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Connecticut   Connecticut Profile

State Profile and Energy Estimates

Profile AnalysisPrint State Energy Profile
(overview, data, & analysis)

Last Updated: June 21, 2018

Overview

Connecticut is located in southern New England on hilly terrain between New York's Hudson River Valley and Rhode Island's Narragansett Bay.1 The state does not have any fossil fuel reserves, but it does have renewable resources.2 The Connecticut River flows south, dividing the state in two, and forms a broad valley that runs through the center of the state.3 That river and other Connecticut rivers provide the state with a renewable resource that has been used since colonial times, and the rivers could provide more hydroelectric power in the future.4,5 In southern Connecticut, the hills give way to the coastal lowlands along the Long Island Sound. Winds that sweep along the shoreline of the Sound give the state a moderate wind energy resource.6 Connecticut is the third-smallest state in land area, and it is the fourth most densely populated state in the nation.7 Its population is concentrated in the southwest, including suburbs of New York City, and along the Connecticut River around the state capital of Hartford and the city of New Haven.8 Municipal solid waste and landfill gas supplied by the state's many residents, along with wood and wood waste, provide Connecticut with abundant biomass resources.9,10

Connecticut is the fifth-lowest energy-consuming state in the nation on a per capita basis. In 2016 the state used less energy per dollar of gross domestic product (GDP) than all other states but New York and Massachusetts.11,12 The transportation sector leads Connecticut's end-use energy consumption, followed closely by the residential sector. The industrial sector consumes the least energy.13 Insurance and financial services; real estate; and professional and business services, all of which are relatively low in terms of energy intensity, are the largest contributors to Connecticut's GDP.14 Other key industries in the state are health care and biosciences; advanced manufacturing; digital media production; fuel cell technology; and tourism.15,16,17

Electricity

Nuclear power and natural gas together supply almost 95% of Connecticut's net electricity generation. A larger share of Connecticut's net generation is provided by nuclear power than in all but three other states. In 2017, the state's 2,088-megawatt nuclear power station, with its two reactors, supplied nearly half of Connecticut's net generation. Natural gas fueled most of the rest. Coal-fired generation supplied more than one-tenth of the state's power a decade ago, but, by 2017, Connecticut's only remaining coal-fired power plant at Bridgeport Harbor Station contributed less than 0.6% of the state's net generation.18,19 Coal-fired power generation in the state will end with the scheduled closure of the Bridgeport Harbor coal plant in 2021.20 Biomass, which provides about 2.5% of state generation, now fuels more electricity generation than coal and petroleum combined.21 Renewable resources and other energy sources provide the remainder. In Connecticut, electricity is generated by independent power producers and municipal utilities.22

Although about three-tenths of the nameplate generating capacity in Connecticut is petroleum-fired, petroleum contributed less than 0.4% of the state's net generation in 2017.23,24 Some of Connecticut's significant petroleum-fired generating capacity is at dual-fired power plants able to burn both petroleum products and natural gas. Higher-cost petroleum fuels are only used in periods of peak power demand, particularly in winter when natural gas supplies are constrained.25,26 As older petroleum-generating units age and maintenance and fuel costs rise, more petroleum units are being shut down. This raises concerns about how to replace their generating capacity.27 The regional grid operator, Independent System Operator-New England (ISO-NE), has promoted demand response as one strategy to maintain grid reliability. Connecticut is second among the New England states in population and in the amount of power reductions its consumers have committed to make during peak demand times and emergencies.28,29

ISO-NE identified several problems that threatened electric power reliability in Connecticut and southern New England as a whole. In response, a group of related transmission projects, known as the New England East-West Solution, were undertaken. The final project, the Interstate Reliability Project, was completed in December 2015 with the addition of a high-voltage transmission line and upgraded substations in Connecticut, Massachusetts, and Rhode Island. With the completion of the New England East-West Solution transmission projects, regional transmission bottlenecks have been removed.30 Connecticut was a net electricity recipient in the past, but the state has been a net provider of electricity to other states since 2009.31

Per capita electricity consumption in Connecticut is among the lowest in the nation.32,33 Demand for air conditioning is low during the mild summer months, and only about one in six Connecticut households use electricity as a primary source for home heating in winter.34,35,36 Connecticut has the highest average retail electricity rates among the Lower 48 states.37 Connecticut promotes energy efficiency and peak demand reduction to help consumers reduce their electricity consumption and their power bills.38

Renewable energy

In 2017, almost nine-tenths of the solar PV generation in Connecticut was small-scale, customer-sited generation.

