Some Renewable Energy Calculations

David Sweetman | Jun 22, 2010

Share/Save  
*Article Revised June 2010*

How many renewable energy facilities covering how much area are required to meet the electrical energy demand of the United States? The following will identify some critical issues along with a possible solution, while demonstrating that renewable energy resource installations could be available to meet the required demand, should sufficient will be exerted to actually install.

One of the major dilemmas facing the widespread implementation of renewable energy resources is resolution of how to distribute the newly installed resources. The existing grid is predicated on the use of very large centralized generation sources, e.g., dams, power plants; while most renewable energy, e.g., photovoltaic, wind, is very conducive for distributed generation.

The existing very large generators are large in the sense of the amount of power they produce per unit area. Renewable sources require much more land area for a comparable power production. A major benefit of this conundrum could be the installation of a large number of small generation sources at existing sites, e.g., houses, businesses, ranches, farms with no requirements to install additional distribution capacity. The downside is how to plan for the transfer of energy from where generated to where needed when the renewable energy generators are not firm, i.e., the amount generated is neither constant nor predictable. This is exacerbated by the financial consideration that nonrenewable generators are generally most efficient and cost effective when operated at full capacity.

A model for solving the problem or more accurately, debugging the solution, is to initiate the widespread use of renewable energy generation in rural areas. Although eventually the largest market will be in urban areas, virtually all problems could be resolved on a small scale by implementation in rural areas first. Rural areas have a small fraction of the total population; however, this fraction is highly independent and well skilled in solving problems. Unfortunately, this is also the segment of the population that has the least disposable income to invest in anything, much less energy with a long term payback. Thus, some sort of cash flow assistance will be required, noting tax credits are of little benefit to those whose income is not sufficient to pay much in taxes.

In order to understand the magnitude of the task, one must consider how much electrical energy is going to be required to be converted from nonrenewable to renewable sources. The United States consumes ~ 4.1 trillion-kWh per year (4.1x1012 kWh/year), note this does not include fossil fuel energy consumption for transportation, heating, and other uses. Since a significant fraction is required for industrial use, which requires large concentrated sources, e.g., existing power plant dams will still be operational for 100 or more years depending on location, one could then reasonably expect the want to generate ~ 3 trillion-kWh per year with renewable sources.

There are 5 primary sources of renewable energy generators in operation today; four sources can be used for large commercial (e.g., utility scale, light industry, or towns) generation and three sources that are primarily for residential use. Depending on size of the installation, two of the sources can be in either category.

  • Geothermal, usually available in ~ 5 MW increments for commercial use. Note, geothermal is generally considered a firm source, so would be preferred for ease of compatibility with existing distribution systems.
  • Wind, usually available in 2-6 MW sources for commercial use and 1-25 kW sources for residential use.
  • Photovoltaic (PV), usually available in 100-200 kW for commercial use and 1-10 kW for residential use.
  • Solar Thermal Electric using conventional generators connected to steam turbines, usually available in 100-500 MW for utility scale production
  • Hydro, usually 1-3 kW for residential use (dammed hydro (could there be a pun here?) is generally not considered renewable and dams are needed for larger hydro units).
  • The following is a rather arbitrary assignment of expected capacities from the various generator types, small hydro is not included for convenience and lack of data on how many streams are available (basically an assumption, the total production will be small compared to the other sources):

    • Geothermal, 0.5 trillion-kWh/year
    • Wind, 1 trillion-kWh/year
    • Photovoltaic (PV), 0.5 trillion-kWh/year
    • Solar Thermal, 1 trillion-kWh/year
    • For geothermal, assume each 5 MW module operates 24 hours per day for 300 days per year (allowing time for maintenance and any possible variation in steam flow). Each module then provides 36 Mega-kWh/year. Thus, approximately 13,900 modules would be required. Note, most geothermal locations in the USA would support the use of either larger modules or multiple modules; therefore, the total number of needed geothermal locations is probably less than 1,000.

      For wind, assume that 0.99 trillion-kWh/year are produced by commercial size wind generators and the rest with residential. Assume that each 5 MW wind generator operates 12 hours per day for 300 days per year (allowing time for maintenance and variations in wind velocity and duration). Each wind generator then provides 18 Mega-kWh/year. Thus, approximately commercial 55,000 wind generators are needed. If each wind generator occupies ~ 1 square mile, then ~ 55,000 square miles are needed, noting that almost all the land near a wind generator can be used for ranching or farming purposes. This represents a small fraction of the land under cultivation in the western USA, where much of the wind resources are. Also, wind generators can be place off-shore.

      For residential wind generators, assume that each 15 kW windmill operates 6 hours per day for 250 days per year (allowing for conversion efficiency, time for maintenance, and variations in wind velocity and duration). Each wind generator then provides 22.5 kilo-kWh/year. Thus, approximately residential 450,000 wind generators are required, which is significantly lower than the total number of small businesses, farms, ranches, and rural residences in the USA. With larger residential windmills, especially for farms and ranches, not so many windmills would be required. A 25 to 50 kW windmill is much more appropriate for farm or ranch use, noting some farms that use well irrigation would need several wind generators or larger, e.g., 150-200 kW wind generators.

      For residential PV, assume a module conversion efficiency of 15% from the nominal solar radiance of 1000 W/m2. Assume a DC to AC conversion efficiency of 85% and operation for 6 hours per day for 300 days per year (allowing for variations for systems installed at a wide variety of locations). Thus each m2 of solar module area will produce 230 kWh/year. In order to generate, 0.5 trillion-kWh/year, there needs to be ~2,175,000,000 m2 of PV modules. This is about 840 square miles of solar PV modules, smaller than most Western state counties. Assuming that the majority, say 1,500,000,000 m2, are directly used on single family dwellings, with the availability of 75 m2 per dwelling (still allowing room for solar hot water heating collectors on the south facing roof), then ~20,000,000 homes are necessary. The remaining PV generation (~ 0.16 trillion-kWh/year) would come from commercial PV facilities. Assuming a capacity of 200 kW operating 8 hours per day (use of at least ground mount single-axis trackers) for 320 days per year (allowing for variations for systems installed at a wide variety of locations) each location would generate 512,000 kWh/year. There would need to be at least 312,500 such installations, with each installation having about 1,570 m2 of PV modules and assuming an area efficiency of 10% (for trackers and mounting) so occupying ~ 4 acres.

