Archive for January, 2007

Cost of New Electricity – Pt 2/2

Tuesday, January 30th, 2007

MIT has just produced a multi-hundred page book, The Future of Geothermal Energy (in the US), focusing on EGS, enhanced (or engineered) geothermal systems.

Some 50 GW in coal plants will need to be retired (and may be!) in the next 15 – 25 years. (Coal plants produce about 5/6 as much energy/GW as do nuclear plants.)

Their findings:

Geothermal energy from EGS represents a large, indigenous resource that can provide base-load electric power and heat at a level that can have a major impact on the United States, while incurring minimal environmental impacts. With a reasonable investment in R&D, EGS could provide 100 GWe or more of cost-competitive generating capacity in the next 50 years.This achievement could provide performance verification at a commercial scale within a 10- to 15-year period nationwide.

Note: if geothermal power is ramped up to 100 GW over 50 years, it will supply 1/2 wedge — just in the US!

Most US resources are in the West, though the Great Plains and South also have resources. Resource data are scarce for Hawaii and Alaska, but there is optimism about Alaska. Electricity prices are also higher there; in rural areas, it is provided by diesel generators.

Cost data are limited, and future costs are speculative. That said, costs appear to drop below 5 ¢/kWh once capacity is somewhat over 100 MW, and begins to rise again at 1,000 MW (=1 GW), dropping with learning and rising as more expensive resources are exploited. At 100 GW, cost/kWh would be over 7 ¢. Of course, R&D and initial government financing are critical.

Enhanced Geothermal System
Enhanced Geothermal System

A number of estimates exist, more or less in the same ballpark. I will use MIT’s report, The Future of Nuclear Power.

If no changes are made in how US nuclear power plants are built, the base cost will be 6.7¢/kWh, for plants with a 40 year lifetime, 85% capacity factor (fueling plus maintenance 15% of the time), and 5-year construction time. (Actual capacity factor is 90%, which brings the cost down 0.4¢/kWh if that remains true in new plants. After 40 years, costs will presumably go below 2¢/kWh, as they have for today’s plants.)

The cost could be as low as 4.4¢/kWh if capital costs can be cut 1/4, construction time drops to 4 years, and the costs of capital drop to that charged for coal and natural gas plants. Hopefully any optimism about how to lower costs is compensated for by pessimism about capacity factor and lifetime.

Advanced Boiling Water Reactor
Advanced Boiling Water Reactor — 4 are now being built in Japan and Taiwan.

Fossil fuels
I am not providing cost estimates for coal or natural gas power. Natural gas emits carbon dioxide and empowers Russia and the Middle East, another cost. Coal power today emits about twice as much carbon dioxide/kWh and both both coal mining and pollution kill lots of people. Carbon capture and storage is much more expensive than nuclear power, emits 10 – 20% as much GHG as coal does today (so it’s better than natural gas today), but is an important option for countries that insist on using coal power.

Cost of New Electricity — Pt 1/2

Tuesday, January 30th, 2007

I’ve been getting lots of questions on the cost of new electricity. How do costs compare?

Estimates are all over the place. Sierra Club uses various government estimates: coal costs from 4.5 – 5.4¢/kWh, wind from 4.7 – 6.3¢, geothermal 4.8¢, hydroelectric from 4.9 – 8.5¢, natural gas from 5.2 – 6.5¢, biomass from 5.5 – 6.4¢, solar from 12.4¢. Nuclear is priced at 5.9¢/kWh with the Lovins caveat that this includes massive federal subsidies and that without these subsidies, nuclear power could not compete with energy efficiency or renewables. Actually, no energy source can compete with efficiency, up to a point.

Re massive subsidies, it is true that since 1950, nuclear power received twice as many federal incentives (covers a variety of subsidies) as renewables, but since 1976, the federal government has spent more on photovoltaic (PV) – solar panels – R&D alone then all fission research. The second largest recipient is solar thermal (concentrating solar power to run a conventional power plant). We hope that solar (many at the state level, $3.2 billion just for the recent CA million solar roofs program) + wind + geothermal incentives in the next few years pass total current subsidies for nuclear power – but if they do, the subsidies/incentives for these sources will be considerably greater/kWh than for nuclear. If so, should we then reject solar power?

