Ecofys (Netherlands)

ABSTRACT Capsule Migration studies of tagged Eurasian Bitterns Botaurus stellaris provide information on the behaviour of this secretive species in relation to weather conditions. Aims To study if cold spells trigger southward migration in resident Eurasian Bitterns. To describe migratory behaviour including flight routes, altitudes, flight direction in relation to wind speed and direction, and general characteristics of stopping sites. Methods Six adult Eurasian Bitterns from Dutch breeding areas were followed for two to five years using ARGOS-PTT/GPS transmitters or GPS trackers. Results Four individuals remained at the breeding sites in winter and did not migrate in response to cold spells. Two individuals covered distances of 300 and 1600 km between stopping sites. They migrated predominantly at night, but over the Sahara they extended flights into daylight hours. Depending on wind assistance, flight speeds (groundspeed) varied between 3.6 and 26 ms−1. Flight altitude varied from just above sea level when facing headwinds, to almost 2000 m above sea level under tail wind conditions. Repeatedly tracked individuals showed substantial variation in routes and stopping sites between successive migrations. These flight patterns appeared influenced by the speed and direction of the winds encountered en route. Conclusions Eurasian Bitterns were either migratory or resident and the latter individuals did not perform facultative movements at the onset of cold spells. The flight speed, flight altitudes, and routes of migrating birds were influenced by wind conditions. This likely explains the variable use of stopping sites between years.

This chapter describes the past developments, current status, and trends in global liquid biofuel production and trade. Apart from providing quantitative overviews, it also elaborates why markets developed as they did. By 2011, close to 2,500 PJ of liquid biofuels were produced globally; over two-third of which were fuel ethanol and the remaining biodiesel. The feedstock base is exclusively regionally specific oil, sugar, or starch crops. Global trade in biodiesel has been and will in the foreseeable future be primarily driven towards the European Union, where renewable energy policies stimulate the consumption of sustainable transport fuels – although the EU biofuels market growth is slowing down. Fuel ethanol is largely produced and consumed in the Americas, with the USA and Brazil dominating global production, trade and deployment. International trade is both supply and demand driven. National support policies increased the domestic market value of biofuels and shaped demand side developments. Trade flows emerged where such policies were not aligned with respective trade measures. Import duties had the strongest effect on trade volumes while trade routes were influenced by tariff preferences. Most trade regimes appear to have been designed and adapted unilaterally along national interests causing market disruptions, trade inefficiencies and disputes.

ABSTRACTThe main windiness index in the Netherlands (Windex‐CBS) has been subject to a decreasing trend since the systematic recording started in 1988. This seriously complicates the estimation of future long‐term wind supply. Therefore, it is necessary to know the main causes of the reported decline.For this purpose, Windex‐CBS, derived from actual wind turbine yields, is compared with two alternative windiness indices. The first index is based on wind speed observations Wland and the second on geostrophic wind speed Gland. Similar indices are formulated for offshore wind supply in the North Sea, Woff and Goff. High mutual correlations between the indices indicate that they do efficiently account for natural variability. Yet, the trends of the different indices do substantially differ from each other.The decrease of Windex‐CBS is twice as large as (200%) the decrease of Wland. The trend of the difference between both indices is highly significant. This suggests that the Windex‐CBS is contaminated by operational or methodological factors. Wland does not suffer from such factors and is therefore the preferred measure of wind supply. Copyright © 2012 John Wiley & Sons, Ltd.

This study assessed technical potentials for energy efficiency improvement in 2050 in a global context. The reference scenario is based on the World Energy Outlook of the International Energy Agency 2007 edition and assumptions regarding gross domestic product developments after 2030. In the reference scenario, worldwide final energy demand almost doubles from 293 EJ in 2005 to 571 EJ in 2050 and primary energy supply increases from 439 EJ in 2005 to 867 EJ in 2050 (excluding non-energy use). It is estimated that, by exploiting the technical potential for energy efficiency improvement in energy demand sectors, this growth can be limited to 8% or 317 EJ final energy demand and 473 EJ primary energy supply in 2050. This corresponds to a potential for demand-side energy efficiency improvement of 44% in 2050, in comparison to reference energy use. In addition, a potential exists for improving energy efficiency in the transformation sector. In 2005, as much as 33% of primary energy supply is lost in the transformation and distribution of primary energy. It is estimated that this share can be reduced to 19% in 2050 by, e.g. improving energy efficiency of fossil-fired power generation (assuming no changes in the fuel mix for power generation). Including the potential for energy efficiency improvement in energy demand sectors, total primary energy supply would then decrease by 10% from 439 EJ in 2005 to 393 EJ in 2050. This contributes to a total potential for energy efficiency improvement of 55% in 2050 in comparison to reference primary energy supply.