      For solar thermal generation, assume each 100 MW of power capacity requires 1000 acres, including all support structures. Since solar thermal requires significant water usage for cooling (up to 1000 acre-feet/year per 100 MW), not all locations are suitable. Assuming a 500 MW plant produces 8 hours per day for 300 days per year, each location produces 1.2 billion-kWh/year. For the 1 trillion-kWh/year, then ~850 plants, occupying 4.25 million acres or 6,640 square miles (the size of larger Western state counties)

      All of these estimations are just that, estimations; however, the numbers clearly show that renewable energy resources can provide the majority of the electrical energy needs of the USA. As renewable energy resources are installed, no new fossil fuel power plants need be built. Eventually, all fossil fuel plants can be allowed to retire, starting with the least efficient first. The transition cannot be smooth, since both nonrenewable and renewable energy sources are only available in discrete units; however, by starting with implementation in rural areas the methods and techniques can be fully developed, which will ease large scale implementation in urban areas.

      Reference
      Click Here and Click Here for information on USA electrical energy production and usage. Many interesting reports are available on the main web site Click Here.

      Related Topics

      Comments

      "tax credits are of little benefit to those whose income is not sufficient to pay much in taxes." -- Exactly. Its so common though, one has to conclude that its designed specifically to benefit the wealthy only.

      Fossil fuel plants are retired - by which you probably mean demolished. What about nuclear? Do they get the hatchet too.

      Nuclear and a lot of renewables and alternatives. The real challenge is choosing the renewables and alternatives. I just hope that if the Commander in Chief reads this, he doesn't assign that job to Stan M.

      Who let this "poser" write an article on an energy? I would expect knowledgeable commentary in a place like this. First, when you construct all these 55,000 wind turbines you are going to need ton construct an equal amount of natural gas plants to go with them. Because, frequently, often daily, and at least weekly, there output will go to at least 10% of their rated capacity. Do we just stop our society? Also, even though our electricity needs did not grow this year, our population did, and expect that in 10 years we will need MUCH MORE electricity to keep our nation running that we have now. We are not going to retire ANY traditional generation plants, because the renewable won't be able to keep up with the growth, let alone be able retire any plants. Anyway, you should educate yourselves and learn at least the basics of "energy" before you write an article. Maybe Grist or Greenpeace etc. would appreciate your "fact" better!

      I'm not attempting to take on the role of moderator but having gone to the trouble of writing several articles for this publication, I try to be considerate of other authors, even when I disagree with them.

      I'd like to believe claims made by the folks who say we have plenty of domestic natural gas, until I read articles like this one: http://onlinejournal.com/artman/publish/article_6042.shtml which suggests exploiting those shale gas reserves will be costly and as risky as drilling for oil a mile under the sea surface. It won't be easy providing clean, bottled water to residents of the densely populated northeastern US if the aquifers and surface water sources become contaminated.

      The public and it's elected leaders are more than a little schizophrenic and not entirely rational when it comes to debates over energy supplies. I was stunned to hear the governors of states with large oil exploration and production businesses in the Gulf of Mexico complaining about BP in one breath and suing to lift the federal moratorium on deepwater drilling in the next. If they're willing to risk yet another environmental catastrophe, then stop beating on BP. If the objective is to avoid another debacle, then take a "time out" while better risk mitigation measures are put in place.

      Eventually, I think we're going to figure out that it is simpler and less costly to deal with a combination of nuclear waste and the infrastructure needed to accommodate a fairly sizable amount of renewable energy production. If we continue to put all of our eggs in the fossil fuel basked, policymakers and the public are eventually going to be faced with a really ugly choice - bring an economy almost entirely dependent on fossil fuels to a grinding halt in order to protect public health, or put public health at risk in order to avoid destroying the economy. Apparently shale gas is found in relatively small pockets, and getting it out of the ground in large volumes requires drilling lots of wells, each of which is a potential contamination hazard. Nuclear waste isn't terribly benign, but the number of point sources is a bit easier to control.

      Whoever wrote the screenplays for Mad Max surprisingly prescient.

      Len,

      ""tax credits are of little benefit to those whose income is not sufficient to pay much in taxes." -- Exactly. Its so common though, one has to conclude that its designed specifically to benefit the wealthy only."

      First, it is interesting that you acknowledge that only the "wealthy" pay taxes. Would you also acknowledge that, since only they pay taxes, that the taxes they pay represent a "fair share" of total taxation? I'm surprised you didn't raise the "free rider" issue.

      Giving things to those who can't afford them is typically referred to either as charity or welfare. In the US, it is also referred to as the Earned Income Tax Credit. Therefore, tax credits really are not only for the "wealthy", or even for the highly educated, highly motived, highly productive among us.

      I suspect you may be an advocate for a far more egalitarian, possibly even a far more communitarian, society than currently exists in either the US or Canada. However, you would do well to remember that citizens in such societies have generally not lived as well as those in freer, more competitive societies.

      Ed

      Jack,

      Nuclear "waste" could also be nuclear "fuel" for different types of reactors. This could become a reality in the very near future, even without lifting the Carter-era ban on reprocessing.

      Ed

      Ed: Actually I'm fairly happy with the level of income inequality apparent in Canada. I think it hits the mark fairly closely. Of course our tax system used to be even more fair prior to the Reagan / Mulrooney neo-con era, but it seems progressive ideas, like progress, need to be re-learned with each generation or so.

      And just from observation, I'd bet that all except a very thin scum on the top live better in the "more communitarian" (love that insinuation. Can u guys still be scared by a "threat" like that?) Canada than in the US.

      "...all except a very thin scum on the top..."

      Being just a little judgemental, are you? :-)

      I believe PV residential installation is all about financing and tax credits... we a right source of financing either PPA or mid term (5 years) financing this could be a reality...

      We're still trying to find out if Heat Rate applies to PV, Trough, and wind generation of electricity or not.

      PNM foil states that it is does not.

      More can come out than goes in? 1 kWh =3412.14163 BTU we've read.

      EPRI employee Rick Shumard, trained as an EE should know.

      But Mr Shumard appears not to want to talk.

      http://www.prosefights.org/nmlegal/ncusif/shumard.mp3

      Maybe we should write EPRI a formal request for an answer?

      http://home.comcast.net/~bpayne37/eprishumard/eprishumard.htm#weiss

      David's article serves a useful purpose, to scope out the problem with numbers, not rhetoric. But by "we" I take it to mean 0.3 million out of 7 billion, or about 4.3% of the folks on this planet.

      Never before has there been such an absolute increase in CO2 emissions as right now. Never before have there been so many additional coal burning power plants being built. Nearly all are traditional Rankine Cycle plants with 34% of the fuel energy going over the fence as electricity, and maybe 32& reaching the consumer. That's about all this system can do and the best overall that has ever been done. While many US coal burners are old, thousands in China and India and Indonesia, South Africa and Brazil and Australia, and Korea, etc. are relatively new - perhaps fifty years from retirement. And somewhere a new one proudly came on line today.

