U. Aswathanarayana (India)
The book deals with five themes.
There is little doubt that the Renewables are the energy resources of the future, for the simple reason that they are not only “green’’ but most of them do not get depleted when used. The BLUE Map scenario envisages a strong growth of renewables (reaching about 20 000 TWh/yr by 2050) to achieve the IPCC target of 450 ppm of CO2.
Wind energy is believed to be the most advanced of the “new’’ renewable energy technologies. Wind power (2 016 GW) is expected to provide 12% of the global electricity by 2050, thereby avoiding annually 2.8 gigatonnes of emissions of CO2 equivalent. Wind power sector would need an investment of USD 3.2 trillion during 2010-2050. The lifecycle cost is projected to be USD 70-130/MWh for onshore wind, and USD 110-131/MWh for offshore wind. The life cycle costs of wind energy are sought to be reduced through resource studies, technology (e. g. larger rotors, greater heights, deep water foundations for offshore turbines), supply chains, and mitigation of environmental impacts.
Solar PV will work wherever the sun shines. Its levelized cost (US cents 20-40/kWh) is several times more than electricity from fossil fuels (US cents 3 to 5/kWh). Solar energy is expected to grow thousand-fold between now and 2050. Technical advances in thin-film production and “building-integrated PVs’’ (BIPV) as well as massive application are bringing down the costs rapidly, however.
Second-generation biofuels, produced by enzymatic hydrolysis of cellulosic feedstock, and gasification of a variety of biomass material, have a great future. Single-cell algae are being used to produce a chemical “mix’’ that is chemically identical to petroleum crude, which is also carbon neutral and sulphur-free. Small (~100kW) power units, which burn biomass wastes like paddy husk, are very useful to villages, which are not connected to grid.
Presently hydropower accounts for 90% of the renewable power generation in the world. Though hydropower is the cheapest way to produce electricity, it has become controversial because of human and ecosystem problems of large dams. Pumped storage is the highest capacity form of energy storage.
Geothermal energy is confined to areas of high heat flow. It is non-polluting and can be generated round the clock. High temperature geothermal sources can be used to generate electricity.
The use of tidal energy to generate power is similar to that of hydroelectric plant. The estimated global potential of wave electricity is 300 TWh/yr. The 740-m long Rance Barrage in France which produces 480 GWh of electricity, is one of the few operating tidal energy plants in the world. Considerable R&D effort is needed to ensure the commercial viability of ocean energy.
Countries have to decide upon the actual optimal mix of RETS, and timing of the policy incentives, depending upon their biophysical and socioeconomic situations. The level of competitiveness will depend upon the evolving prices of competitive technologies. The deployment of Renewable Energy Technologies (RETs) has two concurrent goals: (i) exploit the “low-hanging’’ fruit of abundant RETs which are closest to market competitiveness, and (ii) developing cost-effective ways for a low-carbon future in the long term. Highest priority should be given for the removal of non-economic barriers.
The transition to mass market integration of renewables requires some policy interventions. Such interventions should be able to lead to a future energy system in which RETs should be able to compete with other energy technologies on a level playing field. When once this is achieved, RETs would need no or few incentives for market penetration, and their deployment would be accelerated by consumer demand and general market forces. Technology-specific support schemes need to be fashioned depending upon the level of maturity of a given RET at a given time, employing a range of policy instruments, including price-based, quantity-based, R&D support and regulatory mechanisms.
All RETs are evolving rapidly, in response to technology improvements and market penetration. Renewable Energy policy frameworks should be so structured as to facilitate technological RD&D and market development concurrently, within and across technology families.
Theme 2: How to make Green Energy competitive
The renewable fuels, such as wind, solar, biomass, tides, and geothermal, are inexhaustible, indigenous and are often free at source. They just need to be captured efficiently and transformed into electricity, hydrogen or clean transportation fuels. In effect, the development of renewal energy invests in people, by substituting labour for fuel – renewable energy technologies provide an average of four to six times as many jobs for equal investment in fossil fuels. That said, the most important challenge facing the renewables is to achieve market penetration. This section is addressed to possible ways of making the renewables competitive.
