Chapter 1: Zero... Chapter 1: Net-Carbon Renewable Energy System Feasibility
article: Chapter 1: Net-Carbon Renewable Energy System Feasibility
Chapter 1: Zero-Net-Carbon Renewable Energy System Feasibility
Draft date: February 7, 2008
--By Richard Lance Christie--
Author's note: This is a preliminary draft and a work in progress. (Further explanation.)
Introduction
Vaclav Smil argues in his books that the minimum energy requirement for a civilized lifestyle is a net 2 kilowatts per person. Currently, each U.S. citizen uses a net 9 kilowatts. Two kilowatts apiece for 9 billion people would require world energy production increase 30 percent above that achieved in 2000.
In 1987, the World Commission on Environment and Development, Our Common Future, found that “Properly managed, efficiency measures could allow industrial nations to stabilize their primary energy consumption by the turn of the century.” This referred to the year 2000, not 2100.
Bill McKibben writes: “Energy has become, in short order, the central environmental question, the central foreign policy question, and the central economic question.”
Zero-Carbon Renewable Energy Production Capacity Assessments
Renewable Energy Can Be Fifty Percent of Total U.S. Energy Supply by 2025
According to the U.S. Energy Information Administration, the U.S. generated more than 55 Mwh of renewable energy in 2005, or about 1.5 percent of total U.S. energy production.
On November 30, 2006, 450 renewable energy policy, financial, and technology leaders attending the 5th national policy conference, “Renewable Energy in America: Phase II Market Forecasts and Policy Requirements” in Washington, D.C., announced their collective future deliverable renewable energy capacity to be 550 to 700 gigawatts by the year 2025. This assessment was an evaluative response to the “25x25" policy goal of producing 25 percent of U.S. energy from renewable sources by the year 2025. The industry panel projection of an achievable capacity ranging from a low of 550 gigawatts represents a 50 percent overshoot of the “25x25" policy goal by 2025 as the worst-case scenario. In other words, using off-the-shelf and late-stage developing renewable energy technologies, the U.S. can certainly generate 25 percent, and possibly as much as 40 percent of all its energy needs from renewables by 2025 if the investment is made to install this generating capacity. Conference presentations may be accessed at:
www.acore.org/programs/06policy.php
Section 2: 2004 Pacala and Socolow:
Greenhouse Gas Emissions Can Be Stabilized Now with “Silver Buckshot” Portfolio
Princton’s Dr. Stephen Pacala and colleage Dr. Robert Socolow demonstrated in a 2004 Science article that it is possible to stabilize greenhouse gas emissions now with what they called “silver buckshot:” a portfolio of existing technologies such as solar and wind energy, along with reduced deforestation and increased energy efficiency. To compare options, Pacala and Socolow created a common unit called a “stabilization wedge” which represents 25 billion tons of greenhouse gas emissions avoided over 50 years.
Section 3: 2007 American Solar Energy Society Report
The Phase II conference forecasts are consistent with the American Solar Energy Society’s projection that renewable energy can more than offset the 1.1 to 1.3 billion tons of carbon emissions required per year by 2030 in order to limit the effects of solar warming. The ASES’s report can be accessed at
[Supply link]
Greenpeace and the European Renewable Energy Council commissioned a study by German Aerospace: Energy Revolution: A Blueprint for Solving Global Warming. The study concludes that 80 percent of the world’s energy can be produced from renewable sources with currently available energy technology, resulting in a 50 percent reduction of carbon dioxide emissions globally and a 72 percent reduction in the United States.
Section 5: 2007 Institute for Energy and Environmental Research Study:
A zero-carbon dioxide U.S. economy can be achieved in 50 years without nuclear power
In August 2007 the Institute for Energy and Environmental Research (IEER) published their executive summary of a study to be published as a book in October, 2007, as a special issue of Science and Democratic Action, Volume 15(1) <www.ieer.org/sdafiles/15-1.pdf>. The central finding of Carbon-Free and Nuclear-Free: A Roadmap for U.S. Energy Policy is “...that a zero-CO2 U.S. economy can be achieved within the next thirty to fifty years without the use of nuclear power and without acquiring carbon credits from other countries. In other words, actual physical emissions of CO2 from the energy sector can be eliminated with technologies that are now available or foreseeable. This can be done at reasonable cost while creating a much more secure energy supply than at present. Net U.S. oil imports can be eliminated in about 25 years. All three insecurities - severe climate disruption, oil supply and price insecurity, and nuclear proliferation via commercial nuclear energy - will thereby be addressed. In addition, there will be large ancillary health benefits from the elimination of most regional and local air pollution, such as high ozone and particulate levels in cities, which is due to fossil fuel combustion.”
