I always thought that solar generated electricity would be the future of the World’s energy needs, not calculating the costs or the impact of heaving only solar generated electricity and not heaving fossil fuels at all witch will eventually happen in a couple of decades.
As it turned out there is this guy Derek Abbott Professor of Electrical Engineering at the University of Adelaide in Australia who calculated all the costs and all the finite supplies of material on this planet and guess what turned out?
Nuclear fission:
Nuclear fision
if fission hypothetically supplied the world’s energy needs, there would only be five years’ supply of uranium; and thorium, a suggested substitute, has a recoverable supply of only half of the world’s uranium reserves. So no, basically our supplies would be depleted in 5 years.
Nuclear fusion:
Nuclear fusion
Abbott estimates that the world’s lithium reserves would last about 100 years if it were to supply the world’s energy along with continuing use in industrial applications, such as batteries, glass, ceramics, and lubricants. So, 5 years, 100 years we are doomed anyway, not to mention the costs of such technologies, and the environment friendliness.
Wind:
wind power farm
a typical 1.5-MW wind turbine requires 20 gallons of lubricating oil every 5 years, which would become unsustainable in a few decades. (oil being extracted from fossil fuels as well)
Hydroelectric:
Hydroelectric
currently provides 20% of the world’s electricity, with room for further growth. However, hydroelectricity could not supply the whole world’s power due to the limited availability of waterways. Plus, dams often have negative effects on aquatic ecosystems.
Geothermal:
Geothermal
Abbott says, is that much of the energy is diffuse and unrecoverable, so that geothermal power could ultimately supply only a fraction of the world’s energy needs.
Solar:
solar thermal collectors
Today, the world’s energy consumption is currently 15 TeraWatts (TW) (15 x 10^12 watts). The total solar energy that strikes the Earth is 166 Petawatts (PW) (166 x 10^15 watts). Even with 50% of this energy being reflected back into space or absorbed by clouds, the remaining 83 PW is more than 5,000 times our present global energy consumption. In contrast, the above sources of renewable energy (wind, hydroelectric, and geothermal) can supply less than 1% of solar power potential.
Despite the improvements in silicon solar cells, Abbott argues that they are low efficiencies and heave high environmental impact unlike solar thermal collectors. Abbott calculates that manufacturing enough solar cells to power the world would require 6 million tonnes of arsenic, while the world’s supply is estimated at about 1 million tonnes.
On the other hand, solar thermal collectors are specifically designed to operate under hot temperatures. The idea is to use a curved mirror to focus sunlight to boil water and create steam, which is then used to power, for example, a Stirling heat engine to produce electricity. The system has already been demonstrated in California’s Mojave Desert, which has been using a solar thermal system to heat oil in a closed-cycle instead of water for the past 20 years.
Abbott calculates that, in order to supply the world’s energy needs, the footprint of such a system with pessimistic assumptions would be equivalent to a plot of land of about 1250 km by 1250 km – about 8% of the land area of the hot deserts of the world. With less pessimistic assumptions, the land area could be reduced to 500 km by 500 km, corresponding to 1.7 billion solar dishes that are each 10 meters wide. At massive volumes, if these Stirling engine dishes could be produced at a cost of $1,000 each, the total world cost would be $1.7 trillion – “which is less than the going rate of a war these days,” Abbott noted.
Taken from Physorg.com
Hydrogen:
Hydrogen motor
After connecting these solar farms to the local electricity grid, the electricity could then be used to electrolyze water to produce liquid hydrogen to run our vehicles. Abbott suggests that the next step would be to power public transport, such as buses, using liquid hydrogen. Then consumers could buy liquid hydrogen cars and refuel at public transport depots for a transition period until existing gasoline stations begin providing liquid hydrogen refueling.
According to Abbott, running vehicles on hydrogen rather than electricity is superior in terms of sustainability. The batteries in electric vehicles consume chemicals and finite resources such as lithium, and release high levels of toxic waste. On the other hand, vehicles that burn hydrogen simply emit clean water vapor, and do not require the unsustainable use of chemicals. Other advantages of hydrogen vehicles are that today’s gasoline combustion engines can be retrofitted to run on hydrogen, and the car manufacturing industry has infrastructure tailored to combustion technology.
So, in the end the conclusion is quite simple: Solar thermal collectors combined with hydrogen making for use on vehicles as a fuel is the ultimate solution for the World’s Energy Needs.
