Wind hybrid power systems

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A hybrid wind and solar power system Hybrid Power System.gif
A hybrid wind and solar power system

Wind hybrid power systems combines wind turbines with other storage and/or generation sources. One of the key issues with wind energy is its intermittent nature. This has led to numerous methods of storing energy.

Contents

Wind-hydro system

A wind-hydro system generates electric energy combining wind turbines and pumped storage. The combination has been the subject of long-term discussion, and an experimental plant, which also tested wind turbines, was implemented by Nova Scotia Power at its Wreck Cove hydro electric power site in the late 1970s, but was decommissioned within ten years. Since, no other system has been implemented at a single location as of late 2010. [1]

Wind-hydro stations dedicate all, or a significant portion, of their wind power resources to pumping water into pumped storage reservoirs. These reservoirs are an implementation of grid energy storage.

Advantages

Wind and its generation potential is inherently variable. However, when this energy source is used to pump water into reservoirs at an elevation (the principle behind pumped storage), the potential energy of the water is relatively stable and can be used to generate electrical power by releasing it into a hydropower plant when needed. [2] The combination has been described as particularly suited to islands that are not connected to larger grids. [1]

Proposals

During the 1980s, an installation was proposed in the Netherlands. [3] The IJsselmeer would be used as the reservoir, with wind turbines located on its dike. [4] Feasibility studies have been conducted for installations on the island of Ramea (Newfoundland and Labrador) and on the Lower Brule Indian Reservation (South Dakota). [5] [6]

An installation at Ikaria Island, Greece, had entered the construction phase as of 2010. [1]

The island of El Hierro is where the first world's first wind-hydro power station is expected to be complete. [7] Current TV called this "a blueprint for a sustainable future on planet Earth". It was designed to cover between 80-100% of the island's power and was set to be operational in 2012. [8] However, these expectations were not realized in practice, probably due to inadequate reservoir volume and persistent problems with grid stability. [9]

100% renewable energy systems require an over-capacity of wind or solar power. [10]

Wind-hydrogen system

Wind hydrogen.JPG

One method of storing wind energy is the production of hydrogen through the electrolysis of water. This hydrogen is subsequently used to generate electricity during periods when demand can not be matched by wind alone. The energy in the stored hydrogen can be converted into electrical power through fuel cell technology or a combustion engine linked to an electrical generator.

Successfully storing hydrogen has many issues which need to be overcome, such as embrittlement of the materials used in the power system.

This technology is being developed in many countries. In 2007 there was an IPO of an Australian firm called Wind Hydrogen that aimed to commercialise this technology in both Australia and the UK. [11] In 2008 the company changed its name and turned its operations to fossil fuel exploration. [12]

In 2007, technology test sites included:

CommunityCountryWind MW
Ramea, Newfoundland and Labrador [13] Newfoundland, Canada 0.3
Prince Edward Island Wind-Hydrogen Village [14] PEI, Canada
Lolland [15] Denmark
Bismarck [16] North Dakota, US
Koluel Kaike [17] Santa Cruz, Argentina
Ladymoor Renewable Energy Project (LREP) [18] Scotland
Hunterston Hydrogen ProjectScotland
RES2H2 [19] Greece 0.50
Unst [20] Scotland0.03
Utsira [21] Norway0.60

Wind-diesel system

Wind Hydrogen system on Ramea in Canada Ramea Wind diesel Aug 2007.JPG
Wind Hydrogen system on Ramea in Canada

A wind-diesel hybrid power system combines diesel generators and wind turbines, [22] usually alongside ancillary equipment such as energy storage, power converters, and various control components, to generate electricity. They are designed to increase capacity and reduce the cost and environmental impact of electrical generation in remote communities and facilities that are not linked to a power grid. [22] Wind-diesel hybrid systems reduce reliance on diesel fuel, which creates pollution and is costly to transport. [22]

History

Wind-diesel generating systems have been under development and trialled in a number of locations during the latter part of the 20th century. A growing number of viable sites have been developed with increased reliability and minimized technical support costs in remote communities.

Technology

The successful integration of wind energy with diesel generating sets relies on complex controls to ensure correct sharing of intermittent wind energy and controllable diesel generation to meet the demand of the usually variable load. The common measure of performance for wind diesel systems is Wind Penetration which is the ratio between Wind Power and Total Power delivered, e.g. 60% wind penetration implies that 60% of the system power comes from the wind. Wind Penetration figures can be either peak or long term. Sites such as Mawson Station, Antarctica, as well as Coral Bay and Bremer Bay in Australia have peak wind penetrations of around 90%. Technical solutions to the varying wind output include controlling wind output using variable speed wind turbines (e.g. Enercon, Denham, Western Australia), controlling demand such as the heating load (e.g. Mawson), storing energy in a flywheel (e.g. Powercorp, Coral Bay). Some installations are now being converted to wind hydrogen systems such as on Ramea in Canada which is due for completion in 2010.

Communities using wind-diesel hybrids

The following is an incomplete list of isolated communities utilizing commercial wind-diesel hybrid systems with a significant proportion of the energy being derived from wind.

