The world is focusing on environmental issues, especially climate change and therefore, the idea of growing sustainably has taken center stage globally. India being an active participant has already started taking several initiative towards sustainable development and green energy transition. Hon’ble Prime Minister of India has recently announced during COP26 held at Glasgow that India will take its non-fossil electricity installed capacity to 500 GW by the year 2030. The demand for power is increasing with the increase in economic activity. Availability of affordable and reliable power is a key factor in sustainable growth of the country. Meeting the increasing demand along with the green
energy transition is an opportunity as well as a challenge for the country. This can happen with appropriate policy initiatives and associated regulations which are conducive for transitioning towards clean sources along with sustainable growth of power sector. The huge growth in power sector and requisite policy directives necessitates detailed long term generation expansion plan studies for optimal use of all the resources.
To ensure a sustainable world for future generations, we stand before a substantial, global transformation of the energy sector. Renewable energy technologies have seen a rapid development with a subsequent cost reduction that support the global green energy transition. India is estimated to see the largest increase of energy demand of any country in the world. To respond to this challenge, the Government of India has set unprecedented and ambitious targets for variable renewable energy and a green and sustainable societal transition. In the process to reach the target of 500 GW non fossil power capacity in 2030, long-term energy planning is a crucial tool to align long-term objectives with short-term plans. However, long-term energy planning relies on estimates of current and future power generating technologies’ costs and performances to be a beneficial tool.
Objective of the technology catalogue The main objective of the technology catalogue is to provide generalized information and technical and financial parameters for power generation technologies for analysis of power systems, including economic scenario models and energy planning. In this manner, the technology catalogue will support analysis and decision-making for governmental power planning, but also making these data publicly available for all interested parties. The technology catalogue should therefore be used as a standardized database comprising of inputs from across the Indian power sector. The ambition is that this technology catalogue can act as a common point of reference for the Indian power sector in terms of generation technologies.
Background of the technology catalogue
Technology catalogues have been developed for numerous years in various countries with great success. In Denmark, the first technology catalogue was published more than 15 years ago and today there are six versions publicly available covering different sectors. The technology catalogue experiences have been replicated in collaboration with the Vietnamese, Indonesian, Ethiopian and Mexican governments and now also in India. The applicability across the countries has been proven and is directly used for governmental energy planning. In Denmark, the technology catalogue is the default point of reference for all power system analyses in the government as well as in a large number of research institutions and
universities, public organizations, private companies and NGOs.
Applications of the technology catalogue
It is imperative that the technology catalogue should only be used for certain applications. For example, the technology catalogue on its own cannot be used for prioritizing between technologies as this would require additional studies (e.g. power system modelling analyses, Levelized Cost of Energy analyses, etc.). The technology catalogue presents data in a general, generic level for India as these data inputs are necessary for the governmental energy planning. Hence, the technology catalogue should not be used for the planning of concrete projects as the local conditions will change from project to project and rather individual feasibility studies are advisable for each project.
The qualitative description describes the key characteristics of the technology as concisely as possible.
To enable comparative analyses between different technologies it is imperative that data are actually comparable: All cost data are stated in fixed 2020 prices, excluding taxes and subsidies. The information given in the tables relate to the development status of the technology at the point of final investment decision (FID) in the given year (2020, 2030, 2040 and 2050). FID is assumed to be taken when financing of a project is secured and all permits are at hand. The year of commissioning will depend on the construction time of the individual technologies.
Notes include additional information on how the data are obtained, as well as assumptions and
potential calculations behind the figures presented. Before using the data, please be aware
that essential information may be found in the notes below the table.
The generic parts of the tables are presented below:
Generating capacity for one unit
The capacity is stated for a single unit, capable of producing energy, e.g. a single wind turbine
(not a wind farm), or a single gas turbine (not a power plant consisting of multiple gas.
Coal Power Plant
Brief technology description
The catalogue distinguishes between three types of coal fired power plants: subcritical, supercritical and ultra-supercritical. The names refer to the input temperature and pressure of the steam when entering the high-pressure turbine. The main differences are the efficiencies of the plants.
