Renewable Energy systems- Unit 1 -notes1
- 1. Unit I INTRODUCTION Primary energy sources, renewable vs. non-renewable primary energy sources, renewable energy resources in India, Current usage of renewable energy sources in India, future potential of renewable energy in power production and development of renewable energy technologies. Renewable energy sources Renewable energy sources occur in nature which is regenerative or inexhaustible like solar energy, wind energy, hydropower, geothermal, biomass, tidal and wave energy.
- 2. ‗Energy obtained from natural and persistent flows of energy occurring in the immediate environment‘. An example is solar (sunshine) energy, where ‗repetitive‘ refers to the 24-hour major period. Note that the energy is already passing through the environment as a current or flow, irrespective of there being a device to intercept and harness this power. Such energy may also be called Green Energy or Sustainable Energy. Small hydropower is under renewable source. Large hydropower is also renewable in nature, but has been utilized all over the world for many decades and hence not included in the term ‗alternate or renewable‘. Municipal and industrial waste is also a useful source of energy, but is different forms of biomass. The Ministry of New and Renewable Energy (MNRE) have made efforts during the past few decades to develop and utilize various renewable energy resources in the country. Consequently, wind electric generators, solar water heaters, solar lanterns, street lights, biogas plants, biomass gasifiers and small hydro-electric generators have become commercially available. Wind farms, solar arrays, hydro and biomass power generation are all environmentally benign unlike fossil fuel and nuclear plants. At present renewable sources contribute only 4% of power generation while India has set a target of generating 10% of electricity from renewable sources
- 3. by 2012. It is planned to cover electrification of all those remote villages which are not approachable by grid power supply. Non-renewable energy sources ‗Energy obtained from static stores of energy that remain underground unless released by human interaction‘. Examples are nuclear fuels and fossil fuels of coal, oil and natural gas. Note that the energy is initially an isolated energy potential, and external action is required to initiate the supply of energy for practical purposes. To avoid using the ungainly word ‗non-renewable‘, such energy supplies are called finite supplies or Brown Energy. Five ultimate primary sources of useful energy: 1. The Sun. 2. The motion and gravitational potential of the Sun, Moon and Earth. 3. Geothermal energy from cooling, chemical reactions and radioactive decay in the Earth. 4. Human-induced nuclear reactions. 5. Chemical reactions from mineral sources.
- 4. Renewable energy derives continuously from sources 1, 2 and 3 (aquifers). Finite energy derives from sources 1 (fossil fuels), 3 (hot rocks), 4 and 5. The sources of most significance for global energy supplies are 1 and 4. The fifth category is relatively minor, but useful for primary batteries, e.g. dry cells. Comparison of renewable and non-renewable energy systems Sl.No Features of Comparison Renewable energy supplies (green) Non-renewable energy 1. Sources Natural local environment Concentrated stock 2. Examples Wind, Solar, biomass, tidal Coal, oil, gas 3. Normal state A current or flow of energy. An ‗income‘ Static store of energy. Capital. 4. Life time of supply Infinite Finite 5. Cost at source Free Increasingly expensive 6. Location for use Site and society specific General and global use 7. Scale Small-scale often economic Increased scale often improves supply costs; large-scale frequently favored 8. Context Well adapted to rural situations and decentralized industry. Scale favors urban, centralized industry. 9. Pollution and environmental damage Little environmental harm especially at moderate scale. Environmental pollution is common especially of air and water 10. Dependence Self-sufficient system encouraged Systems dependent on outside inputs 11. Initial average intensity Low intensity, dispersed: ≤ 300W m-2 . Released at ≥100 kW m-2 .
