The relative contribution of waste heat from power plants to global warming

Evidence on global climate change, being caused primarily by rising levels of greenhouse gases in the atmosphere, is perceived as fairly conclusive. It is generally attributed to the enhanced greenhouse effect, resulting from higher levels of trapped heat radiation by increasing atmospheric concentrations of gases such as CO₂ (carbon dioxide). Much of these gases originate from power plants and fossil fuel combustion. However, the fate of vast amounts of waste heat rejected into the environment has evaded serious scholarly research. While 1 kWh electricity generation in a typical condensing coal-fired power plant emits around 1 kg of CO₂, it also puts about 2 kWh energy into the environment as low grade heat. For nuclear (fission) electricity the waste heat release per kWh is somewhat higher despite much lower CO₂ releases. This paper evaluates the impact of waste heat rejection combined with CO₂ emissions using Finland and California as case examples. The immediate effects of waste heat release from power production and radiative forcing by CO₂ are shown to be similar. However, the long-term (hundred years) global warming by CO₂-caused radiative forcing is about twenty-five times stronger than the immediate effects, being responsible for around 92% of the heat-up caused by electricity production.     

Seven steps to curb global warming

Based on best current estimates that the world needs to reduce global carbon dioxide emissions by 70% by 2050, and that there is at best a 10-year window of opportunity available to initiate the enormous changes needed, this paper proposes a set of seven self-contained steps that can be taken at a global level to tackle the problem with some prospect of success. The steps are self-financing and practicable, in that they are based on existing technologies. They involve agreement to create a new international agency charged with formulating and policing a global carbon pricing regime; a complementary step involving global monitoring of greenhouse gas emissions utilizing satellite resources; taking steps to compensate developing countries for preserving rainforest as carbon sinks; the dismantling of newly created trade barriers holding back global trade in biofuels; global promotion of a transition to renewable sources of electricity through facilitation of grid interconnections with independent power producers; a global moratorium on the building of new coal-fired power stations; and recycling of carbon revenues to promote uptake of renewable energy sources in developing countries, particularly Brazil, India and China. Taken as a group, it is argued that these steps are both necessary and sufficient. They call for institutional innovations at a global level that are politically difficult but feasible, given the magnitude of the problems addressed.     

Economic global warming potentials

A reformulation of global warming potentials is propounded, that combines the time-horizon and discounting definitions, and covers both ordinary atmospheric forcing (via greenhouse gases) and its rate-of-change. Insofar as GWPs are used to guide investment and socioeconomic choices, there is merit in adopting cost-benefit techniques. The parametric equivalence of the two definitions applies for the ordinary atmospheric forcing; but for its rat-of-change, only the discounting definition gives realistic results, as shown in application to methane, a short-lived greenhouse gas.     

Fossil-fuel constraints on global warming

In 2008 and 2009 two papers by Kharecha and Hansen and by Nel and Cooper examined possible fossil energy availability and energy consumption scenarios and consequences for future climate. The papers yield somewhat similar results regarding atmospheric CO₂ levels, but they reach substantially different conclusions regarding future climate change. Here, we compare their methods and results. Our work shows that Nel and Cooper's paper significantly underestimates future warming. Nel and Cooper conclude that even if all the available fossil fuels would be burned at the maximum possible rate during this century, the consequent warming would cap at less than 1 °C above the 2000 level. We find that – under Nel and Cooper's assumption of an intensive exploitation of fossil fuels – the global temperature in 2100 will likely reach levels which would lead to severely damaging long-term impacts.     

On the global warming problem due to carbon dioxide

The subject of global warming due to the increased use of fossil fuels is analyzed using a modification of the predator prey equations. The results of the calculation indicate that both the fossil fuels and civilization will both become extinct as time increases.     

Does fossil fuel combustion lead to global warming?

Tropospheric sulfate aerosols produced by atmospheric oxidation of SO₂ emitted from fossil fuel combustion scatter solar radiation and enhance the reflectivity of clouds. Both effects decrease the absorption of solar radiation by the earth-atmosphere system. This cooling influence tends to offset the warming influence resulting from increased absorption of terrestrial infrared radiation by increased atmospheric concentrations of CO₂. The sulfate forcing is estimated to be offsetting 70% of the forcing by CO₂ derived from fossil fuel combustion, although the uncertainty of this estimate is quite large--range 28 to 140%, the latter figure indicating that the present combined forcing is net cooling. Because of the vastly different atmospheric residence times of sulfate aerosol (about a week) and CO₂ (about 100 years), the cooling influence of sulfate aerosol is exerted immediately, whereas most of the warming influence of CO₂ is exerted over more than 100 years. Consequently the total forcing integrated over the entire time the materials reside in the atmosphere is net warming, with the total CO₂ forcing estimated to exceed the sulfate forcing by a factor of 4 (uncertainty range 2 to more than 10). The present situation in which the forcing by sulfate is comparable to that by CO₂ is shown to be a consequence of the steeply increasing rates of emissions over the industrial era.     

