Să vă spun ceva despre Altele. Sunt vorbele lui
Lee R. Raymond,
şeful Exxon Mobil, cel mai mare concern petrolier din lume
"While there can be little doubt that wind and solar will grow rapidly, these start from a very small base and even with extremely rapid growth will only supply about one-half of one percent of the world's energy in 2020"
În română: "Cu toate că nu există dubii că
energia solară şi eoliană vor creşte rapid, ele pornesc de la o bază foarte mică
şi chiar cu o creştere extrem de rapidă vor reprezenta doar jumătate de procent
(0,5%) din energia mondială în 2020."
Hydro-electric power. Originally thought of as a clean, non-polluting, environmentally friendly source of energy, experience is proving otherwise. Valuable lowlands, which are usually the best farmland, are flooded. Wildlife is displaced. Where anadromous fish runs are involved as in the Columbia River system with its 30 dams, the effect on fish has been disastrous. Only to a small extent is hydro-electric power truly renewable. This is when the "run of the river" without dams is used, as, for example with a Pelton wheel. If reservoirs are involved, in order to provide a dependable base load as is the case of most hydro-electric facilities, hydro-electric power in the longer term is not a truly renewable energy source. All reservoirs eventually fill with sediment. Some reservoirs have already filled, and many others are filling faster than expected. A dam site can be used only once.
We are enjoying the best part of the life of huge dams. In a few hundred years Glen Canyon Dam and Hoover Dam will be concrete waterfalls. And, again, the end product is electricity, not a replacement for the important use of oil derivatives (gasoline, etc.) in transportation equipment.
Vă rog să citiţi acest articol al cărui titlu spune tot Large Scale Use of Wind Farms Could Alter Global Climate
This energy source is similar to solar in that it is not dependable. It is noisy, and the visual effects are not usually regarded as pleasing. The best inland wind farm sites tend to be where air funnels through passes in the hills which are also commonly flyways for birds. The bird kills have caused the Audubon Society to file suit in some areas to prevent wind energy installations. Locally and even regionally via a grid (e.g. Denmark) wind can be a significant electric power source. But wind is likely to be only a modest help in the total world energy supply, and the end product is electricity, no significant replacement for oil. As with solar energy, the storage problem of large amounts of wind generated electricity is largely unsolved. Wind cannot provide a base load as winds are unreliable.
The french electricity production has been 506 TW.h in 1997 (1 TW.h = 1.000.000.000.000 W.h).
In order to produce this amount (that is 506.000 GW.h) with windmills delivering 20 GW.h per km2, we should "plant" a surface of 506.000 ÷ 20 = 25.000 km2, that is roughly 5% of the country, or the equivalent of the whole surface occupied by cities, roads and parking lots, even if the required land is only partially mobilized and remains available for other uses (agriculture among others).
With machines of 1 MW of nominal power (that are about 80 m high), yielding roughly 2 GWh per year in a favourable zone, it would be necessary to install more than 250.000 to produce the above mentionned 506 TWh http://www.manicore.com/anglais/documentation_a/windmill.html
Wave energy. All sorts of installations have been tried to obtain energy from this source, but with very modest results. Piston arrangements moved up and down by waves which in turn move turbines connected to electric generators have been tried in The Netherlands, but the project was abandoned. Waves are not dependable, and the end product is electricity, and producing it in significant quantities from waves seems a remote prospect.
Tidal power. It takes a high tide and special configuration of the coastline, a narrow estuary which can be dammed, to be a tidal power site of value. Only about nine viable sites have been identified in the world. Two are now in use (Russia and France) and generate some electricity. Damming estuaries would have considerable environmental impact. The Bay of Fundy in eastern Canada has long been considered for a tidal power site, but developing it would have a negative effect on the fisheries and other sea-related economic enterprises. It would also disturb the habits of millions of birds which use the Bay of Fundy area as part of their migration routes. Tidal power is not a significant power source. The end product is electricity.
Ocean thermal energy conversion (OTEC). Within about 25 degrees each side of the equator the surface of the ocean is warm, and the depths are cold to the extent that there is a modest temperature differential. This can be a source of energy, using a low boiling point fluid such as ammonia which at normal atmospheric temperature of 700F (210C) is a gas, colder water can be pumped from the deep ocean to condense the ammonia, and then let it warm up and expand to gas. The resulting gas pressure can power a turbine to turn a generator. But the plant would have to be huge and anchored in the deep open ocean or on a ship, all subject to storms and corrosion, and the amount of water which has to be moved is enormous as the efficiency is very low. How to store and transport the resulting electricity would also be a large problem. OTEC does not appear to have much potential as a significant energy source, and the end product is electricity.
