Several green energy options have been proposed, namely:
- Nuclear fission reactors of a modified and improved design.
- Land based wind turbines.
- Shore based wave generators.
- Land based solar cells and/or solar thermal generators.
- Green fuels to replace fossil fuels such as alcohol and oil from food crops, waste wood, kelp and algae.
- Land based deep thermal wells.
- Ocean based wind turbines, wave generators and solar cells.
Let us explore each green energy option in sequence and match it to our list of requirements.
Nuclear Fission.A nuclear fission reactor is competitive in cost because the energy is as concentrated as is that from fossil fuels, so a relatively small amount of equipment is needed to exploit it. Such reactors are currently being used for base load (Load Factor ~0.98. Note that Load Factor is the fraction of time a source is on line providing energy) and can operate at ~$0.08/KWH or more. It emits no carbon dioxide. There is enough nuclear fuel to last more than 100 years without using breeder reactors (reactors that generate more fissionable fuel than it uses). If we use breeder reactors, there is enough fuel for several thousand years. Thus it meets all the green energy requirements except one, safety. Safety is the big issue, especially after the Japanese reactors did not fail safe when an earthquake and tsunami damaged them. The vulnerable element in the light water reactors currently being used in Japan and elsewhere is the coolant pump. Backup coolant pumps are always provided, but if all electricity is lost, both inside and outside the facility (as happened in Japan), the backup pumps are useless. The neutron absorbing control rods and emergency shut down systems will deploy without electricity and shut down the fission reaction, but the residual radioactivity in the fuel rods will continue to heat the rods and eventually melt them down (as apparently happened in Japan). If the coolant pump is off line long enough (as also apparently happened in Japan), the rods may melt through the containment vessel and vent radioactive material to the environment. It appears feasible to design some reactors (for example-pebble bed and certain fast reactors) with low enough energy density in the fuel elements so that the residual radioactivity will not melt them down, but instead fail safe. Or, it may be possible to make acceptable modifications to the current light water reactor designs. Getting rid of radioactive spent fuel is also a problem. The fuel elements must either be placed in long term storage, or treated and refined in a reactor until only short term radiation is left. Both these problems require research and development (R&D).
This R&D will generate jobs, but they will be high level jobs (scientists and engineers) until the designs for safe reactors and safe spent fuel disposal methods are obtained and approved. After that, mid level jobs with job leverage building, modifying and operating the reactors will become available. It is expected that this effort and the government approval cycle will take a long time ( greater than one decade), so mid level jobs for the new nuclear plants are not expected for at least one and maybe two decades (long term). Even after one to two decades, the number of new workers produced will not be in the millions. If it were so, the energy would cost too much. The number of workers per KWH produced in nuclear plants is relatively small-larger than the number for fossil fueled plants, but still relatively small. The capital cost of the plant is large, but the fuel cost per KW produced is relatively small, which brings the overall cost down and makes it competitive with fossil fuel plants in most geographic areas and better than fossil fuels in others.
Land based wind turbines. Land based wind turbines are non-polluting but the energy is diffuse, and so requires a large amount of equipment to exploit it. Thus the capitol cost and resulting energy is expensive (~$0.10/KWH or more not accounting for down time), and it is not available all the time (Load Factor ~0.5 to 0.7 in good sites, less elsewhere), so the effective cost is even higher. Also, they require carefully selected windy sites that are not common enough to provide a significant part of the base load. It should be noted, however, that land used for wind turbines can be used for other purposes as well.
The R&D on wind turbines has been done, so they are ready to be installed. The only factor that keeps more from being installed (and thus creating jobs) is the lack of good sites, the low load factor and the high capital and maintenance costs which makes the energy cost high. The only way wind will become cost competitive is if the government subsidizes it (as has been done in the past) or if it is added to a home to provide domestic energy. Here the cost of the generator is small compared the cost of the home, so the high cost per KW is less important. This home market is currently being exploited where wind conditions are favorable. Thus wind turbines are useful, but appear best suited for operation in high energy cost areas on an as available basis, or in conjunction with homes. Wind turbines may eventually gain 10 to 20% of the energy market. A modest increase in new jobs is expected over the long term as fossil fuel becomes more expensive.
