Samsø, Denmark, Strives to Become a Carbon-Neutral Island

Photo of 10 wind turbines from a frontal view, which makes the turbines appear to be a single turbine with rotor blades pointing in many directions toward the sky above.

Ten large offshore wind turbines have helped make it possible for Samsø island to become energy independent.

Although Samsø is not an Energy Development in Island Nations (EDIN) partner or project participant, it serves as an example of the ground breaking work islands around the world are doing to address the energy challenges they face. Samsø stands on the leading edge of energy sustainability, having achieved 100% energy independence in less than five years as a result of a community-wide commitment to renewable energy and energy efficiency.

Through a plan to promote renewable energy use, in 2007, the Danish island of Samsø reduced its annual energy balance to the extent that it now produces as much renewable energy as it consumes from the mainland. Samsø also cut its sulfur dioxide and nitrous oxide emissions by 71% and 41%, respectively. The island achieved these benchmarks by generating energy from wind, sun, and straw-fired heating plants, and by employing residential energy efficiency measures.

Learn more about the project's plans:

Island Background

Samsø is located 15 kilometers (km) off the east coast of the Jutland Peninsula, which comprises most of Denmark. The island is 114 square km and is home to nearly 4,000 inhabitants. Samsø's electricity demand is approximately 27,000 megawatt-hours (MWh), roughly equal to the amount of electricity the island's 11 land-based turbines produce. Samsø's economy is based primarily on agriculture and tourism.

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Project Partners

The following participants were key to the success of this project:

  • NRGi: Local utility company, responsible for all electricity distribution on Samsø
  • Danish Energy Authority: Provided grants for a district heating plant and energy efficiency incentives
  • Kremmer Jensen: Local company that owns one straw-fired heating plant
  • Samsø Energy Company: Partnered with Kremmer Jensen on the Onsbjerg straw-fired heating plant; founded in 1998 to implement projects on the island; closed in 2005
  • Samsø Energy and Environment Office: Founded in 1997 and tasked with promoting renewable energy and assisting Samsø citizens who want to start their own renewable energy projects
  • Samsø Offshore Wind Co.: A collaboration among the Samsø Commercial Council, Samsø Farmers' Association, Samsø Municipality, and Samsø Energy and Environment Office, each of which signed a contract for an offshore wind project. The collaboration was designed to ensure that Samsø owned the project's profits while involving key local players.
  • Cooperatives: Two of the island's 11 land-based wind turbines are owned by a local windmill cooperative (for instance, in Permelille, about 450 people own nearly 5,400 shares of the wind turbine).
  • Private investors: Investors, such as local farmers, own 9 of the island's 11 land-based wind turbines.

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Project Motivation

The project began with Samsø winning a Danish government-sponsored contest for island communities to create the best plan to wean themselves from fossil fuels by 2008. This made the goal of becoming energy independent a grassroots community movement.

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Project Timeline

In 1993, the first district straw-fired heating plant was built. In 1997, Samsø won the government's renewable energy contest. By 2003, Samsø was exporting electricity instead of importing it.

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Project Strategy

The Samsø project incorporated several different strategies:

1. Electricity generation

Shares of the planned wind turbines were reserved for the general public, so that all citizens could have the opportunity to invest in wind development. In addition, all of the turbines on the three land-based wind farms were manufactured by Bonus Energy, which has since been purchased by Siemens.

Samsø Wind Farms
Name Year Erected No. of Turbines (1 MW) Total Annual Production Total Price (USD) State Guarantees Owners




7,600 MWh


$0.12/kWh for first 12,000 full load hours and $0.086/kWh for first 10 years

Wind cooperative owns one, and the other two are privately owned.




7,600 MWh


$0.12/kWh for first 12,000 full load hours and $0.086/kWh for first 10 years

Wind cooperative owns one, and the other two are privately owned.




12,700 MWh


$0.12/kWh for first 12,000 full load hours and $0.086/kWh for first 10 years

All five are owned by private investors.

2. Heating

Energy Efficiency

The main focus for increasing overall energy efficiency has been switching homes from electrical heaters to other heating sources. Additionally, from 1997 to 2005, there was a 10% decrease in heat consumption, attributable to closing the pig slaughterhouse and slight depopulation.

From 1999 through 2002, the Danish Energy Authority provided grants for pensioners to make their homes more energy efficient. The pensioners' own investment had to be at least DKK 25,000 (~US $5,000), and the grant could be up to 50% of investment, with a maximum of DKK 25,000. In total, 192 homes were renovated. This led to an increase in revenue of DKK 8 million (~US $1.4 million) for local carpenters and builders.

Between 1997 and 2002, the Danish Energy Authority paid to have energy advisers audit 113 homes in Ballen/Brundby as well as 31 in Onsbjerg and the small villages of østerby, Besser, and Pillemark/Hårdmark. In addition to performing home energy audits, the advisers recommended residential energy-saving strategies. They also worked to gauge public support for the proposed heating plants in Ballen/Brundby and Onsbjerg.

In 2001 and 2002, the Danish Energy Authority also paid to implement demonstration projects for insulation, using five houses to show alternative insulation products. This gave local businesses a higher level of expertise regarding insulation. The two largest carpentry firms participated in the demo projects and later (in 2005) built the Samsø Energy Academy building.

3. Renewable resources

In 2005, renewable energy accounted for 65% of heat production.

4. NRGi pricing model

Before the heating plant was built, homeowner participation was voluntary and incentivized with a low joining fee (DKK 80; ~US $14). In some areas, connecting to an existing plant is mandatory. The cost to connect to an existing plant is higher (DKK 36,000; ~US $6,000).