IEER observes that reducing U.S. CO2 emissions by 80 percent from 2000 levels by 2050 would still leave U.S. emissions at about 2.8 metric tons per person. If other nations were able to increase their CO2 emissions per person to match this 80-percent-reduced U.S. level, the total world CO2 emissions would be roughly the same as in 2000. Thus, “A U.S. goal of zero-CO2, defined as being a few percent on either side of zero relative to 2000, is both necessary and prudent for the protection of global climate. It is also achievable at reasonable cost.”
The IEER report contains two novel sections which make it a working “blueprint” for achieving a zero-CO2 economy without nuclear power. The first is a set of twelve policy recommendations for the U.S., and the second is a detailed description of all the energy production and storage elements of the national zero-CO2 energy grid and how much each would contribute towards meeting total U.S. energy needs.
1. (1) Enact a physical limit of CO2 emissions for all large users of fossil fuels (a “hard cap”) that steadily declines to zero prior to 2060, with the time schedule being assessed periodically for tightening according to climate, technological, and economic developments. The cap should be set at the level of some year prior to 2007 so that early implementers of CO2 reductions benefit from the setting of the cap. Emission allowances would be sold by the U.S. government for use in the U.S. only. There would be no free allowances, no offsets and no international sale or purchase of CO2 allowances. The estimated government revenues of $30-50 billion a year would be used for demonstration projects, research and development, and worker and community transition. IEER defines “large user” as one who uses more than 100 billion Btu per annum; this would cover about two-thirds of total U.S. fossil fuel use.
2. (2) Eliminate all subsidies and tax breaks for fossil fuels and nuclear power, including guarantees for nuclear waste disposal from new nuclear plants, loan guarantees, and subsidized insurance.
3. (3) Elminate subsidies for biofuels from food crops.
4. (4) Build demonstration plants for key supply technologies, including central station solar thermal with heat storage, large- and intermediate-scale solar photovoltaics, and CO2 capture in microalgae for liquid fuel production.
5. (5) Leverage federal, state and local purchasing power to create markets for critical advanced technologies, including plug-in hybrids.
6. (6) Ban new coal-fired power plants that do not have carbon storage.
7. (7) Enact at the federal level high efficiency standards for appliances.
8. (8) Enact stringent building efficiency standards at the state and local levels, with federal incentives to adopt them.
9. (9) Enact stringent efficiency standards for vehicles and make plug-in hybrids the standard U.S. government vehicle by 2015.
10. (10) Put in place federal contracting procedures to reward early adoptors of CO2 reductions.
11. (11) Adopt rigorous research, development, and pilot plant construction programs for technologies that could accelerate the elimination of CO2, such as direct solar hydrogen production (photosynthetic, photoelectrochemical, and other approaches), hot rock geothermal power, and integrated gasification combined cycle plants using biomass with a capacity to sequester the CO2.
12. (12) Establish a standing committee on Energy and Climate under the U.S. Environmental Protection Agency’s Science Advisory Board.
To deal with the problem of renewable energy intermittency, IEER first talks about integration of different forms of production (e.g., solar, wind, hydroelectric, geothermal, natural gas as standby), then about storage - which is where the IEER report gets creative relative to previous efforts. Surplus renewable energy production could be stored in (1) compressed air; (2) solar thermal energy storage; (3) nanotechnology-based lithium ion batteries now being produced commercially by Altairnano which can be deep discharged 10,000-15,000 times versus the 2,000 deep dischage capacity needed over the life of a plug-in hybrid. IEER proposes that hybrid cars be used as the electrical storage medium in a vehicle-to-grid system (V2G): parked cars would be connected to the grid and charged and discharged according to the state of requirements of the grid and the charge of the vehicle battery. Communications technology to accomplish this via wires or wireless means is already commercial.
Thus, standby power to deal with intermittency of renewable sources in the mature renewables-based, zero-CO2 U.S. energy system would be supplied by stationary storage, the V2G system, combined cycle power plants fueled by biomass, thermal storage in central station solar thermal power plants, hydropower, and compressed air storage in the combined cycle power plants.