There are other estimates. PV is costed at least 20¢/kWh by Kammen, founding director of the Renewable and Appropriate Energy Laboratory, but believes that it can drop to 10 – 14¢/kWh by 2016. But only if we fund R&D – contact your legislator! Note that R&D is funded at levels considered way too low, on many of the energy sources, and especially improving efficiency.

Wind costs are probably right for the US, though add up to 0.3¢/kWh for intermittency. Capacity factor is lower in Germany, so a German windmill will produce only about three fourths as much energy as American.

The solar and wind costs below come from the International Energy Association book, Renewables for Power Generation- Status & Prospects), unless otherwise indicated.

Costs for grid-connected systems are about $4,500 – 6,000/kW. Installation adds another $5,000 – 9,000/kW. Costs are lower in areas with experience and for new construction. Operation and maintenance adds another 1 – 3%. In good locations, costs may be less than $0.20/kWh. Costs in Germany might be 70% greater than in parts of California, because irradiation in CA is 70% greater.

Costs have been coming down by a factor of two each decade; this could continue for a decade or two, bringing costs down to $3,000 – 4,500/kW for PV as early as 2010 (in 1995 dollars).

One kW of nuclear power in the US produces almost 5 times as much electricity as one kW of PV. In Europe, the ratio is even higher.

Wind Power
Wind installation costs are now about $850 – 950/kW for on-land turbines. The turbine’s share of that is $600 – 800/kW; the rest is civil engineering infrastructure and grid connections. In areas where large-scale wind power is used, the grid must be upgraded at significant costs. Germany expects to spend 3 billion euros by 2020 just for the wind-related grid upgrades. (Today, this is $3.0 billion.) Offshore wind turbines are 35 – 100% more expensive than on-land ones, requiring more expensive infrastructure and grid connections.

Germany expands the grid.
Germany expands the grid.

Operating and maintenance can add another half-cent/kWh to the cost, more for turbines in mountainous regions or offshore.

Wind power is likely to cost 5 – 5.5¢/kWh in the US in large quantities – the price of windmills will drop, but transmission lines and inefficient natural gas backup will raise the price.

One kW of nuclear power produces 3.5 times as much electricity as one kW of wind power in the US, 4.5 times as much in Germany.

The Cost of Wind Power

Tuesday, January 30th, 2007

Wind power is a complicated electricity source to evaluate for cost and GHG emissions. Most current estimates ignore the financial and GHG costs of intermittency.

Analysis by Joseph F. DeCarolis and David W. Keith (2006). The Economics of Large Scale Wind Power in a Carbon Constrained World.

If serious efforts are made to slow climate change, then the US electric sector will likely need to cut CO2 emissions in half within the next quarter century. Despite assertions to the contrary (NREL, 2002; UCS, 2003), wind is unlikely to become a competitive means to achieve reductions in air pollution or to enhance energy security. If air pollution reduction is the goal, then deep reductions in air pollutants can be achieved by retrofits to existing coal facilities at costs of order 1 ¢/kWh (Rubin et al., 1997). If energy security is the driving concern, then for many nations, coal provides sufficient security. The reserve/production ratio for coal is about 200 years globally, and 250 years in the US (BP, 2003).

The electric sector will deliver deeper cuts in GHG than other sectors, because it’s technically easier and because it’s easier to target centralized ownership and management. Reducing GHG emissions is windâ’s main advantage.

Summary first:
At a high GHG tax ($500/metric tonne C, $125/ton carbon dioxide), wind power in 2030 can supply up to 70% of electricity (getting that many windmills up and operating, and grid enhancements, by 2030 would be very hard), at a cost of 5 – 5.5 ¢/kWh. The majority of this will be the cost of dealing with intermittency. Distributing wind power over long distances gets the wind from where it is blowing (Great Plains) to where it is needed and averages it out. It is a better choice for high wind use than CAES (see below).

Changing demand helps. Effective methods include letting utilities reduce electricity to refrigerators (for example) parts of the day, and working with commercial and industrial customers on their energy use pattern on a day-by-day basis.

Demand Response Technology
Demand Response Technology reduces demand at peak use hours. It can also reduce demand on low-wind days.