  • District heating plant in Tranebjerg—established 1993/1994
    • Straw-fired (wheat and rye straw) heating plant
    • Total output: 3 MW
    • Initial investment cost: DKK 26.3 million (~US $5.3 million)
    • Price per MW (2010): DKK 829 (~US $147)
    • Joining fee: DKK 25,000 (~US $4567) + DKK 1,200 (~US $219) per meter of piping. Annual subscription fee: DKK 3,500 (~US $639) (2011)
    • Consumers: 400
    • Commercially owned and operated by NRGi
    • By 2005, this facility produced 90% of Tranebjerg's heat supply
  • District heating plant in Nordby/Mårup—established 2001/2002
    • 2,500-square-meter solar collectors for heating (produce ~20% of plant's heat)
    • 900-kW boiler fueled with wood chips (1,250 tons annually) from local forests (produces remaining ~80% of plant's heat)
    • Total output: 1.6 MW
    • Initial investment cost: DKK 20.4 million (~US $4.1 million); DKK 9 million subsidized by Danish Energy Authority
    • Price per MW (2010): DKK 755 (~US $134)
    • Joining and annual subscription rate per year: DKK 2,817 (~US $519)
    • Consumers: 178 (80% of two villages)
    • Commercially owned and operated by NRGi
  • District heating plant in Onsbjerg—established 2002
    • Straw-fired (wheat and rye straw) heating plant (600 tons straw/year)
    • Total output: 0.8 MW
    • Initial investment cost: DKK 8.5 million (~US $1.6 million); subsidized by DKK 3 million grant from Danish Energy Authority
    • Price per MW: DKK 665 (~US $133)
    • Joining fee: DKK 45,000 (~US $8220). Annual subscription fee: DKK 2,600 (~US $474)  
    • Consumers: 76
    • Kremmer Jensen Brothers, a local company, owns and runs the plant
  • District heating plant in Ballen/Brundby—established 2004/2005
    • Straw-fired (wheat and rye straw) heating plant
    • Total output: 1.6 MW
    • Initial investment cost: DKK 16.2 million (~US $3.2 million); subsidized by DKK 2.5 million grant from Danish Energy Authority
    • Price per MW: DKK 735 (~US $130)
    • Joining fee: DKK 45,000 (~US $8220). Annual subscription fee per year: DKK 4,050 (~US $746)
    • Consumers: 240
    • 100% consumer-owned; planning began in 2002, with DKK 2.5 million (~US $500,000) from Danish Energy Authority

5. Offsets

The Samsø transportation sector is not carbon-free, so the island offsets use of fossil fuels for transportation by selling offshore wind power to the mainland.

10 large offshore wind turbines

  • Annual production: 77,500 MWh
  • Samsø Offshore Wind Co. oversaw the contract
  • The Municipality of Samsø financed five turbines, private investors financed three, and the last two were financed by approximately 1,500 shareholders (total) from two separate companies
  • The Danish Energy Authority funded preliminary seafloor and environmental studies

6. Additional programs

  • Job training and certification of blacksmiths, plumbers, and heating service providers/technicians through courses at The Danish Technological Institute
  • Outreach to homes far from towns and heating plants to encourage homeowners to implement renewable energy and energy efficiency measures (e.g., work with energy advisors to calculate plans for heating the homes)
  • Additional small-scale renewable energy production (micro-wind turbines, small-scale solar installations)
  • Establishment in 2006 of the Samsø Energy Academy to disseminate lessons learned during the project. The academy building is highly energy efficient, which attracts visits from energy planners and leads to increased tourism. The academy also houses the Samsø Energy Agency (an offshoot of Samsø Energy Company), Energy Service Denmark, and the Samsø Energy and Environment Office.

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Project Financing

Samsø used a variety of financing options. The local utility (NRGi) owns and operates two heating plants. Private investors (e.g., local farmers) own nine of 11 land-based wind turbines and can depend on a government-guaranteed price for electricity. Communities formed local wind cooperatives to buy two of the 11 land-based wind turbines. One heating plant is community owned and was facilitated by a grant from the Danish Energy Authority. To meet the carbon-negative goal, the Danish government, the European Union, local households and companies, the Samsø municipality, and the energy utility cooperatively invested a total of 55 million euros.

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Major Hurdles and Lessons Learned

Samsø's success can, in part, be attributed to the high level of community involvement. This involvement includes community ownership of facilities, cooperative and private investment, creative use of local resources (e.g., the straw-fired plant), and a committed local champion (Søren Hermansen). Additionally, the island has been able to sell electricity from its offshore turbines to the mainland.

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Current Status

Although the Samsø project has been completed, the island continues to produce renewable energy and offset the energy the population consumes. Samsø recently joined the ISLE-PACT program, comprising 12 different groups dedicated to meeting or exceeding the EU sustainability target of reducing CO2 emissions by at least 20% by 2020.


The following resources provided information about this project.

The Danish Technological Institute

Søren Hermansen, Samsø Energy Academy

Samsø Energy Academy

Samsø, a Renewable Energy-Island: 10 years of Development and Evaluation.

ISLE-PACT Sustainable Energy Actions for Islands

Kolbert, E. "The Island in the Wind," The New Yorker, July 7, 2008.

Williams, F. "A Mighty Wind," Outside, February 2007.

Walsh, B. "Soren Hermansen—Hero of the Environment 2008," Time, September 17, 2008.

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