- 5. Renewable energy resources in India 1. Coal Coal is the prime source of energy in India and accounts for 56% of commercial energy requirement. According to a recent Geological Survey of India report, India has total coal reserves of 240,748 million tonnes. Of this, 73% is of non- coking quality used for power generation and the balance 27% is the coking variety suitable for metallurgical processes. Coal production which was 211.73 million tonnes in 1990–91 rose to 360 million tonnes in 2002–03. India is now the third largest coal producer in the world, ranking behind only the United States and China. India‘s ―Energy Security‖ is based on coal, as coal is the primary source of fuel. The present per capita primary energy consumption in India is 243 kg oe/year (kg oil equivalent per year), which is quite low. Considering population growth, economic development and technological progress, energy usage is expected to rise to about 450 kgoe/year by 2010. With limited petroleum and natural gas reserves, eco-conservation constraints on hydro-electric projects and geo-political approach for nuclear power, coal will continue to occupy the centre-stage of India‘s energy scenario. 2. Oil Crude oil is extracted from oil production wells, drilled either on-shore or off- shore. It is then refined in refineries to obtain petrol, diesel, kerosene, furnace oil, lubricating oil, paraffins, asphalt, tar, etc. In addition, fuel gases like butane, propane and methane, LPG, LNG are also the important products. India is the world‘s sixth largest energy consumer, but produces only 30% of the 110 million tonnes of petroleum products it consumes. Some important information regarding oil reserves is presented below:
- 6. Reserves and production Balance recoverable reserves of crude oil in the country have been declining, falling from 806 million tonnes in 1991 to 732 million tonnes in 2001– 02. Crude oil production in 2003–04 stood at 33.07 million metric tonnes. Oil and gas discovery During the year 2003–04, ONGC (Oil and Natural Gas Corporation) made six discoveries—East Lakhibari (oil) in Assam, Sonamura (gas) in Tripura, Degam (oil) in Gujarat, Sitarampuram (gas) in Andhra Pradesh, NMT-2 (gas) Western Offshore and G-4 in Bay of Bengal. Refineries The oil refining capacity of 18 refineries in the country has reached 127.37 million tonnes per annum which meets the present requirement. However, the demand is growing by 5% annually. It was planned to increase the refining capacity by 26.33 MT by 2007. Further capacity addition make-believe during the 11th five-year plan (2007–2012) is 24 MT by setting up new refineries and 32 MT by expansion of existing refineries. The MoPNG (Ministry of Petroleum and Natural Gas) monitors the entire chain of activities in the oil industry, i.e., exploration and production of crude oil and natural gas, refining, distribution, exports and imports of crude oil and petroleum products. 3. Natural Gas Natural gas is found either free in drilled wells or in association with crude oil. Free gas when present occupies the upper part of the reservoir. The extraction rate of associated gas depends on the rate of crude oil production. Recoverable natural gas reserves during 2001–02 were 763 billion cubic metres (BCM) while Reliance discovered gas in Krishna Godavari basin 150 km off the Andhra Coast and Gulf of Cambay, Cairn Energy in Barmer district of Rajasthan and Gulf of Khambhat (Gujarat), and ONGC in the Arabian Sea and the Bay of Bengal.
