By Guest Blogger Terry Morrone
Professor Emeritus of Physics, Adelphi University
How much do you think it would cost to make the transition to an economy based on alternative energy? It’s a complicated question. I’ll calculate the cost to produce all of our electricity in the United States by alternative means. This is a simpler, well defined but still messy problem. I’ll show that it is possible to make a conservative estimate of the cost. I’ll discuss a total transition in less quantitative terms. If we don’t make the transition soon, the earth will heat up, food production will go down, and we’ll have mass starvation, mass migration and constant war. If we make the transition we’ll have much less pollution and consequently much less disease, much less war and the earth will be a much happier place. I’ve tried to make this report readable to anyone. I thought of calling it “the energy transition for dummies.” I’ve included an appendix to explain some of the mathematical concepts for those interested.
In our new world, we’ll burn no fossil fuels, all cars will be small and electric, we’ll have much more good mass transportation and food production will be decentralized. The single family home might have to go if we don’t find a cheap replacement for our oil based transportation system fast enough. Some of us might live in communities surrounded by farm land and woods, where we can go for long walks and commune with nature. The communities might look something like large airport terminals with moving sidewalks, escalators and trains that run every few minutes. You’ll be able to walk or bicycle to almost any destination without exposure to the elements. Apartments will be on the perimeter overlooking the countryside. If the single family home survives, it will be very energy efficient.
Electricity will be generated mostly from solar or wind energy. Heat and hot water will come from solar thermal collectors. There will be little need for heating since the buildings will be very well insulated. We’ll have to store lots of energy to provide electricity and heating during times when there’s little or no sunlight or wind.
If you don’t feel up to going through the calculations, you can take my word for cost estimates and skip ahead. I’ve included the arithmetic and references so the reader doesn’t have to take my word for anything.
Before going into the cost I’m going to explain scientific notation, since we’re going to be dealing with very large numbers. This section is for dummies. I’m going to write big numbers using E to designate the number of zeros. Thus 1E2 means 1 with 2 zeros after the 1, or 100. Or more precisely, 1E2 is 1 multiplied by 100. For example, 1.23E3 is 1230. The unit of energy I will use is the kilowatt hour. A 100 watt light bulb on for 10 hours uses up 1000 watt hours or 1 kilowatt hour. I’ll abbreviate it 1 kwh. Electricity in the US cost about 11 cents a kwh. Scientific notation is convenient in multiplying or dividing big numbers. When multiplying you add up the numbers after the E’s. For example, 2E4 multiplied by 3E5 is 6E9. I’ll use “X” to indicate multiplication and “/” for division. In division we subtract the number after the E’s. An example of division is 4e5/2e3=2e2. I recommend getting a scientific calculator. Note that 1E3 is a thousand, 1E6 is a million, 1E9 is a billion and 1E12 is a trillion. Also 1 megawatt (MW) is 1E6 watts, 1 gigawatt is 1E9 watts and 1 terawatt is 1E12 watts.
Power sources are rated by a name plate capacity and a capacity factor. Suppose you buy a 1 kw solar panel. The 1 kw is the power generated under standard conditions, with the sun shining all the time. The amount of electricity you can generate depends on a capacity factor, which varies with location. The capacity factor is the average fraction of time the sun is shining. The number of kwh that can be generated in a year is the rating in kw times the number of hours in a year times the capacity factor. In Arizona the capacity factor is about .19. (1) Thus a 1 kw solar panel will generate the number of hours (365×24) times the .19 or 1664 kwh a year. The capacity factor for nuclear power, for example, is the average fraction of the time the power plant is on, or .91. Coal plants are up and running 72 percent of the time. (2) They have to be shut down for repairs or maintenance 28 percent of the time.
In the United States we generate about 4E12 kwh per year (3). About 10 percent already comes from renewables, including water power. So we need renewable sources for 3.6E12 kwh per year. The energy is delivered over a power grid, except for that generated by rooftop solar or backyard wind generators.
I’ll discuss the power grid here. This is another section for dummies. Think of the grid as a system of rivers with flowing water instead of the electric current carried by transmission lines. (Note that electric current flows a lot faster than water.) Along the rivers there are places where water is added. These are the generating stations. There are also places where water is removed. These are the power users or loads. Every time you turn on a light or an air conditioner, you are adding to the load. On a hot day the air conditioner load is large and more current must be added to the grid. Conventional power sources usually produce the same amount of power all the time they are in operation. Sources depending on the sun or wind have variable outputs.
Imagine a grid fed by wind and solar energy. Along comes a cloudy day with no wind over a large section of the country. What can we do? One answer is to have generators that are held in reserve and only turned on when the alternative sources fail. In Texas, where the wind power contribution is significant, power plants using natural gas had to be built to supply power when the wind is weak. Another answer is energy storage, analogous to big water tanks that can supply water to the river at any time. Another answer is to have big grids (analogous to long rivers) so when power generation is low in one area we can transport energy from another area where it is high. This sounds ideal except that energy is wasted in transmission. Variability of supply problems are minimal if alternative sources supply only a small fraction of the energy used. That is the situation today. But as more and more power comes from wind and sunlight, we’ll have to spend a lot to guarantee that electricity is always available when needed.