Renewable resources, including distributed (small-scale, customer-sited) generation, provided slightly less than 5% of Connecticut's net electricity generation in 2017. Biomass fueled more than half of the state's renewable generation, solar power supplied three-tenths, and hydroelectric sources provided most of the rest.39 Most of the state's biomass generating capacity is at facilities fueled by municipal solid waste. Those facilities have more than 200 megawatts of nameplate capacity. Additionally, there is a single 43-megawatt biomass power plant that uses clean wood recovered from construction and demolition as well as wood from forestry and land clearing activities. There are also two landfill gas-fired facilities in the state. A small amount of generating capacity is provided by Connecticut's many hydroelectric facilities, including a pumped storage hydroelectric plant.40 The Rocky River Generating Station in New Milford, Connecticut, was completed in 1928 and was the first pumped-storage hydroelectric project built in the United States.41

All the utility-scale renewable electricity generation in Connecticut came from hydroelectric power and biomass until late 2013, when a small amount of utility-scale solar photovoltaic (PV) generation came online.42,43 By the end of 2017, more than 420 megawatts of utility-scale and small-scale, customer-sited solar PV capacity had been installed in Connecticut.44 The state has initiated a long-term program to encourage distributed generation, such as solar PV panels on residences and businesses.45,46 In 2017, almost nine-tenths of the solar PV generation in Connecticut was distributed generation.47

The state's largest wind potential is on the Long Island Sound coastline, but most of Connecticut lacks wind resources suitable for large-scale generation.48,49 Three offshore wind farm proposals were submitted to the state in early 2018.50 However, Connecticut's first and only utility-scale wind project was installed in the northwestern corner of the state in 2015.51,52 The two wind turbines at that site have a combined capacity of about 5 megawatts.53 ISO-NE has been assessing infrastructure upgrades needed to connect wind resources throughout the region.54

The use of alternative fuels for transportation, including biofuels and electricity, is promoted in Connecticut.55 There are more than 700 public electric vehicle charging locations in Connecticut. The state does not have any ethanol plants, but it does have three public E85 (85% ethanol, 15% motor gasoline) fueling stations.56,57 Connecticut has two biodiesel production plants. The biodiesel plants use multiple feedstocks and have a combined capacity of more than 44 million gallons per year. New England's largest biodiesel plant is in New Haven.58

Connecticut's renewable portfolio standard (RPS) calls for 25% of electricity sold in the state to come from renewable energy sources by 2018 and 28% by 2020. Most of that electricity (20%) is expected to come from sources such as biomass; onshore or offshore wind; solar power; ocean, wave and tidal energy; landfill gas; and fuel cells. The RPS requires that an additional 4% come from trash-to-energy facilities. Another 4% must come from combined heat and power or waste-heat recovery systems that meet specific criteria at commercial and industrial facilities, or from conservation or demand-side management project savings.59 The two investor-owned utilities in Connecticut are required to offer net metering and time-of-use pricing to encourage the use of renewable resources and energy efficiency measures.60,61 In 2020, the state is projected to account for approximately one-third of the New England's renewable energy demand, despite having around one-fourth of the region's population.62,63

Petroleum

Connecticut‘s coastal ports and central river are vital links in supplying petroleum products.

Connecticut does not have any petroleum reserves and does not produce or refine petroleum.64,65 About seven-tenths of the petroleum products that enter Connecticut travel through the port of New Haven, one of the state's three deep water ports. Connecticut's other two deep water ports—New London and Bridgeport—also receive petroleum products.66,67,68 The Connecticut River, to the east, is an important inland water route for sending petroleum products by barge into central Connecticut. River barges carry motor gasoline, diesel fuel, fuel oil, jet fuel, and asphalt through the middle of the state.69 A product pipeline originating in New Haven also runs north to supply Hartford, Connecticut, and central Massachusetts. The pipeline terminates north of Springfield, Massachusetts.70

