Hydropower, Wind Power

New Hydro

Issue 6 and Volume 15.

Design of tidal plant being studied for Brazil

The 40-year-old Bacanga Dam and Reservoir in São Luís in northern Brazil is being studied as a site for a pilot tidal power plant. Researchers in the Department of Ocean Engineering at the Federal University of Rio de Janeiro are studying the feasibility of developing the plant.

The plant would take advantage of the existing dam, gates, and other equipment. Construction would involve installing an intake system and turbine-generator units.

The equipment being considered includes a vertical axis, helical type turbine with an external generator. Two turbine-generator sets would be installed, one to generate when the tide is flowing from the ocean to the reservoir and one when flow is from the reservoir to the ocean.

CNPQ, an agency of the Brazilian Science and Technology Ministry, is financing the studies, which are to be completed in 2008.

U.K. panel backs government ownership of Severn

The United Kingdom’s Sustainable Development Commission (SDC) is backing development of the 8,640-mw Severn Barrage tidal power project. However, the SDC urges that the government own the project to protect environmental and social interests.

A feasibility study is under way regarding development of the project on Severn Estuary between England and Wales. Using conventional hydroelectric equipment, the project would generate an estimated 17 terawatt-hours per year.

SDC estimated the project would cost 15 billion pounds (US$30 billion). It said a government-led project would be cheaper to fund and would avoid the risks involved in privately run energy projects.

In addition to government ownership, SDC said the project should comply with European directives on wildlife habitat and must not divert the government away from wider action on climate change. Carbon-free power is essential to help Britain meet its goal of cutting carbon dioxide emissions 20 percent below 1990 levels by 2020.

The funnel-shaped estuary has the second highest tidal range in the world at more than 14 meters.

The government said the feasibility study also will examine the potential for other tidal power sites in the United Kingdom.

Scotland approves 3-mw Scottish Power wave farm  

Scottish Power plans to have its 3-mw wave power farm at the European Marine Energy Center (EMEC) running by 2008. Earlier this year, the Scotland government granted a planning consent for a wave farm, giving permission to Scottish Power to develop the test project at the EMEC being developed at Orkney.

Scottish Power, which was recently acquired by Spanish utility Iberdrola, says it plans to develop the world’s biggest wave power generation project at EMEC. The utility said the farm could cost 10 million pound (US$19.5 million).

Scottish Power subsidiary CRE Energy Ltd. applied for the government consent in June 2007. It received 4.141 million pounds (US$8.1 million) from the Scottish Executive to deploy the four Ocean Power Delivery 750-kw Pelamis wave power generators.

The four 160-meter-long Pelamis “Sea Snake” wave power generators developed by Ocean Power Delivery should produce enough power for 3,000 homes, Scottish Power said.

In May 2007, Scottish Power formed a company with Hammerfest Strom, 47 percent owned by Norwegian oil firm Statoil, to test its tidal power technology with a full-scale turbine in Scottish waters. The companies plan to install an “underwater windmill” offshore Britain in 2009.

Pumped-storage project planned off Dutch coast

A partnership of consultants, engineers, and designers proposes to build a wind-powered pumped-storage “energy island” off the coast of the Netherlands that would utilize commercially available hydropower generators.

KEMA of the United States, a unit of N.V. KEMA of the Netherlands, is working on the project in partnership with engineering firms Bureau Lievense and technology illustrators Rudolph and Robert Das. They designed the energy island, to store power from an offshore wind farm, as the result of an ongoing feasibility study for Dutch energy companies.

The project, dubbed an “inverse offshore pump accumulation station,” would be built on an artificial island comprising a ring of dikes surrounding a 50-meter-deep “subsurface” reservoir. The island would be built of materials dredged to deepen the interior reservoir. KEMA estimated the project would have a maximum capacity of 1,500 mw.

When there is a surplus of wind energy, the power would be used to pump seawater out of the reservoir into the ocean. When there is a shortage of wind power, seawater would be allowed to flow back into the reservoir through hydro turbine-generators to produce energy.

KEMA said the next phase of the ongoing study is to further analyze costs and benefits of additional regulating reserve, carbon dioxide reduction, and environmental effects.

U.K. grants final consent for Wave Hub testing facility  

The United Kingdom government has granted final consent for the Wave Hub ocean energy test facility to be constructed off the coast of Hayle, Cornwall, England.

The 28 million pound (US$54.8 million) Wave Hub project is a proposed underwater cable system to connect wave energy projects to the national grid. The sponsor of the facility, South West of England Regional Development Agency (RDA), earlier this year approved 21.5 million pounds (US$42 million) for Wave Hub, the final amount of funds needed to build the ocean power project testing site.

Four developers have been chosen to test technologies at the site:

  • Fred Olsen Ltd. of Norway, which plans to install floating buoys attached to a floating platform that converts wave energy to electricity;
  • Ocean Power Technologies of the U.K., which intends to install a 5-mw project based on its PowerBuoy wave energy converter;
  • Ocean Prospect Ltd. and E.ON UK of the U.K., which intend to test ten Pelamis P750 devices developed by Ocean Power Delivery; and
  • Oceanlinx Ltd. of Australia, which plans to combine Oscillating Water Column technology with its patented turbine technology.

The project is to provide the world’s biggest testing ground for wave power devices, an area of 4 kilometers by 2 kilometers, RDA said. The installation is expected to generate up to 20 mw of clean energy, enough to power 7,500 homes.

Norway to build world’s first osmotic power plant

Norwegian utility Statkraft plans to begin building the world’s first prototype osmotic power plant in 2008.

Osmotic power uses osmosis, the movement of water across a partially permeable membrane. In an osmotic plant, sea water and fresh water are separated by a membrane. The sea water draws the fresh water through the membrane, increasing pressure on the sea water side. The increased pressure is used to produce power.

Statkraft said the 2- to 4-kw project would be built at a plant of paper pulp manufacturer Sodra Cell Tofte at Hurum in Buskerud, Norway. It said the seaside site would provide fresh water and sea water, as well as a link to established infrastructure.

The utility said the technical potential for osmotic power in Norway is 12 terawatt-hours, or 10 percent of Norway’s current production.