It would be great if we had a nonpolluting, zero greenhouse gas producing, high capacity factor source of energy. Geothermal energy is such a source, but there’s a catch. It can supply at most 10 to 20 percent of our energy using current technology. Geothermal energy is less expensive than wind energy. Sights where it’s economic to extract geothermal energy are concentrated mostly in the western part of the country. But the potential of geothermal energy is enormous. Using deep drilling techniques developed by the oil industry, it could supply all of our electricity needs, according to a MIT report (4). A research and development investment of only 800 million to 1 billion dollars over 15 years is needed according to the report. At present geothermal energy supplies less than 1% of our energy, but many new plants are being built (5). Using enhanced geothermal systems, a proven technology, 10 percent of our electricity could be generated. (6)
Large solar thermal power plants, with built in energy storage devices, can also supply energy continuously. These plants reflect sunlight from mirrors and concentrate it on a target (usually water) to get very high temperatures. Water is turned into high pressure steam which pushes on turbine blades to produce electricity, much the same way that burning coal or oil produces steam in conventional power plants. It’s easier to store heat then it is to store electricity. So the plants can heat up a storage medium when the sun is shining, and at night use the stored heat to produce electricity. The capacity factor for large thermal plants may go as high as 50 to 77 percent in the future. (7) The increased capacity factor over rooftop solar panels is due to automatic tracking of the sun.
Water power is another reliable non polluting source, but it supplies only about 8 percent of our energy and there’s little hope for expansion. Wind generated electricity is very cheap, but it’s expensive to store the electricity produced. Electricity is stored in batteries, capacitors etc.
A “smart grid” will help cut down on the storage requirements. (8) With a smart grid, information flows from the utility to the customer and from the customer back to the utility. This makes load management possible. Thus if the electricity supply is low, the utility can shut down your air conditioner, for example, to avert a blackout. Or it can shut down machines in a factory. This will be done through an agreement between customer and utility. If a factory owner agrees that his machines can be shut down occasionally, he will be paid for his additional expenses. Another smart grid application is distributed energy storage. A customer with an electric car plugged into the grid could supply energy from his car battery to the grid if needed. Again he would be compensated for the energy supplied and related expenses.
According to a Sandia report, (9), the cheapest form of energy storage is the “flooded lead acid battery.” It stores energy at a cost of $150 per kilowatt hour. Recall 1 kilowatt hour is the energy consumed by a 100 watt light bulb on for 10 hours. But how much storage will we need? According to Denholm and Margolis, (10) in order for a photovoltaic system to supply 50% of a system’s energy, a storage system which provides “substantially less than 1 days worth of average demand” will be required.
Model System
I envision a model system with solar thermal and photovoltaic, wind and geothermal energy sources. Water power we already have. I’ll assume water power, existing alternative power plants, and geothermal will supply 20 percent of the energy. Solar with heat storage will supply another 10. Then 70 percent will have to come from variable sources. A smart grid will be in place. The transmission lines will also have to be upgraded to carry power over longer distances and to carry electricity away from the wind and solar generators. One full day of energy production will be stored and ready to fill in for the variable sources. I’m assuming that with a smart grid, long transmission lines, and both solar and wind working together, that we can get by with one day’s production in storage. The combination of wind and solar is better than the sum of its parts, since on average the chance that there’s no sunlight and no wind is less than the probability that either solar or wind power are unavailable. There are also regions of the country that have little wind, e.g. the southeast. There are also other regions that have a lot of wind but not much sun.
The criteria I’ve used in developing the model include cost, water usage, variability, and EROEI. EROEI is the energy produced over the lifetime of a power generator, such as a wind mill, divided by the energy required to produce it. I’ll discuss this concept later. I’ve chosen only 10 percent for solar thermal with energy storage because it uses up a lot of water, and water is a scarce commodity in the desert regions where these plants are usually built. In fact, water is becoming scarce over most of the country. Photovoltaics, (PV), while expensive uses up little water and wind power uses up hardly any at all. (11). The best choices of electricity generators will evolve with experience. I’m making some guesses so I can estimate cost. I’m choosing that we get 30 percent of our power from PV and 40 percent from wind power. See Table 1 below.
Costs
I’m going to calculate the “overnight” costs. That is the cost using today’s prices, excluding the cost of capital. Let’s start with the smart grid. According to an Electric Power Research Institute estimate, (12), it will cost 165 billion dollars over a 20 year period. That’s cheap.
