By the end of 2013, 6 countries in Europe, 2 countries in North America, and 2 countries in Asia were among the world’s top 10 nations in terms of installed wind power capacity. Collectively these countries boasted an installed wind power capacity of approximately 85% of the world’s total. See Table 2.1 for the basic information on the world’s top 10 countries in terms of installed wind power capacity in 2013.

A total of 103 countries and regions around the globe have been developing and harnessing wind energy, with the United States and some European Union countries in particular accounting for a relatively large share of the world’s total capacity. Wind power has become the largest source of power supply in Denmark and Spain, representing, 34 and 21%, respectively, of the total electricity consumed nationwide. Wind power represents 20, 16, and 9% of total electricity consumption in Portugal, Ireland, and Germany, respectively.

First, the continued growth of single-unit wind power capacity has contributed to higher levels of utilization efficiency, lower unit costs, greater economies of scale, and space economy of wind farms. Wind turbines produced in the 1980s typically had a single-unit capacity of only 20–60 kW. Reflecting the growing trend worldwide of single-unit wind power capacity in recent years, the capacity of the world’s major wind turbine models has increased from between 500 kW and 1 MW in 2000 to 2–3 MW in 2013. In 2013, the average single-unit capacity of newly installed wind turbines in the world was 1923 kW. In China, newly installed turbines had an average single-unit capacity of 1720 kW, with 1.5 MW and 2 MW turbines as the mainstream models. See Fig. 2.2 for the International Energy Agency (IEA) report on the changes in the single-unit capacity and hub height of wind turbines in the world.¹

Second, variable blade pitch control technology has seen major progress to contribute further to turbine stability, safety, and efficiency. Typically, random changes in wind speed and direction cause continuous changes in the angle of attack of the blade, leading to fluctuating output power at the expense of power quality and grid stability. With the employment of variable blade pitch control technology, the angle of blade can be changed in line with the random change in wind speed, and the angle of attack of the wind stream can be maintained within an appropriate range. Power output can be kept stable especially when wind speed exceeds rated wind speed. Variable blade pitch control has been applied extensively in wind turbines (especially large turbines) in recent years. Along with variable pitch applications and power electronics developments, most turbine manufacturers have introduced variable-speed constant-frequency technology (VSCF) and invented variable-speed variable-pitch turbines to align rotational speed change with wind speed and further improve turbine efficiency. Currently, 90% of the world’s installed turbines are VSCF-supported, and the figure continues to rise.

Third, the rapid development of system-friendly wind farm technology contributes to ever-greater controllability and adjustability and gradually improved coordination with conventional power sources and grids. Given the high stochastic volatility and intermittent nature of wind energy, large-scale wind power integration will pose many grave challenges to load balancing, grid safety, and power quality. Conventional wind farms attach more importance to the turbine’s power generation capacity at the expense of the coordination between the turbine, other electrical equipment, grid access for turbines, and wind farms, required to maintain safe and stable grid operations. This produces a serious impact on the maximization of resources and the safety of grid operations. Thanks to the design and control technology employed, a modern wind farm has all the characteristics resembling a conventional power plant, enabling it to fully meet the requirements for generation of performance, as well as stable and safe grid operations. Generally speaking, system-friendly wind farms carry three features. First, they have a wind power prediction system capable of short-term and ultrashort-term projections for dispatching and operation. Second, the turbine is capable of active/reactive power regulation and low voltage ride-through to maintain uninterrupted operation in times of grid fluctuations. Third, there is a focus on optimizing the allocation of active and reactive power control systems to realize remote turbine control.

Fierce competition in the wind power generation equipment market over the years has led to lower turbine prices across the board. With rapidly growing demand and fast-expanding manufacturing capacity, turbine prices are falling significantly, especially after the global financial crisis in 2008. In China, turbine prices fell by 37% on an aggregate basis between 2008 and 2010. Following the restructuring and consolidation of the global wind power market, indiscriminate capacity expansion has been kept in check, market competition has witnessed a return to rationality, and the downward trend of turbine prices has slowed. See Table 2.3 for the turbine prices in the world market and mainland China between 2008 and 2013.