- 7. In March 2004, the gas reserves were 2800 BCM and at present the demand for natural gas is 135 million cubic metres per day (MCMD), which may go up to 319 MCMD by 2012. 4. National Grid for Gas Distribution Gas Authority of India Limited (GAIL) is responsible for transportation and marketing of natural gas. GAIL was set up in 1984, and operates 4000 km of pipeline, including the 2702 km long Hazira– Bijapur–Jagdishpur (HBJ) pipeline extending from the Western Coast to North India and over 1300 km of pipeline in other different states. 5. Gas Conservation The pressure of associated gas is quite low and thus needs boosting before transporting through pipelines. It had been customary in oil industry to burn or flares the low pressure gas as it cannot be easily transported for use. In the wake of energy shortages, ONGC took measures to conserve the gas. It was flaring over 21% of its natural gas output in 1991–92 and this figure was reduced to 5% by March 2002. However, a small degree of flaring has to continue for technical reasons. Current usage of renewable energy sources in India With a population of 1.3 billion, India has a massive demand for energy to fuel its rapidly growing economy. Today, we are a power surplus nation with a total installed electricity capacity of over Four lakh MW.Keeping in mind the sustainable development goals, India's power generation mix is rapidly shifting towards a more significant share of renewable energy. Today, India is the world's third largest producer of renewable energy, with 40% of its installed electricity capacity coming from non-fossil fuel sources. As a developing nation at the time of Independence, India relied heavily on coal to meet its energy demands. However, India has always been committed to looking for more alternative energy sources for sustainable development. The beginning was made with hydropower, with major
- 8. hydroelectric power projects appearing on the scene of India‘s energy arena. Over the years, many policy and regulatory initiatives have promoted hydropower development and facilitated investments. Today, we are 5th in the world regarding usable hydropower potential. Bhabha Atomic Research Centre (BARC) was founded in the 1950s to secure the country's long-term energy independence. Today, we are the only developing nation with indigenously developed, demonstrated and deployed nuclear reactors for electricity generation. This was made possible through several decades of extensive scientific research and technology development. Work on wind energy started in India during the 1960s when the National Aeronautical Laboratory (NAL) developed windmills, primarily for supplying irrigation water. Today, we have the 4th largest wind power capacity in the world, blessed with a constant movement of wind, especially in the Southern, Western and North Western regions. Solar energy-based applications have benefited millions of Indians by meeting their cooking, lighting and other energy needs in an environment- friendly manner. Having achieved large-scale success in solar energy solutions, India has spearheaded the International Solar Alliance (ISA) which is an action- oriented, member-driven, collaborative platform for increased deployment of solar energy technologies. The membership of the ISA is open to all member- states of the United Nations, and 107 countries are signatories to the ISA Framework Agreement at present. The Alliance aims to efficiently utilise solar energy to reduce fossil fuel dependence, thereby creating a greener planet. Biomass has also been an essential source of energy for India. It is renewable, widely available, carbon-neutral and has the potential to provide significant employment in rural areas. Rapidly evolving technology has enabled thermal power plants to have more economical and energy-efficient operations. India has co-fired biomass in thermal plants across the country to reduce its CO2 footprint in thermal power generation. biomass power/co-generation
- 9. programme since mid-nineties. Over 800 biomass power and bagasse/non- bagasse cogeneration projects have been installed in the country for feeding power to the grid. Future potential of renewable energy in power production and development of renewable energy technologies. Renewable energy technologies vary widely in their technological maturity and commercial status. In India, renewable energy is at the take-off stage and businesses, industry, government and customers have a large number of issues to address before these technologies could make a real penetration. India with large renewable energy resources (solar PV, wind, solar heating, small hydro and biomass) is to set to have large-scale development and deployment of renewable energy. The aim of meeting 10% of the country power supply through renewable by 2012 and also ambitious plans for the distribution of biogas plants, solar PV applications and solar city appears to be within reach. Moreover, introduction of tradable renewable energy certificates (REC) could overcome the existing gap that is hindering the application of quota for renewables and thereby creates a vibrant market. India would also have to look for international cooperation in renewable energy through well-defined projects with proper division of labour and responsibilities for specific tasks with equitable financial burden and credit sharing arrangements. Renewable energy development is considered in India to be of great importance from the point of view of long term energy supply security, environmental benefits and climate change mitigation. The Integrated Energy Policy report has recognized the need to maximally develop domestic supply options as well as the need to diversify energy sources. The Committee has placed emphasis on higher use of renewables in all forms of services. It is
- 10. expected that the contribution from renewables in power generation alone can be of the extent of 60,000 MW in the year 2031–2032. By 2031–2032 renewables will be the key driver in social inclusion of the poor in the development process. 2023 marks a step change for renewable power growth over the next five years Renewable electricity capacity additions are forecast to reach 507 GW in 2023, almost 50% higher than in 2022, with continuous policy support in more than 130 countries spurring a significant change in the global growth trend. This worldwide acceleration in 2023 was driven mainly by year-on-year expansion in China‘s booming market for solar PV (+116%) and wind (+66%). Renewable power capacity additions will continue to increase in the next five years, with solar PV and wind accounting for a record 96% of it because their generation costs are lower than for both fossil and non-fossil alternatives in most countries and policies continue to support them. Solar PV and wind additions are forecast to more than double by 2028 compared with 2022, continuously breaking records over the forecast period to reach almost 710 GW. At the same time, hydropower and bioenergy capacity additions will be lower than during the last five years as development in emerging economies decelerates, especially in China. China‘s renewable electricity capacity growth almost triples in the next five years compared with the previous five, with the country accounting for an unprecedented 56% of global expansion. Over 2023-2028, China will deploy almost five times more renewable capacity than the European Union and six times more than the United States, which will remain the second- and third- largest growth markets. The Chinese government‘s Net Zero by 2060 target, supported by incentives under the 14th Five-Year Plan (2021-2025) and the ample availability of locally manufactured equipment and low-cost financing, stimulate the country‘s renewable power expansion over the forecast period.