This is the example of Spain. We have 6.200 MW installed wind power
in the country (with a 18% load factor, as an average, already
choosing the best locations in the country); that is, some 1,116 MW)
and there are licenses to install another 20,000 MW., although the
government was targeting to reach between 13 and 18,000 MW by year
2010. This may result -and is, indeed- impressive (we are ranking
third in the world) but this is generating just 3-5% of the total
present Spanish electricity (not primary energy)
The problem is that with the 6,200 MW installed wind power, plus part
of the 20,000 MW already licensed, the producers are already claiming
publicly that good locations are already coped (the best are already
being exploited or allocated). And we have a country with some
200,000 square miles (1/300 of the total Earth surface). This means
that a country like Spain starts saturating the good wind passes with
some 26,000 MW at 18% load factor; that is, with some 4,680 MW at
100% load factor, which is merely a 12.6% of the total Spanish
electricity generation at present (not the primary energy)
The United States, this privileged country, has 18 times the
territory of Spain, 7 times its population (better inhabitants/km2
ratio), but it has an electricity consumption which is 16 times the
one of Spain. More or less, the same ratio KWh/Km2. Therefore, the US
limit to occupy the best country wind passes will probably, by
extrapolation, be reached at some 15% of their present total
electricity production. Absolutely insufficient. Specially when
considering that what today is 100 level of electricity consumption
will be a level of 200 within 25 years at 3% annual growth.
If the whole world is to be extrapolated, it could start experiencing
problems to select good locations, when reaching about 5,000 GW (5
TW) of installed power at 18% load factor. Or at 1,000 GW installed
power at 100% load factor. Very far away from the theoretical wind
power availability of 1,200 TW in the whole planet Earth and even far
from the above calculated 1/100 of this amount (12 TW, or the amount
potentially available in continental and offshore best wind passes)
You will never see the data in this form in a wind generation or a
wind generators manufacturing company.
We should never forget that every 2.3 MW generator consists in 120
tons of steel and some 12-15 tons of copper, plus graphite
composites, concrete and so -not to speak of those in offshore
platforms-. When reaching to the end of this chapter, please go to
the additions and put everything in steel and cooper production and
double check if this is ecological.
Therefore, we should not necessarily believe to those studies that
claim a huge, virtually unlimited potential in the world, by means of
adding so many MW in such a park, i.e., in the Gibraltar Straight,
and then adding up those of Tarifa (several Km. away) and make the
same calculations and go to individual wind generators and particular
windy places and extrapolate BOTTOM UP to the whole world, as if the
world had no limits. The upper maximum real and absolute limit of
wind world energy is 1,200 TW times 8,760 hours= 10,512,000 TWh per
year, for the whole of the winds of the planet (83 times the present
primary energy consumption by humans). Full stop. And aspiring to
intercept and convert 1/10,000 of the total world energy winds will
be a task of a magnitude much higher than that of going to Mars
(probably with devastating ecological consequences, we do not even
imagine today). And will not be sufficient even to satisfy the
electric demand, not to speak of using the wind generation to boost
the so called "hydrogen economy".
Heavy oil, extra heavy oil, and tar sand
Jean Laherrère, personal communication.
Heavy oil, extra heavy oil, and tar sand
“Saudi Arabia’s oil is so easily reached that it takes little more
than a pipe stuck in the ground to set it gushing out. To get
Shell’s tar sand project [in Alberta, Canada] off the ground, by
contrast, required well over 10,000 employees and a huge
industrial operation ....
Shell’s project is already an incredibly complex operation at its
current output of below 200,000 barrels a day. But that is a drop
in the bucket compared with Saudi Arabia’s daily production of
about 8 million barrels.”
Quotation from the article There’s oil in them tar sands,
The Economist June 28th-July 4th 2003.
2.2 Non-conventional fossil oil
2.2.1 Heavy oil, extra heavy oil, and tar sand
Oil which has migrated over long distances from the source rock to shallow depths has
been exposed to bacteria. The bacteria have removed the light molecular components and
thus degraded the lighter oil into heavier substances: heavy oil, bitumen, tar or asphalt.
Heavy oil and extra heavy oil is by some authors defined as oil with a density of 0.934 -
1.0 g/cm3 and > 1.0 g/cm3 respectively. Heavy oil can be pumped to the surface while extra
heavy oil, which is heavier than water, requires special recovery techniques: steam
injection or the injection of a solvent which liquefies the oil. Bitumen is oil with a viscosity
higher than 10,000 mPa.