Next consider energy storage. Lead acid batteries are cheapest but they are not suitable for electric grid energy storage according to an EAC (Electricity Advisory Committee) report. (8, page 3). Sodium Sulfur batteries would be better, but are more expensive. According to a Sandia report (13, page 21) they store a kwh for $450 today, with costs going down to $350 in 10 years. However others state that, with mass production, the cost could go down to $112 per kilowatt hour (14). In some parts of the country, pumped hydrostorage or compressed air storage is available at much lower prices. Thermal energy storage using gravel could might also cut costs well below $350 per kwh (15). Let’s use $200 per kwh as a compromise estimate. Since we use 4E12 kwh per year, for 1 days storage we’d need 4E12/365 or 1.1E10 kwh. We’d have to multiple this by 200 to get 2.2E12 or 2.2 trillion dollars. This is a huge amount of money, but we won’t have to spend it until the last stages of the transition when all the fossil fuel and nuclear plants are gone. Till then we can use some fossil fuel plants as a reserve to use in emergencies to help the grid supply the demand in unusual situations.
Next consider the cost of supplying 30 percent of our energy (.30x4E12 or 1.2E12 kwh) by PV. The capacity factor is .19 in Arizona and .12 to .15 in Massachusetts. (16) Let’s assume it’s .165 for the US average. Thus a 1 kw solar panel will produce .165×24 x365 or 1445 kwh per year. The number of 1 kw systems would be 1.2E12/1445 or 8.3E8, since each 1 kw system produces 1445 kwh per year. If each roof top has a 2kw system we’d need 415 million rooftops, and we don’t have that many. We’ll have to go to much larger systems which are more efficient than homeowner systems. The cost per kw for already built large systems is about $6600 (17, page 92), but it’s higher for small systems. Let’s assume most of the PV energy will be generated by large systems. The price is dropping and improvements in the technology are likely. (18) New panels costing as little as 1000 dollars per kw are now available (19) and likely to lower the $6600 number. Let’s assume $5000. This does not include inverter, labor and installation costs, which are less per kw for large systems. (Inverters are used to convert the dc current from the panels to ac.) Thus we’d need, at $5000 per kw capacity, the cost would be 5.0E3x8.3E8 or about 4.15E12 or 4.15 trillion dollars.
Next the cost of getting 10% of our power or 4E11 kwh per year from solar thermal. Consider the Andersol power plant in Spain. (20) One unit cost 380 million (3.8E8) dollars to build and produces 180 million kwh per year. To produce 4E11 kwh per year we’d have to spend (4E11/1.8E8) X 3.8E8 or .844 trillion dollars. Another estimate (17, page 89) which uses the average cost of plants already built is $3400 per kw. The plants are usually in very sunny locations so for a capacity factor let’s use .3. Using that factor, 1 kw in capacity would produce 365x24x.3 or 2628 kwh per year. The cost for 4E11 (or 10% of our yearly kwh) is 4E11x3400/2628 or .517E12 or .517 trillion. Let’s use a compromise figure of .75 trillion including storage.
The cost of wind power is a bargain, about $2100 per kw peak. (17, page 84) The world wide wind generating capacity is 159 gigawatts and 340E9 kwh of electricity are produced. The capacity factor can be calculated as .234. This will increase to about .35 for the new bigger and taller wind mills. (The wind is stronger at higher altitudes.) Let’s use a number for the nation estimated by the California Energy Commission of .34. (21 page 44) Thus for 1 kw capacity we get 365x24X.34 or 2978kwh per year. The capacity we will need to generate 40 percent our electricity from wind is .4x4E12/2978 or 5.37E8 kw. At 2100 per kw peak the cost is 1.13E12 or about or 1.13 trillion dollars.
We also need the cost of geothermal energy. The CRS report (17, page 87) lists $3200 per kw. The capacity factor is high, about .9. So 1 kw capacity produces 365×24 x.9 or 7884 kwh per year. The cost to build a capacity to produce 10% of our energy is 4E12x.1/7884 times the cost per kw capacity (3200). Thus the cost is .16 trillion dollars. That’s dirt cheap. If we get to the point where we use deep drilling techniques to mine geothermal energy as envisioned by the MIT report, we’ll have to expend huge amounts of energy to initiate the process. Let’s make a guess that the cost is .5 trillion to get 10 percent of our energy from geothermal.
Finally, we must consider the cost of new power lines. According to Heyeck and Wilcox (22) , if we wish to generate 20% of our electricity from wind, we’ll have to build 19,000 miles of 765 KV (765,000 volts) transmission lines. The cost would be about 60 billion dollars. I’ll guess that to get almost all of our energy from new sources will cost roughly 5 times as much or 300 billion.
Table 1
| Technology | Cost Per kw | Capacity Factor | Percentage | Overnight Cost
trillions |
| Solar Thermal | 3400 | .3 | 10 | .75 |
| Solar PV | 5000 | .165 | 30 | 4.15 |
| Wind | 2100 | .34 | 40 | 1.13 |
| Geothermal | 3200 | .9 | 10 | .5 |
| Storage | 200 per kwh | 2.2 | ||
| Smart Grid | .165 | |||
| Power Lines | .3 |
The total cost is 9.2E12 or 9.2 trillion dollars. I’ve not included the 6% of our energy production lost in transmission. I’m assuming it’s included in the 4 trillion kwh of electrical energy we produce each year.
Energy Cost – Energy Out Over Energy In (EROEI)
We must also consider the energy cost to produce all of the new power plants. Energy out is the amount of energy produced by a power plant over its lifetime. Energy in is the energy needed to build and maintain the plant including the cost of producing materials such as steel and Aluminum. The ratio is usually called EROEI or sometime EROI.