According to IEER’s calculations, “Complete elimination of CO2 could occur as early as 2040. Elimination of nuclear power could also occur in that time frame.” Such early elimination is contingent on technological breakthroughs in solar hyrogen production and in rapid implementation of the V2G hybrid-car-based storage system. Otherwise, zero CO2 emissions and elimination of nuclear power from the U.S. energy production system would take until 2060 to achieve.
Energy efficiency plays a major role in the IEER design. “The use of highly efficient design technologies and building design, generally available today, can greatly ease the transition to a zero-CO2 economy and reduce its cost. A two percent annual increase in efficiency per unit of Gross Domestic Product relative to recent trends would result in a one percent decline in energy use per year, while providing three percent GDP annual growth. This is well within the capacity of available technological performance....For instance, residential and commercial buildings can be built with just one-third to one-tenth of the present-day average use per square foot with existing technology.”
Instead of using food crops for biofuel production, “...biomass that has high efficiency solar energy capture (~ five percent), such as microalgae gorwn in a high-CO2 environment, can form a large part of the energy supply both for electricity production and for providing liquid and gaseous fuels for transport and industry. Microalgae have been demonstrated to capture over 80 percent of the daytime CO2 emissions from power plants and can be used to produce up to 10,000 gallons of liquid fuel per acre per year. Some aquatic plants, such as water hyacinths, have similar efficiency of solar energy capture and can be grown in wastewater as part of combined water treatment and energy production systems.” Five percent solar capture is about ten times that of a corn plant, including both the grain and crop residues.
The IEER list of supply and storage technologies and their probable implementation dates for the U.S. energy system is:
• Solar PV - intermediate-scale 2010 to 2015
• Solar PV - large-scale 2015 to 2020
• Concentrating solar thermal power plants 2015 to 2020
• Microalgae CO2 capture and liquid fuel production 2015
• Wind power - large-scale, land-based Already being used
• Solar PV - intermediate storage ~2020
• Solar PV - intermediate scale with vehicle-to-grid ~2020 to 2025
• Biomass IGCC ~2020
• High solar energy capture aquatic biomass ~2020
• Hot rock geothermal energy 2025?
• Wave energy 2020 or 2025?
• Photolytic hydrogen 2020 or 2025?
• Photoelectro-chemical hydrogen 2020 or 2025?
• Advanced batteries (nanotech lithium ion) 2015
• Carbon sequestration Unk: 15-20 years?
• Ultracapacitors (commercial in certain apps now) 2 015-2020?
• Nanocapacitors (not developed yet - lab testing) Unknown
• Electrolytic hydrogen production (in certain apps now) Unknown - infrastructure
The next table in the IEER report consists of a list of demand side technologies such as plug-in hybrid vehicles and geothermal heat pumps, with the date IEER estimates they are deployable for large-scale use. Deployment of these demand-side technologies increases the efficiency of energy use, and thus represent components of the national conservation of energy strategy. The IEER report also provides an analysis of the costs of CO2 abatement from various energy sources in terms of their cost per metric ton of CO2 abated from pulverized coal-fired electricity generation.
IEER then demonstrates their “reasonable cost” hypothesis with the following table:
Item IEER Scenario Business-as-Usual
All figures combine residential and commercial applications. Business-as-usual uses fuel and electricity prices from January 2006 of about $12 per million Btu and 9.6 cents per kWh. IEER prices are $20 per million Btu and 14 cents per kWh from its supply and storage technology system, powering the more efficient national system of deployed demand-side technologies. Note this is very conservative: the comparison assumes that energy from current fossil fuel and nuclear sources would cost the same per Btu and kWh in 2050 as they did in 2006!
Added efficiency estimates: existing residences = $20,000 per residence each time, assumed to occur in one of every three sales of existing buildings between 2010 and 2050; new = $10 per square foot to attain Leadership in Energy and Environmental Design (LEED) building certification standards. Also included is the cost of replacing appliances every 15 years with then-prevailing advanced appliances. Investments for solar thermal heating, combined heat and power, and geothermal heat pumps are added to the figures in proportion to the residential square footage using them. Commercial efficiency investment is estimated at $10 per square foot which is more than the amount needed to attain the highest LEED “platinum” standards due to additional investments for solar thermal heating, combined heat and power systems, and geothermal heat pumps being assumed.
