The impact of downtime over the long-term energy yield of a floating wind farm

2018 ◽  
Vol 117 ◽  
pp. 1-11 ◽  
Author(s):  
M. Martini ◽  
R. Guanche ◽  
I. Losada-Campa ◽  
I.J. Losada
2017 ◽  
Vol 9 (4) ◽  
pp. 227-255 ◽  
Author(s):  
Sébastien Houde ◽  
Joseph E. Aldy

Through an evaluation of the 2009 Recovery Act's State Energy Efficient Appliance Rebate Program, this paper examines consumers' response to energy efficiency rebates. The analysis shows that 70 percent of consumers claiming a rebate were inframarginal and an additional 15 percent–20 percent of consumers simply delayed their purchases by a few weeks. Consumers responded to rebates by upgrading to higher quality, but less energy-efficient models. Overall the impact of the program on long-term energy demand is likely to be small. Measures of government expenditure per unit of energy saved are an order of magnitude higher than estimates for other energy efficiency programs. (JEL D12, H31, H71, Q48)


Author(s):  
Mykola Stetsiuk

The article analyzes the underlying foundations of Germany’s position regarding the construction of Russia’s Nord Stream 2 pipeline, as well as the impact of this position on the European Union’s joint energy policy and energy security. Against the backdrop of the constantly growing energy consumption both globally and in EU specifically, supplies of energy sources are being increasingly used by exporters as an instrument of political influence. In this context, the Nord Stream-2 pipeline is regarded as such an instrument, primarily by Russia itself. On the other hand, Germany has been supporting the construction of the new Russian pipeline due to the need to ensure uninterrupted supply of cheap natural gas. The latter is of particular significance for the realization of Germany’s long-term energy transformation strategy. However, by sticking to such a position, Germany prioritizes its own political and economic interests over those of EU and individual Member States, which is contrary to one of the main principles of EU’s functioning, i.e., the principle of solidarity. With this in mind, it is reasonable to conclude that Germany is almost single-handedly defining the strategic direction of the entire EU’s energy policy without paying due attention to alternative suppliers and sources.


2021 ◽  
Vol 76 (1) ◽  
pp. 97-116
Author(s):  
Roman Molas ◽  
Halina Borkowska ◽  
Barbara Sawicka

Next-generation biomass feedstocks are needed to optimize sustainability in a wide range of soils and climates. Species that has been recently noticed in Europe is Virginia fanpetals (Sida hermaphrodita L. Rusby). A critical question with research of this species is its field propagation. A long-term (2003–2012), field experiment was conducted to determine the impact of propagation method on yields and productivity this species. The hypothesis was higher yields of S. hermaphrodita biomass from vegetative propagations than from generative propagations, also over the long term. On average, from first 10 years of lifespan of Virginia fanpetals (2003–2012), biomass dry matter (DM) yields were significantly higher by vegetative propagation (16.8 Mg ha–1) as for generative (10.9 Mg ha–1). The average gross energy yield obtained by the vegetative propagation reached 304 GJ ha–1 while by the generative propagation was 196 GJ ha–1. The determined heat of combustion reached 18.1 GJ Mg–1 DM, the ash content was 28 g kg–1, and the nitrogen (N), sulphur (S), and chlorine (Cl) contents were 1.9 g kg–1, 0.52 g kg–1 and 0.23 g kg–1, respectively, regardless of propagation methods.


2013 ◽  
Vol 385-386 ◽  
pp. 1011-1016
Author(s):  
Ying Yun Sun ◽  
Zhao Yu Jin ◽  
Tian Jiao Pu ◽  
Ting Yu ◽  
Wei Wang ◽  
...  

With the continuous improvement of wind power penetration, the impact of the random fluctuation characteristics of wind power on the frequency control of the power system is growing. Currently, researchers began to study the methods of wind farms participation in frequency control to reduce the frequency adjustment pressure of other power plants and increase the wind power penetration. However, the existing simulation software for the short and long term frequency control of the power system is not so good. So in order to analyze the impact of load fluctuations or wind farm power fluctuations on system frequency control, this paper propose a frequency fluctuation simulation method based on the quasi-steady-state method.


