Electricity pricing (sometimes referred to as electricity tariff or the price of electricity) varies widely from country to country and may vary significantly from locality to locality within a particular country. Many factors go into determining an electricity tariff, such as the price of power generation, government subsidies, local weather patterns, transmission and distribution infrastructure, and industry regulation. "Electricity prices generally reflect the cost to build, finance, maintain, and operate power plants and the electricity grid." Some utilities are for-profit, and their prices will also include a financial return for shareholders and owners. Electricity tariffs vary by type of customer, typically by residential, commercial, and industrial connections. Electricity price forecasting is the method by which a generator, utility company, or large industrial consumer can predict the wholesale prices of electricity with reasonable accuracy. The cost to supply electricity varies minute by minute.
Video Electricity pricing
Rate structure
In standard regulated monopoly markets, electricity rates typically vary for residential, commercial and industrial customers. The rates are determined through a regulatory process that is overseen by a public utility commission.
Prices for any single class of electricity customer can vary by time-of-day or by the capacity or nature of the supply circuit (e.g., 5 kW, 12 kW, 18 kW, 24 kW are typical in some of the large developed countries); for industrial customers, single-phase vs. 3-phase, etc. Prices are usually highest for commercial and residential consumers because of the additional costs associated with stepping down their distribution voltage. The price of power for industrial customers is relatively the same as the wholesale price of electricity, because they consume more power at higher voltages. Supplying electricity at transmission-level high voltages is more efficient, and therefore less expensive.
The two most common distinctions between customer classes are load size and usage profile. In many cases, time-of-use (TOU) and load factor are more significant factors than load size. Contribution to peak-load is an extremely important factor in determining customer rate class. Consumer loads may be characterized as peak, off-peak, baseload, and seasonal. Utilities rate each load differently, because each has different implications for a power system.
The inclusion of renewable energy distributed generation and AMI in the modern electricity grid has introduced many alternative rate structures. Simple (or fixed) rate, tiered (or step) rate, TOU, demand rates, tiered within TOU, seasonal, and weekend/holiday rates are among the few residential rate structures offered by modern utilities. The simple rate charges a specific dollar per kilowatt ($/kWh) consumed. The tiered rate is one of the more common residential rate programs, and it charges a higher rate as customer usage increases. TOU and demand rates are structured to help maintain/control a utility's peak demand. The concept at its core is to discourage customers from contributing to peak-load times by charging them more money to use power at that time.
A feed-in tariff (FIT) is an energy-supply policy that supports the development of renewable power generation. FITs give financial benefits to renewable power producers. In the United States, FIT policies guarantee that eligible renewable generators will have their electricity purchased by their utility. The FIT contract contains a guaranteed period of time (usually 15-20 years) that payments in dollars per kilowatt hour ($/kWh) will be made for the full output of the system.
Net metering is another billing mechanism that supports the development of renewable power generation, specifically, solar power. The mechanism credits solar energy system owners for the electricity their system adds to the grid. Residential customers with rooftop PV system will typically generate more electricity than their home consumes during daylight hours, so net metering is particularly advantageous. During this time where generation is greater than consumption, the home's electricity meter will run backwards to provide a credit on the homeowner's electricity bill.
The cost also differs by the power source. The net present value of the unit-cost of electricity over the lifetime of a generating asset is known as the levelized cost of electricity (LCOE). LCOE is the best value to compare different methods of generation on a consistent basis.
In the U.S. the estimated LCOE for different sources are:
Maps Electricity pricing
Price comparison
The table below shows simple comparison of electricity tariffs in industrialised countries and territories around the world, expressed in US dollars. The comparison does not take into account factors including fluctuating international exchange rates, a country's purchasing power, government electricity subsidies or retail discounts that are often available in deregulated electricity markets.
For example, in 2012, Hawaii residents had the highest average residential electricity rate in the United States (37.34¢/kWh), while Louisiana residents had the lowest average residential electricity costs (8.37¢/kWh). Even in the contiguous United States the gap is significant, with New York residents having the highest average residential electricity rates in the lower 48 U.S. states (17.62¢/kWh).
Global comparison
a Denotes countries with government subsidized electricity tariffs.
b Mexico subsidizes electricity according to consumption limits. More than 500kWh consumed bimonthly receive no subsidies. Only 1% of Mexico's population pays this tariff.
c Hawaii.
d Prices don't include VAT (20%)
e San Diego, California high-tier
The U.S. Energy Information Administration (EIA) also publishes an incomplete list of international energy prices, while the International Energy Agency (IEA) provides a thorough, quarterly review.
Eurostat
The following table shows electricity prices both for household and non-household consumers within the European Union (EU) and Iceland, Liechtenstein, Norway, Albania, Republic of Macedonia, Montenegro, Serbia, Turkey, Bosnia and Herzegovina, Kosovo, Moldova and Ukraine.
Electricity price forecasting
Electricity price forecasting is the process of using mathematical models to predict what electricity prices will be in the future.
Forecasting methodology
The simplest model for day ahead forecasting is to ask each generation source to bid on blocks of generation and choose the cheapest bids. If not enough bids are submitted, the price is increased. If too many bids are submitted the price can reach zero or become negative. The offer price includes the generation cost as well as the transmission cost, along with any profit. Power can be sold or purchased from adjoining power pools.
The concept of independent system operators (ISOs) fosters competition for generation among wholesale market participants by unbundling operation of transmission and generation. ISOs use bid-based markets to determine economic dispatch.
