scholarly journals The Consequences of Air Density Variations over Northeastern Scotland for Offshore Wind Energy Potential

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2635 ◽  
Author(s):  
Alain Ulazia ◽  
Ander Nafarrate ◽  
Gabriel Ibarra-Berastegi ◽  
Jon Sáenz ◽  
Sheila Carreno-Madinabeitia

Hywind-Scotland is a wind farm in Scotland that for many reasons is at the leading edge of technology and is located at a paradigmatic study area for offshore wind energy assessment. The objective of this paper is to compute the Capacity Factor ( C F ) changes and instantaneous power generation changes due to seasonal and hourly fluctuations in air density. For that reason, the novel ERA5 reanalysis is used as a source of temperature, pressure, and wind speed data. Seasonal results for winter show that C F values increase by 3% due to low temperatures and denser air, with economical profit consequences of tens of thousands (US$). Hourly results show variations of 7% in air density and of 26% in power generation via FAST simulations, emphasizing the need to include air density in short-term wind energy studying.

2020 ◽  
Author(s):  
Radian Belu

Wind energy usage is increasing at fast rates due to significant technical advances, energy supply security and environmental concerns. Research is focusing among others areas on the development of reliable and accurate wind energy assessment methods. Offshore wind energy resources are usually larger than at geographically nearby onshore sites, which may offset in part higher installation, operation, and maintenance costs. Successful offshore wind energy development relies on accurate analysis and assessment of wind energy resource potential. Offshore wind assessment challenges are related to the wind turbine size, offshore installation challenges, lack of adequate and long-term wind and meteorological measurements, etc. Wind, a highly intermittent phenomenon has large spatiotemporal variability, being subject to sub-hourly, hourly, diurnal, seasonal, yearly, and climate variations in addition to their dependence on the geography and environment. Wind regime characteristics are critical to all aspect of a wind energy project, e.g. potential site identification, economic viability, equipment design, operation, management, or wind farm impacts on the electric grid. For a reliable wind energy assessment, measurements at rotor heights are required at least for one year. If such measurements are not available needs to be substituted by alternative approaches, e.g. measure-correlate-predict or numerical methods. Chapter objectives are to provide the reader with comprehensive reviews of the wind energy assessment and analysis methods.


Author(s):  
Mamman Rabiu Onoruoiza ◽  
Oyewole Adedipe ◽  
Sunday Albert Lawal ◽  
Oluwafemi Ayodeji Olugboji ◽  
Victor Chiagozie Nwachukwu

Vestnik MEI ◽  
2020 ◽  
Vol 5 (5) ◽  
pp. 35-46
Author(s):  
Galina V. Deryugina ◽  
◽  
Evgeniy V. Ignatiev ◽  
Myat Tun Htet ◽  
Mikhail G. Tyagunov ◽  
...  

Nowadays, one of pressing problems in Myanmar is shortage of electric energy, which makes approximately 10% of all electric energy consumed in the country. This shortage can be partially decreased by constructing large-capacity grid-connected wind farms. The last four years have seen a general decline in the growth rates of commissioned wind farm capacities around the world; nonetheless, certain wind energy industry sectors, primarily offshore wind energy, demonstrate a steady growth. In recent years, the market of Asian countries, in particular, that of China, is one of the most rapidly growing offshore wind energy markets. An updated theoretical wind energy potential of Myanmar is given. It is shown that the highest wind intensity is observed on the western and southern coasts of Myanmar, which make approximately 8% of the country’s total area. The theoretical wind energy potential of the Andaman Sea water area near the west coast of Myanmar at heights equal to 10 and 100 m has been evaluated for the first time; eight promising sites for constructing offshore wind farms have been determined, and a model for analyzing efficient wind farms has been selected. A procedure has been developed, using which the optimal composition of a complex of several wind farms with the total capacity equal to 47.6 MW has been found. These wind farms are located at significant distances from each other in Andaman Sea areas, which are characterized by an essentially non-uniform distribution in time of wind intensities in them. Owing to this feature, it is possible to increase the energy generation by 8% and achieve a higher wind farm capacity utilization factor.