Wind power generation costs around the world have shown a steadily downward trend year by year. From 1980 to 2005, wind power generation costs globally went down over 90%. Currently, the investment costs of onshore wind power projects stands at US$ 970–1400 per kW and electricity generation costs at around 10 US cents per kWh. China’s wind power generation costs have dropped to RMB 0.45–0.55 kWh. By 2020, the overall production costs of onshore turbines are expected to fall a further 20–25% and offshore turbines a further 40%, bringing with them lower electricity generation costs. Driven by more advanced wind power technology and growing development capacity, wind power may become more price-competitive as costs are likely to fall to a level comparable to or even lower than conventional fossil fuel-fired power generation costs.

The United States encourages wind power development primarily through policy on production tax credit and quotas for renewable energy development. The production tax credit works as a subsidy calculated on a per kilowatt hour basis, and the renewable energy quotas implemented at the state level have been made into law to set the share of renewable sources, in total electricity consumption at a designated level. In 2008 the United States Department of Energy carried out a feasibility study, 20% Wind Scenario, which found a 20% share of total electricity consumption by 2030 as a practicably achievable target for wind power.

European countries encourage wind power development primarily through subsidies on a per kilowatt hour basis. Under this system, either fixed feed-in tariffs set directly by government are provided, at which power purchased by grid operators is calculated or wind farms can participate directly in tenders with the government providing a subsidy based on market tariffs. According to the National Renewable Energy Action Plan submitted by EU nations in 2010, installed wind power capacity and wind power generation in the European Union are expected to reach over 200 GW and 500 TWh by 2020, respectively, accounting for 12.7% of total electricity consumption in that year. The Turkish government, for instance, is planning to achieve a total installed wind power capacity of 20 GW by 2020.

India has set up the National Clean Energy Fund to fund technology research and projects in clean energy. A total of 17 members from 25 Central Electricity Regulatory Commissions have jointly promulgated the Regulations for Renewable Purchase Obligation and 18 “pradeshes” (provinces) have announced a feed-in tariff setting mechanism for wind power. In addition, India has moved to cut import duty on certain turbine components from 10% to 5% and waive a 4% surcharge on the procurement of related raw materials. By the end of 2013, onshore installed wind power capacity had surpassed 20 GW, with the development of offshore wind power expected to accelerate.

In China, the Renewable Energy Act of the People’s Republic of China sets forth a renewable energy policy system covering priority grid access, benchmark tariffs, and cost apportioning. With effect from 2009, the territory of China has been divided into four different classes of wind resource regions, where four levels of benchmark feed-in tariffs apply, respectively, RMB 0.51, RMB 0.54, RMB 0.58, and RMB 0.61 per kWh, respectively. At the end of 2014, the benchmark feed-in tariffs for Classes I, II, and III wind resource regions were readjusted downward by RMB 0.02 per kWh and the tariffs for Class IV regions have remained unchanged. Also, wind energy development funds were subsidized by means of a renewable energy surcharge imposed on electricity sales to end-users. By 2020, onshore installed wind power capacity is expected to double from the current level to 200 GW.

Among the world’s top 10 countries in terms of installed PV capacity in 2013, 6 were in Europe, 2 in Asia, 1 in North America, and 1 in Oceania. The 10 countries represented 86% of global installed PV capacity. In recent years, China’s solar power industry has grown rapidly, as evidenced by the establishment of a megawatt-grade PV power generation base in Qinghai Province. See Table 2.4 for the basic information on the world’s top 10 countries in terms of installed PV capacity in 2013.

Europe currently leads the world in terms of PV power generation capacity. In 2013, PV power generation became the second most widely utilized new power source after wind energy for the third consecutive year, meeting 3% of Europe’s total electricity needs. In some European countries, PV power generation accounted for an even larger share of maximum load. In 2013, instantaneous PV power output as a share of maximum load amounted to 49% in Germany, 20–25% in Italy and Spain, and even up to 77% in Greece. See Table 2.5 for the PV maximum power output (MPO) in selected European countries in 2013.

More and more countries are actively exploring solar thermal power generation, building and putting into operation a number of typical projects. In 2011, the Sevilla solar thermal farm was completed and commissioned in southern Spain. With an installed capacity of 20,000 kW and molten salt for heat storage, it is the first 24-h operating solar thermal farm in the world. In February 2014, the Ivanpah solar thermal power station was connected to the grid and became operational. With a total installed capacity of 392,000 kW, the power station consists of three concentrated solar power towers with an installed capacity of 133,000, 133,000, and 126,000 kW, respectively. Known as the largest of their kind in the world, the three towers alone accounted for 30% of the total installed solar thermal power capacity then in the United States. In July 2013, the first phase (10,000 kW) of the Supcon (Delingha) 50,000 kW solar thermal farm in Qinghai was successfully connected to the grid, marking a solid step forward in the commercialization of China’s proprietary solar thermal power generation technology.