Output is electricity. The gross electricity efficiency is typically between 35-37% for subcritical
plants. The Auxiliary Power Consumption (APC) of coal-based unit generally varies from 6% to 8% (depending on unit size, type of BFP drive etc.) excluding APC of Pollution control
equipment (PCEs). In general, the self-consumption of the coal-fired plants is about 6.5-7.5%.
The process is primarily based on coal but will be applicable to other fuels such as wood pellets and natural gas. Also, LDO/heavy fuel oil can be used as start-up or reserve fuel.
Subcritical power plants can be from 30 MW and upwards. Globally, supercritical and ultra supercritical power plants are larger and usually range from 400 MW to 1500 MW (Ref. 2). In India, the smallest subcritical power plant unit is of 30 MW and available up to 600 MW. The supercritical units generally have minimum nameplate capacity of 660MW and largest unit being of 800 MW in India.
Regulation ability and power system services
Regulation abilities are particularly relevant for electricity generating technologies. This includes the part-load characteristics, start-up time and how quickly it is able to change its production when already online.
Figure 2-1 provides an overview of the projected contribution from different sources in Business-As-Usual (BAU) scenario in 2021. Considering an effective contribution from other energy sources it is estimated that a 1% ramp rate across all power plants will be sufficient in meeting the required system ramp capability. However, this scenario may change significantly due to higher share of renewable energy in the Indian energy mix. The BAU scenario presented in the graph below considers the scenario without implementation of proposed measures in the study (Ref. 7) such as re-allocation of Hydro & Gas, pumped & battery storage and RE curtailment for grid balancing.
Mature and well-known technology.
The efficiencies are not reduced as significantly at part load compared to full load as with combined cycle gas turbines.
High reliability and low cost of electricity production (in terms of LCOE), especially in countries with local availability of coal.
Provide ramping capabilities for grid security based on power demand.
Coal fired power plants with no pollution control emit high concentrations of NOx, SO2 and particulate matter (PM).
Coal has a high CO2 content.
High water consumption of operations.
Waste management – produces a large quantity of Fly Ash that needs to be reused / disposed.
Coal fired power plants using the advanced steam cycle (supercritical) possess the same fuel flexibility as the more conventional subcritical boiler technology. Inexpensive heavy fuel oil cannot be burned due to materials like vanadium, unless the steam temperature (and hence efficiency) is reduced.
Compared to other technologies such as gas turbines or hydro power plants, the coal
thermal plants have lower ramp rates and are more complex to operate.
Prediction of performance and cost
Projections about the future investment costs of coal power plants can be made by looking at past prices and global capacity developments. Due to the maturity of the technology and the low increase in capacity expected for future years, a low variation in the costs of coal-fired power plants is expected. Moreover, it is possible that the capital cost will increase as a result of the reduction in the technology deployment. It is expected that no or only very few subcritical coal power plants will be constructed in India in the coming years. Using the learning rate methodology, which translates the variation in installed capacity into a cost variation, the future prices for coal-fired power plants were projected. In 2050, coal-fired power plant investment costs are around 1% lower than in 2020. The resulting cost development trend can be observed in Figure 2-2.
Anpara C thermal power station is located in Sonbhandra District of Uttar Pradesh and is one of the series of power plants within Anapara Thermal Power Station (9 units of total 3830 MW installed capacity). This is a private project being operated by LANCO Infratech (privately held) and has two subcritical units of 600 MW each. Both of these units were commissioned in 2011 and employs imported machinery. The total cost of project was estimated to be INR 4000 Crores (2007 prices). The plant sources its coal from adjoining northern coal fields (within 25 km), which is fed through Northern
Coalfield Limited (NCL) owned freight trains. The input coal is estimated to have ash content of 37.4% and sulphur content of 0.6%. The plant had a recorded Plant Load Factor (PLF) of 75% in 2018-2019.