In 2002, there was over 32 GW wind capacity worldwide, at an average cost from 4 – 6 ¢/kWh at good sites. Within two decades, this price may drop to 2 ¢/kWh. Within a few decades, wind might supply 10 – 20% of electricity regionally or worldwide. Wind resources, however, are mismatched temporarily (wind doesn’t always blow, especially when most needed) and spatially (very windy sites are either popular for recreation or far from transmission lines). National Renewable Energy Laboratory estimates that in the next 50 years, [US?] wind power could reach several hundred GW (1,600 GW wind is needed to supply today’s electricity).

What if the use of wind does increase rapidly enough to provide one third or more of electricity? How much will this cost, and what problems need to be solved?

Several problems. Utility operators need to use a minute-to-minute method to balance electricity made with electricity taken from the grid. Backup capacity must exist to deal with days forecast for slow wind, and there must be some backup capacity capable of dealing with hourly changes in plans. Inefficient fossil fuel plants, and hydroelectric, are the most common backup, as it doesn’t make sense to use costly efficient natural gas plants.

The costs of dealing with intermittency aren’t well known when wind is a major contributor; the Danish and German models don’t apply because those wind plants are part of the European grid. The existence of several types of wind subsidies and other reasons makes wind costs difficult to calculate, but hour-to-hour and minute-to-minute variations add up to 0.3 ¢/kWh to the cost of wind power.

Wind blows a lot of some days, not so much on most days, and many days hardly at all. Intermittency affects cost today because it cuts into reserve power. Handling intermittency is a central issue of ramping wind supply up to high levels.

A second challenge is that the wind either doesn’t blow close to the grid or blows in areas where public opposition is likely. Wind power will have to be schlepped long distances from high quality wind sites. In the US, this means most wind power would be delivered from the Great Plains to the coasts. Wind intermittency is reduced when windmills are extended over several hundred miles. In addition to tangling out regulatory issues, there would be a cost for all those high voltage lines.

Storing Wind Energy
The alternative is storing the energy. There are two ways to store wind energy with low capital costs: pumping water uphill and using it later (limited to a few parts of the US), and compressed air energy storage (CAES, possible over 90% of the US). Other ideas such as batteries, flywheels, capacitors, are too expensive or designed for storage for less than an hour.

Water Power Storage
A large water pump storage power generation station is now under construction near the Kizyou town, Miyazaki Prefecture of Japan.

CAES stores air at 80 times atmospheric pressure in salt caverns, abandoned mines, etc. Excess wind-generated electricity runs the compressor. The compressed air is now available for heating, mixing with natural gas, and burning – the combination uses about half as much natural gas as would be needed if natural gas alone were used. Facilities would have to be much larger than those operating today to supply enough energy over the days of calm that can accompany a heat wave.

Back to long distance transmission
Long distance transmission is a lower GHG emissions option when wind power is significant.

When carbon taxes rise to $140/metric tonne carbon ($35/ton carbon dioxide), wind plus natural gas backup plus transmissions lines can compete as an electricity source. When the tax rises to $500/tC ($125/ton carbon dioxide), CAES makes sense. At several hundred dollars/tC, transmission lines over long distances come in. It does not make sense to use both long distance HV lines and CAES, as some of the benefit of storage is lost. At $500/tC, the cost of wind power is in the 5 – 5.5 cent/kWh range, about 2 cents of which is for the windmill.

An even higher tax does not benefit wind, because so much wind is wasted when the supply exceeds demand, and because backup must be used when there is no wind, no matter how high the cap. So wind will contribute at most 70% of electricity (with the rest natural gas and hydroelectric?).

Editorial comments:
One cent/kWh above today’s costs is fairly cheap.

If 70% of electricity comes from wind power (close to impossible in 2030), and 30% from natural gas, then GHG emissions/kWh in the US (50% coal, 22% petroleum plus natural gas) will decline by three fourths. If I understand this correctly, then this result would be good for 2030, but not for 2050. Where hydroelectric power provides backup, the reduction will be more impressive. (Hydroelectric power may be more problematic in western states in years to come.)

If wind power is less than 70% of the mix, then upgrading the grid won’t be so important — a smaller area will supply the wind power, and wind will supply less than 70% of wind + backup. If natural gas is backup, the reduction in GHG emissions will be less impressive.

In France, switching to wind power would increase GHG emissions.

