Electricity Grid
What is an ancillary services market?
Ancillary services: 200 flywheels that provide "frequency regulation" to NYISO and PJM Interconnection
There are five types of U.S. electric utilities. They developed during three stages. Know the five types, the three stages, and the initial decade when each began.
Stages: Stage 1 (1890's) Public Power Utilities ("Municipals" or "Munis") Investor-owned Utilities (IOUs) Stage 2 (1930's) Federal Power Programs Cooperatives (Co-Ops) Stage 3 (1970's) Independent Power Producers Utilities: Municipal Electricity Investor-owned Utilities Federal Power Programs Cooperatives Independent Power Producers
Understand the implication of the 2016 Supreme Court ruling in Hughes v. Talen.
State encouraged natural gas generator into the market, agreed to pay difference between clearing price and cost of doing business (including the cost of attracting investors).
What are some ways in which wind and solar are motivating changes to the grid? Why is transmission thought to be so important to the growth of sustainable energy on the grid?
Wind and solar originate in new locations. Ideally located where there are strong primary energy resources (wind and sun). Locations may not correspond to existing grid infrastructure. Perhaps solar / wind should be built near retiring thermal generators...
Understand that a siting process is the approval pathway for a new transmission line. Does the public have a say in the process in the U.S.? What about in China?
"Broadly speaking, there will be insufficient transmission capacity to fully utilize forecasted wind capacity additions over at least the next three years without curtailment, less than-ideal hedging arrangements, or other problems."
What new power did the Federal Power Act of 1935 give to federal agencies vis-à-vis the electricity markets?
1935, the Federal Power Act Federal jurisdiction covered interstate and wholesale electricity generation and transmission markets. States control retail electricity markets.
How did the 1992 Energy Policy Act change U.S. monopoly electricity markets?
1992 Energy Policy Act Authorized FERC to order "wheeling" - the transport of third party power over utility lines owned by a utility. Wheeling represented restructuring of the electricity transmission market.
Be able to explain how different power plants have been deployed traditionally to support based and peak load.
Base load Minimum level of demand on an electrical grid over a span of time, traditionally serviced by powerplants with slow ramp times (e.g., coal and nuclear). Peaker plant (Peakers) Power plants that generally run only when there is a high demand for electricity. These plants can ramp more quickly (e.g., natural gas and hydro).
Know the timeline for municipal / state vs. federal involvement in regulation of the electricity industry. 1900 - 1910s vs. 1930s, 1970s, 1990s.
Between 1907 and 1927, electrical output increased from 5.9 million kWh to 75.4 million kWh. By the late 1920's, problems emerged in the industry 1933 - Tennessee Valley Act Authorized the TVA Board to construct transmission lines to serve "farms and small villages that are not otherwise supplied with electricity at reasonable rates." • 1936 - Rural Electrification Act Financing for electricity infrastructure, money often provided to co-ops • 1937 - first Power Marketing Administration (PMA) Often focused on hydro for electricity In the U.S., they are largely an outgrowth of 1970's restructuring and deregulation efforts.
What is an energy market? What is the difference between a "day ahead" and a "real-time" auction market?
Competitive electricity markets for electricity in the very near term - one day (Day Ahead) or minutes (Real-Time). Producers of electricity offer their output to load serving entities (LSE) and "power marketers" who sell to others. Regulated by FERC. Texas depends upon market demand pricing (up to $9,000 / MWh)
How did the 1978 PURPA legislation change U.S. monopoly electricity markets?
Congressional act passed (1978). Sought to Reduce imported oil consumption Motivate domestic electricity generation and market competition (A crack in the monopoly model) Industrial combined heat and power (CHP) as a new (distributed) energy resource. Later used to spur solar and wind.
What is the name and number associated with the wind energy conversion efficiency limit?
Conversion efficiency limit = 59.3% (Betz's limit)
What electricity industry agencies administer energy markets?
FERC i think or LSE
Know the voltage levels typically found at the generation, transmission, and distribution stages of the U.S. grid.
Generation: < ~20 kV Transmission: > ~100 kV Distribution: < ~20 kV
What is a capacity market? How does a capacity "auction" market work in the electricity industry?
Grid operators (e.g., RTOs, ISOs) must ensure sufficient electricity to meet expected demand - plus a reserve. Generators offer their energy for delivery several years into the future. Operators enter agreements so that they know they can call (i.e., dispatch) electricity from specific facilities in the future. At the end of an auction, suppliers secure a base of compensation - even if plant is not called upon. Regulated by FERC. Texas does not have...
Know the basic layout and method of energy generation for the following renewable energy technologies: Hydro, concentrating solar power, geothermal, wind turbine, and tidal.
Hydro = turbine spin Solar power = pn junction jump Geothermal = turbine spin wind turbine = turbine spin tidal = turbine spin
Know the role / functions that RTO's / ISO's are authorized to play in the U.S. electricity market.