Shore based wave generators. Shore based wave generators are also non polluting, but the energy is diffuse, and so requires a large amount of equipment to exploit it. Thus the resulting energy is expensive, but not as expensive as land based wind turbines (~$0.09/KWH or more not accounting for down time), but it is not available all the time (Load Factor ~0.4 to 0.6 in good sites, less elsewhere), so the effective cost is even higher. Again, they require carefully selected wave sites that are not common enough to provide a significant part of the base load. Thus they are not suited for base load.
The R&D on wave generators has been done, so they are ready to be installed. The only thing that keeps more from being installed (and thus creating manufacturing and installation jobs) is the lack of good sites, the low load factor and the high capital and maintenance costs which makes the energy cost high. It is seldom practical to add them to a home, so this procedure for making them more popular is not available as it was with wind turbines. The only way wave generators can become competitive is if the government subsidizes them. Thus they are useful, but appear best suited for operation in high energy cost areas at the end of a long transmission line on an as available basis. Large numbers of new jobs are not expected from this area.
Land based solar cells and/or solar thermal generators. Land based Solar cells and solar thermal systems are non-polluting, but are dependent on sunshine, the most diffuse of all energy sources. Thus they require a lot of equipment and are one of the most expensive sources (~$0.17/KWH or greater, not accounting for down time), and they don't operate all the time (Load Factor: ~0.4 to 0.6 in desert zones, less elsewhere) which increases the effective cost even more. Both need huge tracts of carefully selected land for each KW of power generated. (~0.1 KW/sq meter) which drives up cost. Furthermore, this land can't be used for other purposes. In general, solar generators are not suited for areas near the ocean where clouds and fog are common. Thus land-based solar cells and solar thermal systems are not suited for base load generation where they must be economically competitive and reliable. Solar cells appear best suited for specialty use where cost and area is less important such as on top of electric cars to extend their battery range, or on top of houses to cover the day-time peak load. Here cells are used in conjunction with much more valuable items (cars and houses) so cost is of secondary importance. Solar thermal is useful near isolated desert communities because an energy storage system has been developed for them. Here, climate conditions and isolation from base load generators work together to make these generators more competitive.
Most of the R&D on solar cells and solar thermal has been done. The most important remaining research is the effort to increase the efficiency (and/or reduce the cost) of solar cells. Contracts are currently out to accomplish this goal. Success in this endeavor will make solar cells more attractive in the above-mentioned applications and gradually increase their use. Thus, a few new jobs (hundreds to thousands) in the R&D part of this area are expected in the near term. A more significant increase in new jobs is expected over the long term in this area as the cost of fossil fuel increases.
Sustainable synthetic fuels. Fuels obtained from plants and trees are non-polluting, but are dependent on sunshine, the most diffuse of all energy sources. The efficiency of conversion is less than that of solar cells, so in general, they will be the most expensive energy source. There is a mitigating factor, however. Some feed-stocks are available from other activities that reduce costs. Corn is available from efficient farmland operations. Alcohol from corn is currently being produced and used with gasoline to power autos. This option cannot be thought of as a long them solution, however. As population increases, the corn must be used for food as increasing corn prices show. The same is true of diesel oil from soybeans. This is not true of alcohol from waste wood. This source gets its feedstock from lumber processing and brush clearance operations throughout the US. This waste wood would normally remain unused. Long term production is possible and also desirable. It could help satisfy the need for a partial replacement for fossil fuels for portable applications (autos, trucks and aircraft), but it is not expected to replace them. Fuels from kelp and algae have to be grown, however, so they are subject to the bad economics of diffuse energy operations with large land use and capital outlay. These energy sources may become locally competitive in small markets, but they can't replace fossil fuels for base load. Also they may have an environmental impact. Thus energy from plants is best suited to supply a portion of the fuel required for portable power plants such as cars, trucks and aircraft.