EROEI is difficult to compute and published values vary greatly. For example, geothermal electric power generation values vary from 2 to 13. (23) There is more agreement on wind. I’m going to use values based on a few typical websites (24-28). The values I’ll use are shown in Table 2.
Recovery time is the time needed to recover the energy used in construction.
Table 2
| Technology | EROEI | Recovery Time (years) | Lifespan (years) |
| Wind | 20 | 1 | 20 |
| Solar Thermal | 10 | 2.5 | 25 |
| Solar PV | 10 | 2.5 | 25 |
| Geothermal | 10 | 2.5 | 25 |
| Coal | 6 | 5 | 30 |
| Oil | 6 | 5 | 30 |
| Natural Gas | 10 | 2.5 | 30 |
| Nuclear | 10 | 2.5 | 30 |
The EROEI of Coal and Oil were once much higher, but the easy access days are over. To get oil we now have to drill for miles, sometimes under the ocean. To get coal whole mountains have to be moved. In 1930 the EROEI of oil was at least 100. The EROEI of corn based ethanol is around 1(29), so it’s foolish to use it. The EROEI of natural gas is falling rapidly. (30) Even without the threat of global warming, we would be turning to alternative energy for economic reasons.
We also require the energy needed to produce the energy storage system. We’ll need the relationship, derived in the appendix, energy in = payback time times energy generated per year. I could not find any references on costs in energy to build storage, but let’s make a rough estimate. We have an estimate of the price per kwh of the Sodium Sulfur battery. If we estimate the fraction of its price that’s due to energy we can estimate the energy. These batteries are encased in big steel chambers, something like a windmill. A windmill, from above, costs $2100 per kw and the energy cost is T times (number of kwh per year) or 1 X 2978=2978 kwh. At 11 cents per kwh this is 327 dollars. Thus the fraction of the dollar cost for energy is 327/2100 or .156 of 15.6 percent. Let’s use 15 percent energy cost for storage. Thus, referring to Table 1, the energy cost in dollars is 2.2E12X.15 or 3.3E11. At 11 cents per kwh we get 3E12 kwh. Assuming the 15 percent energy cost in dollars for transmission lines is the same as for storage, we have to add .3E12X.15/.11 or .41E12 kwh. We’ll neglect the energy cost of the smart grid.
Building a power plant takes energy. Because of the menace of global warming, and in particular the danger of a runaway greenhouse effect (more about this later), we would like to change to technologies that produce no greenhouse gases without increasing emissions in the process. For example, we would like to avoid building new coal plants to provide energy to build solar panels. But is this possible?
Let’s consider using wind generated electricity to build new wind mills. Since the recovery time is 1 year, it takes one year’s worth of energy from a single wind mill to produce another wind mill, and it takes about a year or less to build a wind mill. So first let’s calculate how many wind mills we need to meet 40 percent of our electricity needs. The number kwh needed per year is 1.6E12 and each kw capacity produces 2978 kwh per year (see above). New wind mills have about a 5 megawatt capacity, so each one produces 5000×2978 kwh per year or 1.49E7 kwh per year. To produce 1.6E12 kwh we will need 1.07E5 or about 107,000 wind mills.
Let’s say we build 1 wind mill using energy derived from any convenient source. So at the end of year 1 we have one wind mill. Then using the power from that wind mill we build another. It takes a year, so at the end of year 2 we have 2 wind mills. In the third year we build 2 additional wind mills and have 4 at the end of year 3. Every year the number of wind mills doubles and we’re using all the wind power to build additional wind mills. After 18 years we’d have 131072 wind mills, more than enough. But it took 18 years, and during that time we’ve had to get by without electricity from wind.
We’ve also had to double production every year which isn’t very practical. If we tried to get energy for the transition from the other alternative sources the situation is much worse. It would take approximately 2.5 times as long since the EROEI values are only about 10 and the energy is produced over a longer time frame (25 years instead of 20). Thus some of the energy for a short transition, for example 20 years will have to come from fossil fuels.
A better scenario is to assume that we produce wind mills at a constant rate, investing some fossil fuel energy at the beginning. The amount of fossil energy needed to initiate the process is calculated in an Appendix. I’ll state the results here. This energy is called the renewables hump. (31,32) As pointed out in (32) the best way to overcome it is through conservation.
I show in the Appendix that if we make the transition in 20 years, we’ll have to come up with roughly 10.45 percent of our energy production in the first year (.418e12 kwh), 8.58 percent in the second year, 5.88 percent in the third year and .975 percent in the fourth year. If we include electrifying our transportation system (see below) we’ll have to increase the percentages by a factor of 1.37. That is, the percentages for the first 4 years become 14.3, 11.8, 8.06 and 1.34. The amounts can be reduced by putting off building storage, finding more efficient storage, putting off building solar PV or building smaller numbers of alternative plants in the early years. Greenhouse emissions would be less if we started a huge conservation program and used the saved energy to create our new energy infrastructure. We’d be wise not to increase our energy consumption in spite of growing population. I think it’s possible. We could drive smaller cars, use energy efficient light bulbs, and insulate our buildings better.