Public – private partnership is the most effective way to achieve success in the operation of the Innovation Chain: Basic Research ^ Research & Development ^ Demonstration ^ Deployment ^ Commercialization (diffusion). The goal of the RD&D policy should be to design ways and means by which the value of a public good (say, climate change) is built into commercial and innovation systems. The role of the government is most effective when it is able to combine supply-push (i. e. focus on RD&D and technology standards) with Demand-pull (i. e. focus on influencing the market through economic incentives such as regulation, taxation or guaranteed purchase agreements). Generally, renewable energy technologies tend to be more expensive than incumbent technologies, like fossil fuels. Technology Learning can be made use of to bring down the costs of the green technologies, through reduction in production costs and improved technical performance.
The Levelized Cost of Energy (LCOE) which is calculated by levelizing the different scales of operation, investments and operating time periods between various forms of energy generation, can be made use of to make investment choices and evaluate the efficiency benefit arising from an investment. The value of one unit of energy depends upon when, where and how it is available. The capacity value of an energy system is given by the energy that can be reliably delivered at the time of the peak consumption, whereas the energy value of a system is the total amount of energy delivered over the course of a year. The efficiency and economics of a renewable energy facility are optimized on this basis.
A combination of policy incentives and discentives (such as, Cap-and-Trade regimes, Green Certificates, loans at low interest rates, tax credits, accelerated depreciation), enhancing the demand for green energy starting with government establishments, publicity campaigns and innovative marketing, are required in order for the green energy to achieve high market penetration.
Theme 3: How to reduce CO2 emissions and improve efficiency and employment potential of Supply-side EnergyTechnologies
For the mitigation of climate change, CCS (Carbon dioxide Capture and Storage) is a technology option that would allow the continued use of fossil fuels. Pulverised coal combustion (PCC) accounts for 97% of the coal-fired capacity. Supercritical steam plants and Integrated coal gasification combined cycle (IGCC) plants have been able to achieve high thermal efficiencies of 42 to 45%. Post-combustion capture of CO2, followed by geological storage, is nearest to commercialization. CCS has considerable flexibility in technological improvement, such as the use of new absorbers. Flue gas scrubbing with amines is the most promising for plants of 500 MW or higher capacity. Transport of CO2 is the key for CCS deployment. Pressure vessels can be used to transport CO2 in the liquid form. Pipeline transport may be used for supercritical CO2 above the critical point (31.1°C; 73.9 bars). Sleipner-type offshore storage of CO2 has technical, social, political and economic advantages.
Present global nuclear share of electricity amounts to ~15% (370 GWe), and it helps reducing the global emission by ~3 giga tonnes of CO2. Nuclear power is slated grow to 473-748 GWe by 2030. It is seen as a renewable energy, considering its vast energy potential. Current nuclear reactor technologies are based on the utilization of thermal or slow neutrons to fission low-enriched uranium (3-5% 235U) using light water as moderator and coolant. Most of the reactors currently operating utilize less than 1% of the fissionable content of the fuel. The rest is treated as waste in once-through fuel cycles. In a closed fuel cycle the unutilized materials are recycled. In fast breeder reactors the energy utilization of the fuel is multiplied by almost 100 times, as the reactor “breeds’’ more fissile material than it consumes. India has come up with the design of a low-enriched uranium – thorium fuelled, heavy water reactor (AHWR-LEU), whose fuel cycle is proliferation-resistant, and which can be deployed without ant safety and security prescriptions. Such a technological innovation allows the bypassing of proliferation and security legal frameworks which are difficult to enforce.
Next Generation Green Technologies, which are in the process of development, may have a potential comparable to other renewable energies. Biomass gasification is potentially more efficient than the direct combustion of the original fuel. In the town of Gussing in Austria, a plant supplies 2 MW of electricity and 4 MW of heat, generated from wood chips, since 2003.
The global marine energy resource is estimated to be the order of 200 GW for osmotic energy; 1TW for ocean thermal energy; 90 GW for tidal current energy; and 1-9 TW for wave energy. The total worldwide power in ocean currents has been estimated to be about 5 000 GW. It is estimated that capturing just 1/1 000 of the available energy from the Gulf Stream, would supply Florida with 35% of its electrical needs. On an average day, 60 million km2 of tropical seas absorb an amount of solar radiation equal in heat content to about 250 billion barrels of oil. Ocean thermal energy conversion (OTEC) uses the temperature difference that exists between deep and shallow waters to run a heat engine. The osmotic pressure difference between fresh water and seawater is equivalent to 240 m of hydraulic head. Theoretically a stream flowing at 1 m3/s could produce 1 MW of electricity. The worldwide fresh to seawater salinity resource is estimated at 2.6 TW.
Tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Wave energy can be considered as a concentrated form of solar energy. Useful worldwide resource has been estimated at >2TW. Low head hydropower applications use river current and tidal flows to produce energy. If the viable river and estuary turbine locations of the US are made into hydroelectric power sites it is estimated that up to 130 000 gigawatt-hours per year could be produced.
Enhanced Geothermal System (EGS) technologies “enhance’’ geothermal resources in hot dry rock (HDR) through hydraulic stimulation. It is reported that in the United States the total EGS resources from 3-10 km of depth is over 13 000 zetta joules. Out of this over 200 ZJ would be extractable, with the potential to increase this to over 2 000 ZJ with technology improvements.
Algae can be used to produce not only several kinds of fuel end products, but also byproducts which have wide ranging applications in chemical and pharmaceutical industries. They can be grown using land and water unsuitable for plant and food production. They are energy-efficient. They consume carbon dioxide. They can be mass produced. Algae may be cultivated in photobioreactors, and harvested using rotary screening methods. Expeller press and ultrasonic assisted extraction technologies may be used to produce energy products, such as, biodiesel, ethanol, methane, hydrogen, etc.
Theme 4: How to reduce CO2 emissions and improve efficiency and employment potential of Demand-side EnergyTechnologies
2050 is only 40 years away. During the next five to ten years, it is imperative that we shift to long-term trajectories while meeting the interim targets in respect of Industry, Buildings and Appliances and Transport. This would involve undertaking the required RD&D programmes, improving efficiencies, achieving increased market penetration, making appropriate investments, changing of the policies, and so on.
Industry: Industry-caused CO2 emissions (6.7Gt in 2005) constitute about 25% of the total worldwide emissions. Iron and steel industry accounts for about 30% of the CO2 emissions, followed by 27% from non-metallic minerals (mainly cement), and 16% from chemicals and petrochemicals production. If the Best Available Technologies (BATs) are applied worldwide, current CO2 emissions can be reduced by about 19% to 32%. Improvements in steam supply systems and motor systems have the potential to raise efficiencies from 15% to 30%. If CHP is included in the process designs, it will reduce heat demand per unit of output. There are three main ways in which CO2 emissions from the industries can be reduced: (i) through improvements in efficiency that can be brought about through the recycling of waste materials, and changes in the product design, (ii) feedstock substitution, such as the greater use of biomass, and (iii) CO2 capture and storage (CCS).
Buildings and Appliances: The buildings sector employs a variety of technologies for various segments, such as building envelope and its insulation, space heating and cooling, water heating systems, lighting, appliances and consumer products. Local climates and cultures profoundly affect energy consumption, apart from the life styles of individual users. Buildings are large consumers of energy – in 2005, they consumed 2 914 Mtoe of energy. The residential and service sectors account for two-thirds and one-third of the energy use respectively. About 25% of the energy consumed is in the form of electricity. Thus the buildings constitute the largest user of electricity. Globally, space and water heating account for two-thirds of the final energy use. About 10-13% of the energy is used in cooking. Rest of the energy is used for lighting, cooling and appliances. The end-uses dominated by electricity consumption are important from CO2 abatement perspective, in the context of the CO2 emissions related to electricity production. CO2 emissions can be reduced significantly through the use of Best Available Technologies in the building envelope, HVAC (heating, ventilation and air conditioning), lighting, appliances and cooking. Heat pumps and solar heating are the key technologies to reduce emissions from space and water heating.
Transport: Presently, transport accounts for about 19% of global energy use and 23% of energy-related carbon dioxide emissions. High growth rates are forecast for surface, air and marine transport for decades to come. Hence the transport energy use and CO2 emissions are projected to increase by nearly 50% by 2030 and more than 80% by 2050.