      Where most of these new coal-burners are going on line there wouldn't be base line capacity for decades so most renewable projects would be fatuous and would deny electric service to those who have never had it.

      The solution offered by the article does not deal with oil - currently the largest source of energy on the planet. Far from reducing the fossil fuel usage crunch the advent of electric cars will exacerbates it. In many countries electric cars will be running on coal, countries that do not have base load capacity without having to charge car batteries.

      For forty years I have been saying only nuclear energy (preferably fusion) and population control could save us. (And that was before the specter of global warming.) Alas, sadly I don't see any reason to change my tune.

      Bill Payne, 3413 BTU = 1 kWh in the same sense as 12 inches = I foot. Neither statement tells us anything at all about energy or distance.

      I think the confusion stems from the fact electricity (as we know it and use it) is all "man-made." A typical pound of coal releases about 10,000 BTU when burned. In a traditional power plant, even a new one, a pound of coal (let's say 10,000 BTU) power plant produces 1 kWh. The heat rate can for convenience be reckoned either by BTU or pounds of steam at the calorific value of the fuel.

      A conventional power plant buys energy (fuel) in BTUs whether its in the form of coal, or gas. From which they make as much electricity (kWh) as they can. Since wind and solar generators of electricity don't pay for their energy supply their situation is quite different. So far those who pay for their energy produce electricity at lower cost than those using "free" energy. This has to change soon or we are toast..

      David
      I think you are, in part correct but your discount of small hydro is way off. Thru the USDA Rural Development program there is opportunity for irrigators, farmers and ranchers to "cash" in on some of their resources. Most of these projects are small hydros, there is the potential to produce 250kw and up to as much as 10 mw but the licensing is expensive and the investment dollars are on hold.
      I work for a small company that licenses, builds and operates small hydro; across the US there is the potential for 30,000mw of such energy. The sweet part is most of these would back feed the grid reducing the need for additional transmission upgrade. The real problem is the service agencies and their slow reaction time during the licensing process. Most if not all of these projects have a very small but mitigatable environmental effect and can improve the use of the water resource for the stakeholders.

      Of all the things I've had over my lifetime that made life worth living, the things I'd give anything to have back, even for one day, the things that even the memory of I cherish------not one single one had anything at all to do with money, coal, oil, nuclear energy or stuff.

      I’d like to suggest a new measure of evaluating energy options:

      Energy Utilization Capability = expected efficiency x expected capacity factor

      The idea is to understand the fundamental physical ability of potential energy sources to meet our needs.

      Using rough averages available from industry, looks something like this:

      Natural gas = 47% capability
      Nuclear = 32% capability
      Coal = 31% capability
      Wind = 6% capability
      Solar = 1% capability.

      Carrying the exercise further, let’s say we want 100 megawatts of electrical power delivered to the grid. The energy required is as follows:

      Natural gas = 210 mW
      Nuclear = 310 mW
      Coal = 320 mW
      Wind = 1650 mW
      Solar = 5715 mw

      In other words, wind must harvest about 6 times as much energy as fossil and nuclear units while solar must harvest about 20 times as much.

      The above simple analysis assumes that having more wind and solar units make up for their low energy utilization capabilities. The situation is actually much worse because the renewable energy is only available during very select periods (solar) or somewhat random periods (wind) and in both cases, the energy can not be stored.

      Without question, attempting to replace fossil and nuclear units with renewable power will require extremely large numbers of wind turbines and solar units. Throwing in the cost to build these units throws the whole idea into the realm of economic nonsense.

      Good idea Michael, let's call it the Keller Number.

      As more and more wind farms are built each will be located on a bit little less ideal location as to wind velocity, capacity factor, distance from the grid, distance from a population center, access roads RR or navigation, land lease cost and all the other things that factor into siting. (Thermal solar needs large amounts of cooling water unless they settle for abysmal efficiency.)

      And we would end up with a huge excess of installed capacity eating up huge amounts in fixed costs. I remember an analysis of a few years back that suggested that wind energy capacity was not feasible over about 20% of total installed capacity. I can imagine many fossil fuel plants idling for long periods.(A place like Denmark could go higher because they can, at least for now, buy electricity from their neighbors. Sad to say but Denmark doesn't really matter.)

      Fred Linn, I wish I had something to say, something to offer. Who is to say what's important in the long run.better than that individual. Empty as wishes seem, I can only wish you well.

      Glenn C. You've got to watch your language. I thought that I was the only one in this and other forums to use words like "poser", although I give it a French intonation, because I want people to think that I speak fluent French, when in reality I speak rotten French.

      Anyway, what the hell is going on. Why do people attempt a civilized debate using civilized language on this wind thing? Don't they know that they are being made fools of. Of course they know, but they don't care, and they reason that their children and grandchildren can take care of themselves.

      I had a thing going with a young lady in Germany when I was in the army, and she told me that the happiest day in her life was when she saw or heard Mr Hitler
      in some gig shortly after the war started. I'm talking here about somebody who knew about books and ideas, but it never occured to her what would happen if her hero lost the war - which he did, and she and her family were run out of the Sudetenland.

      Believe me, I've never encountered the kind of ignorance that is common garden where wind is concerned, and I spent 4 years in the ranks of Uncle Sam's infantry. Incidentally, some of them contribute articles and comments to EnergyPulse. Yes, some wind is justified. We live in democracies, and moreover, as they say in the song 'The man that got away', "fools will be fooled", but not 55,000 windmills that will require X megawatts of backup. Of course, in Germany they are talking about coal as a backup, and so maybe that is a great solution. I wonder what that young lady and her great grandchildren think about that.

      And Don H., Denmark matters to me, because by hooking into the Swedish grid the Danes increase the price of the electricity I buy. By extension. if the Danes had chosen some nuclear instead of wind and coal, my electric bill would be lower as would theirs. Of course, the Swedes were too dumb to understand this, even if it had been explained to them in block letters a foot high.

      Gee, why all the acrimony about wind? It's not THAT expensive, and in the mid-term, we have some notion of demand that can make use of the intermittent supply (PHEVs). If wind/solar are considered too risky for baseline supply replacement, then perhaps we add them as we add electrification to our vehicles? This would actually make our electrical supply more secure, as the capacity added to power vehicles can be shared for non-vehicle use as well. Better than shipping more money overseas for ever-more-expensive oil.