For a much more optimistic take on wind power, see the link provided in a comment to the post on Socolow wedges.

Germans to End Coal Subsidies by 2018

Monday, January 29th, 2007

Germany, with a population of 82 million, spends more than $3 billion/year subsidizing coal. That’s almost $400/person. From Deutsche Welle,

Government subsidies — not jobs — are to be cut back drastically and may be history as early as 2018.

I don’t know if they can actually promise to not cut jobs.

Krupp Coal Excavator
Krupp Coal Excavator

The excavator,

can excavate 240,000 tons of coal or 240,000 cubic metres of overburden daily – the equivalent of a football field dug to 30 meters (98 ft) deep. The coal produced in one day fills 2400 coal wagons….operation requires 16.56 megawatts of externally supplied electricity.

How Many Wedges Do We Need? — pt. 2/2

Sunday, January 28th, 2007

Socolow-Pacala analyses for different wedges, with some caveats.

Decarbonizing Power (Electricity)
One wedge could be supplied by 700 GW of new nuclear plants with a 90% capacity factor (plus replacing others as they reach the 60 year or so limit on use). This would triple installed capacity (so that the use of nuclear power would rise a little faster than the production of electricity in general). Assuming that the new nuclear power plants are an equal mix of EPR (1.6 GW), ESBWR (1.5 GW), and AP 1000 (1.15 GW), about 10 – 11 new nuclear power plants would be needed per year (plus replacement plants) to achieve this. For comparison, Kansas is planning to build coal plants totaling 2.1 GW, and Texas is considering coal plants totaling 9 GW. [Either the figures for nuclear power are too high or those for wind and solar are too low. If the renewables numbers are valid, then new construction would be closer to 650 GW, or 13 GW/year.]

To get one wedge from wind power, assuming 26% capacity factor (actually 20% in Germany, 27% in US, this will go down if wind power expands to less windy areas), 2400 GW in new wind power must be installed over 50 years, 3100 GW if Germany’s experience is more valid, more if the shift into less windy areas is needed, even more to compensate for the use of inefficient natural gas power plants to even out wind power with a compressed air energy storage system. [I’ve corrected their analysis – either their figures for nuclear power are too high, or their figures for wind and solar are too low.] Windmills erected today are expected to last 20 – 30 years. Unless this improves a lot soon, windmills will need to be built even more rapidly. The current installed wind power is 60 GW, so as much wind power, more or less, needs to be added (plus replacements) each year for the next 50 years, if wind is to supply one wedge.

Wind Farm
Wind Farm Wind power requires hydroelectric or, more commonly, natural gas, backup — most days, wind is considerably below 27% average capacity in the US, 20% average capacity in Germany.

Photovoltaic (solar) power (PV) is assumed to have a 26% capacity factor, higher than estimates for new PV in the US Southwest. For areas of the world further from the equator, such as Europe, the capacity factor will surely be lower. [Again, the analysis includes a mismatch between assumptions for nuclear power and solar.] Current US capacity factor for PV is 19%; assuming that this increases to 30% over 5 decades, then a world average of perhaps 25%? makes sense. Energy payback times are 2 – 5 years, so electricity production must be increased to shift to PV’s. Or to put it differently, with a payback time of 3 years, a PV system lasting 30 years produces only 90% of the electricity apparently produced (from the IEA book, Renewables for Power Generation- Status & Prospects). For one wedge, 2500 GW of PV (lifetime about 30 years) must be installed, more than 2700 GW if energy payback times are counted. The addition (doesn’t count replacement) of PV would average 5 GW/year. The addition will need to equal about 6 times total current installed capacity, or 1.7 times estimated installed capacity for 2010. These numbers look impossible; however, there is considerable optimism about the ability to add solar power, especially at low latitudes. The California Million Solar Roofs Initiative subsidizes PV installation, with a goal of 3 GW by 2017, and anticipates an increase in capacity factor from 18% to 20%. (pdf) Note that installing 3 GW over 12 years is considerably less than the 9 GW of coal power Texas wants to build today. Coal power plants have a capacity factor of 75%, so produce about 4 times as much electricity per installed capacity as does PV. Nuclear has a capacity factor of 90%, so nuclear produces about 5 times the amount of electricity per installed capacity as PV.

