As promised, I looked into at what I think is the most expeditious plan to handle global warming. As is my wont, I will preface my recommendations with a bit of analysis that will serve as a foundation for my later work.
1) Global warming is real and that contribution of human activity to this is significant and will increase in the future. 2) The results of global warming will be significant, with financial costs that will run in the multiple trillions of dollars and millions of human lives. 3) The increase in CO2 gasses into the atmosphere will stop and be reversed only when there is a cost effective alternative, portable energy source that does not involve the emission of CO2 or there is an cost effective means of removing significant amounts of CO2 gasses from the atmosphere. The idea behind this notion is that, even if US and Europe were to cut greenhouse gas emissions in half in the next 20 years, total emissions would still soar. China is expected to produce more than twice the total emissions of the US and the EU before that time. Whatever solution is obtained, it must make economic sense to developing as well as rich nations. 4) Bridge solutions, eg solutions that are not sustainable forever but will work for 50-100 years need to be considered as candidates for a total solution. The reason for this is that, based on past experience, world wealth and technology increase significantly over timeframes of this magnitude. As long as we continue to fund research in areas that could provide longer term solutions (lasting 50+ years), then we dont need to pick one now. Indeed, if one looks at the track record of futurists, one sees that humans have a very bad track record predicting where the significant technological breakthroughs will be 50 years from now. So, while we can guess what would be the best choice for our descendents 100 years from now, there is no reason to believe that this guesses will be any better than the 100 year old guesses were for today. 5) Apples to apples comparisons should be made. One shouldnt use one set of criteria for cool sounding solutions and another for solutions that sound unappealing. 6) We should recall that the best is oft the enemy of the good. A truism of engineering is that engineering departments and new ventures have died over fights over the very best. In engineering, the second best solution today is far superior to the best in a year. Having set a basis for my argument, let me next argue for the proper roll of government. In particular, I am considering the governments of the wealthier nations: (e.g. the EU, Japan, the US). I see governments as providing two essential roles. First, governments should fund underlying R&D efforts. The roll that is clearest for the government here is the funding of basic science that has promise of producing long term technological capacities. Examples of this would by synthetic biology, mesoscopic physics, and material science. I think it is also reasonable for the government to address basic engineering questions: like high density capacitors, underground CO2 compression and storage, and efficient energy storage. The second would be to provide a carbon tax and a subsidy of non-CO2 emitting energy sources. The 1.9 cent subsidy now provided by the US government is a good example of this. As I will mention later, this was sufficient to develop a thriving Texas wind energy business. That subsidy is at a rate that matches, roughly a $25/ton of CO2 carbon tax. Such a combination would be strong incentive in the area of electricity, but it is not clear that it would be enough to replace non-electrical energy consumption. I made the role of government general on purpose. Governments have the bad tendency of picking technologies with the best political support, not the best technologies. The overwhelmingly disproportionate spending on ethanol support by the US is an example of this. OK, having said that, lets go to green technologies. The first and most obvious one is nuclear power. Nuclear power is a well proven technology. It has been used competitively with fossil fuel plants. The subsidies for nuclear power have mostly been indirect benefits from governmental nuclear weapons research. Nuclear power has been subject to criteria for safety that has not been paralleled by most other industries. In particular, risk is assessed using a linear model to assess damage from low level radiation, even though studies of low level radiation, on average, show a very small benefit to low level radiation. I discuss this at some length in my blog at http://science-community.sciam.com/blog/Dan-Ms-Blog/300001389 But, the essence of the report is that, if the linear model is correct, it should be apparent in the dependence of morbidity rates on natural background radiation. In particular, if the linear model is correct, the high levels of radon in the Denver area should result in a very strong signal in lung cancer deaths among non-smokers particularly non-smokers in households that do not contain smokers. But, instead, the large scale test from that area show a homesis effect: death rates are lower. Now, with the uncertainties in correcting for different people with different risks living in different areas makes this result consistent with no effect. But, after 60 odd years of analysis, the evidence is, with the rare exception that can be ascribed to statistical anomalies, that there is no measurable risk associated with low doses of radiation. Given this, and given the low measured death rate when a near worst case scenario took place (Chernobyl with less than 100 deaths according to the official commission monitoring the situation), it seems a no-brainer that the benefits in reducing CO2 emissions outweigh the relatively small risk inherent in nuclear power. Further, even the accidental death rate associated with other power sources compare unfavorably with nuclear energy (including Chernobyl). There are some difficulties associated with nuclear power. In particular, the use of breeder reactors could enhance the possibility of weapons grade fuel being used. One possible