      I also disagree with Mr. Keller's energy metric. He has biased it against wind and solar as their efficiencies of harvesting their energy sources are low. But he doesn't account for the fact that wind and the sun are free energy sources (at least for now! :O ). If the sun is the basis for energy input, then it should be part of the coal and NG calculations as well, as they originally came from plant sources. So multiply those figures by 1%. But that would just be silly, wouldn't it?


      A better metric would somehow combine availability and storage. So electricity (100% exergy) is basically 100% usable. Storage is harder to quantify, but lumps of coal would be the lowest cost energy storage (just need a bin) whereas a battery or capacitor are more more expensive forms of energy storage.

      What keeps resonating with me in all these discussions is the value of a electricity consumption source that can make use of intermittent input. PHEVs can do that. Plus, they allow us to displace the use of oil, which has peaked. They'd probably be the right thing for our country to do strategically even if they couldn't make use of solar/wind power. Improved HVAC designs can work with intermittent input as well.

      You can rant that wind is expensive, but look at how a U.S. utility prices a nuclear power plant. And is building a coal-fired plant really a wise thing to do, given the likelihood of carbon taxing? (Ed Reid's notable lost capitalization.) Given our present situation, the RIGHT thing to do is work toward improved efficiency so additional plants wouldn't even be needed at this point. And work to shift the demand curve towards a more even distribution day to night. One talks about the wasted resources of idle wind turbines. The same can be said of the low capacity of the grid every night of the year.

      Here are some rough numbers of the effects of EVs:

      It takes a lot of concatenations of "ifs." Suppose we replace 10% of our vehicles over the next ten years with EVs, that would be 25 million or 2.5 million per year. If the vehicles replaced used 1.5 gal/day (say 25 mpg x 1.5 x365 = 13700 miles per year) at 12 HPH/ gal (that's about 25% thermal efficiency) they would need to get 3.36 x 10^8 kWh from the grid per day. (25 x 10^6 x 1.5 x 12 x .746) allowing for loses from power plant to getting it into a battery I saw above that our electricity usage is 4.1 x 10^ 12, so these EVs would increase electricity demand by 365 x 3.36 x 10 ^8 / 4.1 x 10^12 or 3.0 percent. This doesn't seem a problem as charging ought be done at low demand hours.

      The replaced vehicles were using 1.5 x 25 x 10^6/42 = 0.89 million B/D. So at the end of our ten year project our daily consumption of liquid fuels might have been reduced one million out of 20 million barrels. But in ten years our fuel demand could well have gone up over a million barrels per day.

      Replacing a second 10% with EVs becomes more difficult as the fraction of vehicles suitable for EV service gets smaller and the fraction of vehicles such as 18 Wheelers, getting circa 5 to 8 mpg, goes up as does the fraction of hybrids, not likely to be replaced. The prospect of a great leap in battery performance grows less likely every year.

      As a footnote to my comments just above: In the US where EV batteries would be charged with electricity about 50% generated by coal, replacing a gasoline engine car with an EV would be about a push as to CO2 emissions. However in the biggest current car market, China, where over 80% of electricity is generated from coal EV's will make more CO2 than petroleum engine cars. Other rapidly growing car market countries are in the same boat.- petroleum fueled cars would be less polluting. On a world-wide basis there seems to be no reason for great production of EVs except for impending oil depletion and hence future soaring oil prices. The question is not if but when.

      As for not expecting a great improvement in batteries for EVs we have to consider how little better are the batteries of today vs over a hundred years ago when you could buy competing electric cars with 40 mile ranges. (They were boulevard cars that could move at a stately 25 mph or so if the way were clear. But the traffic would not often allow them to move faster than horse-drawn vehicles. A draft horse at a trot is still very slow. Trotters and pacers pulling light buggies did much better for a few miles. The fastest movers were bicycles, with riders called scorchers. I recently had an opportunity to observe midtown traffic from a hotel window. Bicycles did best by quite a margin by moving between motor vehicles to the head of the line stopped by a red light. The last time I saw average traffic speed for Chicago Loop and Midtown Manhattan they were about the same as when there were still some horses in use.)

      Flash: yesterday, by a large majority, the Finnish parliament approved two new reactors. As you know, the one that is under construction is 3 billion dollars over budget, but Areva will gladly eat that for the experience gained in building the reactor. After all, the South Koreans are going to construct 4 reactors in the UAE for 5 billion a reactor, which means that it is only a matter of time before that cost will be 4 billion. That's economics. As for the math, I think that I'll leave that to persons who did not fail the first course in university math twice.

      Fred,

      I would guess that there are many fewer anti-nuclear groups, environmental activists and lawyers in the UAE; and, that their ability to delay approval and construction is significantly lower than in the US. :-)

      Ed

      Don,

      The EV-95 battery pack had an energy density of about 63 Wh/kg. And a power rating of 200W/kg.

      This compares with a typical lead-acid cell of about 30-40 Wh/kg and also about 200W/kg.

      Since the EV-95 NiMH batteries have lasted a long time, the durability is at least comparable to lead-acids, if not better. I don't know if you consider 2X not much better. I think it is. They are good enough for PHEVs right now. Another 2X improvement would be nice, but not required.

      It's a shame they stopped building them about 8 years ago. And I'm not convinced Lithium Ion is a better option. The research moved to them when the patents fouled the NiMH technology.

      Ok Fred, interesting news. From NYTimes, "The two light-water reactors, which will generate a combined 3,200 megawatts, are estimated to cost as much as 10 billion euros ($12.5 billion)." Thats $3,906 per kw, still a very high number for electrical generation (if they can hold it?) Somebody really needs to get into that issue, esp. standardization, and figure out how to get the cost back to where it was ten years ago allowing for inflation.

      Don: I've done that one (gasoline vs. electric CO2 emissions) before with a different conclusion if i recall correctly, though the issue at that time was cost, not CO2 emissions. From Electric Auto Association - CO2-Emissions of Electric Autos

      [QUOTE]In Germany, for example, the average CO2-Emissions of Electric Powerplants today are ca. 500 grams for the production of 1 kilo-Watt-hour (kWh) : 500 g/kWh.

      This is a very high value, because ca. 50 % of the Electric Energy for Germany is still produced in Coal Powerplants, what is very sad.

      But even with this high average of 500 g/kWh, the average CO2-Emissions of an Electric Auto are even in Germany very low in comparison to the emissions of a "convential" car with Internal Combustion Engine. [/QUOTE]

      QUOTE]In Germany, for example, the average CO2-Emissions of Electric Powerplants today are ca. 500 grams for the production of 1 kilo-Watt-hour (kWh) : 500 g/kWh.