PV panels
PV Panels Compare the price of electricity from photovoltaic panels at the site to the retail price of electricity. PV doesn’t have to reach wholesale prices to be cost-effective.

Fuels can be decarbonized using ethanol as it’s made today (ugh), though this method won’t work for airplanes — ethanol energy/volume ratios too low (maybe it’s OK for shorter trips?). Some newer ideas — such as plug-in hybrids – highly fuel-efficient hybrids powered by nuclear power and fueled by cellulosic ethanol – are not even examined.

How Many Wedges Can We Reject?
Given current assumptions on reducing GHG emissions (and next year’s assumptions are not likely to be more optimistic), it seems foolish to reject any wedge. If calculations are incorrect, if solar improvements are slower than expected, or wind more problematic, if there are changes in climate that reduce the effectiveness of installed PV or wind systems, if increased carbon dioxide levels in the atmosphere and changes in the climate reduce the productivity of crops for biofuels, if desalination becomes an important and heretofore uncounted demand on electricity systems, if the necessary rate of GHG emissions reduction is determined to be faster than currently predicted, the costs of optimism could be catastrophic.

Arguments that we should reject any of these wedges usually fall into two categories. The first is that, just in case climate scientists are overly pessimistic, perhaps we should go slow. After all, there will be costs to change. Most analyses show that erring on the side of more GHG reductions is likely to be cheaper.

The second argument is, not nuclear. To be convincing, the anti-nuclear people should demonstrate that nuclear power is really bad, on the same level as climate change, or direct deaths from using coal or natural gas, and that solutions can exclude coal, natural gas, and nuclear with plenty of room for error.

There are other issues besides climate change. Solutions that depend disproportionately on natural gas make American hunters unhappy and give disproportionate economic and political power to Russia and the Middle East. Shifting to nuclear powered plug-in hybrids more rather than less rapidly will decrease the power of oil producers. Fossil fuels pollute and are dangerous to workers and the environment.

Not sure how the energy sources compare in terms of health and the environment? Take a quiz to test your knowledge.

How Many Wedges Do We Need? pt. 1/2

Thursday, January 25th, 2007

Updated the number of wedges 3/08

Socolow Wedge
Socolow Wedge

The term solution is often reserved today for technologies or policies that can be implemented immediately, and ramped up over 50 years to save 1 gTC/year in the 50th year (1 billion metric tonnes carbon, about 3.7 metric tonnes carbon dioxide, about 4 tons carbon dioxide). Over 50 years, 25 gTC (92 gTCO2) will be kept out of the atmosphere. Possible future methods (fuel cells, fusion power) of reducing GHG emissions, and smaller contributions from current technologies (wave motion) may help, but they are currently getting less attention.

Articles on solutions often refer to the seven wedges needed to stabilize greenhouse gas emissions by 2050 (first referred to in the Pacala-Socolow article in Science, subscription needed). However, most analyses in the climate community indicate that lower emissions targets are crucial. The California goal is to reduce GHG emissions to 80% below 1990 levels.

While the number of 7 wedges to stabilize is widely cited, the underlying assumptions are not. Pacala and Socolow look only at carbon dioxide emissions (so they exclude deforestation, for example) and concrete, ignoring all other greenhouse gases. They assume 1.5% increase/year while Intergovernmental Panel on Climate Change Working Group 3 (Mitigation) reports assumptions of 1.1% to 2.5% increase/year between now and 2030, with more recent assumptions higher.

Biological and other feedback mechanisms have not been counted: a changing climate produces positive feedback. Darker plants grow in warmer climate, absorbing more of the sun’s energy; lianas (vines) replace trees (more carbon added to atmosphere); decreased carbon storage in the soil; a reduced carbon uptake by the ocean — allocate a portion of a wedge, or more, to compensate for positive feedback.

IPCC doesn’t use wedges, and no one looks at any plans that lead to stabilization beginning this year. To simplify the matter, suppose we do introduce as many wedges as are needed this year, and reduce GHG linearly over the next 50 years, to 80% below 2008 levels, assuming a 2%/year increase from 2004.