2019 ◽  
Vol 7 (10) ◽  
pp. 361 ◽  
Author(s):  
Gabriel Ibarra-Berastegi ◽  
Alain Ulazia ◽  
Jon Saénz ◽  
Santos J. González-Rojí

The only regional evaluation of Lebanese wind-energy potential (National Wind Atlas) dates back to 2011 and was carried out by a United Nations agency. In this work, data from the most recent reanalysis (ERA5) developed at the European Center for Medium Range Weather Forecast (ECMWF), corresponding to the 2010–2017 period, were used to evaluate Lebanese offshore-wind-energy potential. In the present study, wind power density associated to a SIEMENS 154/6 turbine was calculated with a horizontal resolution of 31 km and 1 hour time steps. This work incorporated the impact of air density changes into the calculations due to the seasonal evolution of pressure, temperature, and humidity. Observed average offshore air density ρ 0 was 1.19 kg / m 3 for the 2010–2017 period, but if instead of ρ 0 , hourly ρ values were used, seasonal oscillations of wind power density ( W P D ) represented differences in percentage terms ranging from −4% in summer to +3% in winter. ERA5 provides hourly wind, temperature, pressure, and dew-point temperature values that allowed us to calculate the hourly evolution of air density during this period and could also be used to accurately evaluate wind power density off the Lebanese coast. There was a significant gradient in wind power density along the shore, with the northern coastal area exhibiting the highest potential and reaching winter values of around 400 W / m 2 . Finally, this study suggests that the initial results provided by the National Wind Atlas overestimated the true offshore-wind-energy potential, thus highlighting the suitability of ERA5 as an accurate tool for similar tasks globally.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naveed Akhtar ◽  
Beate Geyer ◽  
Burkhardt Rockel ◽  
Philipp S. Sommer ◽  
Corinna Schrum

AbstractThe European Union has set ambitious CO2 reduction targets, stimulating renewable energy production and accelerating deployment of offshore wind energy in northern European waters, mainly the North Sea. With increasing size and clustering, offshore wind farms (OWFs) wake effects, which alter wind conditions and decrease the power generation efficiency of wind farms downwind become more important. We use a high-resolution regional climate model with implemented wind farm parameterizations to explore offshore wind energy production limits in the North Sea. We simulate near future wind farm scenarios considering existing and planned OWFs in the North Sea and assess power generation losses and wind variations due to wind farm wake. The annual mean wind speed deficit within a wind farm can reach 2–2.5 ms−1 depending on the wind farm geometry. The mean deficit, which decreases with distance, can extend 35–40 km downwind during prevailing southwesterly winds. Wind speed deficits are highest during spring (mainly March–April) and lowest during November–December. The large-size of wind farms and their proximity affect not only the performance of its downwind turbines but also that of neighboring downwind farms, reducing the capacity factor by 20% or more, which increases energy production costs and economic losses. We conclude that wind energy can be a limited resource in the North Sea. The limits and potentials for optimization need to be considered in climate mitigation strategies and cross-national optimization of offshore energy production plans are inevitable.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4435
Author(s):  
Travis C. Douville ◽  
Dhruv Bhatnagar

The significant offshore wind energy potential of Oregon faces several challenges, including a power grid which was not developed for the purpose of transmitting energy from the ocean. The grid impacts of the energy resource are considered through the lenses of (i) resource complementarity with Variable Renewable Energy resources; (ii) correlations with load profiles from the four balancing authorities with territory in Oregon; and (iii) spatial value to regional and coastal grids as represented through a production cost model of the Western Interconnection. The capacity implications of the interactions between offshore wind and the historical east-to-west power flows of the region are discussed. The existing system is shown to accommodate more than two gigawatts of offshore wind interconnections with minimal curtailment. Through three gigawatts of interconnection, transmission flows indicate a reduction of coastal and statewide energy imports as well as minimal statewide energy exports.


2020 ◽  
Vol 31 (4) ◽  
pp. 26-42
Author(s):  
Gordon Rae ◽  
Gareth Erfort

In the context of the Anthropocene, the decoupling of carbon emissions from electricity generation is critical. South Africa has an ageing coal power fleet, which will gradually be decommissioned over the next 30 years. This creates substantial opportunity for a just transition towards a future energy mix with a high renewable energy penetration. Offshore wind technology is a clean electricity generation alternative that presents great power security and decarbonisation opportunity for South Africa. This study estimated the offshore wind energy resource available within South Africa’s exclusive economic zone (EEZ), using a geographic information system methodology. The available resource was estimated under four developmental scenarios. This study revealed that South Africa has an annual offshore wind energy production potential of 44.52 TWh at ocean depths of less than 50 m (Scenario 1) and 2 387.08 TWh at depths less than 1 000 m (Scenario 2). Furthermore, a GIS-based multi-criteria evaluation was conducted to determine the most suitable locations for offshore wind farm development within the South African EEZ. The following suitable offshore wind development regions were identified: Richards Bay, KwaDukuza, Durban, and Struis Bay. Based on South Africa’s annual electricity consumption of 297.8 TWh in 2018, OWE could theoretically supply approximately 15% and 800% of South Africa’s annual electricity demand with offshore wind development Scenario 1 and 2 respectively.


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