      I cannot believe the number can be this low as we are told that 50% of German electricity is generated from coal.

      So t got out my slide rule and did some arithmetic. This figure, 500 g/kWh is what I calculate for methane. (I actually calculate 523, for methane, 714 for gasoline, 1510 for the coal I selected I have given the numbers as they rolled out and am aware this precision is not justified.)

      As for gasoline burning vehicles I did the following calculation: Consider a car getting 30 mpg at 60 mph, i.e. using 2 gal/hour. At about 25% thermal efficiency a gal of gasoline makes about 12 HP hours, or is developing 12 x 2 = 24 HP or 17.9 kW. (At this output the engine is not near optimum e) Two gal of gasoline contains 12/14 x 2 x 6 = 10.3. # carbon.which makes 44/12 X 10.3 = 37.7 # CO2.

      (37.7/17.9) x 1000/2.2 = 858 g/kWh. This number is close to the number I got above making electricity out of gasoline in a power plant. If I had selected a hypothetical car that got 36 mpg the numbers would be identical.

      Here are handy approx. ratios to remember: 3: 1.5: 1 CO2 emissions coal to oil to methane.

      If a EV gets its charge from a system using over 50% coal energy it is "emitting" more CO2 than if it were burning petroleum in an ICE.

      I'm not ready to write off any energy source unless it walks, talks and quacks like a perpetual motion machine. Every method of extracting energy and every method of producing motor fuels and electricity from primary energy sources has adverse environmental impacts. Putting all of our eggs in one basket might arguably be more cost effective, but it is not prudent. Spreading the risk a little might be more expensive, but if we become dependent on a single idea and it fails (Chernobyl), we're up the proverbial creek with out a suitable means of propulsion.

      Especially at current prices, neither wind nor solar will provide more than a large minority fraction of our electricity requirements. I suspect the same will hold true for nuclear until and unless someone perfects a way reduce the radiation risk much closer to zero than it is today.

      As for relying on conservation to reduce the need for new power plants, that's not going to happen until and unless the price of electricity become much higher.

      Jim, My earliest memories are of a world without plastic wrap or aluminum foil, air transportation, broadcast network radio, dial phones, any kind of plastic goods (except for maybe Bakelite telephones and hard rubber combs.), diesel locomotives, mechanical AC, frozen foods, microwave ovens, color photography, with coal-bunkered ships and steamshovels that were steamshovels, and no antibiotics, synthetic detergents, synthetic fibers, power mowers, no automaic hot water, no wash'n wear garnents - not to mention anything havinng to do with solid state electronics.

      But we did have the lead/sulfuric acid battery in everythig that moved. Just as my grandfather and father had. And just like we have today, world wide.

      Revison 1 to my 7/2/10 CO2 calcualtions.

      The figure for coal should be 1000 g CO2/kWh, not 1500 g/kwh.

      (Various coals cover a wide range of compostions, heating values, ash and moisture content - and not reported consistently. I had used an atypical set of properties for my 7/2 calculation.

      Now, using a moisture free coal 90.47% carbon, 4.53% hydrogen , this means 0.6 atome of hydrogen to 1 atom of carbon and 5 % inerts my new result is 1000 g/kwh with a heat rate of 10,000 BTU/ kwh, thermal e of 34.13% I used for each fuel. New dual cycle methane plants of course do better.) Sorry.

      Len, it's vacation time in Scandinavia, so I am not trying to find out anything about those two new Finnish reactors. However even if it were the dead of winter I wouldn't bother, because nothing from the NY Times or the Kabul Times means anything to me on this subject. I'm sure that you and most of the people in this forum know as well as I know that when push comes to shove nuclear capacity will be constructed for about $2000/kW. They can probably do that in China today, and once you get a number like that for Gen 3 equipment, then we are in business.

      BUT, what I want is MY bottom line accepted: somewhat more nuclear, and a lot more renewables and alternatives, with the 'lot more' chosen by intelligent people and not 'snot-nose' Ivy Leaguers on Wall Street, or dumb politicians who want to next next to some of the ladies in the anti-nuclear booster club.

      Fred

      The more I learn about the costs of nuclear plants the less I know. Consider this from Wikipedia:

      "2007 estimates have considerable uncertainty in overnight cost, and vary widely from $2,950/kWe (overnight cost) to a Moody's Investors Service conservative estimate of between $5,000 and $6,000/kWe (final or "all-in" cost).[13]

      However, commodity prices shot up in 2008, and so all types of plants will be more expensive than previously calculated[14] In June 2008 Moody's estimated that the cost of installing new nuclear capacity in the U.S. might possibly exceed $7,000/kWe in final cost.[15]"

      Professor, two questions please: Do we know what the last-built nuclear plant cost and whose economy can build more at that cost?

      Don, this business of cost is a key issue, and Len Gould has one answer: getting the costs back to where they were ten years ago, allowing for inflation. In other words, they are too high now and should be lowered, and they can be lowered.

      I also have an answer. In Finland the new 1600 MW(e) reactor was supposed to cost 5 billion, and instead it is going to be about 8 biliion. The Finns react to that by putting themselves down for 2 more reactors. They know what energy - or its absence - is all about. The South Koreans have sold 4 reactors (with installations) for 20 billion, and I think that reactors are being constucted in China for less than that. Now lets see what this means in terms of cost.

      It is completely wrong that a ready-to-go reactor can be sold to Finland by the French for 5 billion (as Areva thought), the South Koreans can build essentially the same size reactors for 5 billion, the Chinese can... the ____ can, and the Americans, Swedes, etc cannot. Siemens (Germany) has joined with Rosatom (Russia) to peddle reactors, etc. No matter what they cost now, after they get in the swing of constructing them again the cost will come down. To me the equilibrium cost today of a 1600 MW reactor is at most 5 billion. Note the word "equilibrium". Accordingly I don't care what Moody or the New York Times etc say that the cost is or will be. Moreover, once they start building reactors - or large reactor components - like they should build them - in factories - the cost will definitely be lower.

      I don't know who will construct the new Finnish reactors, but if it is Areva they must have learned a few things from the one in Finland that ran 3 billion over estimated cost. That had to eat that 3 billion, and I doubt whether they look forward to doing that again, nor plan to.

      That's not the complete answer. No answer is complete unless something is said about the general ignorance of voters concerning nuclear energy, and the gusto and dedication of the anti-nuclear booster club. Some of the most intelligent people in Sweden believe that wind can compete with nuclear energy, although this idea is crazy. Or, as a colleague once said to me, Joseph Goebbels would shake his head if he heard some of the anti-nuclear propaganda: he was just a babe in the woods. Once the voters and TV audiences think that e.g. wind is better than nuclear, that becomes a psycological barrier that keeps nuclear costs from being lowered. Stop and think about it. They constructed 12 Swedish reactors in 13-14 years, starting from just over zero. Isn't it absurd to believe that they couldn't do that again if they had to.