Replacements of Old Power Plants
We have estimated the cost of building new power plants as 9.2 trillion dollars. But about 22% of existing power plants will reach retirement age in the next 10 years. (33) To replace these plants with new conventional plants would probably be just or more expensive as new wind power plants because of the added cost of emission controls. Another report states that about 30 percent of power plants are near the end of their lives and another 15% are past the end of their lives. (34, page 21) Part of the money for the transition will come from the portion of our utility bills normally used for plant replacement. We pay utilities about .4 trillion a year for our electricity. If we wait long enough, say 50 years, we’ll only have to pay for the normal utility replacements and the costs of energy storage and transmission lines. But we might not have a planet we can live in.
Electric Transportation System
If we change to electric cars, we’ll need more electricity during the transition period. I’ll compute here the cost to generate enough electricity to transform the entire transportation sector. According to the department of energy, the US transportation sector consumed about 27,000 trillion Btu in 2009. (35) This is equivalent to 7.9E12 kwh. This is twice as much as the US entire annual electricity consumption. But we won’t need this much energy because electric cars are much more efficient than conventional cars. By efficiency I mean the energy needed to go from “well to wheel.” It’s the total energy needed per mile of travel. For conventional cars, it includes the energy needed to extract and transport the oil and refine it. For electric cars it includes the energy needed to build the power plants and the batteries. The efficiency of electric cars is about 76 percent (36) and the efficiency of gasoline cars is 25% (37). Diesel cars and trucks do better, about 35 per cent (37), but only about 35 percent of fuel used is diesel. (38) The weighted average efficiency is 28 percent.
Thus the electric energy we would need is 7.9E12X28/76 or 2.9E12kwh per year. Since we can’t electrify jet planes we’ll need 9 percent less about 2.6E12 kwh per year.
This is not that much less than the 4E12 kwh used to generate all our electricity. The 9.2 trillion cost of the transition would go up to 15.2 trillion dollars. We might not be able to produce the energy required by alternative means. We might not be able to get enough Lithium or other materials needed for batteries. But again conservation may come to our rescue. We don’t need SUV’s and big cars. Cars in Europe get much better gas mileage. The average American car gets only 20 miles per gallon. There’s plenty of room for improvement.
China has 120 million electric bicycles and sales of them are increasing all over the world (39). They get hundreds or sometimes over a thousand miles per gallon equivalent. A friend of mine commutes to work on one. It has pedals, goes about 20 miles per hour and has a range of 30 miles. In the winter he pedals just enough to keep warm. We need a much better mass transit system including high speed trains, which could reduce the need of air travel. A detailed discussion of changes needed to eliminate our dependence on cars is beyond the scope of this report. If we doubled our transportation efficiency, using small electric cars and mass transit, we could the cost of the transition would drop from 15.2 trillion to 12 trillion dollars.
Reduction in Green House Gas Emissions
The statistics in this paragraph come from an Energy Information Administration report (40) pages 4 and 7. The United States produces about 7000 million (7E9) metric tons equivalent of carbon dioxide. A metric ton is 1000 kilograms or 2200 lbs. There are other greenhouse gases besides carbon dioxide, for example, methane. It’s convenient to represent all by the amount of carbon dioxide that produces the same greenhouse effect. Thus the term carbon dioxide equivalent is used. We produce about 19 percent of the world total of greenhouse gases. Electricity production produces 39 percent of the emissions. By switching to non fossil fuel electricity we would reduce US greenhouse emissions by roughly 39 percent and world greenhouse emissions by 8 percent. By switching to an all electric transportation system we’d cut back on greenhouse emissions by an additional 28 percent. I’ve neglected the greenhouse emissions produced in building alternative energy power plants. Most of them will be built using alternative energy. (See appendix.)
Health and Environmental Benefits
A recent study showed that the health cost of producing CO2 averages $31 per ton in developed countries. (41) It isn’t the CO2 that does the damage, but the other compounds that are generated along with it. The medical cost comes to 217 billion dollars a year. Another estimate (42) is 62 billion dollars yearly for health costs from coal alone. If we got rid of all the CO2 generated in electricity production (39%) and transportation (28%) we would save 145 billion dollars per year. Neither of the reports takes into account the global warming cost. Over a 20 year transition period we would save about 10 years of health costs or 1.45 trillion dollars. This would drop the cost of the transition to about 10.5 trillion dollars.
The cost of coal cannot be measured in economic terms. According to Robert F. Kennedy Jr. (43)
“Mountain top mining poisons water supplies, pollutes the air and destroys hundreds of miles of North America’s most ancient and biologically diverse hardwood forests and permanently impoverishes local communities. Millions of dollars earned from this criminal enterprise land in the coffers of the politicians now jockeying to lead our country to a ‘new energy future.’ Mountaintop removal is one of the biggest environmental holocausts in human history. Wherever you live, you have a connection-and a responsibility.”