In the solar cell industry, global capacity was estimated at approximately 78 GW and production at approximately 39.5 GW in 2013, with a capacity utilization rate of around 50.6%. In 2013, global c-Si solar cell capacity reached approximately 69.6 GW. Ranking first globally, China claimed the lion’s share of this amount, with 49.30 GW or 70.8% of the world’s total. In 2013, global production of c-Si solar cells was estimated at approximately 35.5 GW, divided in the ratio 3:1 between the poly-Si and mono-Si cell types. Production in mainland China totaled 21.5 GW, accounting for around 60.6% of the world’s total and ranking first globally. Production in Taiwan totaled 8.5 GW, accounting for around 23.9% of the world’s total and ranking second globally. Production in Southeast Asia, Japan, and South Korea was around 2400 MW, 1700 MW, and 1500 MW, respectively, accounting for 6.8, 4.8, and 4.2% of the world’s total in the same order. In 2013, global TFSC cell capacity totaled around 8.41 GW, doubling the level in 2010. By technology type, production capacity of Si-based, CIGS TFSC, and CdTe TFSC cells accounted for 50, 22, and 28%, respectively. In 2013, global TFSC cell production totaled about 3.95 GW, up 9.1% from 2010.

In the solar components industry, global production capacity surpassed 76 GW and production reached 43 GW in 2013. Production capacity of c-Si cell components was estimated at around 68.4 GW, compared to around 8000 MW for TFSC components, and 230,000 kW for concentrator solar cell components. China was the largest producer with an output of 27.4 GW in 2013, with c-Si cell components representing 99% of total production. Europe ranked second, producing 3.8 GW, around 20% of which was attributable to TFSC components. Japan produced about 3.5 GW, with c-Si cell components and TFSC components accounting for 71.4 and 28.6%, respectively of the total. Southeast Asia, South Korea, and the United States produced 2.8, 1.7, and 1 GW, respectively.

PV power generation costs are falling quickly. Generation costs per kilowatt hour are falling significantly due to maturing PV power generation technology, increasing equipment utilization hours, and declining system-manufacturing costs. In solar resource-rich regions like California, Germany, and Italy, generation costs per kilowatt hour have dropped to a level below end-user tariffs and are increasingly drawing closer to conventional power tariffs set based on the most stringent environmental standards. In 2013, Germany achieved a generation cost of US$ 0.11–0.19 per kWh, which could go down to US$ 0.08 per kWh if the annual solar irradiation intensity should exceed 2000 kWh/m².² Large ground-mounted PV solar power plants in Western China achieved a generation cost of RMB 0.7–0.9 per kWh, and the figure in Eastern China was RMB 0.9–1.2 per kWh.

At US$ 4000–9000 per kW, the investment costs of solar thermal power generation are relatively high around the world, with the unit cost varying greatly with solar resources and the availability and capacity of heat storage facilities. The cost of building the Delingha solar power tower in Qinghai without a heat storage system cost is estimated at RMB 18,500 per kW, compared to RMB 27,800 per kW for a tower with a 2-h heat storage system.

The costs of solar thermal power generation around the world remain higher than those of PV power generation. Take operating projects as an example, 40% of Spain’s solar thermal power plants are equipped with a 4-h energy storage system and governed by a feed-in tariff rate of US$ 0.4 per kWh. In Morocco, the Ouarzazate solar thermal power plant, with a 160,000 kW installed capacity and a 3-h energy storage system, is governed by a feed-in tariff rate of US$ 0.19 per kWh. At 110,000 kW, the Nevada Crescent Dunes solar power tower with a 10-h heat storage system is governed by a feed-in tariff rate of US$ 0.135 per kWh, but the actual tariff stands at around US$ 0.19 per kWh after adjustment for the preferential policies implemented. Based on different technology packages and combinations of units, the generation costs of solar power towers in China can be controlled at RMB 1.2–1.5 per kWh.