Hydrogen no longer a high cost solution to global warming: New ideas

This paper contains brief statements about three new low-cost methods of obtaining clean hydrogen in massive amounts.

In the first method, new technology for converting solar energy and water to hydrogen at a price of $2.50 for an amount of hydrogen equal in first law energy to that in a gallon of gasoline seems to follow from a company's announcement of their new technology, already working, in one fully industrialized plant, producing electricity at a price corresponding to that from coal.

In the second method, pure hydrogen (no accompanying CO₂) can be obtained from natural gas and heat. The cost would be a little less than that of the low-cost hydrogen from water decomposition (and avoid storage of hydrogen for the 18 h/day of zero solar light).

In the third method, CO₂ is extracted from the atmosphere and combined chemically with the low-cost hydrogen to produce methanol. On being used to produce heat or electricity (fuel cell), CO₂ is left over. However, the amount of CO₂, thus added to the atmosphere is just equivalent to the amount removed. The presence of low-cost hydrogen from water means that the resulting methanol will also be of low cost and be a cure for global warming without a radical change of distribution method.     

Designing a friendly space for technological change to slow global warming

What is the best strategy to encourage research and development on new energy technologies in a market economy? What steps can ensure a rapid and efficient transition to an economy that has much lower net carbon emissions? This paper shows that, under limited conditions, a necessary and sufficient condition for an appropriate innovational environment is a universal, credible, and durable price on carbon emissions. Such a price would balance the marginal damages from carbon emissions against the marginal costs of abating emissions; it should not contain a correction factor for inducing technological change. This result, which the paper calls “price fundamentalism,” applies principally to the market-oriented part of research and innovation. It is subject to qualifications regarding the efficacy of intellectual property protection and the proper level of carbon prices, and it applies primarily to market sectors. The role of appropriate prices on emissions is a central part of public policies to encourage technologies to combat global warming.     

Expected halt in the current global warming trend?

The variation patterns of global temperature were considerably turbulent from about 1870 up to 1940. Then just after 1940 these patterns underwent a sunspot-related change and adopted to relatively less turbulent variability. It is established here that these global temperature patterns are currently in the process of undergoing a sunspot-related change from the post-1940 relatively less turbulent variability back into relatively more turbulent variability. This apparently imminent state of more turbulent variability is expected to stop and at least slightly reverse the global warming trend, which has been going on since about 1965. Besides, it is shown separately that the mean of ‘global mean temperature variations’ reaches the next peak at about the year 2005 after which it will expectedly be on a decreasing trend. Finally, it is shown that, contrary to projections made in the Third IPCC Assessment Report, Greenland is currently in an ongoing cooling trend which is expected to last up to at least the year 2035.     

How the next US president should slow global warming

This paper addresses the energy technologies and policies that the next US president should immediately implement to slow global warming. Increased reliance on renewable energy through deployment of a National Renewable Portfolio Standard will help meet increased electrical demand in a sustainable way. Carbon regulation through an internationally fungible cap and trade system will help make renewables more cost competitive with conventional energy. Mandating National Energy Efficiency Portfolio Standards will also help decrease electrical demand and reduce the need for large investments in new generation. Within the transportation sector, plug-in hybrid and electric vehicles should be rapidly deployed to shift this sector's liquid fuel requirements to the electrical grid.     

Mitigating the anthropogenic global warming in the electric power industry

One of the most current and widely discussed factors that could lead to the ultimate end of man's existence and the world at large is global warming. Global warming, described as the greatest environmental challenge in the 21st century, is the increase in the average global air temperature near the surface of the Earth, caused by the gases that trap heat in the atmosphere called greenhouse gases (GHGs). These gases are emitted to the atmosphere mostly as a result of human activities, and can lead to global climate change. The economic losses arising from climate change presently valued at $125 billion annually, has been projected to increase to $600 billion per year by 2030, unless critical measures are taken to reduce the spate of GHG emissions. Globally, the power generation sector is responsible for the largest share of GHG emissions today. The reason for this is that most power plants worldwide still feed on fossil fuels, mostly coal and consequently produce the largest amount of CO₂ emitted into the atmosphere. Mitigating CO₂ emissions in the power industry therefore, would significantly contribute to the global efforts to control GHGs. This paper gives a brief overview of GHGs, discusses the factors that aid global warming, and examines the expected devastating effects of this fundamental global threat on the entire planet. The study further identifies the key areas to mitigate global warming with a particular focus on the electric power industry.     