Another study shows that air pollution is responsible for 5 percent of male cancer deaths and 3 percent of female cancer deaths. (44) That comes to about 22,000 deaths per year.
Growing Pains
Increased production of alternative sources may encounter material shortages that could limit growth. For example, the new low cost solar panels use Cadmium Telluride. Cadmium may soon be in short supply. However, there is hope that large deposits will be found under the sea and on land if we step up exploration efforts (45). Other less rare semiconductor materials may also be used. (46)
The wind industry is running into supply shortages in steel and other materials. (47) Steel production in the US may have to be increased.
Solar thermal power plants usually use water to condense the steam used to drive electric generators. However, plants near the sea can use sea water for cooling and “dry cooling” is also possible. (48)
My feeling is that all the obstacles can be overcome if a world-wide scientific and industrial effort is pursued diligently.
Financing the Transition
Let’s say we’ll need about 12 trillion plus or minus a few trillion, to change to alternative energy for utilities and transportation. Where will we get the money?
According to Bloomberg News, the cost of the bank bailout was 11.6 trillion dollars. (49) A more up to date estimate is 7.23 trillion. (50) It’s hard to know exactly how much it is, because of the secretive nature of the Federal Reserve System. At any rate it’s not far from the cost of the energy transition. Thus when the interests of our power elite are at stake, spending 11 trillion is not a problem. Our defense budget is about 1 trillion a year. If we cut it in half, the savings would amount to 10 trillion over a 20 year period. Tax cuts for the rich under Reagan and Bush have cost the country trillions of dollars in revenues.
Getting the money for the transition would be easy if we had a government that represented the poor and middle classes as well as the big corporations. We could simply tax the rich, increase taxes on corporations, lower the defense budget, and if needed print the rest.
Millions of jobs would be created and the quality of life improved. There would be economic dislocations of course. For example, coal miners would be out of work and the cancer industry would take a big hit. But we have a crumbling infrastructure in this country, and millions of workers are needed to repair it. Jobs could be created in areas of the country hardest hit by the transition. A good economic system should be able to put workers to work to do the jobs that need to be done. A good government should be able to take actions to avert ecological disaster. At the moment we have neither.
The Rest of the Transition
We haven’t discussed the greenhouse gases produced in homes, office buildings and factories. I’ll not go in detail here, but solar thermal collectors could provide much of the needed heat and hot water. Better insulation would cut cooling as well as heating costs. The energy return (EROEI) of conservation is much higher than that of new power plants. (51)
Building smaller cars actually saves money. Decentralized agriculture would eliminate the need to transport food thousands of miles and create jobs in cities.
Eating less meat, or better still no meat at all, would greatly reduce greenhouse gas emissions.
According to a report published by the United Nations Food and Agriculture Organization, livestock production produces 18 percent equivalent of world production of greenhouse gases and 33 percent of the global arable land used to producing feed for livestock. (52) Meat production is growing rapidly. It’s an environmental disaster, producing disease, erosion, deforestation and water pollution.
Dangers in Not Reducing Greenhouse Emissions
There are 2 main causes for climate change, aside from the very slow changes caused by continental drift and the steady increase in the radiation from the sun. They are periodic orbit changes and the greenhouse effect. Many times in the past the earth has been warmed by an increase in solar radiation due to an orbit change. The increased temperature causes the permafrost to release greenhouse gases into the atmosphere and causes a decrease the reflectivity of the earth due to melting snow. These 2 effects (and a few others of lesser importance) cause the temperature to rise further, amplifying the effect of the increased solar radiation. After a while the solar radiation decreases, and climate system acts again to amplify the effect. The earth returns to the original state. This is a simplified picture but it explains more or less the historic mechanism of climate change.
The danger for us is that the earth climate system exhibits positive feedback. That is an initial change causes changes that increase the original effect. What’s happening now has never happened before. Warming has been triggered by an increase in greenhouse gases due to the burning in fossil fuels. This is causing more greenhouse gases to be released. The danger is that the feedback, or self reinforcing effect, will get out of hand, and the temperature will rise much more than expected.
I like to think of the world climate system as a black box which has an input and an output. The output is temperature and the input is the greenhouse gases produced by man. But there’s a complication. The output is fed back though another black box (a feedback box) and added to the input. It’s impossible to know the exact effect of increasing greenhouse gases on the temperature because we do not fully understand the parameters describing the feedback box. We do know they depend on temperature. We also know that in the past feedback has been weak enough so that a runaway greenhouse effect never occurred. But we’ve never been in this position before. Much of the world’s forest cover has disappeared and man is producing far more energy than ever before. If the feedback input to the climate system is greater than the original man made input, the temperature will rise whether we reduce emissions or not. Most climate scientists think this will not happen, but some think it’s a possibility. The temperature rise will stop only after the parameters of the feedback box change, probably due to increased radiation from a very hot earth and the complete lack of snow cover. Most climate scientists agree that the emissions vaguely agreed to at the Copenhagen conference will not meet the goal of limiting the temperature rise to 2 degrees Celsius. (53) So far the rise in temperature rise is only .6 degrees Celsius, and this is causing extreme climate events, and a reduction in food production. We’re gambling with the future of the planet.