The United States provides policy support for the PV industry in terms of technology research and tax refund. An investment tax credit program is available to refund 30% of the total investment in a lump sum or over a specified period of years, which is equivalent to a front-end investment subsidy for PV projects. In 2010, the Senate Committee on Energy and Natural Resources voted through the Million Solar Roofs Initiative, with plans to invest at least US$ 250 million each year as a roof-mounted PV project subsidy from 2013 to 2021. Furthermore, many State governments promulgated incentive policies on solar power generation. For example, California officially commenced the California Solar Initiative in 2007, planning to invest approximately US$ 2.2 billion over a 10-year period in front-end investment subsidies or feed-in tariff subsidies for solar power projects with a total capacity of nearly 2 GW. It is anticipated that installed PV capacity will have surpassed 100 GW by 2021.

Europe provides primarily tariff-based stimulus packages for PV power by requiring grid operators to purchase PV power as a priority and pay for the power based on government-mandated fixed feed-in tariffs, or by offering grid operators appropriate subsidies based on market tariffs, a policy similar to that applicable to wind power. Meanwhile, Germany and some other European countries encourage end-use consumption of electricity generated by customer-side PV projects, with any residual electricity to be fed into the grid. The significant fall in PV power generation costs has led the European countries to cut back upon incentives and lower subsidy levels in an orderly manner. It is expected that Germany will begin to scrap its subsidy policy for new PV power generation projects from 2017. According to the National Renewable Energy Action Plan submitted by European Union member nations in 2010, European Union countries will have installed a total solar power capacity of over 90 GW by 2020, including 84 GW of solar PV power. The Turkish government, for instance, has planned to build a total installed PV power capacity of 5 GW by 2020.

India launched the Jawaharlal Nehru National Solar Mission in 2009, with specific principles and directions proposed for building India into the world’s major solar energy consumer. A robust policy and management framework was also established to achieve the goal of building 20 GW of installed grid-connected PV capacity and 2 GW of installed off-grid PV and thermal capacity in three stages by 2022. In 2014, Indian Prime Minister Narendra Modi set another goal to bring installed PV capacity to 100 GW, five times the target envisaged in the Jawaharlal Nehru National Solar Mission, by 2020.

China started implementing the Golden Sun Project in 2009 to subsidize approximately 50% of the initial investment for industrial parks and other operators of PV–DG programs, opening up a new era of large-scale development in PV power generation. By the end of 2012, the installed PV–DG capacity of the Golden Sun Project exceeded 6 GW. In 2013, China formally promulgated a policy governing PV power tariffs. Under the policy, China was divided into three solar resource regions according to the availability of solar energy and construction costs. Benchmark feed-in tariffs were set at RMB 0.9, RMB 0.95, and RMB 1 per kWh, respectively for the three regions and PV–DG power generation projects were offered an RMB 0.42 per kWh subsidy. According to plan, China’s installed PV power capacity will have reached 100 GW by 2020, approximately 65 GW of which was attributed to ground-mounted PV power stations.

All in all, global wind and solar energy development is growing rapidly, with increasingly sophisticated technology and improved economics. Given government support worldwide, the prospects of this energy sector are bright, and a foundation is laid to resolve the increasingly severe energy and environmental problems.

As the fastest-developing source of energy, clean energy will gradually become the world’s dominant energy source. From 2000 to 2013, global installed wind and solar power capacity registered an annual growth of 25.0 and 40.9%, respectively, and the share of nonhydroelectric renewable energy rose from 1.8% to 4.8%. In some European nations and the United States, clean energy has now become the key source of electricity. In 2013, Denmark derived 32.1% of its total electricity generation from wind energy, and Germany derived 25% of its total electricity generation from renewable energy. If global wind and solar power generation maintains annual growth of 12.4%, clean energy will be able to meet 80% of the world’s total energy demand by 2050, forming a new energy development pattern dominated by clean energy to help fundamentally resolve the various energy concerns we face today. The future energy structure will exhibit a clear trend toward cleaner energy.