In addition to the people directly involved in construction and operation of the project, employment opportunities in subsidiary industries and service sectors as well as self -employment opportunities are also anticipated.
Gas Power Plant
Brief technology description
The principle of a gas power plant is to derive power from burning fuel in a combustion chamber and using the combustion gases, which have a high pressure and high temperature, to drive a turbine. The most common fuel type is natural gas. The thermal energy of the gas is transformed into rotating energy by the turbine and is later converted to electricity by the electric generator. The gas turbine operates on the principle of the Brayton cycle This process is similar to how steam drives a steam turbine in a Rankine cycle. Gas power plants can be distinguished between open cycle and combined cycle. Both types are described in brief in the following sections.
The major components of open cycle (or simple-cycle) gas turbine (OCGT) power unit are: a compressor, a combustion chamber, a turbine and a generator.
Open cycle gas turbines are generally of two types: 1) Industrial turbines (also called heavy duty) and 2) Aero-derivative turbine. There are limited Aero-derivate installations in India.
The gas turbine and the steam turbine might drive separate generators (as shown) or drive a shared generator. Where the single-shaft configuration (shared) contributes to cost effective installation operation, the multi-shaft (separate) has a slightly better overall performance and comparatively higher reliability. The condenser is cooled by sea water/surface water source (circulating water).
Examples of market standard technology
Globally, the best technology commercially available today regarding simple cycle gas turbines is a medium size gas turbine with integrated recuperator that can reach approximately 38% electrical efficiency (5 MWe unit) Typically, the efficiency ranges between 20% and 35%.
Example of market standard technology for gas power plants
In the following table are some examples of market standard technologies for gas power plants.
Biomass Power Plant
Brief technology description
Biomass can be used to produce electricity or fuels for transport, heating and cooking. The figure below shows the various products from biomass.
This chapter focuses on solid biomass consisting mostly of agriculture residues namely bagasse and rice straw (including husks) for combustion to power generation. Direct, traditional uses of biomass for heating and cooking applications rely on a wide range of feedstock and simple devices, but the energy efficiency of these applications is very low because of biomass moisture content, low energy density, inefficient combustion and the heterogeneity of the basic input. A range of pre-treatment and upgrading technologies have been developed to improve biomass characteristics and make handling, transport, and conversion processes more efficient and cost effective. Most common forms of pre-treatment include: drying, shredding, pelletization and briquetting, torrefaction and pyrolysis, where the first two are by far the most commonly used in India.
Gasifier technologies offer the possibility of converting biomass into a producer gas, which can be burned in simple or combined-cycle gas turbines at higher efficiencies than the combustion of biomass to drive a steam turbine. Although gasification technologies are commercially available, more needs to be done in terms of R&D and demonstration to promote their widespread commercial use.
The investment costs of biomass power plants largely depend on the type of feedstock – size, calorific value, chemical composition etc. – as this affects the pre-treatment processes. Economy of scale also plays an important role. Biomass plants in India are relatively small, operate in condensing mode and display a lower efficiency compared to biomass fired powerplants in e.g. Europe. However, compared to similar installations in other countries, the Indian biomass plants demonstrate comparable efficiencies.
Wind Turbines, onshore
Brief technology description
Wind turbines work by capturing the kinetic energy in the wind with the rotor blades and transferring it to the drive shaft. The drive shaft is connected either to a speed-increasing gearbox coupled with a medium- or high-speed generator, or to a low-speed, direct-drive generator. The generator converts the rotational energy of the shaft into electrical energy. In modern wind turbines, the pitch of the rotor blades is controlled to maximize power production at low wind speeds, and to maintain a constant power output and limit the mechanical stress and loads on the turbine at high wind speeds. A general description of the turbine technology and electrical system, using a geared turbine as an example, can be seen in the figure below.