2015 ◽  
Vol 51 (5) ◽  
pp. 3353-3369 ◽  
Author(s):  
Bin Xu ◽  
Ping-An Zhong ◽  
Zachary Stanko ◽  
Yunfa Zhao ◽  
William W.-G. Yeh

Author(s):  
А.А. Кутузова ◽  
Д.М. Тебердиев ◽  
В.М. Косолапов ◽  
Л.С. Трофимова ◽  
А.В. Родионова ◽  
...  

Исследования проводили в ФНЦ «ВИК им. В. Р. Вильямса» на базе трёх долголетних полевых экспериментов: в опыте 1 изучали многоукосное использование ранних и среднеспелых злаковых травостоев в среднем за 28 лет (1993–2020 годы), в опыте 2 — люцерно-злаковые травостои для позднего звена укосного конвейера в среднем за 7 лет пользования (2013–2020 годы), в опыте 3 проведено сравнение четырёх технологических систем создания и использования травостоев за последние 28 лет (в среднем за 47–74-й годы пользования, 1993–2020 годы). Цель исследований — определение агроэнергетической эффективности 15 технологий по созданию усовершенствованных злаковых и бобово-злаковых травостоев, а также шести систем ведения долголетних сенокосов при производстве сырья для заготовки высококачественного сена и сенажа. Применение нового метода агроэнергетической оценки антропогенных затрат не только подтверждает высокую экономическую эффективность создания сеяных травостоев на лугах, но и впервые в конкретных (цифровых) показателях устанавливает роль разнообразных природных факторов. На долголетних злаковых травостоях (в течение 28 лет жизни трав) обеспечивается производство сырьевой массы для заготовки объёмистых кормов (сена и сенажа) первого и второго классов. Совокупные антропогенные затраты энергии на этих травостоях в среднем за 28 лет составили 16,3–17,1 ГДж/га при двухукосной и 23,2–23,6 ГДж/га — при трёхукосной технологии, на люцерно-злаковых травостоях при двух укосах в среднем за 7 лет — 5,2–5,8 ГДж/га. Затраты окупались сбором обменной энергии на ранних и среднеспелых агроценозах с доминированием корневищных злаковых видов в 2,8–3,3 раза, а на люцерно-злаковых травостоях — в 10,6–11,0 раз. В структуре производства обменной энергии основная её часть обеспечивалась за счёт возобновляемых природных факторов: 67–70% — на злаковых травостоях и 90% — на бобово-злаковых долголетних травостоях. The research took place at the Federal Williams Research Center of Fodder Production and Agroecology and consisted of three long-term field trials. The trial 1 was aimed at studying the multi-cut use of short- and mid-season gramineous for 28 years (1993–2020). The trial 2 tested alfalfa-gramineous swards for late cutting for 7 years (2013–2020). The trial 3 compared four technological systems of sward development and cultivation for the last 28 years (1993–2020). The aim of this research was to determine the energy efficiency of 15 cultivation technologies for optimization of gramineous and legume-gramineous swards as well as six systems of long-term hayfield cultivation to obtain high-quality hay and haylage. New method evaluating anthropogenic costs proved high economic efficiency of sown swards but also showed the impact of various natural factors. Long-term gramineous swards (28 years of life) provided raw material for bulk feed production (hay and haylage) of the first and second grade. For such swards total anthropogenic costs amounted to 16.3–17.1 GJ ha-1 under two cuts and 23.2–23.6 GJ ha-1 — under three cuts for 28 years. For alfalfa-gramineous swards total anthropogenic costs amounted to 5.2–5.8 GJ ha-1 for 7 years. The costs were paid back by 2.8–3.3 times through the exchange energy yield from short- and mid-season ecosystems with higher proportion of rootstock grasses, from alfalfa-gramineous swards — by 10.6–11.0 times. The great part of exchange energy was provided through renewable natural factors: 67–70% — from gramineous swards and 90% — from the legume-gramineous ones.


Author(s):  
Aidan Keane ◽  
Iain Nisbet ◽  
Gabriele Calvo ◽  
George Pickering ◽  
Jake Tulloch ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document