Clean energy substitution can help resolve environmental problems, including air, soil, and water pollution, arising from fossil energy development and utilization. Fossil energy is known to be contributing to serious environmental pollution by producing substantial emissions of CO_2, sulfur dioxide (SO₂), NO_x, dust, mercury (Hg), and other toxic metals in the production, transportation and utilization processes. On a whole life cycle basis, clean energy is far less pollution-intensive than fossil fuels in development and utilization terms. Under the current technical and economic conditions, replacing coal power per kilowatt hour with wind power or solar PV power can save 2.2 g of SO₂, 2.0 g of NO_x, and 0.38 g of dust emissions. In 2013, China produced a total of 140 TWh of wind power, contributing to 308,000 tons less SO₂, 280,000 tons less NO_x, and 53,000 tons less dust. The substitution of clean energy for fossil energy can avoid environmental pollution caused by energy development and utilization, improve mankind’s living environment significantly, and reduce healthcare spending for the benefit of the community.

Clean energy development is a common choice around the world to boost development momentum and generate new economic growth. Recovering from the international financial tsunami that dealt them a heavy blow, all countries have been seeking a new driver of economic growth. To revitalize the economy, the United States and European countries have chosen to develop the new energy industry to boost the national economy. In 2001, the United States invested only US$ 286 million in clean technology in 2010 – the figure rose to US$ 4.6 billion in 2010, representing a more than 15-fold increase. In 2012, 14% of venture capital investments found their way into the clean energy technology sector.³ As pointed out by the All-of-the-Above Energy Strategy as a Path to Sustainable Economic Growth published by the White House,⁴ the energy industry contributed increasingly to United States GDP growth between 2000 and 2013, and the lower energy imports helped cut trade deficits. The world has now resorted to clean energy investment or grid infrastructure upgrading and retrofitting projects, as an important means of boosting economic growth. As forecast by the IEA,⁵ global energy infrastructure investment will total US$ 37 trillion between 2012 and 2035 (based on the United States dollar’s exchange rates in 2011), averaging US$ 1.6 trillion or around 1.5% of the global GDP every year. Developing countries are expected to step up investment notably and non-OECD countries are expected to record a total energy investment equal to 61% of the world’s total.

Clean energy development is of strategic significance. In recent years, international energy development has witnessed profound changes. The worsening resource constraints and environmental problems have led to an international consensus on the need to combat global climate change together, with many countries deciding on clean energy as a strategic national goal of energy development. When the world economy has moved into a new round of adjustment aimed at securing a leadership position in the international technology race especially after the financial crisis, the world’s major economies, such as the United States and the European Union, have launched policies with an unprecedented focus on clean energy, like the Green Energy Project and the Green New Deal. The European Union’s 20–20–20 strategy in 2007 was designed to achieve a 20% reduction in GHG emissions from 1990 levels by 2020, with the share of renewable energy in primary energy consumption to rise from 8.2% to 20% in 2006, and energy utilization efficiency to improve by 20%. In January 2014, the European Commission promulgated the 2030 Framework for Climate and Energy Policies, setting a further goal to cut GHG emissions by 40% and to derive at least 27% of energy output from renewables by 2030. In the United States, the American Clean Energy and Security Act approved in 2009 presented for the first time a national emission control program. Renewables targets at the national level were also formally proposed to meet 20% (15% attributable to wind, solar, and biomass energy) of electricity needs by 2020 through renewable energy development and energy efficiency improvement. In June 2014, the Environmental Protection Agency announced plans to cut carbon emissions from power plants nationwide by 30% by 2030. As for Japan, the government has reassessed the role of nuclear power in electricity supply after the Fukushima nuclear incident, with renewables expected to become the new focus of energy development. Not just the developed countries, the developing countries are also attaching great importance to renewable energy development. Globally, more than 120 countries have so far developed relevant laws, regulations or action plans with the aim of achieving strategic renewable energy goals by statutory or mandatory means. Renewable energy development has become a strategic option for most countries in the world.

Technology for clean energy allocation over large areas. Globally, wind energy resources are distributed primarily in the Arctic, central and northern Asia, northern Europe, central North America, east Africa, and the near-shore regions of each continent. Solar energy resources are distributed primarily in equatorial areas, for example, north Africa, east Africa, the Middle East, Oceania, and central and South America. Water resources are concentrated primarily in the major drainage basins of South America, Asia, North America, and Central Africa. Most of these clean energy-rich areas are remote, sparsely populated, and far away from load centers. Besides, the major clean energy bases on each continent are also distributed inversely with the centers of energy consumption. Therefore, the key to efficient energy utilization lies in how to deploy an intracontinental, intercontinental, and even global energy allocation system to accommodate concentrated development and long-distance delivery of clean energy.