About four-fifths of the petroleum consumed in Connecticut is used in the transportation sector, primarily as motor gasoline.71,72 Connecticut is one of several states that require the statewide use of reformulated motor gasoline blended with ethanol to reduce smog-forming and toxic pollutants.73 The residential sector, where nearly half of Connecticut households use fuel oil or other petroleum products as the primary energy source for home heating, consumes much of the rest of the petroleum used in the state.74,75 Connecticut, like several nearby states, has phased in the use of ultra-low sulfur diesel (ULSD) heating oil that has only 15 parts per million of sulfur.76,77 Three Northeast Home Heating Oil Reserve sites have been created by the U.S. Department of Energy to hold ULSD as a buffer against possible future fuel disruptions. One site is in Groton, Connecticut.78 The Groton reserve's first release of ULSD was made in November 2012 to alleviate regional fuel delivery shortages resulting from Hurricane Sandy.79

Natural gas

Connecticut does not have any natural gas reserves or production.80,81 Interstate natural gas pipelines supply the state.82 Historically, natural gas was brought in from producing areas in Canada and from the U.S. Gulf Coast and Mid-Continent regions, but natural gas produced from Appalachian shales, particularly the Marcellus Shale of Pennsylvania, is now arriving in the state.83,84,85,86 Additional pipeline projects that could bring more natural gas to the region are planned.87 Almost all of the natural gas that arrives in Connecticut comes through the state of New York. About half of the natural gas that enters the state is used in Connecticut, and the rest is shipped on to Rhode Island or back to New York.88

Assurance of natural gas supply has become a critical energy issue for Connecticut’s electricity generators.

The electric power sector is the largest consumer of natural gas in Connecticut, accounting for almost half of the natural gas used in the state.89 As increasing amounts of natural gas are used for electricity generation in Connecticut and throughout New England, assurance of a sufficient natural gas supply has become a critical energy issue for the region.90 More than one-third of Connecticut households use natural gas as their primary fuel for home heating.91 Like other New England states, Connecticut does not have any underground natural gas storage facilities and depends on pipeline storage and underground storage capacity in nearby states to meet winter peak demand.92

Coal

Connecticut has no coal resources, and the limited amount of coal consumed for power generation in the state is imported from other countries.93,94 In the past, coal was also shipped to Connecticut from West Virginia mines, but no domestically produced coal has been received in the state since 2011.95,96 Connecticut's use of coal for electricity generation has declined sharply in the past decade.97,98 The 50-year-old Bridgeport Harbor plant, the only coal-fired electricity generator still in operation in the state, is scheduled for closure in 2021.99 The plant operator plans to replace it with natural gas-fired generating capacity.100