solution to this is the poisoning of the fuel with other material that would have to be separated out to obtain bomb grade material. But, if we accept breeder reactors, the projections are that we can have nuclear based electricity for at least 100 years. The second green technology, in terms of practicality, is wind. Large scale wind farms are now being built in Texas. The size of their output far exceeds the requirements imposed by the state ledge. In addition, the mandate included an easily out for the industry if there were any problems making money off the farms. Instead, Texas is way ahead of the mandate curve and still building. As of the 1/08, Texas had about 4400 MW of capacity in operation with another 1200 under construction. This strongly indicates that with the 1.9 cents/kWh subsidy, wind power is economically feasible. It should be noted though, that there are problems with wind power. The main problem is its duty function since the power goes as the cube of the wind speed, the power output is highly variable. My understanding is that, in combination with natural gas (which has half the capital cost of coal but a much more expensive fuel), wind makes sense as a small player. But, if you look at projections, and the problems seen in Germany with the need for reserve conventional capacity (at about 95% of the total wind capacity) as their total wind capacity goes towards 10% of electricity usage, we see the limits on the feasibility of wind. An effective, efficient, inexpensive storage mechanism for large amounts of energy is required if wind will get out of the single digits. These are the two green energy sources that are economical with a 1.9c/kWh subsidy as well as show a potential for growth (most hydroelectric potential in the developed world is tapped out.) In addition, China is including nuclear in their mix, so even there the costs are not prohibitive. Now, lets get to some other green energy sources that have been discussed. Solar heating has been mentioned, and it works in some market as a hot water source. But, its applicability is limited. China (which is cited as representing 80% of solar heating use) is increasing its CO2 production at a breathtaking rate. There is nothing Ive seen that indicates that solar heating will represent more than a fraction of a percent of energy consumption. Solar electric power has been featured at Scientific American with a promise of a future significant drop in price. But, even in Euros, the price has risen over the past 4 years. The cost is about $4.71 per installed watt of peak capacity(according to solarbuzz.com) as of now. The price for large scale (industrial) applications averages north of 20 cents/kWh. Clearly, a massive drop is needed before even a 5 cents/kWh subsidy will make this energy source viable. Further, like wind, it suffers from the fact that the production is not constant, and a storage mechanism is needed. Geothermal works well where the temperature gradient in the earth is high. But expansive use is not practical .the best sites are already used, and low gradient geothermal isnt efficient at all. One sees arguments for wave, current, and tidal electricity, but those are still vaporware. Now, from the most probable to the least probable energy source listed above, there is one common factor: they are sources of electricity. In the case of nuclear energy, it can provide a steady source of electricity, but it is hard to ramp up for peak demands. Thus, it must either be supplemented by another means, such as natural gas, or a storage mechanism must be developed. This need is much stronger for wind and solar power than it is for nuclear power, since their power generation is very uneven, requiring storage capacities in the many GWh range for a country the size of the US. There are a number of candidates for this. An obvious, relatively inefficient one, is pumping water up a hill to run through turbines at later times. The overall efficiency (Power Out/Power In) is about 60%. Scientific Americans article on a grand solar plan touts compressed air storage, which has been used in a location in Germany and Alabama. These sites quote efficiencies in the 75% to 80% range. These efficiencies are obtained, though, in the combination of compressed air with natural gas burning and Ive looked but havent found numbers on compressed air storage without involving the burning of natural gas. Further, suitable locations are not trivial to findompressed air storage is uncertain, and the costs are a noticeable fraction of the cost of producing energy. http://www.sandia.gov/ess/About/docs/haug.pdf And, the efficiency is expected to be about 70% http://en.wikipedia.org/wiki/Compressed_air_energy_storage so, were talking about the price per kWh being beyond what is feasible with the present 1.9 cent/kWh subsidy. From what Ive seen, the plant is feasible because the utilities only pay a small fraction of the cost. For a pilot test, thats reasonable, but its not a long term solution. With a multiplier of 1/efficiency in the original energy costs and an addition 70% costing for energy storage, were looking at multiplying the price of the original energy by 2x to 2.5x. Clearly, significant improvements must be made. Most of these improvements need to be in the area of price, as far as I can see. The physics of the compression of the gas makes it relatively difficult to not lose energy to thermal emissions. Maybe we could hook such a system up with well insulated thermal energy storage systems to improve efficiencies 5% to 10%, but that would add to the cost. Having said all that, if we can get wind turbine energy costs down another factor of two and lower the storage costs, we maight have a possibility. Those are maybes, mind you, but I dont see any sure things in this area. The next storage mechanism to be considered is battery storage. This has been debated on brin-l earlier, with the argument that electric cars are practical, usable, but were killed by a conspiracy of corporate interests with government cooperation. But, the battery business, apart from cars, is a multi-billion