ISO: entities to ensure comparable and nondiscriminatory access to regional transmission systems and to foster electricity generation competition. RTO: Manage bulk power transmission system in region for reliability Ensure non-discriminatory access to transmission grid by customers and suppliers Run bid-based markets to determine economic dispatch of generation Plan regionally for generation and transmission
What is the role of an inverter in a solar photovoltaic system?
Inverter - A device that converts direct current into alternating current.
In which form is electricity most often transmitted through today's electrical grid? Why? For a next generation sustainable energy system grid, what form would we like to transmit electricity over long distances? (Discussed in the Supergrids section.)
Its AC After WW II, developments of solid-state electronics made it possible to transform direct current (DC) voltages in a manner similar to what had been done with alternating current (AC) since the 19th century. DC transmission should still occur at high voltage to minimize resistance losses. Biden has proposed $100 B for transmission.
What strategies have been recommended to ease approval of new transmission line construction?
More aggressive use of existing authority. Less consideration for private property rights. State or federal action to facilitate greater use of demand response, energy storage, and distributed generation resources. Assertion of federal supremacy A technology solution? Smart Wires, Inc., power flow control.
In recent years, why have merchant providers found it difficult to construct new high voltage transmission lines in the U.S.? What are some reasons that states in particular have contributed to difficulty in approving new transmission lines?
Multiple questions of difficulty: Is a transmission line always a public use? What if the line is built by a private "merchant" transmission company, not a public utility? What if line is built to provide power solely to customers in other states? What if the line is to provide power to a single, large, private customer? States: State statutes may require consideration of only in-state needs or benefits. States may not be empowered to consider the regional benefits of a proposed project. Some state laws do not allow merchant providers to obtain siting permits or exercise eminent domain. In some states, investor-owned utilities have the "right of first refusal."
Be able to explain the difference between capacity factor and nameplate capacity.
Nameplate capacity - the nominal full generating capacity of facility (kW, MW, GW) [Mine: 14.95 kW] Capacity factor - the actual energy output divided by the maximum possible energy output over a given period of time (percentage).
Be able to explain how the core structure of a solar cell generates electricity.
P-N junctions (look at other electricity set) Photons hit the solar cell. Their energy is absorbed by valence electrons that are promoted to the conduction band.
What is the equation used to estimate the maximum power generation capacity of a hydroelectric power plant?
Power (Watts) = h r q g h r = Water density (1000 kg/m3 ) g = 9.81 m/sec2 q = Water flow (m3 /sec) h = falling height (m)
How did the 1996 FERC Orders 888 and 889 change U.S. monopoly electricity markets?
Required transmission owners to offer nondiscriminatory service to others: "Open access." Separated generation / transmission. Encourage open publication of market-clearing prices for electricity in competitive markets. Suggested (did not require) formation of independent system operators (ISOs) - entities to ensure comparable and nondiscriminatory access to regional transmission systems and to foster electricity generation competition.
Know the early timeline of development that set the stage for today's electricity industry, i.e., scientific discovery (1830's), engineering invention (1870 / 80s), business development (1880s).
Scientific discovery 1831, Electromagnetic induction • Engineering invention 1877, First U.S. patent for an electricity generator 1879, First practical light bulb was invented 1885, AC transformer • Business opportunity 1879, Cal. Electric Light Company began op. in San Fran. 1882, Pearl St. station in NYC 1886, Great Barrington, MA (transformers and distribution)
Know the difference between a solar cell, module/ panel, and array.
Solar (Cell < Module < panel < Array)
As an independent power producer, what steps are involved in establishing a new electricity generation station in Virginia?
Step 1: Obtain a "Certificate of Convenience and Public Necessity" from the State Corporation Commission. Certificate not required for 5 MW or smaller facility. (Source 1, Source 2) "The following information shall be provided for all proposed (i) electric generating facilities with rated capacities..." Step 2: Obtain necessary environmental permits Virginia Dept. of Environmental Quality (S1, S2) Federal Land Managers, EPA (NEPA review) Establishing a Generator in VA Step 3: Comply with FERC (and NERC - North American Electric Reliability Corp.) connection rules (Source) Possible Step 4: Bid (price & quantity) with PJM to earn a Capacity Market contract. This is a "uniform price" market. Possible Step 5: Bid (price & quantity) with PJM in their forward markets. These are "uniform price" markets. Day-Ahead Real-Time (Balancing) Establishing a Generator in VA Possible Step 6: Sign a Power Purchase Agreement with a Muni, Co-op, or IOU in state, perhaps using PURPA guidance. Possible Step 7: Sign a Power Purchase Agreement with a large business that consumes more than 5 MW of electricity.
This century, how does the amount of long-distance transmission capacity construction in China compare to the U.S.?
The US pales in comparison. Like its a struggle for the US and China got a bunch
How does an AC transformer work? When was it invented? What is the difference between a step-up and a step-down transformer? What are the two elements of an AC generator that are also found in a transformer, required to enable a change in voltage? Recognize the basic equation for voltage transformation. The equation relates voltage to turns of a coil.