The IEER report contains two tables which show the source for delivered energy between 2005 and 2050 (natural gas, petroleum, coal, biofuels, solar thermal, electricity, and efficiency) in Quadrillions of Btu, and then the source of the electricity component in billions of kWh from coal, natural gas, oil, nuclear, hydropower, geothermal+wood waste+landfill gas, solid biomass, biomass-derived gas, geothermal hot rock, wind, solar PV central station and intermediate, solar PV small scale, solar thermal & other, and combined heat and power systems from 2005 to 2050. In the former table, natural gas, petroleum and coal all drop to zero by 2050; in 2050 efficiency accounts for about half of the delivered Btu, electricity for about 8 percent, solar thermal for about 3 percent, with the rest of delivered Btu shown as being from biofuels. In the latter table, coal, natural gas, oil, and nuclear all drop to zero by 2050; hydropower’s kWh contribution is about constant, geothermal grows only slightly, while the rest of these sources expand to account for a total production of roughly 3750 billion kWh among them to meet a total national electricity demand projected at roughly 4300 billion kWh in 2050.
The McKinsey and Company report, “Reducing U.S. Greenhouse Gas Emissions: How Much at What Cost?” was released in December, 2007. McKinsey is a private investment analysis firm commissioned by a coalition of corporations and conservation groups including Royal Dutch Shell, Pacific Gas and Electric, the Natural Resources Defense Council, and Environmental Defense, to analyze the economic cost feasibility of attaining various levels of anthropogenic greenhouse gas abatement. McKinsey found it will only cost a few billion dollars net to achieve a 3.5-4 gigaton cut in U.S. greenhouse gas emissions by 2030. Overall mitigation costs under the most stringent cut scenario still averaged less than $50 per ton of greenhouse gas emission reduction. Eighty percent of the greenhouse gas abatement they describe in their financial models was achieved using technologies available today on a commercial scale; the other twenty percent was achieved using technologies in late-stage commercial development such as cellulostic alcohol and plug-in hybrid vehicles.
In the section which breaks out “clusters of abatement potential,” McKinsey clusters are: buildings and appliances, transportation, industry, carbon sinks, and power [generation].
- Improving energy efficiency in buildings and appliances can produce 710 (midrange) to 870 (high-range) megatons of abatement.
• Increasing fuel efficiency in vehicles and reducing the carbon-intensity of transportation fuels can produce between 340 and 660 megatons (same ranges) abatement. McKinsey notes that, “Though the savings from fuel efficiency may offset the incremental cost of the abatement option over a vehicle’s 12- to 15-year lifecycle, these options require up-front investment by automakers and thus higher vehicle costs for consumers. Lower-carbon fuels, such as cellulostic biofuels, could abate 100 megatons to 370 megatons of emissions, though this potential is highly dependent on innovation rates and near-term commercialization of these technologies. Plug-in hybrid vehicles offer longer-term potential if vehicle cost/performance improves and the nation moves to a lower-carbon electricity supply.”
- Pursuing various options across energy-intensive portions of the industrial sector can produce 620 to 770 megatons (mid and high range) abatement. “Despite offering direct bottom-line benefit, these options must compete for capital and, without clear incentives to control GHG emissions, may not receive funding.”
- Expanding and enhancing carbon sinks can abate 440 megatons (mid-range) to 590 megatons (high-range). “Increasing forest stocks and improving soil management practices are relatively low-cost options.”
- Reducing the carbon intensity of electric power production can abate 800 megatons (mid-range) to 1,570 megatons (high-range). “This potential derives from a shift toward renewable energy sources (primarily wind and solar), additional nuclear capacity, improved efficiency of power plants, and eventual use of carbon capture and storage (CSS) technologies on coal-fired electricity generation. Options in the power plant sector were among the most capital-intensive ones evaluated. These options also tend to have the longest lead times, given bottlenecks in permitting, materials and equipment manufacturing, and design, engineering, and construction.”
McKinsey points out the theme of greater “energy productivity” that “pervades these clusters.” “Improving energy efficiency in the buildings-and-appliances and industrial sectors, for example, could...offset some 85 percent of the projected incremental demand for energy by 2030, largely negating the need for the incremental coal-fired power plants assumed in the government reference case. Similarly, improved vehicle efficiency could roughly offset the added mobility-related emissions of a growing population, while providing net economic gains.”