CO2 emitted (doesn’t count deforestation) plus concrete:
integrate 26e^0.02t from year 4 to year 54, because it’s already 4 years after 2004: total = 2,420 gT CO2

Linear decrease from 2008 to 2058 from 26 gT CO2 to 80% lower:
50*[1/2*(26 + 20%*26)] = 780 gT CO2

To keep 2,420 – 780 = 1640 gT CO2 out of atmosphere:
1640 gT/92 gT/wedge = 18 wedges

The assumptions for the calculations are too simple. Other analyses assumes that GHG will continue to rise until 2000-2015, and then fall more rapidly. If 2000 is assumed to be the year of peak emissions, then more wedges are needed, if 2015, fewer. The assumption in World Energy Outlook 2004 is a 1.7% yearly increase in CO2 for the reference scenario, less than 2%, which in turn is less than the highest estimates. If the rate of increase in carbon dioxide due to business as usual is larger than 2%, or the rate of emissions reduction desired is more rapid, even more wedges will be needed. The opposite is true as well. More wedges are needed to achieve an 80% reduction by 2050, compared to 2058. BAU assumptions after 2030 differ.

Even faster reductions would lower the risk of catastrophic sea level rise, and reduce overall harm from climate change. After 2050, the goal is to zero out carbon emissions to protect the ocean, though many marine experts would like to see much more rapid decreases in carbon emissions.

Inez Fung
Inez Fung is among those worried that the “breathing biosphere” may be overwhelmed, and that as the climate warms, ocean mixing slows, reducing ocean absorption of carbon dioxide.

The Carbon Mitigation Institute posts Socolow-Pacala analyses for different wedges.

According to their information (with caveats provided by me), how easy is it to get to 18 wedges? Some double counting occurs: we can reduce emissions from driving by one half either by driving half as much, or reducing the greenhouse gas intensity by half. Doing both does not reduce GHG emissions by 100%.

The largest number of wedges, and immediately the cheapest (they can be done at negative cost, up to a point), are from improved efficiency. An IPCC paper estimates that 2 wedges could come from improvements in buildings (perhaps more?); these include either voluntary or mandated easy behavior changes, such as better building design, retrofitted changes to current stock, improved appliances, changing light bulbs from incandescent, etc. Doubling fuel economy of light duty vehicles from 30 to 60 mpg could produce one wedge savings. Reducing average car use from 10,000 miles/year by half could also produce a wedge. Living in smaller, colder or warmer, darker housing is not evaluated, but I would suspect that there will be a shift to more apartments in larger cities. Perhaps mandates on temperatures in public buildings could lead to changed temperatures in private ones.

Will more bicyclists and pedestrians be part of a wedge?

Biological and Geological Sequestration
Deforestation and afforestation could provide a wedge – decrease current deforestation to zero and add quite a bit of forest. Conservation tillage could help. Some of this analysis may be based on older more optimistic calculations. More efficient coal plants or/and long-term storage (geological sequestration) of the carbon emissions can help.

Deforestation of the African Rainforest

to be continued….

Anti-Nuclear Power and Pro-Fossil Fuels

Monday, January 22nd, 2007

Back when I began looking at energy issues and discovered I was so wrong on nuclear power, I looked into why people dislike nuclear power. Many reasons were given.

See Wikipedia’s summary on how the public does risk analysis -“ one interesting result from the surveys of Slovic, et al (eg, Perceived Risk: Psychological Factors and Social Implications [and Discussion]) is how non-experts rate risk – they consider nuclear power the riskiest activity in spite of considering it safer than food coloring in normal years and safer than automobile accidents in disaster years. Not only do non-experts not know how safe or unsafe various activities are, perceptions of risk do not correlate with perceptions of danger. More frequent nuclear power plant accidents might even lead to a lower perceived sense of risk.

Of the half dozen or more explanations I read a decade ago, the one I gave least credence to at the time was coal company influence. Yes, coal and oil companies provide talking points on climate change, talking points adopted by substantial numbers with no connection to coal interests. But I had never heard of them providing anti-nuclear information – mainstream environmentalists do this without help.

They don’t have to buy talking points; they have another method. Fossil fuel interests buy politicians, in the US, Australia, and Germany.

NNadir at Daily Kos discusses former German Chancellor Gerard Schroeder, from the left of center Social Democratic Party, in Bait and Switch: German Nuclear Phase Out, Renewables, Coal and Carbon Dioxide:

In case you’re wondering about what Gerhard Schroeder is doing now that he’s left politics, one of his new jobs is as a Member of the Supervisory Board of Gazprom, the Russian natural gas conglomerate, a conglomerate that benefited by Schroeder’s policies, in particular with respect to the European Baltic gas pipeline.