Wind turbines are designed to operate within a wind speed range, which is bounded by a low “cut-in” wind speed and a high “cut-out” wind speed. When the wind speed is below the cutin speed the energy in the wind is too low to be utilized. When the wind reaches the cut-in speed, the turbine begins to operate and produce electricity. As the wind speed increases, the power output of the turbine increases, and at a certain wind speed the turbine reaches its rated power. At higher wind speeds, the blade pitch is controlled to maintain the rated power output. When the wind speed reaches the cut-out speed, the turbine is shut down or operated in a reduced power mode to prevent mechanical damage.
The annual energy output of a wind turbine is strongly dependent on the average wind speed at the turbine location. The average wind speed depends on the geographical location, the hub height, and the surface roughness. Hills and mountains also affect the wind flow, and therefore steep terrain requires more complicated models to predict the wind resource, while the local wind conditions in flat terrain are normally dominated by the surface roughness. Also, local obstacles like forest and, for small turbines, buildings and hedges reduce the wind speed like wakes from neighbouring turbines. The increase in wind speed from 50 m to 100 m height is around 20% for typical inland locations.
Typical offshore turbine capacities
Technology innovation has led to an increase in offshore turbine size in terms of tip height and swept area, and this has raised their maximum output. The rotor diameter of commercially available offshore turbines increased from just over 90 meters (m) in 2010 (3 MW turbine) to more than 164 m in 2016 (8 MW turbine) while the swept area increased by 230%. The larger swept area allows for more wind to be captured per turbine. A 12 MW turbine is currently being tested for full scale market launch and has a rotor diameter of about 220 m (Ref. 3). Also a 14 MW turbine with a 222 m rotor diameter is being tested for later commercial launch and 15 MW turbines with even larger rotors have already been announced to come to the market before 2025 (Ref. 31). The average size of offshore wind turbines grew by a factor of 3.4 in less than two decades and is expected to continue to grow, with 15-20 MW turbines expected by 2030.
Generally, this increase in turbine size and rated power has increased the capital cost of each individual turbine and foundation, as larger turbines require more material, pose construction and installation challenges and require larger foundations. At the same time moving to larger turbines reduces the number of turbines/foundations and reduces the operation and maintenance costs, most often leading to lower levelized costs of electricity. Nevertheless, real case feasibility studies (Ref. 18) illustrate that turbine model selection should be performed considering trade-offs between the pure minimization of costs and the maximization of capacity factors, especially in low wind conditions.
Examples of market standard technology
High efficiency solar cells and modules have been available for a decade based on interdigitated back contact or hetero-junction cell technologies. PV modules with an efficiency of more than 20% are already commercially available. However, a typical global average value for commercially available PV modules today is 17-20 %. Figure 9 shows the efficiencies of a wide range of commercially available PV modules.
Not only the efficiency but also the reliability of PV modules has improved significantly over the last years. Based on extensive research in materials science and accelerated/field tests of components and systems, manufacturers now offer product warranties for materials and workmanship up to 25 years and power warranties with a linear degrading warranty from initially 97% of the peak power value to a level of 87% after 25 years.
This section describes battery storage using Lithium-Ion batteries. There are other battery technologies, which might be relevant to utility scale installations, and there are other energy storage technologies that may also be relevant. Lithium-Ion batteries are in focus here because this technology is relevant across a very broad spectrum of applications, it has demonstrated a reasonable longevity, and the ongoing R&D into Lithium-Ion batteries has resulted in an aggressive development in cost. For the moment, Lithium-Ion offers the highest degree of versatility at a reasonable cost.
A LIB contains two porous electrodes separated by a porous membrane. A liquid electrolyte fills the pores in the electrodes and membrane. Lithium salt (e.g. LiPF6) is disolved in the electrolyte to form Li+ and PF6 ions. The ions can move from one electrode to the other via the pores in the electrolyte and membrane. Both the positive and negative electrode materials can react with the Li+ ions. The negative electrode in a LIB is typically made of carbon and the positive of a Lithium metal oxide. Electrons cannot migrate through the electrolyte and the membrane physically separates the two electrodes to avoid electrons crossing from the
negative to the positive electrode and thereby internally short circuiting the battery. The
individual components in the LIB are presented in the figure below.