Tar sand is a sandstone which contains very heavy oil (bitumen). Tar sand deposits near
the surface are mined with huge 400-tonne payload shovels (4-metre tall tyres) and dumped
into a hot-water mixer where the sand (84 - 92 % by volume) sinks to the bottom. From
deeper deposits in-situ mining methods are applied. The bitumen is extracted by the
injection of steam into vertical and horizontal multi-directional wells to create a fluid mix
of hot water and bitumen. After recovery, the bitumen is treated with steam to crack it into
Large extra heavy oil and tar sand deposits are found in Alberta, Canada, and in the
Orinoco Belt in Venezuela.
The production of synthetic oil from extra heavy oil and tar sand has a significant
influence on the oil and/or gas reserves available for use outside the oil industry itself. In
addition to electricity consumption and oil consumption in shovels and trucks and in and
refinery processes, it takes about 35 cubic metres of gas to produce 1 barrel of bitumen
from tar sand by the in-situ steam injection recovery method (below 50 metres of
overburden) and to hydrogenate the bitumen into crude oil. Somewhat less where surface
mining is feasible. As about 80% of the oil will have to be recovered by the in-situ method,
the production of 174 Gb will take about 5,500 billion cubic metres of gas. This
corresponds to most of the present gas reserves in the USA and Canada (7,000 billion cubic
metres). Some of this gas can be replaced by oil, but then the oil reserves must be reduced
Thus, for tar sand the energy used in the mining and the subsequent refinery processes
equals 25 - 30% of the energy gained in the oil produced. Moreover, large amounts of
water is used in the mining process and large amounts of hazardous waste has to be
Oil shales are oil source rocks (clay, fine grained-sand, calcite, etc.) containing organic
material - mainly from algae - which were not buried deep enough for the temperature be
high enough for the conversion into oil or gas to take place. At the lower temperatures the
organic material was converted into kerogen21. When heated to about 350o C, kerogen
breaks down into recoverable gaseous and liquid substances resembling petroleum. Oil
shale rock is mined in open pits, then crushed and heated. The volume of the waste
products is bigger than the volume of the oil shale mined and the production processes
require substantial amounts of energy. Large deposits of oil shale are found in the United
States, Brazil, Russia, and Australia.
Synthetic oil from coal and natural gas
Oil can be synthesised from coal and from natural gas. Based on carbon from coal22,
synthetic oil was produced in Germany during World War II and in South Africa during
the trade boycott. Presently, the possibility of producing oil from natural gas (gas to liquid,
GTL) at remote sites with no gas-pipeline connections (such as Eastern Siberia) is being
considered. However, the energy consumption in the synthesising processes is very high.
In the GTL process about 45% of the gas us ed is used to fuel the process itself23. Thus, to
gain 1 GJ in the form of oil about 1.54 GJ in the form of gas is used.
In the so-called Bergius process, developed in Germany during World War
I, oil is formed
in a process where coal and hydrogen react at a temperature of about 500o C and a pressure of several
hundred bar. Per tonne of coal, about 160 litres of petrol, 190 litres of diesel, and 130 litres of fuel oil
can be produced.
A coal deposit covers a wide area having huge ‘resources’ but only at
places with thick seams or ease of access do the ‘resources’ become
‘reserves’ to be mined. It is largely a matter of concentration. Thus, if prices
rise or costs fall then lower concentrations become viable ‘reserves’. It is the
same with mineral mining.
Oil is different because it is a liquid which collected in certain places. It
is either there in profitable abundance or it is not there at all. The oil-water
contact in the reservoir is abrupt. So it is not a matter of concentration. The
notion of huge ‘resources’ being converted to ‘reserves’ as needed is deeply
embedded in economic thinking, but it does not apply to conventional oil. But,
of course, the tar sands behave like coal. Colin J. Campbell
What about free energy? Didn't Nikola Tesla invent some machine that produced free energy? Couldn't we just switch to something like that?
While free energy technologies such as Cold Fusion, Vacuum Energy and Zero Point Energy are extremely fascinating, the unfortunate reality is that they are unlikely to help us cope with the oil depletion for several reasons:
currently get absolutely zero percent of our energy from these sources.
3. We've already had our experiment with "free energy." With an EPR of 100 to 1, oil was so efficient and cheap an energy source that it practically was free.
4. The development of a "free energy" device would just put off the inevitable. The Earth has a carrying capacity. If we are able to substitute a significant portion of our fossil fuel usage with "free energy", the crash would just come at a later time, when we have depleted a different resource. At that point, our population will be even higher. The higher a population is, the further it has to fall when it depletes a key resource. The further it has to fall, the more momentum it picks up on the way down through war and disease. By encouraging continued population growth, so-called "free energy" could actually make our situation worse.
5. Even if a functional free energy prototype came into existence today, it would take at least 25-50 years to retrofit our multi-trillion-dollar infrastructure for such technology.