We Support Lee has posted A Directory of Posts that Link Anti-Nuclear Interests with Fossil Fuel Interests.

Anti-nuclear, pro-fossil fuel policies and politicians from Australia, Germany, Wisconsin, Maine, and Texas are among those included. The intention of SPD and green politicians in Germany to continue closing nuclear plants, replace them with fossil fuel plants, and oppose strict greenhouse gas emissions reductions makes me curious about German Greens.

Relative Dangers of Energy Sources

Thursday, January 11th, 2007

Which energy sources are the most dangerous? Which cost the most lives every year/kWh? Which have the highest risk of costing lives in the future.

Test your knowledge of the dangers – from mining to accidents to waste – from various energy sources. Then return to this blog to share your thinking.

Oil is rarely used to make electricity in the industrialized world. But there are proposals that coal or/and nuclear power be used to replace oil in plug-in hybrids. Would we benefit?

Score 13 – 14 — your knowledge is excellent!
Score 11 – 12 — you still score considerably above average
Score 10 — still above average
Score 9 or fewer — um, are you getting your information from the sources I once used?

Some time in the next month or two, I want to follow up with a blog discussion on spiritual dimensions of policy choices, and behavior choices.

Update: Also see Nuclear Power in a Warming World

Has Weather Changed Where You Live?

Tuesday, January 9th, 2007

RealClimate’s post on El Nino, Global Warming, and Anomalous U.S. Winter Warmth has led to people all over the world writing in to say, geez, do you know what we’re seeing here?

Tulips in Vaasa, Finland. Brussel’s temperature is 8 C* above normal. Colorado’s snow is not counterevidence because snow increases as temperature goes up, if still below freezing (warmer air can hold more moisture).

Berkeley saw a few freezing nights, or close — not good for some of the local flora. Of course, one prediction of climate change models is more extremes.

*Multiply degree C by 1.8 to get degree F.

Carbon-Negative Biofuels

Sunday, January 7th, 2007

A study described in the December 8 Science magazine found that a low-input (you water it when you plant) high-diversity mixture of native grassland perennials can produce net greenhouse gas savings.

Biofuels, plants used for fuels such as ethanol or biodiesel, are generally considered greenhouse gas neutral if the carbon dioxide taken in equals the carbon dioxide released when the fuel is burned, or more commonly, as a greenhouse gas source because fuels require energy for planting, production, etc. Even under the best circumstances, some energy (which could come from the plants) is needed to produce fuels, and some energy to transport them.

Worldwide, there are some 1,200 million acres (500 million hectares) in abandoned degraded farmland. Tilman, et al, grew from 1 – 16 species/plot on “agriculturally degraded and abandoned nitrogen-poor sandy soil” and examined energy produced/acre and carbon dioxide stored in the soil/acre. Increasing the number of species/plot (up to 16) increased both the energy produced and the rate carbon dioxide was stored. For 16 species, the amount of carbon stored is greater than the amount produced in making and transporting the biofuels.

This method could produce fuel equivalent to 13% of today’s petroleum, plus 19% of today’s electricity (above that needed to produce the fuels?) The use of degraded land would also initially store about 4 metric tonnes carbon per hectare per year for the first decade, 2.7 – 3 metric tonnes carbon for subsequent decades. [Note: The amount of carbon the soil can hold is expected to go down as temperatures increase.]

There are serious questions about using good farmland for fuels when the need for food and fiber are increasing along with the population and per capita consumption. But biofuels grown this way could be a financial incentive to restore damaged land, and reduce greenhouse gas emissions. Sounds like a win-win.

Grass mixture including switchgrass
Grass mixture including switchgrass

The 2030 Challenge

Thursday, January 4th, 2007

From the Energy Star site:

The American Institute of Architects Board of Directors and US Conference of Majors adopted the 2030 Challenge that call for a 50 percent reduction of fossil fuel used to construct and operate buildings by the year 2010, with the target of carbon neutrality by 2030. These aggressive goals align well with the ENERGY STAR core mission to reduce energy use in commercial buildings and prevent CO2 emissions.