Paths to Sustainability
We should immediately take the steps that produce the greatest reduction in greenhouse gas emissions per unit cost. Conservation, recycling, auto size reduction, and a reduction in meat consumption are high on the list. The energy savings from using recycled materials are huge. (54) We also should be pouring billions into research on energy saving technologies. There’s a good chance that the costs of electricity generation and energy storage could be greatly reduced. Wind power is cost competitive today with other forms power generation. We should immediately begin a crash program to build wind mills and transmission lines to carry the electricity they generate. We also need a government sponsored education program to convince the public on the need for change and to combat corporate propaganda.
The government should subsidize energy efficient communities instead of suburban sprawl. Mass transit should be greatly improved. There should be a department in Washington dedicated to planning the energy transition.
I’ve shown that we have the resources to make a complete transition in 20 years or less. To get rid of all out fossil fuel power plants and to electrify the transportation system would cost about 12 trillion, plus or minus a few trillion. It will cost less if medical savings are taken into account. We will have to make a huge effort at conservation to avoid increasing emissions during the transition. If we make the transition other countries will follow.
Political power determines the decisions made in Washington. We’ll get nowhere without it. We need massive public pressure. Will we have to wait for more environmental disasters for it to develop? Will it come soon enough to avert huge loss of life? Will the public be passive observers or will they take action? More equality and more democracy would help move the process along, and the fight for social justice is linked to the fight for our survival.
Appendix, Calculating the Fossil Fuel Energy Needed to Initiate the Energy Transition
The relationship between the recovery time (T), lifetime (L), and EROEI is
T=L/EROEI
This is reasonable since if EROEI is 1 (energy in = energy out), then the recovery time is L. If EROEI is 2, it takes L/2 years to recover the input energy and so on.
We need a formula for the energy in needed to produce E1 kwh per year. That is, we want to build a power plant with a given L and EROEI that produces E1 kwh per year. We know that for a plant that had an energy cost of EIN, the total output in L years is EIN X EROEI. To get output per year we simply divide by L and get
E1 = EIN X (EROEI)/L (1)
I’ll label the formulas so we can refer to them later. Solving for EIN we get
EIN = E1 X L/EROEI (2)
In terms of T (the payback time) we get the convenient formula
EIN = E1 X (T) (3)
To calculate the fossil energy inputs necessary to produce a number of solar thermal plants, we need another parameter. It’s the time it takes to build a power plant. We’ll assume that the energy is put into a power plant over a period of D years and it takes D years to get the plant up and running. Another parameter is the time interval between building batches of power plants. We’ll call it t. It’s not necessarily 1 year. The energy output of a plant that took EIN units of energy to build, in time t is from (formula 3) above (EIN) X (t)/T which I’ll in compact form as Et/T. In this section, from now on, if I write 2 symbols together it means multiply, So Et is E times t.
It’s helpful to make a table on which we list the amount of alternative energy produced in a period as a function of the period number (horizontal) and the batch number of power plants (vertical).
During each period, E units of energy are used to build a batch of power plants. At the beginning the energy is all derived from fossil fuels, but after a while alternative energy is used as it becomes available. The delay time is 1 period.
Table 3
| Period
Batch |
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 0 | 0 | Et/T | Et/T | Et/T | Et/T | Et/T | Et/T | Et/T | Et/T |
| 1 | 0 | 0 | Et/T | Et/T | Et/T | Et/T | Et/T | Et/T | Et/T |
| 2 | 0 | 0 | 0 | Et/T | Et/T | Et/T | Et/T | Et/T | Et/T |
| 3 | 0 | 0 | 0 | 0 | Et/T | Et/T | Et/T | Et/T | Et/T |
| 4 | 0 | 0 | 0 | 0 | 0 | Et/T | Et/T | Et/T | Et/T |
| 5 | 0 | 0 | 0 | 0 | 0 | 0 | Et/T | Et/T | Et/T |
| 6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Et/T | Et/T |
| 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Et/T |
| Alternative
Energy |
0 | Et/T | 2Et/T | 3Et/T | 4Et/T | 5Et/T | 6Et/T | 7Et/T | 8Et/T |
The first batch of power plants is built during period 0, and no Alternative energy is produced until period 1. The second batch is build during period 1 and it produces no energy until period 2, and so on. E units of energy are used to build power plants in each period. The amount of alternative energy produced in a period is PEt/T, where P is the period number. If the delay time was greater than 1, the numbers in the table would be pushed to the right by D-1 boxes. Thus a more general formula for the for the energy produced in a period is
EP=(P-D+1)Et/T (4)
The formula applies for EP, the energy produced in a period, greater or equal to zero. To get the net energy produced we subtract the input energy, E, for each period. Calling it NEP:
NEP=(P-D+1)Et/T – E (5)
Now I’m going to tabulate the net energy produced in each period by all the batches. I’ll count the energy needed to build power plants as negative and the alternative energy as positive. Here’s the table assuming the delay is 1:
| Period | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| Net energy | -E | Et/T-E | 2Et/T-E | 3Et/T-E | 4Et/T-E | 5Et/T-E | 6Et/T-E | 7Et/T-E |
When the net energy is negative we have to use fossil fuel energy to make up for the deficit. Consider first the case of wind energy. I’ll assume that it takes a year to build a plant. The value of the payback time, T, is 1 year, the period length, t, is 1. The net energy for period 1 is 0 and it’s positive for later periods. Thus we only have to use fossil energy in the first period, but how much is the amount E?