Technology for clean energy grid connection and consumption. Judging by the development trend, wind, and solar power tends to be generated in large bases, consumed on a large scale, developed in a distributed manner and utilized locally. A robust smart grid features a robust grid structure to accommodate the complementary strengths of different power-producing regions, improve system-wide consumption of electricity generated by large renewable energy bases, realize large-capacity, long-distance power transmission, and ensure system safety and stability. A robust smart grid allows concentrated access for random and intermittent power sources and efficient application of distributed power supply systems to support large-scale development of wind and solar energy.

Wind and solar power technology under extreme conditions. Although the Arctic and Equatorial areas are strategic energy bases of global importance and abound in concentrated energy, the fact that these regions are extremely cold or hot gives rise to challenging working conditions, which spells the urgent need to seek breakthroughs in a new series of energy development technology capable of withstanding inclement weather conditions. The Arctic is a high latitude, highly humid area, so major technological innovation is required for the tower and blade materials of wind turbines in order to cushion the impact of the freezing cold on utilization efficiency and improve the tolerance of the equipment to the Arctic’s extreme climate. An offshore turbine must be able to withstand strong wind load, corrosion, tidal impact, and other special conditions. Continued improvement in operation and maintenance skills is also necessary. Construction of large solar PV power stations or solar thermal power stations in north Africa, the Middle East, and similar equatorial areas rich in solar energy resources requires important breakthrough technologies and processes to overcome challenging weather conditions, for example, high temperature, temperature difference, wind, and sand.

Market competitiveness of clean energy. The cost differentials between clean energy and fossil energy will gradually narrow, with the cost of clean energy generation technology falling, and the generation cost of conventional fossil energy rising year after year. When the cost gap is eventually closed, clean energy will become competitive as grid parity becomes possible. Grid parity includes grid- and user-side parity. The former means that on-grid tariffs for clean energy generation and fossil fuel generation are identical and the latter indicates that the cost of clean energy generation on the user side is on a par with the relevant end-user tariffs. Global wind power and solar energy will achieve on-grid parity in 2020 and 2025, respectively, and user-side parity even earlier as predicted by the IEA and other international organizations.

Safety issues associated with grid integration of distributed power generation: A high level of grid access for distributed power sources turns distribution networks into active grids, thereby causing a series of technical problems with voltage stabilization, relay protection, short-circuit current, and power quality. When a higher proportion of distributed generation is reached, distribution networks will feed power back to transmission networks in individual time slots, which will change the current flows and distribution of the power grids and significantly increase the complexity of managing grid dispatch operations.

Full cost accounting for clean energy: The emission of GHGs like CO₂ during the development and use of conventional fossil energies leads to climate change. Air, water, and soil pollution caused by large quantities of pollutants has caused serious ecological damage detrimental to human health. The ecological and environmental benefits of clean energy can be fully manifested and the competitiveness of clean energy in the energy market significantly enhanced if these hidden environmental costs are reflected as part of the real costs of developing and using fossil energy. Therefore, the government should take full account of the environmental costs of fossil energies by implementing pricing and tax measures, such as resource, effluent, and carbon taxes, which can not only accelerate the trend toward cleaner fossil energies, but also create a level playing field for clean energy development.

Mechanism for developing clean energy markets: In clean energy development, the focus is on fostering a competitive market, leveraging the role of market forces in determining the areas and directions of investments, and introducing market plurality to facilitate technological progress and lower costs through competition. In clean energy utilization, the focus is on building an electricity market where electricity tariffs fluctuate with market supply and demand to fundamentally resolve the mismatch between clean energy generation and consumption. Restricted by natural and meteorological conditions, clean energy generation is often out of sync with load characteristics. Generally, more wind power is generated after midnight when demand is at its lowest. As a result, surplus wind power cannot be fully used and can only be abandoned. By building a mechanism to introduce market competition for user-side resources, users are encouraged to consume more clean electricity in periods of high generation and less in periods of low production. Industrial users are also encouraged to come up with a more rational production program so that power loads can be transferred to low ebb periods. At the same time, in response to the market mechanism in force, users can store any clean electricity unused during nighttime ebb periods in an energy storage facility and release it for use in daytime periods of high demand. In this way, economic returns can be obtained and efficient utilization of clean energy achieved.

