Availability Based Tariff (ABT) is a frequency based pricing mechanism applicable in India for unscheduled electric power transactions. The ABT falls under electricity market mechanisms to charge and regulate power to achieve short term and long term network stability as well as incentives and dis-incentives to grid participants against deviations in committed supplies as the case may be. [1]
ABT Mechanism in Electricity sector in India is adopted since the year 2000 and in a few other countries for pricing bulk power across various stakeholders. ABT concerns itself with the tariff structure for bulk power and is aimed at bringing about more responsibility and accountability in power generation and consumption through a scheme of incentives and disincentives. As per the notification, ABT was initially made applicable to only central generating stations having more than one SEB/State/Union Territory as its beneficiary. Through this scheme, the Central Electricity Regulatory Commission (CERC) looks forward to improve the quality of power and curtail the following disruptive trends in power sector:
The ABT scheme has now been expanded to cover the Intrastate systems as well. [2] The power generation or grid capacity has increased substantially in last fifteen years particularly after the Electricity Act 2003 by introduction of competition and unbundling of vertically integrated utilities (SEBs) into separate entities in charge of electricity generation, electricity transmission, and electricity distribution. Deregulation and competition has facilitated participation of private sector on large scale in electricity generation, transmission and distribution. Of late, Indian electricity sector is transforming from perennial deficit to surplus electricity availability. [3] The volume of purchased electricity that could not be transmitted to the buyers due to transmission lines congestion is only 0.3% of the total electricity consumed in the financial year 2013–14. [4] It means that the actual power deficit in India is less than 1% excluding under priced electricity demand. ABT/DSM mechanism needs improvements to address the requirements of all stake holders (including final electricity consumers) for encouraging least cost electricity generation / tariff based on demand verses availability in the grid. [5] [6] There is a need of well represented Electric Reliability Organization to involve all the grid participants for framing guidelines for power system operation and accreditation which is presently looked after by the CEA
Bulk power purchasers can buy electricity on daily basis for short, medium and long term duration from reverse e-auction facility. [7] In reverse e-auction, availability based tariff /Deviation Settlement Mechanism (DSM) is applied to settle the failed commitments by the electricity sellers or buyers [8] [9] The electricity prices transacted under reverse e-auction facility are far less than the prices agreed under bilateral agreements. [10] [11]
For those power generators who have made power purchase agreements (PPA) with Discoms and need not participate in day ahead market (DAM) trading on daily basis, the pecking order among the power generators in a state is called merit order power generation where the lesser variable generation cost electricity producer is selected out of the available generators to maintain the normal grid frequency. [12] IEX is also implementing real-time round the clock trading or one hour ahead trading which will take care of intra day market dynamics. [13] GoI also permitted electricity trading on exchanges with forward and derivatives contracts. [14]
A reverse auction is not a perfect price discovery mechanism or balanced market coupling where single price is applicable to all traders when there is no transmission constraints. [15] However, when the demand is slightly more than the supply, the market discovered price (Rs/KWh) would go steeply high and vice versa. When there is a transmission constraint to export power to a region, the difference between the market-discovered prices of different regions are unreasonably high. In reverse auction trading, the buyers pay a very high price/KWh (many times more than the cost of power from the diesel generator sets) for the incremental purchases.
In 2021, CERC proposed a grid management system where ancillary service providers are fully responsible for maintaining grid frequency within the safe range similar to prevalent practice in developed countries. [16] [17] Generators and Discoms are not required to keep the grid frequency in the permitted range under this proposal and the applicable power tariff is delinked from the grid frequency. Observing its detrimental effects on grid safety, it was discontinued after implementing for a few weeks.
Availability, for the purpose of the ABT order means the readiness of the generating station to deliver ex-bus output expressed as a percentage of its ex-bus rated capacity (MCR). Electricity is a commodity whose cost of storing is more than its production cost. The most economical method for electricity generation, transmission and distribution is just in time production where the availability and reliability of the entire system shall be very high to meet the unpredictable electricity demand on minute to minute basis.
Availability of thermal generating station for any period shall be the percentage ratio of average Sent Out Capability (SOC) for all the time blocks during that period and the rated MCR / SOC of generating station. The SAIDI (System Average Interruption Duration Index) is commonly used as a reliability indicator by electric power utilities.