Endnotes

1 Community Collaborative Rain, Hail & Snow Network, The CoCoRaHS ‘State Climates' Series, Connecticut's Climate, An Overview of Climate in Connecticut, accessed May 13, 2018.
2 U.S. Energy Information Administration (EIA), Connecticut Profile Data, Reserves, accessed May 13, 2018.
3 Community Collaborative Rain, Hail & Snow Network, The CoCoRaHS ‘State Climates' Series, Connecticut's Climate, An Overview of Climate in Connecticut, accessed May 13, 2018.
4 Connecticut Department of Energy and Environmental Protection, Dams In Connecticut: Their History, Use and Regulation, updated March 15, 2012.
5 Connecticut Department of Energy and Environmental Protection, Renewable Energy, Hydropower, updated October 2017.
6 U.S. Department of Energy, Energy Efficiency and Renewable Energy, WINDExchange, Wind Energy in Connecticut, accessed May 13, 2018.
7 U.S. Census Bureau, American FactFinder, Community Facts, United States, 2010 Census, Compare States for Population, Housing, Area, and Density, Table GCT-PH1.
8 U.S. Census Bureau, Connecticut: 2010, 2010 Census of Population and Housing (June 2012), Table 5, Population, Housing Units, Land Area, and Density: 2010; and Percent Change: 1all980 to 2010, p. 7.
9 U.S. EIA, Electricity, Form EIA-860 detailed data, 2016 Form EIA-860 Data, Schedule 3, 'Generator Data' (Operable Units Only).
10 National Renewable Energy Laboratory, Geospatial Data Science, Biomass Maps, accessed May 13, 2018.
11 U.S. EIA, State Energy Consumption Estimates 1960 through 2016, DOE/EIA-0214(2016) (June 2018), Table C12, Total Energy Consumption Estimates, Real Gross Domestic Product (GDP), Energy Consumption Estimates per Real Dollar of GDP, Ranked by State, 2016.
12 U.S. EIA, State Energy Consumption Estimates 1960 through 2016, DOE/EIA-0214(2016) (June 2018), Table C13, Energy Consumption Estimates per Capita by End-Use Sector, Ranked by State, 2016.
13 U.S. EIA, State Energy Consumption Estimates 1960 through 2016, DOE/EIA-0214(2016) (June 2018), Table C10, Energy Consumption by End-Use Sector, Ranked by State, 2016.
14 U.S. Bureau of Economic Analysis, Connecticut, accessed May 14, 2018.
15 Gray, Jason, "Top 5 Industries of Connecticut: Which Parts of the Economy are Strongest?" Newsmax (February 26, 2015).
16 U.S. Bureau of Economic Analysis, Interactive Data, GDP and Personal Income, Regional Data, Annual Gross Domestic Product (GDP) by State, GDP in current dollars, All industries, Connecticut, 2016.
17 Ct.gov, Industries, accessed May 14, 2018.
18 U.S. EIA, Connecticut Electricity Profile 2016, Table 5, Electric power industry generation by primary energy source, 1990 through 2016.
19 U.S. EIA, Electric Power Monthly (February 2018), Tables 1.3.B, 1.4.B, 1.7.B, 1.9.B.
20 Hladky, Gregory B., "Connecticut's Last Coal-Fired Power Plant To Be Closed," Hartford Courant (February 12, 2016).
21 U.S. EIA, Electric Power Monthly (February 2018), Tables 1.3.B, 1.4.B, 1.5.B, 1.15.B.
22 ISO-New England, Connecticut, 2013-14 State Profile (February 2014).
23 U.S. EIA, Electricity, Form EIA-860 detailed data, 2016 Form EIA-860 Data, Schedule 3, 'Generator Data' (Operable Units Only).
24 U.S. EIA, Electric Power Monthly (February 2018), Tables 1.3.B, 1.5.B.
25 Connecticut Department of Energy and Environmental Protection, 2018 Connecticut Comprehensive Energy Strategy (February 8, 2018), Electric Power Sector, ISO-NE Winter Reliability Program, p. 153.
26 Van Welie, Gordon, State of the Grid: 2018, ISO on Background, ISO New England (February 27, 2018), Shifting Fuel Mix Before and During the Two-Week Outbreak of Arctic Cold, p. 23.
27 ISO-New England, Retirements of Non-Gas-Fired Power Plants, accessed May 17, 2018.
28 U.S. Census Bureau, American FactFinder, Community Facts, United States, 2010 Census, Compare States for Population, Housing, Area, and Density, Table GCT-PH1.
29 ISO-New England, Connecticut, 2013-14 State Profile (February 2014).
30 Tiernan, Tom, "Interstate Reliability Project in New England placed into service," Transmission Hub (December 21, 2015).