Wind and solar power are non-dispatchable. Such power is normally sold before any other bids, at a pre-determined rate for each supplier. Any excess is sold to another grid operator, or stored, using pumped-storage hydroelectricity, or in the worst case, curtailed. Curtailment could potentially significantly impact solar power's economic and environmental benefits at greater PV penetration levels. Allocation is done by bidding.
The effect of the recent introduction of smart grids and integrating distributed renewable generation has been increased uncertainty of future supply, demand and prices. This uncertainty has driven much research into the topic of forecasting.
Driving factors
Electricity cannot be stored as easily as gas, it is produced at the exact moment of demand. All of the factors of supply and demand will therefore have an immediate impact on the price of electricity on the spot market. In addition to production costs, electricity prices are set by supply and demand. However, some fundamental drivers are the most likely to be considered.
Short-term prices are impacted the most by weather. Demand due to heating in the winter and cooling in the summer are the main drivers for seasonal price spikes. In 2017, the United States is scheduled to add 13 GW of natural-gas fired generation to its capacity. Additional natural-gas fired capacity is driving down the price of electricity, and increasing demand.
A country's natural resource endowment, as well as their regulations in place greatly influence tariffs from the supply side. The supply side of the electricity supply is most influenced by fuel prices, and CO2 allowance prices. The EU carbon prices have doubled since 2017, making it a significant driving factor of price.
Weather
Studies show that generally demand for electricity is driven largely by temperature. Heating demand in the winter and cooling demand (air conditioners) in the summer are what primarily drive the seasonal peaks in most regions. Heating degree days and cooling degree days help measure energy consumption by referencing the outdoor temperature above and below 65 degrees Fahrenheit, a commonly accepted baseline.
In terms of renewable sources like solar and wind, weather impacts supply. California's duck curve[cite] shows the difference between electricity demand and the amount of solar energy available throughout the day. On a sunny day, solar power floods the electricity generation market and then drops during sunless evening, when electricity demand peaks.
Hydropower availability
Snowpack, streamflows, seasonality, salmon, etc. all affect the amount of water that can flow through a dam at any given time. Forecasting these variables predicts the available potential energy for a dam for a given period. Some regions such as the Egypt, China and the Pacific Northwest get significant generation from hydroelectric dams. In 2015, SAIDI and SAIFI more than doubled from the previous year in Zambia due to low water reserves in their hydroelectric dams caused by insufficient rainfall.
Power plant and transmission outages
Whether planned or unplanned, outages affect the total amount of power that is available to the grid. Outages undermine electricity supply, which in turn effects price.
Economic health
During times of economic hardship, many factories cut back production due to a reduction of consumer demand and therefore reduce production-related electrical demand.
Global Markets
The UK has been a net importer of energy for over a decade, and as their generation capacity and reserves decrease the level of importing is reaching an all-time high. Their fuel price's dependence on international markets has a huge effect on the cost of electricity, especially if the exchange rate falls. Being energy dependent makes their electricity prices vulnerable to world events, as well.
Government Regulation
Governments may choose to make electricity tariffs affordable for their population through subsidies to producers and consumers. Most countries characterized as having low energy access have electric power utilities that do not recover any of their capital and operating costs, due to high subsidy levels.
In the United States, federal interventions and subsidies for energy can be classified as tax expenditure, direct expenditures, research and development (R&D), and DOE loan guarantees. Most federal subsidies in 2016 were to support developing renewable energy supplies, and energy efficiency measures.
Power quality
Excessive Total Harmonic Distortions (THD) and not unity Power Factor (PF) is costly at every level of the electricity market. Cost of PF and THD impact is difficult to estimate, but both can potentially cause heat, vibrations, malfunctioning and even meltdowns. Power factor is the ratio of real to apparent power in a power system. Drawing more current results in a lower power factor. Larger currents require costlier infrastructure to minimize power loss, so consumers with low power factors get charged a higher electricity rate by their utility. True power factor is made of displacement power factor and THD. Power quality is typically monitored at the transmission level. A spectrum of compensation devices mitigate bad outcomes, but improvements can be achieved only with real-time correction devices (old style switching type, modern low-speed DSP driven and near real-time). Most modern devices reduce problems, while maintaining return on investment and significant reduction of ground currents. Power quality problems can cause erroneous responses from many kinds of analog and digital equipment, where the response could be unpredictable.
Phase balancing
Most common distribution network and generation is done with 3 phase structures, with special attention paid to the phase balancing and resulting reduction of ground current. It is true for industrial or commercial networks where most power is used in 3 phase machines, but light commercial and residential users do not have real-time phase balancing capabilities. Often this issue leads to unexpected equipment behavior or malfunctions and in extreme cases fires. For example, sensitive professional analogue or digital recording equipment must be connected to well-balanced and grounded power networks. To determine and mitigate the cost of the unbalanced electricity network, electric companies in most cases charge by demand or as a separate category for heavy unbalanced loads. A few simple techniques are available for balancing that require fast computing and real-time modeling.
See also
- Cost of electricity by source
- Energy economics
- Feed-in tariff
- Stranded costs
- Levelised energy cost
- Electricity market
- Electricity liberalization
- Demand response
- Spark spread
- Electricity billing in the UK
- Electricity meter
- Fixed bill
References
External links
- JCM Contour Map
- Electricity Price Forecasting
- Electricity Price Comparison Service UK
- Electricity Price Check BG
Source of article : Wikipedia
0 Comments