      I keep thinking back to the early 2000's when AECL Canada had just come off delivering the two reactors at Quinshan "on time, on budget and in less than 48 months from first concrete to first criticality" they and Dominion Energy in the US formed that consortium to sell ACR reactors into the US at "US$1,400/kw for the first two, US$1,200 / kw for additionals, on your approved site, price guaranteed". Ok, so agreed, the $Cdn has gone up from $0.62 to $0.95 since then, and commodities prices have increased. The exchange rate change takes the price to $1,838 to $2,145. Say actual steel, concrete commodity costs constitute 20% of total cost and those have doubled, thats $2,206 to $2,574 .

      US utilities turned them down at that time, (?because of the cost?). Presumeably they had cheaper options at that time?

      So what the heck gives?

      Don: In your calculations of emissions, are you counting a kwh of gasoline as equivalent to a kwh of electricity for vehicle propulsion? If so, that's where the error is, as electricity is about 2x more useful (about twice the miles per kwh) as an energy input to an electric vehicle than gasoline is to an ICE vehicle.

      Len, - and here I thought I was being over-scrupulous in explaining my calculations. I used 12 HP hours per gal of gasoline used in a car going 60 mph getting 30 mpg. 6# x 20,000 BTU x 778 / 1.98 x 10 ^ 6 x 10^ 6 = 47.2 HP hours(@ e of 100%) per gal of gaso. At e of 25% we get 11.8 HP hours net. Since all gasolines do not weigh exactly 6# and do not have a calorific value of 20,000 BTU per pound you can supply your own numbers. As to the e I chose for the example I consisted 25 % a good number for this calculation. On the test stand this engine might well hit 30%. In the real world we use auto engines at far less than max output nor at the most favorable rpm/load.

      If we consider going from fuel value to high voltage ac from the grid to useable dc watt hours in a EV battery we might get an e of .3413 x .97 x .85 x .95 = 26.7% e. I said I used 10,000 BTU per kWh. Again, use your own numbers if you don't like mine.

      As for my revised coal number for CO2 emitted per kWh generated, while I can support my first number, to comport without endless explanations I used a very different set of properties, as I previously explained. I see calorific values for coals from <8,000 BTU to > 14,000 BTU per pound. I see moisture contents of zero (obviously dried) to 10% for example, and other significant differences. Curiously my first number of 1500 g/kWh is three times the value for methane, 500 g/kWh. This three to one ratio is what the greens have been using for many years as their most potent argument to campaign against coal.

      I do not think anything I have said in this post changes anything I have said in past posts. When I make a post such as this one I find many typos and errors before I send it. It's almost a sure thing that I don't catch them all. .

      Thank you for the dissertation on nuke costs Professor..

      Seems as if I recently saw some numbers for a coal burner to be built in Wisconsin, numbers that I found shocking. They went something like this: 1.1 to 1.3 billion for a 300 meg coal burning plant, or $3700 to $4300 per kW. This makes your nuclear plants look cheap!

      I wonder what the Chinese and Indians and South Africans and Brazilians, and Indonesians, etc. are paying for their hundreds of new coal burners.

      Don and folks, let me give you an inkling of what's wrong. Somebody preaches nonsense, and nobody stands up and tells that somebody and the rest of the audience that nonsense is being preached. I'm not talking about a beer garden in MUnich in the l930s, but seminar rooms and conferences filled with people with degrees from distinguished institutions, and not store-front universities of the type that awarded me my first degree.

      Fred

      It looks to me like the "cost" of building generating stations tracks the price the electricity market will bear a lot closer than any real cost-to-build factor. Which came first, doubling of retail electricity prices or doubling of the cost of large generating stations?

      A few observations:

      The cost of building a power plant tracks the price of the steel and concrete used to build the facilities. If the demand for these materials goes up, so does the cost of the power plant. If a power plant uses a lot of steel and concrete (e.g. a nuclear plant), it will cost more than one that does not (e.g. a natural gas plant).

      A large cost component in the US is related to the years required to obtain the various permits (i.e. bureaucratic "hoop-jumping") needed to build the facility. Nuclear plants are significantly more difficult to license, with "indirect" Owner costs as well as financial risk much greater than other types of power plants.

      If the demand for power is reduced (like now in the US), then the market price of power will not be enough to justify the building of expensive power plants. Natural gas and coal (if environmental roadblocks can be cleared) plants will be built to cover increased power needs.

      Ordinarily, few (if any) renewable energy plants would be built because of their high cost and erratic power generation. However, the public is being forced to subsidize an economically unsound investment that really does very little to deal with global warming. A much wiser "forced investment" (aka subsidy) would be: (1) upgrade the millions of inefficient heating and cooling equipment sitting in homes via tax rebates and (2) stop the "feed-in" tariff madness being promulgated by the "green mafia”.

      Strategically, nuclear power makes a lot of sense. However, the tactically driven marketplace in the US does not support such an investment. Either the cost of nuclear plants must come down dramatically or the cost of other types of generating plants must rise significantly.

      In other regions of the world with more limited fuel resources, the economic justification for nuclear power is much better.

      Michael, I cannot find fault with your observations. Bur what is gnawing at me is that I see coal burners quoted at more than some nukes, and I see a range of 3 to 1 in the cost of similar nukes.

      ----" Here are handy approx. ratios to remember: 3: 1.5: 1 CO2 emissions coal to oil to methane.

      If a EV gets its charge from a system using over 50% coal energy it is "emitting" more CO2 than if it were burning petroleum in an ICE."----

      Why not just forget the batteries and recharging and run the vehicle on methane?

      Methane costs less than petroleum anyway, considerably less.