CommunityCountryDiesel (in MW)Wind (in MW)PopulationDate CommissionedWind Penetration (peak)Notes
Mawson Station [23] Antarctica 0.480.602003>90%
Ross Island [24] Antarctica 31200965%
Bremer Bay [25] Australia1.280.602402005>90%
Cocos [26] Australia1.280.08628
Coral Bay Australia2.240.60200793%
Denham [27] Australia2.611.026001998>70%
Esperance [28] Australia14.05.852003
Hopetoun Australia1.370.603502004>90%
King Island Australia6.002.5020002005100%Currently (2013) expanding to include 2 MW Diesel-UPS, 3 MW / 1.6  MWh Advanced Lead Acid battery and dynamic load control through smart grid [29]
Rottnest Island [30] Australia0.640.602005
Thursday Island, Queensland Australia0.45 ?
Ramea [31] Canada2.780.406002003Being converted to Wind Hydrogen
Sal Cape Verde 2.820.60200114%
Mindelo Cape Verde 11.200.9014%
Alto Baguales Chile 16.92.0018,703200220%4.6 MW hydro
Dachen Island [32] China1.300.1515%
San Cristobal, Galapagos Island [33] Ecuador 2.42007Expanding to cover 100% of island's energy needs by 2015
Berasoli [34] Eritrea 0.080.03Under tender
Rahaita Eritrea 0.080.03Under tender
Heleb Eritrea 0.080.03Under tender
Osmussaar [35] Estonia  ?0.032002
Kythnos Greece 2.770.31
Lemnos Greece 10.401.14
La Désirade Guadeloupe 0.880.1440%
Sagar Island [36] India0.280.50
Marsabit Kenya 0.300.1546%
Frøya Norway0.050.06100%
Batanes [37] Philippines 1.250.182004
Flores Island [38] Portugal 0.6060%
Graciosa Island Portugal 3.560.8060%
Cape Clear Ireland 0.070.06100198770%
Chukotka Russia0.52.5
Fuerteventura Spain0.150.23
Saint Helena [39] [40] UK0.481999–200930%
Foula UK0.050.063170%
Rathlin Island UK0.260.99100%
Toksook Bay, Alaska [41] United States1.100.305002006
Kasigluk, Alaska [41] United States1.100.305002006
Wales, Alaska [42] United States0.401602002100%
St. Paul, Alaska [43] United States0.300.68100%
Kotzebue, Alaska United States11.00199935%
Savoonga, Alaska [41] United States0.202008
Tin City, Alaska United States0.232008
Nome, Alaska United States0.902008
Hooper Bay, Alaska [41] United States0.302008

Wind-diesel hybrids at mining sites

Recently, in Northern Canada wind-diesel hybrid power systems were built by the mining industry. In remote locations at Lac de Gras, in Canada's Northwest Territories, and Katinniq, Ungava Peninsula, Nunavik, two systems are used to save fuel at mines. There is another system in Argentina. [44]

Wind-compressed air systems

At power stations that use compressed air energy storage (CAES), electrical energy is used to compress air and store it in underground facilities such as caverns or abandoned mines. During later periods of high electrical demand, the air is released to power turbines, generally using supplemental natural gas. [45] Power stations that make significant use of CAES are operational in McIntosh, Alabama, Germany, and Japan. [46] System disadvantages include some energy losses in the CAES process; also, the need for supplemental use of fossil fuels such as natural gas means that these systems do not completely make use of renewable energy. [47]

The Iowa Stored Energy Park, projected to begin commercial operation in 2015, will use wind farms in Iowa as an energy source in conjunction with CAES. [48]

Wind-solar systems

Horizontal axis wind-turbine, combined with a solar panel on a lighting pylon at Weihai, Shandong province, China Eole et Helios.jpg
Horizontal axis wind-turbine, combined with a solar panel on a lighting pylon at Weihai, Shandong province, China

A combine use of wind-solar systems results, in many places, to a smoother power output since the resources are anti-correlated. Therefore, the combined use of wind and solar systems is crucial for a large-scale grid integration..

Wind-solar grid supply

In 2019 in western Minnesota, a $5m hybrid system was installed. It runs 500 kW of solar power through the inverter of a 2 MW wind turbine, increasing the capacity factor and reducing costs by $150,000 per year. Purchase contracts limits the local distributor to a 5% maximum of self-generation. [49] [50]

Wind-solar building

The Pearl River Tower in Guangzhou, China, will mix solar panel on its windows and several wind turbines at different stories of its structure, allowing this tower to be energy positive.

Wind-solar lighting

In several parts of China & India, there are lighting pylons with combinations of solar panels and wind-turbines at their top. This allows space already used for lighting to be used more efficiently with two complementary energy productions units. Most common models use horizontal axis wind-turbines, but now models are appearing with vertical axis wind-turbines, using a helicoidal shaped, twisted-Savonius system.

Solar panels on turbines

Solar panels on the already existing wind turbines has been tested, but produced blinding rays of light that posed a threat to airplanes. A solution was to produce tinted solar panels that do not reflect as much light. Another proposed design was to have a vertical axis wind turbine coated in solar cells that are able to absorb sunlight from any angle. [51]

See also

Related Research Articles

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Energy storage is the capture of energy produced at one time for use at a later time to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an accumulator or battery. Energy comes in multiple forms including radiation, chemical, gravitational potential, electrical potential, electricity, elevated temperature, latent heat and kinetic. Energy storage involves converting energy from forms that are difficult to store to more conveniently or economically storable forms.

Renewable energy Energy that is collected from renewable resources

Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy stands in contrast to fossil fuels, which are being used far more quickly than they are being replenished. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation.

Compressed air car

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Grid energy storage

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Peaking power plant

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Stand-alone power system

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Solar hybrid power systems

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