I have come to the dismal conclusion that whereas Al Gore and the Democrats are entirely correct about the menace of global warming, there is little hope that it can be stopped by the remedies they are exploring. Several websites address the idiocy of the phrase "clean coal", but the alternatives they propose are inadequate and not as environmentally benign as hydroelectric power.
The solutions proposed are energy efficiency, direct solar power, wind turbines, biofuels, geothermal power, tidal power, and maddest of all, carbon dioxide sequestration.
Energy efficiency is the best of the proposed solutions, but as long as there's a market for gas-guzzling SUV's, and as long as carpooling and bicycling to work are not seriously considered, there's not a lot of hope for even achieving the 20% to 30% that might be possible.
Perhaps the silliest of all is the idea of subsidizing corporate private research into nuclear power. Corporate competition discourages the sharing of research information. Even so, there are brave and honest folk engaged privately in the hope of saving the world from dependency upon fossil fuels.
The Molten Salt Reactor(MSR) and the Integral Fast Reactor(IFR) were a generation beyond anything that the proprietary energy companies have ever considered.
Both are meltdown-immune, and would therefore have survived even the Fukushima-Daiichi tsunami.
They contain the solution to global warming, foreign petroleum dependence, existing nuclear waste, and the disposal of Cold War surplus warhead plutonium.
At the beginning of the very month of the Chernobyl disaster, model EBR-2 of the Integral Fast Reactor demonstrated its immunity by actual deliberate test.
The IFR was far beyond even the level of success of the research done by the French (Phénix) or pre-Thatcher British (at Dounreay) governments.
The Thatcher government 'privatised' the British Central Electricity Generating Board, with the result that many nuclear power plants in Britain which seemed to have been quite safe and efficient are now 'decommissioned' at great expense, partly no doubt because the institutional memory carried in actual human brains was lost by their being relieved of their jobs.
The original web documents about the IFR were archived at UC Berkeley,
under IFR Archive index and they seem to be gone
Part of it is here. But a copy of the main paper is here
The Molten Salt Reactor, MSR, is another, possibly better, approach. Its chief advantage is that it does not inherently need as high a level of enrichment as Fast Neutron Reactors. The original AEC experiment ran from about 1964 to 1969.
A very recent design variant is called the "Waste Annihilating Molten Salt Reactor", WAMSR, designed to run at the enrichment level of the actinides in "spent" current PWR and BWR fuel. That's the so called "Long Lived Deadly Waste" that is 96% of the not-really-spent fuel. In other words, it's most of the original uranium and about one third of the plutonium that the reactor synthesized. These Light Water reactors start with fuel enriched to 3.6%, and run the fuel rods until that level drops to half, 1.8%. At that point, the presence of fission products interferes too much with the neutron production chain. Although these reactors do produce and use up by fission some fissile plutonium from the non-fissile bulk of the uranium, a typical fuel rod needs to be replaced in about three years.
Direct solar power, whether photovoltaics or solar-driven Stirling engines, requires about twenty square miles of area, per gigawatt capacity, under cloudless skies. Southern California Edison attempted perhaps the most successful of such projects. You obviously can hardly get half a gigawatt-year of energy per year per gigawatt of capacity. Unless the apparatus follows the sun, the maximum production factor is one third, by simple trigonometry.
Biofuels grown in fields cannot by any stretch of the imagination provide more energy per year per square mile than the yield from burning fast-growing wood or grasses (e.g. bamboo or miscanthus) grown is such fields. Ethanol from corn or sugar-cane clearly provides less energy than burning the entire plant. The figures are available for willow coppicing, and it is important that the energy cost of fertiliser be included. Willow can be grown without significant fertilising. But even so, it takes about a square mile to harvest a megawatt-year's worth in a year. The entire State of Iowa is just over 56 thousand square miles. So -- optimistically, if it were all planted in willow trees, or other whole-crop plants, it could supply just over 56 thousand megawatt-years per year. One MJ, megaJoule, is the energy of one million Watts for one second. One gigaWatt year is 3600*24*365 thousand MJ The United States consumed 18.8 million barrels per day (MMbd) of petroleum products during 2009; one barrel of oil equivalent is 6,120 MJ If, instead of corn, we could plant every acre of Iowa in a crop that could ALL be converted to fuel, it would supply about 4% of the US demand for oil -- well, actually, two thirds of 4% because whatever micro-organism you employ will have to be fed some of the carbon. The gas that makes bread rise and beer fizz uses one in every three carbon atoms of the sugar. That's what feeds the yeast.
Wind turbines are not only an eyesore, at 600 feet high for a turbine of 6 megawatts nameplate capacity.
They cannot be scheduled, because you cannot schedule the wind, and the power of the wind varies from minute to minute. It's gusty.
They are a bigger menace to flying wildlife, per kilowatt-hour or megawatt-year delivered, than hydroelectric turbines are to migratory fish.
Steerable heliostats, over a wide area, following the sun by computerised motors to focus all of the incident radiation at the top of a tower with a heat driven generator. are a different kind of menace. The radiation flux just outside the machine room windows is of course intense. At Ivanpah on the California/Nevada border air temperatures can reach 1,000 degrees Fahrenheit. The radiation ignites bird feathers, because they are good insulators. That plant in 2015 produced 74.4 MW.years of energy in that year, but also consumed 565 thousand MCF of natural gas. The Wikipedia article erroneously records it as mcf, and for all I can guess it might be MMCF. 'M' here is the Ancient Roman symbol for a thousand, not the metric one for a million. MM, of course, is here intended as 'a thousand thousand'.
Geothermal power is inexpensively available only at the world's geothermal hotspots. The same goes for tidal power, and not all of the proposals are environmentally benevolent.
Carbon dioxide sequestration would involve the sequestration of 44 tons of carbon dioxide (CO2) per 12 tons of carbon. In other words, if you compress the gas to the density of coal, which is a factor of more than a thousand, it still would not fit in the space that the coal came from. Compressing a gas costs energy, which you do not get back if you can successfully bury it. The problem is vastly more difficult than the disposal of the wastes of a nuclear power plant, because for every ton of nuclear waste, coal burning has millions of tons of gases. It's easier to sequester solids.
The IFR design is passively immune to the loss-of-power / loss-of-coolant problems that occurred at Three Mile Island and Chernobyl. The immunity is implicit in the design, and was proved by actual test at the beginning of April 1986. That was the very month when Chernobyl's operators bungled their job, and the secrecy surrounding it caused people to be exposed to radioactivity. This was much worse than the Three Mile Island incident, which did not actually cause any proven casualties at all.