From the 2030 °Challenge site:

Stabilizing emissions in this [building] sector and then reversing them to acceptable levels is key to keeping global warming to approximately a degree centigrade (°C) above today’s level.

To accomplish this we are issuing the 2030 Challenge asking the global architecture and building community to adopt the following targets:

That all new buildings, developments and major renovations be designed to meet a fossil fuel energy consumption performance standard of 50% of the regional (or country) average for that building type.

That at a minimum, an equal amount of existing building area be renovated annually to use 50% of the amount of fossil fuel energy they are currently consuming (50% of the regional average through innovative design strategies, the application of renewable technologies and/or the purchase (1/5 maximum) of renewable energy).

That the fossil fuel reduction standard for all new buildings be increased to:

60% in 2010
70% in 2015
80% in 2020
90% in 2025
Carbon-neutral by 2030 (using no fossil fuel GHG emitting energy to operate).

US GHG emissions contribution from buildings is 38%; world contribution is 48%. California building sector contributes less than the transportation sector.

Heat Loss Analysis
Heat Loss Analysis

How Do Life-Cycle Greenhouse Gas Emissions of Electricity Sources Compare?

Wednesday, January 3rd, 2007

Nuclear, wind, and solar power emit no greenhouse gases (GHG) when operating, but there are life-cycle emissions, in mining and refining uranium, building aluminum frames for photovoltaic (solar) panels, and manufacturing concrete and steel for wind and nuclear power. A life-cycle analysis looks at all of the costs from getting the fuel, construction and decommissioning, transportation, and operation.

Several analyses exist, you can go here to see others. Solar GHG emissions are dropping as technology improves (also true for other electricity sources).

GHG emissions from electricity production
Greenhouse gas emissions from electricity production

If nuclear electricity (rather than coal electricity) is used for uranium enrichment, nuclear life-cycle emissions drop further.

Wind, solar, and nuclear are the major remaining low GHG sources of electricity, as there are few expansion possibilities for hydroelectric.


For some sources of energy, the major GHG emissions occur in building the plants.

From Per Peterson at UC, Berkeley: Current and Future Activities For Nuclear Energy in the United States:

• Nuclear: 1970’s vintage PWR, 90% capacity factor, 60 year life
— 40 MT steel/MW (average)
— 190 m3 concrete/MW (average)
• Wind: 1990’s vintage, 6.4 m/s average wind speed, 25% capacity factor, 15 year life
— 460 MT steel/MW (average)
— 870 m3 concrete/MW (average)
• Coal: 78% capacity factor, 30 year life
— 98 MT steel/MW (average)
— 160 m3 concrete/MW (average)
• Natural Gas Combined Cycle: 75% capacity factor, 30 year life
— 3.3 MT steel/MW (average)
— 27 m3 concrete/MW (average)

[MT = million metric tonne]

Concrete + steel are >95% of construction inputs, and become more expensive in a carbon-constrained economy.

Because nuclear power operates at 90% capacity, 1 MW/0.9 (1.1 MW) of installed capacity is needed to produce 1 MW power. Similarly for wind, installed capacity must be 1 MW/0.25 (4 MW) to average 1 MW power.

Wind plus natural gas (or other backup power plants) requires natural gas plants to be built. These do not add much GHG compared to the GHG emissions in windmill construction; they are, however, expensive.

For an example of a photovoltaic (solar panel) GHG analysis, see Life Cycle Energy Consumption and GHG Emissions of a Field PV Plant (pdf).

Carbon Capture and Storage

CCS gasifies coal and burns the products in oxygen rather than air, so only 1/5 as much waste gas is produced.

According to Accounting Rules for CO2 Capture and Storage (pdf), more CO2 is stored than would have been emitted without CCS, because so much extra energy is required for the process, about 40%. If only the upstream emissions still exist, GHG emissions from coal would be reduced to between 250 and 430 g CO2/kWh, 40% more than upstreams emissions for current coal use, to account for the extra energy required. This reduces coal GHG emissions below those from natural gas.

Update Some of the upstream costs from coal come from the current mix for electricity, some from natural gas escaping to the atmosphere during coal mining, some other. Reducing fugitive emissions from natural gas and switching to electricity produced by CCS will reduce upstream emissions for coal.