Electric energy substitution can improve energy efficiency in an all-round manner. In terms of utilization, electric energy is convenient and precisely controllable; in terms of conversion, electric energy can be converted to/from various forms of energy, and all primary energy sources can be converted into electric energy; in terms of allocation, electricity can be produced on a large scale, transmitted over long distances and instantly sent to any end user through a distribution system. Driven by industrialization, urbanization, informatization, agricultural and rural electrification, and new technology application, electricity is chosen for its unique characteristics and is extensively used to power economic and social growth in all countries. The advent of electricity has made large-scale and automated production in the agricultural and industrial sectors possible to substantially improve labor productivity and product quality. The electronics and information industries also benefit from the extensive use of electric power. By increasing the share of electricity in energy end-use to promote electric energy substitution in the areas of industry, transport, commerce, as well as urban and rural living, we can not only enhance utilization efficiency, but also increase economic output and improve energy efficiency at the community level. According to data published by China, the economic efficiency of electricity is 3.2 times that of oil and 17.3 times that of coal, meaning that the economic value created by electricity of 1 ton of standard coal-equivalent is comparable to that created by oil of 3.2 tons of standard coal-equivalent, and coal of 17.3 tons of standard coal-equivalent.

Implementing electric energy substitution policy is crucial for improving electrification levels. Generally, there are two measures of the level of electrification. One is the share of electricity in primary energy consumption and the other is the share of electricity in terminal energy consumption. The course of development in developed countries fully demonstrates that the level of electrification increases with economic progress and social affluence. As indicated by the progress of power development, electricity as a share of energy end-use has shown a clear upward trend in both developing and developed countries. The share is over 20% in the majority of developed countries. Electric energy is expected to account for more than 50% of energy end-use globally by 2050, with clean energy developing rapidly. Electricity as a share of primary energy consumption in the world increased from 34% in 1990 to 38.1% in 2012. The figure is expected to rise further to nearly 80% by 2050.

Electricity technologies like heating, heat pumps, electric kilns, and electric cookers have been well developed and are well placed to replace coal. Take electric boilers for example, the heat supply technology was developed swiftly and used extensively with the improving socialized production and living standards in the early twentieth century. Powered by an adequate supply of electricity, electric boilers provide energy efficiency, cleanliness, safety, and other advantages unrivalled by any other heating equipment. Promoting the development of electric boilers then became an inexorable trend. Electric boilers were first produced and used in Europe in 1926. The United States and Europe began to promote electric heating in 1930. In the 1950s and 1960s, electric heaters became vastly popular. Currently, electricity as a share of heating energy is 90% in Norway, 80% in Japan and the Republic of Korea, 70% in France, and 50% in the United States, Canada, Denmark, and Sweden.

As the world’s largest consumer of coal, China still has room to grow to substitute coal with electric energy. Currently, there are about 620,000 electric boilers in operation in China where industrial coal-fired boilers number around 370,000. The sheer number of coal-fired boilers in China means a high level of coal consumption every year, not to mention the problems of high energy consumption, wastage, and environmental pollution still associated with many of these coal-fired boilers. By promoting the use of electricity instead of coal for industrial, commercial and household purposes, such as electric boilers with heat storage capability (electric heating), heat pumps, electric kilns, and distributed electric heating systems, China is expected to be able to cut down approximately 320,000 tons of sulfur dioxide, about 260,000 tons of nitric oxide and 13,000 tons of PM_2.5 particulates each year by 2020. If clean energy is supplied to meet new demand for electricity, 160 million tons of coal for direct combustion and approximately 320 million tons of CO₂ can be saved. With the technological progress on electric energy substitution, it is anticipated that China’s direct combustion of coal will have gone down 60% by 2030 and basically eliminated by 2040.

Substituting electric energy for coal also helps improve people’s livelihoods. Serious air pollution and potential safety hazards exist in China and some other less developed countries, where burning coal to stay warm in the winter remains a common practice in rural areas. There are fatalities caused by gas poisoning in northern China’s countryside each year. Gas poisoning incidents are actually preventable by promoting distributed electric heating, cooking, and bathing to ensure power safety.

