net
energy” to power civilization. In support of this claim, energy
decline adherents often post graphs like this one, showing that
renewables (especially solar PV) have low ERoEI compared to
fossil fuels. More recently, Hall and Prieto have published a
book, Spain's photovoltaic revolution, in which they claim that
the ERoEI of solar PV in Spain is only 2.45, which is far lower
than the ERoEI of fossil fuels.
>
> In fact, those claims are entirely wrong. Renewables have
ERoEI ratios which are generally comparable to, or higher than,
fossil fuels. Although peak oilers reach a different conclusion,
that is because they are carrying out the calculation
incorrectly. They are ignoring or not including massive waste
heat losses (generally 60% or more) from combustion engines
which drastically reduces the ERoEI of fossil fuels. Those waste
heat losses provide no energy services to society, and should be
counted as losses, but are wrongly counted as "energy returns"
by peak oilers. Furthermore, peak oilers are ignoring or not
counting other large energy losses of fossil fuels. Those
omissions exaggerate the ERoEI of fossil fuels relative to
renewables. When the calculation is carried out correctly,
renewables have higher ERoEI ratios than fossil fuels.
>
> In other words, the notion that renewables have ERoEI ratios
which are lower than fossil fuels, is simply mistaken. It arises
from performing invalid, apples-to-oranges comparisons, or from
not counting energy losses of fossil fuels.
>
>
> Fossil fuels have very low ERoEI ratios
>
> Take this graph as an example. It compares the ERoEI of solar
PV for electrical power, against the ERoEI of coal and gas for
heat. That comparison is invalid, because it’s an
apples-to-oranges comparison. Thermal power plants (like
coal-burning plants) waste approximately 2/3ds of their energy
as waste heat. Waste heat is radiated out into the atmosphere
from the power plant, and provides no energy services to
society. This massive energy loss from fossil fuels is not
counted in that graph of ERoEI, thereby artificially inflating
the ERoEI of fossil fuels. If we subtract the energy losses from
conversion of thermal energy to electricity, then the ERoEI of
fossil fuels declines by approximately 2/3rds relative to solar
PV. Conversely, we could also increase the ERoEI of solar PV by
approximately 3x, thereby providing an energy quality
correction. As a result, the ERoEI for thermal power plants
which generate electricity is approximately 2/3rds lower than
the graph indicates, or (conversely) the ERoEI of solar PV is
approximately 3x higher.
>
> It’s simply meaningless to compare the ERoEI of electricity
generation from renewables, against the ERoEI of heat from
fossil fuels, because heat is an extremely low-quality kind of
energy which is far less capable of performing work. This is an
elementary principle of thermodynamics. In order to convert heat
to work, we must lose the vast majority of that heat as waste.
For example, the vast majority of energy from fossil fuels is
simply rejected as waste heat from power plants or internal
combustion engines, and so shouldn’t be counted as an “energy
return” in ERoEI calculations.
>
> In general, the ERoEI of fossil fuels is extremely low.
Natural gas may have an ERoEI of 10, but that falls to 5 when
considering the massive waste heat losses emitted from natural
gas turbines (generally less than half of the energy in gas is
converted to electricity). Coal may have an ERoEI of 30, but
that declines to 10 when considering that coal power plants lose
approximately 2/3rds of the energy of the coal as waste heat.
>
> The ERoEI of oil is particularly low because it's used in
inefficient internal combustion engines inside of vehicles. Most
car engines lose about 80% or more of the energy from gasoline,
as waste heat, when you include both engine and transmission
losses. As a result, the ERoEI of energy which actually turns
the wheels of the car (rather than heating the outside
atmosphere) is not 14.5 for oil, as commonly claimed, but only
2.9.
>
> Renewable sources of energy do not suffer from those
tremendous losses. Although renewables sources of energy do
suffer from power grid losses, those losses are minor (usually
less than 5%).
>
> As a result, the ERoEI ratios of renewable sources of power
are often much higher than their fossil fuel counterparts. Wind
turbines have an ERoEI of 18, compared to 10 for coal or 5 for
natural gas. Solar PV panels powering battery-electric cars have
an ERoEI of about 7 (deducting grid losses and recharging heat
losses), compared to 2.9 for oil in gasoline-powered cars.
>
> Incidentally, the extremely low ERoEI of oil for driving cars
and trucks (2.9), refutes the notion that an ERoEI less than 8
would lead to the collapse of industrial civilization. That
claim is extremely common in energy decline circles, but it was
pulled out of thin air and was wrong to begin with for several
other reasons. In fact, modern industrial civilization has been
growing for decades (especially China and Korea) with ERoEIs far
lower than 8.
>
>
> Hall and Prieto’s criticism
>
> More recently, a book by Hall and Prieto, has become all the
rage in energy decline circles. That book claims that the ERoEI
of solar PV is grossly exaggerated. Hall and Prieto adjust the
ERoEI of solar PV downwards, by adding all kinds of incidental
energy costs. They add every incidental energy cost they can
think of, like the energy costs of building fences around the
solar farm, and so on. They even add energy costs for things
like corporate management, security, taxes, fairs, exhibitions,
notary public fees, accountants, and and so on (monetary costs
are converted into energy by means of a formula). Sometimes,
their estimates of those costs are absurdly high. According to
Hall and Prieto, the ERoEI of solar PV is only 2.45 when all
those things are added.