This future is not sustainable. In order to achieve a low-carbon, sustainable future, it is necessary for the governments to embark on two pathways simultaneously: Firstly, through appropriate regulatory mechanisms, governments should strive to improve the efficiency of today’s vehicles and for the deployment of transition technologies such as plug-in hybrids. Secondly, RD&D should be promoted for the development and deployment of long-term technologies, such as, biofuels, electric and fuel cell vehicles. Governments should make investments in infrastructure such as efficient, affordable and dependable public transportation (as in Singapore), and providing incentives for making rail travel preferable to air travel for journeys around 600 kms. International cooperation is essential to reach these goals.
The world average of Transmission and Distribution losses is 14.3% of the gross electricity production. It is high in India (31.9%) and low in Japan (8.7%). High voltage D. C. transmission is coming into vogue, as it is more economical than A. C. transmission for long distances (>500 km). Electricity can be stored, but only through other forms of energy. Pumped storage is the preferred option. It has an efficiency ranging from 55 to 90%, system rating of about 100MW, and discharge times of hours. Pumped storage plants can respond to load changes almost instantly (less than 60 seconds). Compressed air energy systems (CAES) have efficiencies of about 70%. The biggest problem with CAES is finding suitable storage caverns. Aquifer storage is a good possibility for CAES Superconducting Magnetic Energy Storage (SMES) stores electrical energy in superconducting coils. SMES has the advantage of being able to control both active and reactive power simultaneously. Also, it can charge/discharge large amounts of power quickly.
Electricity demand of a given geographical unit depends upon the size of the population, their life-style, climate, agriculture, industry, tourism, etc. Also, it is highly dependent upon the time of the day (e. g. the demand for air-conditioning is maximum at noontime). Under the provisions of “smart’’ grid, industrial, residential and commercial users in an area are linked with various power generating units (thermal, wind power, solar PV, nuclear power, etc.) in the area. When it becomes necessary to reduce the peak demand in the area, the central control system may turn down the temperature of heaters, or raise the temperature of some appliances (such as air conditioners and refrigerators) to reduce their power consumption. This essentially means delaying the draw marginally. Though the amount of demand involved in this exercise is small, it will have significant financial impact on the system, as electricity systems are sized to take care of extreme peak demands, though such events occur very infrequently.
“Bloom Box’’, recently unveiled by K. R. Sridhar, has the potential to revolutionize electricity production. It is a fuel cell device consisting of a stack of ceramic disks coated with secret green and black “inks’’. It can convert any renewable and fossil fuel (e. g. natural gas, biogas, coal gas, etc.) into electricity, 24 x 7. Since no combustion is involved, there would be no noise, smell or emissions.
Theme 5: A Green New Deal
The present fossil fuel dependent energy generation and consumption is the largest contributor of carbon emissions, and being the cause of global warming ought to be replaced with low carbon sources of energy, such as renewables and nuclear. Low carbon and renewable energy generation by wind, solar, hydro and nuclear (uranium can be extracted from sea water) could resolve the energy and climate challenges of humanity. Investing in these technologies and sources will generate millions of jobs, revive the economy and bring overall socio-economic development. In order to establish this change, we also need transmission and distribution networks based on the smart and super smart grid technologies, which will facilitate distributed electricity generation, improve efficiency in transmission, resolve peak load challenges and provide options for the users to control their consumption patterns. These green goals have to be supplemented with qualitative improvement in the user end, such as de-carbonizing the transport, building and industrial sectors of the economy. By analyzing the low carbon possibilities of energy generation, transmission and consumption/use, this chapter shows how a green new deal with integrated energy goals for a low carbon future and sustainable development can be promoted.
There is urgent need to take measures towards greening the economy and reducing the carbon emissions to keep up with the emission targets for the future well being of the planet. The necessary policy making is this area is complicated by a variety of factors—huge investments needed in Research and Development, rapidly emerging newer technologies, focus on long-term goals as opposed to short-term gains, addressing infrastructure and employment issues, and addressing the needs of various actors in the whole process. This chapter while highlighting the urgency of the issue makes an analysis of the challenges and prospects based on experiences from select countries across the world. There is also a necessity for the suitable integration of the green energy policies across various sectors to derive maximum benefit.
There are ways of addressing poverty in the context of environment and climate change. Lack of economic opportunities forces people to exploit the natural resources around them unsustainably, leading to destruction of forests and other carbon sinks.