During the fiscal year 2014–15, 1,043 billion KWh of electricity (three times that of National Grid) was supplied and met 138,215 MW maximum peak load. [18] The total installed generation capacity is 267,637 MW at the end of fiscal year 2014–15. Its size is of global scale comparable only with EU grid, NERC grid, China electricity grid and Russian electricity grid. [19] However, Indian grid lacks the basic features of smart grid for optimum use of its deployed resources. [20]
Generally the top 10% of the unrestricted daily peak load (MW) persists only for 1% (15 minutes) of the total duration and its energy share (MWHr) is of the order of 0.2% of the daily energy supplied. Instead of generating this substantial extra power for a short duration, automatic selective load shedding can be implemented on bulk consumers possessing with standby power facility to eliminate the load spikes without inconvenience to most of the consumers. [21] [22] Alternatively, working captive power plants start feeding to the grid by giving break to the captive power supply up to a maximum of 30 minutes duration. The standby generator / captive power owner would be paid for providing grid reserve ancillary services.
With an installed capacity of proper mix of base load and variable load generation capability (excluding low capacity utilisation or secondary power or negative load type on daily basis such as solar, wind, etc. without storage) equivalent to the unrestricted annual maximum peak load, the most effective and economical smart grid shall be able to cater more than 99 percentile duration unrestricted load/demand on daily basis with 100% stable operation of the grid. [23] [24] The purpose of smart grid is to supply required electricity at optimum cost with reliability to the final consumers. [25] [26]
The Petroleum and Natural Gas Regulatory Board (PNGRB) was created in the year 2005 to regulate downstream activities in the petroleum and natural gas sector. [48] There is requirement of natural gas TSO also for imparting optimum use of the gas on hourly basis for meeting peak load in the electricity grid and minimize gas transport distances. [49] The available gas should be stored up to rated pressure in the pipe grid for generating power during peak demand hours on a daily (or more) basis. [50] The natural gas carrying capacity utilization of GAIL pipelines is not exceeding 33%. [51] Thus available limited gas quantity is used to meet the peak electricity loads by all gas based power stations. [52] Gas turbine power plants are operated at 32.6% capacity factor as peaking power plants only in the US though being a surplus natural gas producer with lower price and the natural gas contributes largest portion (35.06%) of the total electricity produced. Also gas should not be transported from a power deficit region to a power surplus region by the gas grid and generated power from gas there shall not be transmitted back to the power deficit region to avoid misuse of the gas and power grid infrastructure. Natural gas TSO would also serve other sectors such as petro-chemical plants, CNG, fertilizer plants, PNG, LNG, etc. as per their hourly requirement in addition to receive gas from various types of natural gas producers and importers. [53] [54]
Indian Gas Exchange (IGX) started online gas trading platform for physical delivery of natural gas. [55] Initially, the company has identified Dahej, Hazira and Kakinada as delivery points and will subsequently include Dhabol, Kochi, Ennore and Mundra terminals. [56]
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a transmission network. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid.
An electricity market is a system that enables the exchange of electrical energy, through an electrical grid. Historically, electricity has been primarily sold by companies that operate electric generators, and purchased by consumers or electricity retailers.
The electric power industry covers the generation, transmission, distribution and sale of electric power to the general public and industry. The commercial distribution of electric power started in 1882 when electricity was produced for electric lighting. In the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry. What was once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become an essential aspect for normal operation of all elements of developed economies.
The utility frequency, (power) line frequency or mains frequency is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains electricity by country.
The National Grid is the high-voltage electric power transmission network serving Great Britain, connecting power stations and major substations, and ensuring that electricity generated anywhere on the grid can be used to satisfy demand elsewhere. The network serves the majority of Great Britain and some of the surrounding islands. It does not cover Northern Ireland, which is part of the Irish single electricity market.
India is the third largest producer of electricity in the world. During the fiscal year (FY) 2022–23, the total electricity generation in the country was 1,844 TWh, of which 1,618 TWh was generated by utilities.
The Electricity Act, 2003 is an Act of the Parliament of India enacted to transform the power sector in India.
Dynamic Demand is the name of a semi-passive technology to support demand response by adjusting the load demand on an electrical power grid. It is also the name of an independent not-for-profit organization in the UK supported by a charitable grant from the Esmée Fairbairn Foundation, dedicated to promoting this technology. The concept is that by monitoring the frequency of the power grid, as well as their own controls, intermittent domestic and industrial loads switch themselves on/off at optimal moments to balance the overall grid load with generation, reducing critical power mismatches. As this switching would only advance or delay the appliance operating cycle by a few seconds, it would be unnoticeable to the end user. This is the foundation of dynamic demand control. In the United States, in 1982, a (now-lapsed) patent for this idea was issued to power systems engineer Fred Schweppe. Other patents have been issued based on this idea.
A load-following power plant, regarded as producing mid-merit or mid-priced electricity, is a power plant that adjusts its power output as demand for electricity fluctuates throughout the day. Load-following plants are typically in between base load and peaking power plants in efficiency, speed of start-up and shut-down, construction cost, cost of electricity and capacity factor.