>
> Once again, the calculation is incorrect, and the comparison
is invalid. Hall and Prieto are adding every incidental energy
cost to solar that they can think of. However, such energy costs
are not included in the ERoEI calculations of fossil fuels. For
example, the ERoEI of oil does not include the costs of security
in the middle east, or the costs of pipelines, tankers, tanker
trucks, road wear from tanker trucks, construction of gas
stations, energy costs of driving to the gas station to refuel,
the highway patrol, and countless other things. If those costs
were counted, then ERoEI of oil (which is already low, at 2.9,
when including waste heat losses) would only decline further.
>
> It's necessary to perform an apples-to-apples comparison here.
If we're going to add up every incidental energy cost of solar
PV, then we must perform the same procedure for oil. Only then
would we have a valid comparison.
>
> If you carry out a detailed accounting procedure for both
solar and oil, then the ERoEI of oil will be even lower in
comparison, than it already was. The incidental costs of oil are
almost certainly higher than those for PV. Whereas oil is a
scarce substance which requires massive extraction and
transportation costs, silicon is the most abundant mineral in
the Earth’s crust (sand, rocks) and does not require expensive
or elaborate techniques of extraction or transportation. Whereas
oil comes from unstable regions and requires massive security
and military costs, silicon requires only a few security
cameras. Whereas oil is subject to ongoing transportation costs,
silicon needs to be transported only once during the lifetime of
the solar cells. In general, the incidental costs of oil are far
higher than those for solar PV. As a result, if we include those
incidental costs in both cases, the adjusted ERoEI of oil will
be even lower in comparison than it already was.
>
> Again, when you perform valid, apples-to-apples comparisons,
the ERoEI of solar PV is higher than that of oil or natural gas.
Oil for transportation in cars has an ERoEI of only 2.9 (because
of waste heat losses), but that is before we include incidental
costs such as security, infrastructure, and so on, so oil’s
total ERoEI would only decline, and would likely be lower than
2.
>
> Hall and Prieto’s analysis is mistaken in other ways. Their
estimate of 2.45 for PV is certainly far too low. They include
things like taxes and land leases, which are not energy costs,
but redistributions of money. Taxes provide services for
society, so they should be counted as energy returns, not energy
costs. If taxes in Europe on gasoline were counted as an energy
cost, then the ERoEI of oil there would certainly fall to below
1. Also, Hall and Prieto include massive energy costs for
premature retirement of solar cells because of rapidly advancing
technology, but those cells won't be prematurely retired because
they are paid for in advance and almost free to operate at that
point, regardless of their efficiency compared to newer panels
(newer panels would simply be added for future projects). Also,
Prieto and Hall include things like administrative expenses,
employees’ salaries, and so on, using a formula for converting
dollars to energy which is far too high and is just wrong. You
would obtain a far lower figure by converting salaries to energy
using a more reasonable formula, of dividing the entire energy
expenditure of a country by its entire GDP in order to obtain a
conversion factor.
>
> A correct calculation of the the ERoEI of solar PV including
everything, would be more like 6, not 2.45. You can derive this
figure by removing everything from Hall and Prieto’s analysis
which is not an energy cost (such as taxes or land leases), and
by using a more reasonable formula to convert monetary costs to
energy.
>
>
> Conclusions
>
> In short. Renewables generally have higher ERoEI ratios than
their fossil fuel counterparts. When you carry out a valid,
apples-to-apples comparison, the ERoEI of renewables is
generally better. This is because the ERoEI of fossil fuels is
actually very poor--generally less than 5--when you correctly
subtract the massive waste heat losses of combustion engines,
and also subtract the massive incidental costs (such as security
costs) of fossil fuels.
>
> The only circumstance where fossil fuels have a higher ERoEI
for renewables is when generating heat for smelting of ores or
making cement or glass. That’s because such applications do not
take place inside inefficient combustion engines, and so don't
require subtracting the enormous waste heat losses of such
engines. As a result, such applications still favor fossil
fuels. Coal has a much higher ERoEI for this purpose than solar
thermal plants, and (more importantly) is much cheaper. However,
those uses are only a small fraction of total energy usage.
Those uses will probably be the last energy uses which are
converted from fossil fuels to other sources of energy, possibly
more than 100 years from now.
>
> Not that ERoEI matters much anyway. The whole idea is a
mistake. What matters is the cost (in money) of net energy, for
an energy source. If the cost of net energy is low, then the
ERoEI is just totally unimportant. For example, if it were
possible to build a 1 GW fusion power plant very easily out of
duct tape for only $10, then it wouldn’t matter at all if it had
an ERoEI of less than 2. We could just build more of them, and
thereby produce the same amount of net energy as a higher-ERoEI
(but more expensive) energy source. As long as an energy source
has an ERoEI higher than 1, the ERoEI ceases to matter, and what
matters is the total cost of net energy. This is discussed
further here.
>
>
HTML http://bountifulenergy.blogspot.com/2014/07/renewables-have-higher-eroei-than.html
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No, I'm not going to bother with the BALONEY from those
challenging this post here. At the link above I launched into a
lengthy back and forth with a fossil fueler that, to his credit,
managed to be polite even when he retreated into snark from lack
of an argument. The fossil fuelers here have ZERO objectivity on
this issue. I no longer feed the trolls here. You know who you
are. Hang on to your wallets.
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