Income poverty leads to inefficient use of energy in house holds, and the absence of electricity and clean fuels for the household use drastically reduces the productivity and socio-economic well being of the people. This can be overcome by combining poverty eradication and development projects with climate change mitigation programs. Investment in energy and electricity generation projects, especially renewables, will induce economic and social development and provide energy security. Eradicating poverty can be made a part of climate mitigation action. Climate change induced natural calamities affects the tropical countries which are mostly underdeveloped and vulnerable. Looking at the climate change mitigation discourse, it is clear that the world is getting serious about the role of socio economic development in protecting the environment and mitigating climate change and also realizing that the investments can be combined.
Paul Krugman, Nobel laureate in Economics, wrote a highly thought-provoking article entitled, “ Building a Green Economy’’, in the New York Times of Apr. 5, 2010. Climate Change is a classical case of “negative externality’’ – economic actors (say, a coal-fired thermal power station and the user of electricity) impose costs on others, without paying a price for their actions. Two approaches have been attempted to limit the negative externality – pollution tax and cap-and-trade. Acid rain is caused by the emissions of sulphur dioxide from power plants. It was controlled by the government prescribing compliant effluents, and taxing the power plants that were emitting beyond the permissible limits. Pollution tax is a disincentive. A company avoids pollution tax by reducing its pollution to be within compliant limits. Recently, US EPA formally declared CO2 as a pollutant attracting pollution tax. Pollution tax in respect of CO2 is vigorously opposed by the coal industry. In the case of cap-and-trade, the government issues a limited number of licenses to pollute. Companies which need to pollute more need to buy licenses from those which have pollution to spare. The incentive here is for a company to reduce pollution to avoid paying for extra pollution.
Pollution tax accrues to the government. In the case of cap-and-trade, the potential revenue goes to the industry instead of the government.
According to Nicholas Stern, author of the famous Stern Report, the emission of carbon dioxide and other greenhouse gases, is the “biggest market failure the world has ever seen’’. Markets cannot be trusted to set the matters right, and government interventions cannot be avoided. Many of the costs of climate change arise from skewed climate patterns, with more droughts, floods and severe storms. It should not be forgotten that London is at the same latitude as Labrador. Without the Gulf Stream, western Europe would be barely habitable. Poor countries are most vulnerable. Industrialized countries have certain amount of flexibility, but they cannot altogether escape the adverse effects. For instance, the American Southwest could become a dust bowl, if mitigating steps are not taken.
Climate change by 2100 will lower the gross world product by 5%, while stopping it would cost 2%. Then why not go for stopping it? This is because we have to spend the money now in order to protect the future generations, and many are reluctant to do so. The last time when the earth experienced warming at about the present level was during the Palaeocene- Eocene thermal maximum about 55 million years ago when temperatures rose by 11 degrees Fahrenheit. As is well known, this is the time of mass extinctions! Martin Weitzman argues that our policy analysis should be based on the non-negligible probability of utter disaster, forget about the uncertainty of Climate models and difference of opinion of ways of mitigating the adverse consequences of the climate change. Krugman supports Weitzman, and aggressive action to reduce emissions.
• Tidal lagoons can be constructed as self contained structures, not fully across an estuary.
Tidal stream generators draw energy from currents in much the same way as wind turbines. Tidal stream turbines may be arrayed in high-velocity areas where natural tidal current flows are concentrated such as the west and east coasts of Canada, the Strait of Gibraltar, the Bosporus, and numerous sites in Southeast Asia and Australia. Some of the operating and proposed facilities are shown in Table 11.3.2.
The higher density of water means that a single generator can provide significant power at low tidal flow velocities. Water velocities at about one-tenth of the speed of wind provide the same power for the same size of turbine system. However this limits the application in practice to places where the tide moves at speeds of at least 1m/s even at neap tides (Lecomber, 1979).
Tidal stream generators are an immature technology. Only a few commercial scale production facilities are yet routinely supplying power. No standard technology has yet emerged as the clear winner. But large varieties of designs are being experimented with, some very close to large scale deployment.
Several prototypes have shown promise, but they have not operated commercially for extended periods to establish performances and rates of return on investments. The devices could be classified into four, although a number of other approaches are also being tried (Table 11.3.3).
The cost associated for developing tidal power station can vary depending on the capacity. Project Severn Estuary in UK cost US $15 billion which produces about 8000 MW. The proposed 2200 MW tidal power station project in San Berandino cost about US $3 billion.