There is a significant amount of R&D to be done on synthetic fuels from waste wood, kelp, and algae. This R&D must be pursued to the point where cost and capability are known. Then the competitive position of each option in the overall energy scheme of the US can be established. A few tens of thousands jobs in R&D could result from government contracts in the political near term. More jobs (many tens of thousands) will come during the early production stage in the near to long term. The large number of jobs that might result when production ramps up will have to wait for the long term.
Land based deep thermal wells. Deep thermal wells are non-polluting and expected to be competitive in cost because the energy is concentrated as with nuclear fission and fossil fuels and so, with the exception of the well, requires a relatively small amount of equipment to exploit it and the fuel (heat from deep in the earth's crust) is free. The land area required is small and modest in cost. New chemical drilling techniques for the well show promise in holding the cost of the very deep well down, but experimental cost details are not yet available. If the pilot well is inexpensive enough, deep thermal wells can be used to provide base load. The fuel (earth heat) is available near enough to the surface in many areas on the earth, and will last for the foreseeable future. It is non-polluting. It can use existing electrical distribution systems. The resulting wells can even be used to sequester carbon dioxide. The only disadvantages of this generator are that it is vulnerable to earthquake damage, and it is useable only in areas where the hot rocks needed are close enough to the earth's surface to make drilling the well economically feasible. The vulnerability to earthquake damage may make it undesirable for earthquake zones such as coastal California, and the hot rocks are nearer the surface in the west of the US than in the east, but the potential operational area appears to be huge.
The R&D on deep thermal wells is well under way. A pilot well is being drilled. If the well is found to be economical in producing energy, expansion into large energy production is expected to proceed rapidly because there are fewer political and safety problems to overcome in order to get permits than, for example, for nuclear fission reactors. The number of workers required per KW produced is relatively small, however, because each well produces a large amount (megawatts) of power, and the workers needed per well is small. So millions of jobs will not be forthcoming in this area. Certainly, the jobs it does produce will not come in the political near term. It will take at least five years to see a significant increase in jobs in this area.
Ocean based wind turbines, wave generators and solar cells. These energy sources are non-polluting and capable of generating large amounts of energy but depend on diffuse energy sources, so they would be expected to require a large amount of equipment and so be expensive. This turns out to be wrong for five reasons:
- They can be built and operated all together on one vessel to save capital and maintenance expense.
- The operator lives on the vessel and grows his/her food on the vessel as well to save operating expense. Part of the operator's pay is the food and living quarters provided for him and his family who can also live aboard.
- The owner will often be the operator to save overhead and capitol expense.
- The vessel can be moved to find optimum operating conditions (Load Factor ~0.85 to 0.95)
- The three energy sources complement each other, so one is operating at near optimum almost all the time.
Thus, the cost per KWH is estimated at ~$0.03/KWH or more. Note that each vessel produces only a modest amount of power (100 to 400 KW), so many millions of vessels are required to obtain the total power required in the US, but each vessel is expected to be profitable by itself. Here we appear to have found a means of taking the money we normally would pay to the owners of oil and gas fields and pay it to US workers who will produce the energy we use. The energy produced (electricity) can be converted into nitrogen fertilizer concentrate immediately with easy transport to land, and a ready market. This frees up natural gas (currently used to make fertilizer) for use to generate base load electricity. It can also be converted into hydrogen and oxygen, or, by use of the plant residues from the food grown, converted into natural gas and oil and transported to land. Thus, it can provide fuels for portable applications (autos, trucks and aircraft). This synthetic gas and oil from ocean energy can gradually replace the fossil natural gas and oil as it peaks out and the US can move smoothly into renewable energy.
The R&D on ocean based wind turbines, wave generators and solar cells is nearly complete. The prototype is 95% done. After prototype completion, production can be turned over to existing boat building yards, so moving into production phase can be quickly accomplished. There is a ready market for the product (fertilizer) of the vessel, so production should increase steadily. Millions of jobs can result when you count the construction workers and the operators of the vessels. These jobs are not subject to replacement by computers and robots. With this energy source, we pay no more for the energy and our money will go to American workers. However, these jobs will not come in the political near term. It will take at least five years to see a significant increase in jobs in this area.