The alternating current (AC) transformer was invented in 1885. In the 19th century, and for most of the 20th century, there was no viable, comparable solution for DC voltage transformation. Allows engineering designers to prepare power (P) for movement as different ratios of current (I) and voltage (V). Equation: Vp/Vs = Np/Ns
Where in U.S. law is the concept of eminent domain established? What is the concept of just compensation? What entities in the U.S. have been grant the right to apply eminent domain in the arena of electricity systems? Which similar entities are not able to apply eminent domain?
The governmental right to take private property for public use / benefit upon payment of just compensation. Fair market value of property that must be paid to a land owner who has had his or her property taken by the government.
What is the role of a turbine vane? How does a modern turbine vane differ in design from an old-fashioned vane on a farm in the 19th century?
The shape of the turbine vane is typically intended to produce lift - just like in the wing of an airplane. Invented in 1884. Used pressurized steam to rotate a shaft. In the mid-1990's, 90% of U.S. electricity generation came from steam turbines
How do competitive wholesale electricity markets work?
These markets focus upon the buying and selling of power between electricity generators and resellers such as utilities, independent power producers, and electricity marketers (B2B).
What are the functions of a generator, a turbine, and a transformer in electricity generation? Understand how these components work together to initiate electricity flow across the grid.
Turbine Converts linear flow to rotation Generator Converts motion to electricity Transformer Modifies the ratio of current to voltage in a conductor
There are three main U.S. electricity interconnects and a fourth in the main part of North America. What are the four sub-grids or interconnects?
Western, Texas, Eastern, Quebec
Understand the difference between wholesale and retail markets.
Wholesale - provide to middle man. retail - sale to final customers.
A critical issue in electricity transmission is power loss along a conducting wire. The following two phenomenon lead to power loss and are of particular concern during long-distance electricity transmission.
a) For both AC and DC electricity, the voltage drops as it flows along a wire. The drop is directly proportional to the current passing down the wire (Vdrop =IR). This loss in AC or DC is termed resistance. To counter this effect in long distance transmission, high voltage / low current is employed. b) For AC electricity, there is an additional power loss that occurs along a wire. It originates as the current lags behind the voltage. This loss in AC is termed reactance. While reactance can be compensated for along a wire, that periodic compensation requires equipment and Page 10 of 20 costs money. (This concept was discussed during the Supergrids section of Emerging Innovation.)
Why was alternating current favored for electricity transmission throughout the 20th century?
a) In the 20th century, scientists and engineers knew how to transform the voltage of alternating current: low voltage at the power plant high voltage for transmission low voltage at the consumer's point of use. They did not have a comparable ability to change the voltage of direct current. DC transformers (based upon solid-state electronics) were invented in the 1950's and commercialized in the 1980's. b) The use of alternating current enabled construction of centralized power generation stations. Power stations are expensive. By centralizing such facilities, economies of scale could be achieved, i.e., electricity could be provided in the least expensive way to many customers.
What is the equation for voltage drop in a wire? Given that voltage drop, what strategy is used to transmit direct current or alternating current-based power over long distances? Can you look at the voltage drop equation and explain how to optimize long distance power transmission?
deltaVoltage = (Resistivity in a wire*Current*length)/(Cross sectional area)
If a single solar cell generates 0.7 V of electricity, how does one organize cells in a module to achieve higher voltages, e.g. 24 V? How does one organize cells to achieve higher currents?
in series, so one cell is attached to another cell and so on. Increase current by attaching in parallel, so one node connects to 2 different cells
What are four factors that contribute to variability in solar photovoltaic energy production?
location Time of Day Weather Seasonal
Understand the electricity industry implications of the Supreme Court's 1927 ruling in Rhode Island v. Attleboro Steam.
this case involves the constitutional validity of an order of the Public Utilities Commission of Rhode Island putting into effect a schedule of prices applying to the sale of electric current in interstate commerce.
Appreciate the diversity of electrical industry structure across the U.S. today.
yeah
Broadly, deregulation is a legal change that seeks to inject competition into the electricity markets. Restructuring involves the actual systemic moves away from vertically-integrated monopolies.
yeah
In the early years of the electricity industry, why were monopolies allowed to develop? In Virginia, IOU's, Munis, and Co-ops all have monopoly rights.
yeah
Know that collectively, utilities and regulatory agencies are tasked with ensuring reliable, affordable, universally-available, and (increasingly) clean electricity to customers.
yeah
Know the basic layout of these power plants: simple cycle combustion turbine, combined-cycle power plant, combined heat and power, and nuclear.
yeah
There are important state and federal electricity regulatory agencies. Know the two Virginia state agencies typically involved in regulating electric utilities (i.e., State Public Service Page 11 of 20 Corporations, State Departments of Environmental Protection) and their roles. At the federal level, know FERC and the duties it is empowered to undertake.
yeah