Electric cars are powered by electricity with highly efficient rechargeable batteries or fuel cells. They are clean and pollution-free with the greatest potential for the substitution of electricity for oil. Although conventional internal-combustion engine vehicles are still dominant, clean electric cars are the way forward and set to reshape the automobile industry of the twenty-first century. In terms of energy utilization efficiency, the energy conversion efficiency of fuel oil to power transport systems is 15–20%, with little room for major enhancement. On the contrary, with up to 90% efficiency in the conversion of electricity into kinetic energy, coupled with a 90% recharging efficiency of storage batteries, the efficiency of converting electric energy into motive power can reach 90%. The efficiency of converting natural gas, oil, and coal into electric energy is 55–58, 50–55, and 40–50%, respectively. On this basis, the energy utilization efficiency of electric cars is 1.5–2 times that of oil-powered cars. Electric cars have the advantages of much improved energy utilization efficiency and zero emission. China’s car ownership is forecast to exceed 200 million by 2020. Assuming electric car ownership of five million, based on mileage of 20,000 km per car each year, and average oil consumption per 100 km of 10 L, 7.1 million tons of gasoline consumption can be reduced, and 15 million tons of CO₂ emissions saved every year.

Shore power technology means that quayside power supply systems are provided to supply power to berthed ships, which need not rely on oil-fired engines on board for power supply. Shore power that meets the demand of berthed ships for electricity to power up lightning, communication, air conditioning and water pumps, can eliminate exhaust emissions during power generation and noise pollution during the operation of generating units on board. So the use of shore power can dramatically reduce energy costs, as opposed to ship-mounted generators, which are economically unsound, being costly, and with a low generating efficiency.

“Delivering electricity from afar” is crucial for solving environmental issues in areas where load centers are located. China’s load centers are situated in the relatively well-developed mid-eastern regions, covering 12 provinces (including municipalities directly under the central government) and accounting for 45% of the country’s population, approximately 58% of the national GDP, and 13.5% of the nation’s land area. For a long time, numerous coal-fired power plants have been constructed in areas where load centers are located. About 75% of the nation’s installed coal power capacity is concentrated in mid-eastern regions, with a power plant built per 30 km along the Yangtze River. The sheer number of power plants has far exceeded the carrying capacity of the local environment, with local population density exacerbating further the risk of health damage and associated losses due to environmental pollution. In eastern China’s Yangtze River Delta region, sulfur dioxide emissions per kilometer reaches 45 tons annually (20 times the national average), turning the region into acid rain-afflicted areas with frequent smoggy weather. The transport and storage of coal from western and northern areas to central and eastern regions year after year is the culprit of serious air pollution. In 2013, an Action Plan for the Control of Air Pollution was published by the State Council to curb new coal-fired power capacity in the western and northern regions, replace coal with electricity, and satisfy the growing demand for energy. What this means is that the need for long-distance transport of large quantities of coal will be eliminated, dust problems in the transport process removed, and the mid-eastern regions no longer be exposed to soil, air, and water pollution from the storage and burning of coal.

Clean electricity supply is the inevitable outcome of clean substitution. The shift from fossil energy to clean energy requires a transition to clean energy at the energy development stage and to electricity consumption at the end-use stage. Similarly, the allocation of energy should help realize the transition from delivery of fossil energy to transmission of clean electric power. Large-scale development of clean energy will inevitably result in long-distance transmission of clean electricity and substantial growth in power consumption, making transmission of clean electricity the major form of energy transport in the future.

Clean electricity supply will be a progressive process. Thanks to the UHV power transmission technology, thermal power, wind energy, and solar power in the western and northern parts of China as well as hydropower in southwest China are delivered to eastern and central parts of China on a large scale from a long distance to meet the demand for electrical power and alleviate the strain on the local environment. In the future, along with the large-scale development of clean energy in western and northern parts of China, the proportion of thermal power will gradually go down and transmission of clean electricity focused on wind, solar, and hydroelectric power will play a dominant role in supplying clean electricity continuously to the eastern and central regions. According to State Grid Corporation of China’s plan, a UHV AC/DC power grid with a capacity of 0.45 GW for large-area allocation will be fully developed by 2022 to meet the requirement for delivering clean energy of 550 GW and consuming clean energy of 1700 TWh annually, which will save 700 million tons of raw coal together with 1.4 billion tons and 3.9 million tons of CO₂ and SO₂ emissions, respectively.

Looking into the future, along with the development of wind energy in the Arctic and solar energy in the Equatorial region as well as clean energy bases on different continents, a sufficient supply of clean electricity will be delivered to load centers on each continent through UHV and EHV grids, making the transmission of “clean electricity from afar” completely achievable.