- 11. Meanwhile, expansion accelerates in the United States and the European Union thanks to the US Inflation Reduction Act (IRA) and country-level policy incentives supporting EU decarbonisation and energy security targets. In India, progressive policy improvements to remedy auction participation, financing and distributed solar PV challenges pay off with faster renewable power growth through 2028. In Latin America, higher retail prices spur distributed solar PV system buildouts, and supportive policies for utility-scale installations in Brazil boost renewable energy growth to new highs. Renewable energy expansion also accelerates in the Middle East and North Africa, owing mostly to policy incentives that take advantage of the cost- competitiveness of solar PV and onshore wind power. Although renewable capacity increases more quickly in sub-Saharan Africa, the region still underperforms considering its resource potential and electrification needs. Renewable energy resources make up 26% of the world‘s electricity today, but according to the IEA its share is expected to reach 30% by 2024. The resurgence follows a global slowdown in 2019, due to falling technology costs and rising environmental concerns. Renewable energy in the future is predicted that by 2024, solar capacity in the world will grow by 600 gigawatts (GW), almost double the installed total electricity capacity of Japan. Overall, renewable electricity is predicted to grow by 1 200 GW by 2024, the equivalent of the total electricity capacity of the US. Solar Will Become 35% Cheaper By 2024 When the sun shines onto a solar panel, energy from the sunlight is absorbed by the PV cells in the panel. This energy creates electrical charges that move in response to an internal electrical field in the cell, causing electricity to flow. Industry experts predict that the US will double its solar installations to four million by 2023. In 2018, the UK had over one million solar panel installations, up by 2% from the previous year and Australia reached two million solar
- 12. installations in the same year. A big reason for this increased uptake is the fall in prices to install the panels. The cost of solar PV-based power declined by 13% in 2018, while Carbon Tracker predicts that 72% of coal-based power will become globally unprofitable by 2040. The IEA(International energy agency) report found that solar energy will account for 60% of the predicted renewable growth, primarily due to its accessibility. Compared with the previous six-year period, expansion of solar energy has more than doubled. The cost of solar power is expected to decline by 15% to 35% by 2024, spurring further growth over the second half of the decade. Future Capacity of Solar Energy Wind and hydropower often require users to live in specific locations, but solar offers more freedom; the sun rises and sets on a predictable schedule, and it‘s not as variable as running water or wind. Residential solar power is expected to expand from 58 GW in 2018 to 142 GW by 2024, and annual capacity additions are expected to more than triple to over 20 GW by 2024. China is expected to register the largest installed residential solar capacity in the world by 2024, with the strongest per capita growth in Australia, Belgium, the Netherlands and Austria. Onshore Wind Energy Capacity Will Increase 57% By 2024 To generate electricity using wind, wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity. The adoption of wind power is becoming more prominent due to increased capacity. Onshore wind capacity is expected to expand by 57% to 850 GW by 2024. Offshore wind capacity is forecast to increase almost threefold to 65 GW by 2024, representing almost 10% of total world wind generation.