      Fred (Linn) well said. Energy conversion always costs energy. The less times you convert the less you lose. Simple physics but lost on most people. Natural gas cars are a much better option and with all that shale gas and coal bed methane coming on stream prices will be stable for a long time to come. All that gas will be looking for a market place. That place is your gas tank...which will truly be a GAS tank.
      I agree with you too that we place way too much emphasis on materials "things" and that overemphasis is the cause directly of our energy woes. There is not one thing I treasure more than my family and I would give away everything I have for one extra day with my Dad who passed away 20+ years ago. His favorite saying was a line from the theme song from the Thomas Crown Affair "is the jingle in your pocket worth the jangle in your head". The older I get the more I understand what he was getting at.
      Getting back to the article though - as I have said many times here - the problems with energy sources such as the wind a the sun is storage. I am not against them but you cannot operate our present society on intermittent power supplies which demands electricity at near 100% reliably at all times. Also lost in the enthusiasm is that it takes a great deal of energy to make solar panels compared to the energy produced therefore they are energy sinks not energy producers. That of course is the very reason for centralized power plants. The energy to build is much less than the energy produced over the life. Building solar and wind turbines is increasing the demand for energy wherever in the world they are made. Nuclear does that too of course but over a 30 - 40 year life the energy output far exceeds the energy input. I suspect that is not the case for solar and marginal for wind.
      There is also a very large assumption that country folk actually want wind turbines and solar farms. In many areas the answer is a very clear NO so I would go back to the drawing board with that one. Wolfe Island in Ontario which is right in the middle of a migration route for many species of birds was vehemently opposed by residents (and one can easily see why). A recently posted video on YOU TUBE of an environmentally friendly wind turbine chopping up a large bird of prey should serve as a reminder that wind turbines are not benign.

      Of course I was delighted that the Finnish Government has decided to build two more nuclear plants and that the Swedish Parliament has also decided to replace the 10 reactors it has left with new ones once they wear out...so much for the nuclear phase-out rhetoric.

      Add that to the 24 under construction in China, 4 in Abu Dhabi and countless refurbishment projects around the world and you can see the nuclear industry is doing very well. The World Nuclear Association puts the total under construction in the world now at 61 with a further 130 in the planning stages. Even Vietnam is planning to go nuclear.

      If all the goodies of life are what is important to you and highly reliable cheap electricity is what you desire - nuclear is the only way to obtain it. If you don't want all the goodies then follow the recipe of the article here.

      Really it is your choice. Be careful what you choose.

      Malcolm

      Malcolm, I think that it's a good idea to be careful with your estimates of the amount of natural gas (and perhaps also methane). There are a lot of crooks out there saying that things are one thing when actually they are another. Maybe shale gas is the real thing, and maybe not, but some very smart people are saying that it is not going to take us where we want to go.

      As Fred points out, there's some fairly religious "science" going on above, eg.

      Malcolm: "it takes a great deal of energy to make solar panels compared to the energy produced therefore they are energy sinks not energy producers." -- the only one for which I have done very accurate calculations is solar thermal plants, which at the present typical efficiency of about 15% return their total energy investment, all materials and labour in, in about three to six months depending on assumptions. I'd estimate that modern thin amorphous PV would be only slightly worse, perhaps 12 to 18 months.

      And anyone taking a youtube video as a reference for the danger of modern wind generators to birds needs to re-evaluate. IF anyone can prove there is a problem worth addressing, I'm sure the industry is capable of inserting small audio or visual signaling devices into the turbine blades at manufacture to keep the birds away, but I'm quite sure even that has never been justified by any rational inquiry.

      Are we perhaps seeing some of the reasons for the present ridiculous costs of nuclear generation, eg. if such is the level of logic of its engineering community?

      Don,
      Coal plants cost are much less expensive than comparable nuclear plants, as demonstrated by legions of power industry reports. However, throw in attemptiing to sequester greenhouse gases from a coal plant and we now have a horse race.

      I would like to see your calculations Len. It depends on what you include and of course where you locate your panel. For Ontario your numbers are very optimistic. Let's see them so I can analyze what you did. If your solar plant is in Arizona - perhaps. Not in Ontario. Indeed if your payback calculations are that good one wonders why every roof in North America does not have such an installation. Could it be that across large swathes of North America frigid temperatures in winter reduce the heat output to about nil. But post the calc's and let us have a look.

      Coal bed methane is being fed into TransCanada Pipelines for distribution throughout North America from BC as we speak. So no religion...just engineering. Pipeline companies do not make billion dollar pipeline investments for some short lived resource and I have a preference to believe those who put their money on the table. In addition the keystone pipeline is now feeding Canadian Tar sands oil directly to refineries in the US south and is being further enhanced to deliver over a million barrels a day. The Keystone development is a major engineering undertaking and it is hard to believe that those who invested in it and built it expected the tar sands to run out any time soon. Perhaps I am wrong here Fred but companies are putting big bucks into shale gas and coal bed methane. I don't think they would do that without good reason. But you're the expert on that topic so there may be an economic explanation that I am missing.

      Michael. while it is true that coal plants that freely emit their waste into the atmosphere are cheaper than nuclear plants the use of the word "comparable" is key to the argument. To make an accurate comparison one must compare like with like other wise it is not a comparison at all. To be comparable therefore you must include the cost of the waste. Nuclear plants are by law required to include the cost of used nuclear fuel storage in their electricity costs. Coal plants are not required to do that. So the true and valid comparison for cost purposes is to compare a nuclear plant of let's say 1000MW with zero air emissions and all waste costs accounted for with a similar sized coal plant that is forced to account for its waste in the same way. Nuclear is cheaper.

      Malcolm

      Michael, the coal burner quotes I saw and referred to were not for CO2 capture - just plain old Rankine Cycle plants as far as I know. And that's why I am puzzled.

      As far as I know there is not one carbon capture power plant in the world.

      New subject. Since shortly after my birth I have been consistently calling gasoline gasoline and natural gas gas. On countless occasions I have been puzzled (and annoyed) by the common practice of calling both gas even in the same paragraph.. Lately I have been calling natural gas methane to avoid using the word gas which has become near worthless.As it comes out of the ground natural gas can contain significant amounts of C 2,3,4,5 hydrocarbons:ethane, propane, butanes, and pentanes a liquid. These are usually separated out leaving nearly all methane. So what we cook with isn't even natural gas gas but a processed natural gas which then isn't natural. Naturally this becomes confusing.

      Never the less I wish gasoline would be called gasoline. I would be proud to have it on my tomb stone as my life' work...

      Don,

      In the UK, gasoline is "petrol". (I saw a British person in Texas order some "chips" only to be mad to find out that she had gotten "crisps". In the UK, chips are french fries, and crisps are potato chips.)

      If I got this right, the gas company pumps something that's about 95% methane, 5% CO2, and a few other traces allowed, including the odorant. This replaced "town gas" or "coal gas" which was syngas or H2 and CO. This is the stuff that you could kill yourself with by sticking your head in the oven. (Worked for Sylvia Plath.)

      There's a documentary about gas fracturing coming out soon. Seems the miracle of all this new NG available comes at a price.

