Assessment of Power Quality Characteristics of Wind Farms

In this paper the main parameters to assess the power quality of grid embedded wind farms are presented. International standards to assess and quantify the power quality of grid connected wind turbines exist for some years now, and are here extrapolated to wind farms aggregates when possible being the correspondent methodologies identified in the document. Recently, the grid code requirements posed a novel challenge to this technologic area, particularly since they were issued with national or local objectives and without particular normalized global concerns. The form how the international standards are evolving in order to cope both with the power systems industry local requirements, but also with the global wind turbine manufacturers principles is addressed in the paper

Dynamic models of wind farms for power system studies: status by IEA Wind R&D Annex 21

Dynamic models of wind farms for power system studies are at present not a standard feature of many software tools, but are being developed by research institutes, universities and commercial entities. Accurate dynamic wind farm models are critical; hence model validation is a key issue and taken up by IEA Wind R&D Annex 21. This international working group includes participants from nine countries, and has since start-up in 2002 developed a systematic approach for model benchmark testing. This paper present this methodology, including example benchmark test results, but also gives an overview of the various wind farm models now being available from both Annex partners and external entities

Offshore wind farm site selection in Norway : using a fuzzy trigonometric weighted assessment model

Maximising the energy potential of offshore wind farms requires an in-depth assessment of technological, economic, sociopolitical, and environmental aspects. Given the large economic impact of large-scale projects, a robust site selection procedure is critical for limiting financial risks while supporting informed investments. This research uncovers a novel and multidisciplinary approach for boosting the efficacy of Norwegian and global offshore wind farm siting investments. The proposed method uses a two-stage fuzzy mathematical model that considers technical, economic, logistical, and environmental factors. It combines the Ordinal Priority Approach (F-OPA) and Trigonometric Weighted Assessment (TRWA) technique by using an in-depth techno-economic assessment. An alternative reactive power compensation model, power loss calculations, and associated techno-economic analysis were performed for the investigated offshore wind farm locations. Furthermore, the energy economic calculations are carried out to provide support for the proposed decision-making framework. The proposed methodology was tested through a case study, focusing on ranking Norwegian offshore wind farm sites selected from potential locations announced by The Norwegian Water Resources and Energy Directorate (NVE). Within the Norwegian offshore wind farm sites, the approach demonstrated a versatile and efficient decision-making process at both individual and collective levels, identifying the Sandskallen-Sørøya Nord project as a pivotal investment priority and providing valuable managerial insights to enhance Norway’s offshore wind initiatives. The model’s stability was affirmed through a sensitivity analysis, underscoring its potential to enhance renewable energy policy and decision-making globally

Offshore Wind Energy Technology

Offshore Wind Energy Technology offers a reference based on the research material developed by the acclaimed Norwegian Research Centre for Offshore Wind Technology (NOWITECH) and material developed by the expert authors over the last 20 years. This comprehensive text covers critical topics such as wind energy conversion systems technology, control systems, grid connection and system integration, and novel structures including bottom-fixed and floating. The text also reviews the most current operation and maintenance strategies as well as technologies and design tools for novel offshore wind energy concepts

Impacts of large amounts of wind power on design and operation of power systems, results of IEA collaboration

There are a multitude of studies made and ongoing related to cost of wind integration. However, the results are not easy to compare. An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. IEA WIND R&D Task 25 on "Design and Operation of Power Systems with Large Amounts of Wind Power" has produced a state-of-the-art report in October 2007, where the most relevant wind power grid integration studies are analysed especially regarding methodologies and input data. This paper summarises the results from 18 case studies with discussion on the differences in the methodology as well as issues that have been identified to impact the cost of wind integration

Aromaattien poistoprosessin optimointi

Työn tavoitteena oli kehittää toimiva ja mahdollisimman energiasäästävä sivuvirtareaktorikonseptiin perustuva aromaattien hydrausprosessi. Prosessissa voidaan käsitellä tavallista rikkipitoisempaa syöttöä. Lisäksi haluttiin selvittää prosessin investointikustannukset kokonaan uutena sekä sovellettuna Porvoon jalostamolle. Kirjallisuusosassa tarkasteltiin jalostamon keskitisleiden ja niiden tuotteiden ominaisuuksia, säännöksiä epäpuhtauksien rajoittamisesta ja tulevaisuuden näkymiä. Erityisesti tarkasteltiin kaupallisia keskitisleiden aromaattien poistoprosesseja. Tutkimusosassa simuloitiin sivuvirtareaktoriprosessia tyypillisellä keskitislesyötöllä, jonka aromaattipitoisuus oli 24 p-% ja rikkipitoisuus 10...50 p-ppm. Simulointi tehtiin Neste Oy:n kehittämällä Flowbat-simulointiohjelmalla. Simulointien perusteella valittiin prosessin konfiguraatiolle toimivin ja käytännöllisin ratkaisu, jolle suoritettiin lämmönsiirron ja energiakäytön optimointi pinch-menetelmään perustuvalla ADVENT-ohjelmistolla. Optimoidulle prosessille laskettiin investointi- ja käyttökustannukset. Prosessisimuloinnin tärkeimmät tulokset ovat kolonnin sivuvirran ulosotto kaasufaasissa, palautusvirran kevyiden yhdisteiden erotus ennen kolonniin palauttamista sekä syöttövirtaan tarvittava uuni. Pinch-optimoinnin perusteella pystyttiin vähentämään uunin tehoa 3,4 MW ja minimoimaan ilmajäähdytystä tuottamalla 1 MW kuumaa vettä ja 6,4 MW MS-höyryä (16 bar). Uuden prosessin investointihinnaksi saatiin 116,5 Mmk ja Porvoon jalostamolle sovelletulle prosessille 59,2 Mmk. Käyttökustannukset ovat 7,5 Mmk/a. Kannattavuusarviota prosessille ei suoritettu. Syötön analysoinnin yhteydessä ilmenneiden puutteiden poistamiseksi esitettiin uusi lähestymistapa ongelmaan. Tulokset antavat käsityksen prosessin konfiguraatiosta ja koosta, sen tarvittavasta laitteistosta ja käyttöhyödyketarpeesta. Prosessisyötön rikkipitoisuutta oli vähennettävä 50:stä 10 p-ppm pitoisuuteen jotta laitteiden koot ja energiankäyttö pysyisivät järkevällä tasolla

Design and operation of power systems with large amounts of wind power : Final report, Phase one 2006-08, IEA WIND Task 25

There are already several power systems coping with large amounts of wind power. High penetration of wind power has impacts that have to be managed through proper plant interconnection, integration, transmission planning, and system and market operations. This report is a summary of case studies addressing concerns about the impact of wind power s variability and uncertainty on power system reliability and costs. The case studies summarized in this report are not easy to compare due to different methodology and data used, as well as different assumptions on the interconnection capacity available. Integration costs of wind power need to be compared to something, like the production costs or market value of wind power, or integration cost of other production forms. There is also benefit when adding wind power to power systems: it reduces the total operating costs and emissions as wind replaces fossil fuels. Several issues that impact on the amount of wind power that can be integrated have been identified. Large balancing areas and aggregation benefits of large areas help in reducing the variability and forecast errors of wind power as well as help in pooling more cost effective balancing resources. System operation and working electricity markets at less than day-ahead time scales help reduce forecast errors of wind power. Transmission is the key to aggregation benefits,electricity markets and larger balancing areas. From the investigated studies it follows that at wind penetrations of up to 20 % of gross demand (energy), system operating cost increases arising from wind variability and uncertainty amounted to about 1 4 /MWh. This is 10 % or less of the wholesale value of the wind energy