Net Energy Wind Power (E=.842E11)
| Period | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| Net energy | -E | 0 | E | 2E | 3E | 4E | 5E | 6E |
For wind power to produce 40 percent of our electrical energy each year or 1.6E12 kwh by period 19, the energy input per year is .842E11. (Solve (4) for E with Ep=1.6E12, t=1, D=1)
I’ll tabulate next the net energy during each period for solar photovoltaic (PV), as follows (with t=1, T=2.5, D=1)
Net Energy Photovoltaics (E=1.58E11)
| Period | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| Net energy | -E | -.6E | -.2E | .2E | .6E | E | 1.4E | 1.8E |
The energy input per year in this case is from (formula 4) 1.58E11
Solar thermal plants and geothermal plants take longer to build than wind mills or PV plants, since they are usually bigger and more complicated. I’ll assume the delay time is 3 years. I’ll assume a batch of plants is started every year, so t=1. Recall T=2.5. The net energy table is shown below.
Net Energy Solar Thermal and Geothermal (E=1.18E11)
| Period
batch |
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 1 | -E/3 | -E/3 | -E/3 | .4E | .4E | .4E | .4E | .4E | .4E |
| 2 | 0 | -E/3 | -E/3 | -E/3 | .4E | .4E | .4E | .4E | .4E |
| 3 | 0 | 0 | -E/3 | -E/3 | -E/3 | .4E | .4E | .4E | .4E |
| 4 | 0 | 0 | 0 | -E/3 | -E/3 | -E/3 | .4E | .4E | .4E |
| 5 | 0 | 0 | 0 | 0 | -E/3 | -E/3 | -E/3 | .4E | .4E |
| 6 | 0 | 0 | 0 | 0 | 0 | -E/3 | -E/3 | -E/3 | .4E |
| 7 | 0 | 0 | 0 | 0 | 0 | 0 | -E/3 | -E/3 | -E/3 |
| 8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -E/3 | -E/3 |
| 9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -E/3 |
| Net Energy | -E/3 | -2E/3 | -E | -.6E | -.2E | .2E | .6E | E | 1.4E |
The net deficit -2.8E. Since solar thermal and geothermal have to supply 20% of our energy needs,
or .8E12, from formula (4), we find E=1.18E11.
We haven’t taken into account the cost of building the energy storage system and transmission lines. I estimated an energy cost of 3.41E12 kwh. Spread out over 20 years, the yearly cost is .17E12 kwh.
The last table is based on the tables for wind, PV, and solar thermal and geothermal. We’ll add in another line for storage. It’s the net energy for all the sources together and to get it we use the different E values for each table. To save writing, all the numbers in the table have to be multipled by 1E12 to get the number of kwh.
Net Energy Gain All Sources and Sinks (kwh X 1E-12)
| Period | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 19 |
| Wind | -.084 | 0 | .084 | .168 | .253 | .337 | .421 | .505 | .589 | .674 | 1.52 |
| PV | -.158 | -.095 | -.032 | .032 | .095 | .158 | .221 | .284 | .347 | .411 | 1.04 |
| Geo+ST | -.039 | -.078 | -.118 | -.071 | -.024 | .024 | .0708 | .118 | .165 | .212 | .682 |
| Storage | -.17 | -.17 | -.17 | -.17 | -.17 | -.17 | -.17 | -.17 | -.17 | -.17 | -.17 |
| Total | -.418 | -.343 | -.235 | -.039 | .156 | .352 | .547 | .742 | .938 | 1.133 | 3.072 |
The net energy deficit (or renewables hump) is the sum of all the negatives in the last line of the table, i.e. -1.035E12 kwh. If we also totally electrify our transportation system, the 4E12 kwh per year needed goes up to about 5.3E12 kwh per year. The 1.035E12 energy deficit is increased to 1.37E12 kwh. The worst yearly deficit is in the initial period. It’s about 10 percent of the yearly output of all power plants. To lessen the deficit we can use less electricity (conservation), put off building storage for a few years until more alternative energy is available, put off building PV plants for a few years, or a combination of all 3. We could use conventional plants to supply energy in place of storage in the early stages of the transition. It would be best not to build more conventional power plants since they would emit greenhouse gases. Note also that it’s not necessary to build the same number of power plants every year, as I’ve assumed. There’s many ways to go about the transition and the optimum way cannot be found without trying many scenarios and without having better information.
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http://mdsolar.blogspot.com/2008/01/eroie.html
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http://theenergycollective.com/TheEnergyCollective/51360
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