31 U.S. EIA, Connecticut Electricity Profile, 2016, Table 10, Supply and disposition of electricity, 1990 through 2016.
32 U.S. EIA, Electric Power Monthly (February 2018), Tables 5.4.B.
33 U.S. Census Bureau, Data, State Population Totals and Components of Change: 2010-2017, Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2017 (NST-EST2017-01).
34 U.S. EIA, Residential Energy Consumption Survey (RECS), 2009 RECS Survey Data Housing Characteristics, Air Conditioning in Northeast Region, divisions, and states (HC7.8).
35 Community Collaborative Rain, Hail & Snow Network, The CoCoRaHS ‘State Climates' Series, Connecticut's Climate, An Overview of Climate in Connecticut, accessed May 18, 2018.
36 U.S. Census Bureau, American FactFinder, Connecticut, Table B25040, House Heating Fuel, 2016 American Community Survey 1-Year Estimates.
37 U.S. EIA, Electric Power Monthly (February 2018), Table 5.6.B.
38 Connecticut Department of Energy and Environmental Protection, Energy Efficiency, updated March 20, 2018.
39 U.S. EIA, Electric Power Monthly (February 2018), Tables 1.3.B, 1.10.B, 1.12.B, 1.14.B, 1.15.B, 1.17.B.
40 U.S. EIA, Electricity, Form EIA-860 detailed data, 2016 Form EIA-860 Data, Schedule 3, 'Generator Data' (Operable Units Only).
41 H2O Power, Rocky River Generating Station, accessed May 16, 2018.
42 U.S. EIA, Electricity, Form EIA-860 detailed data, 2016 Form EIA-860 Data, Schedule 3, 'Generator Data' (Operable Units Only).
43 U.S. EIA, Connecticut Electricity Profile 2016, Table 5, Electric power industry generation by primary energy source, 1990 through 2016.
44 Solar Energy Industries Association, Solar Spotlight Connecticut (March 12, 2018).
45 NC Clean Energy Technology Center, DSIRE, Connecticut, Residential Solar Investment Program, updated June 6, 2017.
46 NC Clean Energy Technology Center, DSIRE, Connecticut, Low-Interest Loans for Customer-Side Distributed Resources, updated May 12, 2015.
47 U.S. EIA, Electric Power Monthly (February 2018), Table 1.17.B.
48 U.S. Department of Energy, Energy Efficiency and Renewable Energy, WINDExchange, Connecticut 80-Meter Wind Resource Map, accessed May 16, 2018.
49 U.S. Department of Energy, Energy Efficiency and Renewable Energy, WINDExchange, Connecticut Offshore 90-Meter Wind Map and Wind Resource Potential, accessed May 16, 2018.
50 Turmelle, Luther, "Three wind power projects submitted to Connecticut DEEP," The Hour (April 4, 2018).
51 U.S. EIA, Electricity, Form EIA-860 detailed data, 2016 Form EIA-860 Data, Schedule 3, 'Generator Data' (Operable Units Only).
52 American Wind Energy Association, Connecticut Wind Energy, accessed May 18, 2018.
53 National Renewable Energy Laboratory, 2017 State of Wind Development in the United States by Region (April 2018), Section 5.6.1, p. 73-74.
54 ISO-New England, Transmission, accessed May 16, 2018.
55 U.S. Department of Energy, Energy Efficiency and Renewable Energy, Alternative Fuels Data Center, Connecticut Laws and Incentives, accessed May 16, 2018.
56 U.S. Department of Energy, Energy Efficiency and Renewable Energy, Alternative Fuels Data Center, E85 Fueling Station Locations by State, and Electric Charging Station Locations by State, accessed May 16, 2018.
57 "U.S. Ethanol Plants, All Platforms, Operational," Ethanol Producer Magazine, updated May 11, 2018.
58 "U.S. Biodiesel Plants, operational," Biodiesel Magazine, updated December 13, 2017.
59 Connecticut Department of Energy and Environmental Protection, Public Utilities Regulatory Authority, Connecticut Renewable Portfolio Standard, updated December 2017.
60 NC Clean Energy Technology Center, DSIRE, Connecticut, Net Metering, updated October 4, 2016.
61 Direct Energy, Connecticut-Only Time of Use (TOU) Offer, accessed May 16, 2018.
62 Connecticut Department of Energy and Environmental Protection, 2014 Integrated Resource Plan for Connecticut (March 17, 2015), p. 46.
63 U.S. Census Bureau, Data, State Population Totals and Components of Change: 2010-2017, Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2017 (NST-EST2017-01).