US demilitarization and global warming : An empirical investigation of the environmental peace dividend

In the paper input-output methods are used to generate ballpark empirical estimates of the implications for global warming of the projected demilitarization of the US federal budget. The impact is found to be qualitatively ambiguous, and highly sensitive to the manner in which the funds saved are distributed. The effect is adverse where the budgetary savings are used to fund economy-wide cuts in personal taxation and/or deficit reduction. In other cases the effect may be neutral or beneficial.     

The status and prospects of renewable energy for combating global warming

Reducing anthropogenic greenhouse gas (GHG) emissions in material quantities, globally, is a critical element in limiting the impacts of global warming. GHG emissions associated with energy extraction and use are a major component of any strategy addressing climate change mitigation. Non-emitting options for electrical power and liquid transportation fuels are increasingly considered key components of an energy system with lower overall environmental impacts. Renewable energy technologies (RETs) as well as biofuels technologies have been accelerating rapidly during the past decades, both in technology performance and cost-competitiveness — and they are increasingly gaining market share. These technology options offer many positive attributes, but also have unique cost/benefit trade-offs, such as land-use competition for bioresources and variability for wind and solar electric generation technologies. This paper presents a brief summary of status, recent progress, some technological highlights for RETs and biofuels, and an analysis of critical issues that must be addressed for RETs to meet a greater share of the global energy requirements and lower GHG emissions.     

Implications of fossil fuel constraints on economic growth and global warming

Energy Security and Global Warming are analysed as 21st century sustainability threats.     

Solar assisted absorption cooling cycles for reduction of global warming: A multi-objective optimization approach

This work addresses the use of absorption cycles combined with solar energy for reducing the green house gas (GHG) emissions in the cooling sector. The problem of satisfying a given cooling demand at minimum cost and environmental impact is formulated as a bi-criterion non-linear optimization problem that seeks to minimize the total cost of the cooling application and its contribution to global warming. The latter metric, which is assessed following the principles of life cycle assessment (LCA), accounts for the impact caused during the construction and operation of the system. The concept of Pareto optimality is employed to discuss different alternatives for reducing the contribution to global warming that differ in their economic and environmental performance. We also analyze the effect of taxes on CO₂ on the economic and environmental performance of the system. The capabilities of the proposed approach are illustrated through a case study that addresses the design of a solar assisted ammonia-water single effect absorption cooling system with 100 kW of cooling capacity considering Barcelona weather conditions. We show that reducing the contribution to global warming considering the current energy prices and taxes on carbon dioxide emissions is technically viable but economically not appealing. We also discuss the conditions under which reducing the CO₂ emissions could become economically attractive.     

Surface reflectance and conversion efficiency dependence of technologies for mitigating global warming

A means of assessing the relative impact of different renewable energy technologies on global warming has been developed. All power plants emit thermal energy to the atmosphere. Fossil fuel power plants also emit CO₂ which accumulates in the atmosphere and provides an indirect increase in global warming via the greenhouse effect. A fossil fuel power plant may operate for some time before the global warming due to its CO₂ emission exceeds the warming due to its direct heat emission. When a renewable energy power plant is deployed instead of a fossil fuel power plant there may be a significant time delay before the direct global warming effect is less than the combined direct and indirect global warming effect from an equivalent output coal fired plant – the “business as usual” case. Simple expressions are derived to calculate global temperature change as a function of ground reflectance and conversion efficiency for various types of fossil fuelled and renewable energy power plants. These expressions are used to assess the global warming mitigation potential of some proposed Australian renewable energy projects. The application of the expressions is extended to evaluate the deployment in Australia of current and new geo-engineering and carbon sequestration solutions to mitigate global warming. Principal findings are that warming mitigation depends strongly on the solar to electric conversion efficiency of renewable technologies, geo-engineering projects may offer more economic mitigation than renewable energy projects and the mitigation potential of reforestation projects depends strongly on the location of the projects.