      With respect to CO2 emissions, I find it odd and a little paradoxical that wind/solar electricity can fuel a PHEV with no CO2 emissions and displace gasoline use at a lower cost (at least if you ignore battery costs). This is because gasoline is a very expensive fuel: about $0.28 per kW-hr (realized) and that without taxes. ($2.00 divided by 7 kW-hr, which is about what an IC engine nets out of a gallon of gasoline.)

      I can't quite square that except to comment that PHEVs deployed to displace gasoline seems to be a good thing to do.
      On the other hand, charging with battery pack from a coal-fired plant is even less expensive, but produces more CO2 emissions. Yet we are forced to put the electricity from solar/wind and that from coal into the same market basket.

      Malcolm,
      There is no "price tag" on greenhouse gas emissions. Attempting to make an "emissions free" comparison with nuclear (or any other power source) is therefore essentially impossible.

      Will there be a "price-tag" on CO2 emissions? Uncertain. However, I do not believe such uncertainty is a good enough reason to embark on building extremely expensive nuclear power plants, at least in the US where we are blessed with a number of different fuel source options.

      New coal plants are unquestionably much cheaper than nuclear plants until the debt to build a nuclear station is paid off, then nuclear generally will be more cost effective. There are comparison studies that simply report fuel and O&M costs while ignoring the cost to build power plants - strikes me as a less than proper approach, however. (Don, that might be the source for the data you ran into).

      Mike

      Yes Michael, I entirely agree. Such a comparison cannot realistically be made because we do not have a value for CO2. I was being a bit philosophical because while nuclear plants are required to "price-in" their by products no other generating option is required to do so. Also I am reluctant to call used nuclear fuel bundles waste since they contain some very useful materials as well as most (98%) of the original U235 atoms. But I do see and agree with your point.

      We seem to also be falling into the trap that nuclear plants must necessarily be expensive. They industry has repeatedly (except for France) gone for one-off designs that change with every plant built. It simply is no longer acceptable to do that. If the price is to come down mass production methods must be introduced into the nuclear program.

      While it may not seem like it (based on our abysmal track record) a nuclear plant is the ideal candidate for mass production methods and modularized construction. Most plants now operating were virtually hand built on site - a completely stupid approach from a cost control perspective.

      But in order to do that one needs national nuclear programs (like China has) which will ensure continuous construction of identical designs. They are also much easier to maintain and will also. reduce OM and A costs.

      But good points Michael.

      Malcolm

      Jim, It has taken me many years to come to grips with such Americanisms. As a British Ex-pat living in Canada (which I love by the way) using words like "trunk" to describe the boot of my car and "fender" to describe the wings has taken some getting used to. I cannot even count the blank looks I have had from sales assistants in countless convenience stores when I ask where the crisps are? However I am having some success (albeit slow) in convincing North Americans to spell Aluminium with TWO 'I's". Still it's hard to expect too much from folks who dumped perfectly good tea into Boston Harbour.

      Of course I much prefer North America which is why I am still here after all these years. All I need to do now is convince you to build a few hundred new nuclear plants so you don't have to rely on oil so much and teach you how to spell colour correctly and my work is complete.

      While we may have our disagreements from time to time the people who post here are without doubt some of the best thinkers on energy I have come across .... and believe it or not..... have changed my views on some important issues - notably Professor Fred

      So thanks to all. Keep up the thinking. The world needs more people who think.

      Malcolm

      On the other topic of your post Jim you point to the fact that the gas fracturing process is not so benign and I agree. While I am no expert in the process it seems to involve very large amounts of water and the wastes produced are not particularly friendly to the environment. But the rewards are so great that I think it is worth it. It is interesting to note that the US for the first time in many years became the worlds largest producer of natural gas - largely as a result of gas shale production. Of course there is the possibility that these gas reserves are overestimated and may not last as long as predicted but there is a lot of money being invested and I doubt the oil and gas companies would do that on a whim.

      If natural gas reserves are as large as predicted it will be gas - not coal - plants that will be built. That is because their costs are very predictable and they can be placed close to load centres. In Ontario natural gas plants are being built largely to displace coal plants but they also provide the grid a lot of flexibility and can be operated remotely with few operating staff.

      I am sure Fred will have some views on this but it appears like their is a major change coming in the gas marketplace.

      Malcolm

      That's right Malcolm. I've spent a lot of time studying the gas market, and so it is difficult for me to believe that the US has a huge amount of gas reserves waiting to be exploited.

      But it might be so. and If it is, all of us might be in luck, because as you and I know gas is probably also just a transition fuel to an optimal and sustainable energy arrangement. The final picture will contain a lot of renewables and alternatives, and somewhat more nuclear - without which the renewables and alternatives will underperform.

      I thought about spending some time explaining tht to the folks in the cheap seats, but they don't want to hear it.

      I am not so sure about those renewable energy sources, Fred.

      From a purely engineering and cost standpoint, they make little or no sense. Harvesting such diffuse, intermittent and unreliable energy strikes me as an inherently poor approach. The money is better spent on efficiency improvements and more mainstream energy production methods, in my opinion.

      However, throw politics into the mix and there is no telling where we end up.

      I agree that natural gas may be somewhat of a roll of the dice longer range, but we in the US are not exactly strategic thinkers.

      "The money is better spent on efficiency improvements and more mainstream energy production methods"

      This is a huge comment Michael. This might be a surprise to some readers but our governments that are forcing the renewable energy sources on us know this statement to be very true. They already know the cheapest megawatt to generate is the megawatt the grid doesn't use in the first place. However they believe they can get this without spending substantial public moneys on efficiency improvements.

      They believe much of the spending will come from industry as governments force new regulations on manufacturers to achieve ever higher efficiency standards for consumer products. It's already happening for light bulbs and large-screen TV's for example. The only public money being spent is on handout grants or tax breaks for upgrading building efficiencies in residential and industrial facilities, and electric machine upgrades for factories.

      As for efficiency upgrades of large grid generators, these will happen at the expense of the owners of generators (utility companies and ultimately rate payers) but with the help of government tax incentives already in place for R&D if they are implementing any leading-edge technologies.

      Michael, if they don't try to do too much too soon with renewables; I think that we might have a chance. One thing though is certain: this century is the end of the line for fossil fuels. Moreover, as Don Hirshberg and a few others and perhaps yourself know, the global resource base is not going to be able to sustain the kind of population that will be attending the New Years Eve parties and celebrations on Dec. 31, 2099 - at least, sustain it at the nice bourgeois level that the TV advertisements and infotainment suggest. Renewables and alternatives might enable a large fraction of the world population after this century to enjoy the mobile telephones, chit-chat about the World Cup, and lousy TV programs that they so enjoy.