64 U.S. EIA, Connecticut Profile Data, Reserves, accessed May 14, 2018.
65 U.S. EIA, Connecticut Profile Data, Supply & Distribution, accessed May 14, 2018.
66 Connecticut Port Authority, About Us, Why Connecticut?, accessed May 14, 2018.
67 City of New Haven, Port Authority, Terminals, accessed May 14, 2018.
68 Moffatt and Nichol, Connecticut Deep Water Port Strategy Study (September 2012), p. 3-4.
69 City of Middletown, Connecticut, Department of Planning, Conservation, and Development, Harbor Management Plan, Chapter One: Background Information for the Harbor Management Plan, Water and Waterfront Uses and Facilities, accessed May 14, 2018.
70 Buckeye Partners, L.P., System Map, accessed May 14, 2018.
71 U.S. EIA, State Energy Data System, Table F15, Total Petroleum Consumption Estimates, 2016.
72 U.S. EIA, State Energy Consumption Estimates 1960 through 2016, DOE/EIA-0214(2016) (June 2018), Table C8, Transportation Sector Energy Consumption Estimates, 2016.
73 Larson, B. K., U.S. Gasoline Requirements, ExxonMobil (January 2018).
74 U.S. EIA, State Energy Data System, Table F15, Total Petroleum Consumption Estimates, 2016.
75 U.S. Census Bureau, American FactFinder, Connecticut, Table B25040, House Heating Fuel, 2016 American Community Survey 1-Year Estimates.
76 State of Connecticut, Substitute House Bill No. 6360, Public Act No. 13-298, An Act Concerning Implementation Of Connecticut's Comprehensive Energy Strategy And Various Revisions To The Energy Statutes, Sec. 46 (a) (2) (2013), accessed May 16, 2018.
77 U.S. EIA, "Heating Oil Futures Contract Now Uses Ultra-Low Sulfur Diesel Fuel," Today in Energy (May 10, 2013).
78 U.S. Department of Energy, Office of Fossil Energy, Northeast Home Heating Oil Reserve (NEHHOR), accessed May 14, 2018.
79 U.S. Department of Energy, Office of Fossil Energy, Northeast Home Heating Oil Reserve (NEHHOR) Releases, accessed May 14, 2018.
80 U.S. EIA, Connecticut Profile Data, Reserves, accessed May 14, 2018.
81 U.S. EIA, Connecticut Profile Data, Supply & Distribution, Interstate Natural Gas Pipelines, accessed May 15, 2018.
82 U.S. EIA, International and Interstate Movements of Natural Gas by State, Connecticut, 2011-16, accessed May 15, 2018.
83 Spectra Energy Partners, Operations, Algonquin Gas Transmission, accessed May 15, 2018.
84 Kinder Morgan, Natural Gas Pipelines & Facilities, Asset Map, Tennessee Gas Pipeline, accessed May 15, 2018.
85 Iroquois Gas Transmission System, System Map, accessed May 15, 2018.
86 U.S. EIA, International and Interstate Movements of Natural Gas by State, New York and Pennsylvania, 2011-16, accessed May 15, 2018.
87 Enbridge, Access Northeast, accessed May 15, 2018.
88 U.S. EIA, International and Interstate Movements of Natural Gas by State, Connecticut, 2011-16, accessed May 15, 2018.
89 U.S. EIA, Natural Gas Consumption by End Use, Connecticut, Annual, 2012-17.
90 ISO-New England, Natural Gas Infrastructure Constraints, accessed May 15, 2018.
91 U.S. Census Bureau, American FactFinder, Connecticut, Table B25040, House Heating Fuel, 2016 American Community Survey 1-Year Estimates.
92 U.S. EIA, Underground Natural Gas Storage Capacity, by State, Total Storage Capacity, Annual, 2011-16.
93 U.S. EIA, Connecticut Profile Data, Reserves, accessed May 15, 2018.
94 Bailey, Hugh, "Bridgeport's coal plant in for the long run," CT Post (October 11, 2014).
95 U.S. EIA, Annual Coal Distribution Report 2016 (November 2017), By Coal Destination State.
96 U.S. EIA, Annual Coal Distribution Report, Archive, 2011-15, Domestic distribution of U.S. coal by destination state, Connecticut.
97 U.S. EIA, Electricity, Detailed State Data, 1990-2016 Net Generation by State by Type of Producer by Energy Source, accessed May 15, 2018.
98 U.S. EIA, Electric Power Monthly (February 2018), Tables 1.3.B, 1.4.B.
99 U.S. EIA, Electricity, Form EIA-860 detailed data, 2016 Form EIA-860 Data, Schedule 3, 'Generator Data' (Operable Units Only).
100 Hladky, Gregory B., "Connecticut's Last Coal-Fired Power Plant to Be Closed," Hartford Courant (February 12, 2016).