McKinsey advocates that a comprehensive greenhouse gas abatement program for the U.S. should proceed quickly, using a portfolio of strong, coordinated policies to capture GHG reductions efficiently across industry sectors and geographies, accelerating development of a low-carbon energy infrastructure. Among the portfolio of strong, coordinated policies McKinsey lists:
- Visible, sustained [market] signals to create greater certainty about the price of carbon and/or required emissions reductions; this will help encourage investment in options with long lead times and/or lifecycles.
- A coordinated economy-wide abatement program or set of programs. Because abatement options are highly fragmented and widely distributed across sectors and geographies, any approach that does not simultaneously unleash a full range of abatement options risks missing proposed 2030 reduction targets and/or driving up total cost to the economy.
- Exchange mechanisms (e.g., trading schemes, offsets, tax credits) to create fungibility across fragmented markets, create greater market transparency, and drive least-cost solutions.
The McKinsey report concludes: “This project evaluated the costs and potentials of more than 250 abatement options available in the U.S. We did not examine economy-wide effects associated with abating greenhouse gases, such as shifts in employment, impact on existing or new industries, or changes in the global competitiveness of U.S. businesses. The project did not attempt to assess the benefits to society from reducing global warming. The report also did not attempt to address other societal benefits from abatement efforts, such as improved public health from reducing atmospheric pollution or improving national energy security.”
From other sources, I think the bulk of the evidence supports the expectation that shifting to a renewables-based, GHG-abating energy economy in the U.S. would create more and better-paying jobs than were lost, improve global competitiveness of U.S. businesses in an international economic environment which is scaling back GHG emissions, improve public health due to air and water quality improvements; and greatly improve national security and the national economy through shift from imported fossil fuel energy sources which have adverse effect on balance of trade deficits and are subject to disruption due to international political instability or hostility, to domestically-produced renewable sources which are not subject to foreign disruption and recycle dollars spent on them in the domestic economy.
Section 7: Why Build the Alternative Energy System Now?
Robert Kaufmann said in WorldWatch January/February 2006: “If the infrastructure for the alternative energy source is put in place before the peak arrives, the energy used to do so will have a relatively small impact on non-energy sectors. Conversely, if society waits until the peak, constructing the large infrastructure for the alternative fuel will siphon large amounts of energy from the non-energy sectors of the economy at the very time that the total supply and energy surplus from oil is shrinking. In short, society has to pay the costs for the transition. We can pay them now, while we have oil in the bank, or we can pay them later, when our oil bank account is emptying.”
In a December 4, 2007 article in the U.K. Guardian, George Monbiot illustrated why much larger cuts in greenhouse gas emissions than had been discussed would be necessary to prevent global warming from exceeding 2 degrees Centigrade. He starts with the IPCC table that shows the world needs to cut total emissions of greenhouse gases to roughly 15 percent of the volume emitted in 2000 by the year 2050 to prevent warming exceeding 2 degrees Celsius. Monbiot looked up the global figure for carbon dioxide production in 2000 and divided it by the current population, resulting in a “baseline” figure of 3.58 tonnes of CO2 per person. An 85 percent cut if population remained constant results in a global output per person budget of 0.537 tonnes by 2050. The UK currently produces 9.6 tonnes and the US 23.6 tonnes per person. Reducing these figures to 0.537 tonnes by 2050 requires a 94.4 percent cut in the UK and a 97.7 percent cut in the US. If world population rises to 9 billion in 2050 as UN projections assert, the cuts needed to reach total emissions goals rise to 95.9 percent in the UK and 98.3 percent in the US. Monbiot then points out that 18 percent of global warming currently is accounted for by greenhouse gas emitted by “feedbacks” - warming accelerating natural release of greenhouse gases from forests, peat bogs, and the like. In order to compensate for these emissions which are not subject to human control, “to stabilise temperatures at 1.5 degrees above the pre-industrial level requires a global cut of 100%. The diplomats who started talks at Bali yesterday should be discussing the complete decarbonisation of the global economy.” Monbiot goes on to demonstrate why this is not impossible, since you can run almost the entire energy system on renewable power that does not emit greenhouse gases.
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