dollar business. With roughly 75 million portable PCs shipped in the US alone, we see that just the portable computer battery business is a multi-billion dollar business. PC lifetime is important, and the ability to provide even a 25% longer lifetime with the same price and weight is an important competitive advantage .so there is significant incentive to make a better battery. >From looking at the best available electric cars (e.g. the Tesla) and their capabilities, Id argue that drop in replacements (the way hybrids are now) for present vehicles will require a number of advances. For example from the wikipedia on the Tesla, we see it costs about $100k, is a two seater with a range of 220 miles. To replace the standard American compact car, it will have to come down about a factor of 5-6 in cost, extend its range, etc. Im guessing battery improvements of 2x in weight/performance and 5x in price performance would be needed. The market for this already exists, so there is no need for a government sponsorship of engineering efforts (although basic research efforts in different, better types of batteries are still worth funding). Hydrogen was a big deal for a while, but according to Wikipedia http://en.wikipedia.org/wiki/Hydrogen_vehicle there are a lot of efficiency problems along the supply chain. Googling the question, I find that hydrogen is now produced from methane ..and that while the theoretical efficiency of producing it from electric power is OK (80%-90%), no one seems to be doing it on a massive basis. This sends a clear red flag to me. In theory, it is doable, but the practicalities are beyond us now. This is a technology that I wouldnt count on nor would I spend resources on large scale engineering efforts (e.g. like the 200+ million dollar compressed air facility that I do support), but one that Id invest R&D dollars in fundamental research on the problems. Super-capacitors have also been suggested. But, from my scanning, they are mostly in the research phase .with commercial applications being limited to providing quick bursts of power to start truck engines. So, they are behind batteries on the learning curve and are probably further out. Flywheels are another potential source, but conventional materials do not have sufficient energy densities for practical use in storing large amounts of energy. Portable uses also have obvious problems. So, while these are not impossible, there will have to be significant advances in material science before they are practical. Again, my argument is that basic research is needed. If we cannot easily convert electricity into portable sources of energy, what about biofuels? Biofuel is probably the most popular new green energy source. But, as my analysis at my blog shows, ethanol cannot be a solution to the USs fuel needs. If we use all the US corn production for ethanol, it would supply < 15% of last years gasoline consumption by private autos. Other natural alternative, such as sugar beets, switchgrass, etc. wont solve the problem, because the math doesnt work out. If prime land and intensive techniques are used, then biofuels push food production out of the market. The present rise in food prices is primarily the result of this. If marginal lands, no fertilization, etc. is used, then yields are low. We can be more efficient in producing ethanol from corn, sugar beets and sugar cane, but the underlying inefficiency of these food sources as energy storage techniques puts up a roadblock. The only real possibility that I see is changing the rules of the game. There is a reasonably well funded effort to do that with synthetic biology. http://www.innovationwatch.com/choiceisyours/choiceisyours-2007-07-15.htm This group is not the group that Gautam knows, but he and I have been talking about this for months. In principal, it can work, because one can engineer algae that produce complex hydrocarbons. Unfortunately, the ones that have been produced and that have worked have been extremely susceptible to infestation by fungi. A group that Gautam knows (he knows the founder personally) has come up with a novel solution. They are in the process of building a right-handed version of this algae. Its fairly well known that DNA and proteins are left handed. But, according to many in the field, there is not an a priori reason why this must be so. Thus, it should be possible to construct mirror image duplicates of the DNA and assorted proteins that will function in the same manner. Im more skeptical of this than Gautam is. Im a strong believer in Murphys laws. In this case, the unknown variables usually are against you is the one Im thinking of. But still, its a worthwhile try. If it works as it is supposed to, one could have reasonably priced biofuel within 5-10 years. And, this algae, while it will require a very particular environment, is extremely efficient at converting the energy of sunlight into chemical energy in the form of complex hydrocarbons. In essence, it would take CO2 and water to produce fuel that we could burn, releasing CO2 and water into the air. But, since the CO2 had been taken out, the net addition is zero. One other solution that has some promise is the sequestering of CO2 in the earth. CO2 is compressible, and there is no reason we cannot put it into depleted oilfields. The only question is the cost. But, a carbon benefit to match the tax would seem quite appropriate in this regard. I certainly could go on, but this is L4 in length already. Just to summarize, I dont see any single magic bullet. Rather I see a number of things that have varying degrees of probability of working and varying timeframes. While a single magic bullet would be a lot more sexy, an approach that is akin to having a lot a centering passes in football with the thought that, with each one having a chance to lead to a goal, one will, seems much more pragmatic to me. Dan M. -------------------------------------------------------------------- mail2web.com - Microsoft® Exchange solutions from a leading provider - http://link.mail2web.com/Business/Exchange _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