A black start is the process of restoring an electric power station or a part of an electric grid to operation without relying on the external electric power transmission network to recover from a total or partial shutdown.
Load management, also known as demand-side management (DSM), is the process of balancing the supply of electricity on the network with the electrical load by adjusting or controlling the load rather than the power station output. This can be achieved by direct intervention of the utility in real time, by the use of frequency sensitive relays triggering the circuit breakers, by time clocks, or by using special tariffs to influence consumer behavior. Load management allows utilities to reduce demand for electricity during peak usage times, which can, in turn, reduce costs by eliminating the need for peaking power plants. In addition, some peaking power plants can take more than an hour to bring on-line which makes load management even more critical should a plant go off-line unexpectedly for example. Load management can also help reduce harmful emissions, since peaking plants or backup generators are often dirtier and less efficient than base load power plants. New load-management technologies are constantly under development — both by private industry and public entities.
The electricity sector in New Zealand uses mainly renewable energy, such as hydropower, geothermal power and increasingly wind energy. As of 2021, the country generated 81.2% of its electricity from renewable sources. The strategy of electrification is being pursued to enhance the penetration of renewable energy sources and to reduce greenhouse gas (GHG) emissions across all sectors of the economy. In 2021, electricity consumption reached 40 terawatt-hours (TW⋅h), representing a 0.2% increase compared to the consumption levels in 2010.
An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids consist of power stations, electrical substations to step voltage up or down, electric power transmission to carry power over long distances, and finally electric power distribution to customers. In that last step, voltage is stepped down again to the required service voltage. Power stations are typically built close to energy sources and far from densely populated areas. Electrical grids vary in size and can cover whole countries or continents. From small to large there are microgrids, wide area synchronous grids, and super grids.
Andhra Pradesh Power Generation Corporation Limited is power generating organization in Andhra Pradesh. It undertakes operation and maintenance of the power plants and also setting up new power projects alongside upgrading the project's capacity. Under the recommendations of Hittenbhayya committee setup by TDP Govt..
The Transmission Corporation of Andhra Pradesh (APTRANSCO) is the electric power transmission company of Andhra Pradesh state in India.
A wide area synchronous grid is a three-phase electric power grid that has regional scale or greater that operates at a synchronized utility frequency and is electrically tied together during normal system conditions. Also known as synchronous zones, the most powerful is the Northern Chinese State Grid with 1,700 gigawatts (GW) of generation capacity, while the widest region served is that of the IPS/UPS system serving most countries of the former Soviet Union. Synchronous grids with ample capacity facilitate electricity trading across wide areas. In the ENTSO-E in 2008, over 350,000 megawatt hours were sold per day on the European Energy Exchange (EEX).
Central Electricity Regulatory Commission (CERC), a key regulator of the power sector in India, is a statutory body functioning with quasi-judicial status under sec – 76 of the Electricity Act 2003. CERC was initially constituted on 24 July 1998 under the Ministry of Power's Electricity Regulatory Commissions Act, 1998 for rationalization of electricity tariffs, transparent policies regarding subsidies, promotion of efficient and environmentally benign policies, and for matters connected Electricity Tariff regulation. CERC was instituted primarily to regulate the tariff of power generating companies owned or controlled by the Government of India, and any other generating company which has a composite scheme for power generation and interstate transmission of energy, including tariffs of generating companies.
Power sector of Andhra Pradesh is divided into 4 categories namely Regulation, Generation, Transmission and Distribution. Andhra Pradesh Electricity Regulatory Commission (APERC) is the regulatory body. APGENCO deals with the electricity production and also maintenance, proposes new projects and upgrades existing ones as well. The APGENCO also set up a Special Purpose Vehicle (SPV), named as Andhra Pradesh Power Development Company Limited (APPDCL), a joint venture company of APGENCO and IL&FS to set up Krishnapatanam thermal power project.
The National Grid is the high-voltage electricity transmission network in India, connecting power stations and major substations and ensuring that electricity generated anywhere in India can be used to satisfy demand elsewhere. The National Grid is owned, and maintained by state-owned Power Grid Corporation of India and operated by state-owned Power System Operation Corporation. It is one of the largest operational synchronous grids in the world with 417.68 GW of installed power generation capacity as of 31 May 2023.
Home energy storage devices store electricity locally, for later consumption. Electrochemical energy storage products, also known as "Battery Energy Storage System", at their heart are rechargeable batteries, typically based on lithium-ion or lead-acid controlled by computer with intelligent software to handle charging and discharging cycles. Companies are also developing smaller flow battery technology for home use. As a local energy storage technologies for home use, they are smaller relatives of battery-based grid energy storage and support the concept of distributed generation. When paired with on-site generation, they can virtually eliminate blackouts in an off-the-grid lifestyle.
