[en] In the increasingly commercialised wind power marketplace, the lack of precise assessment methods for the output of an investment is becoming a barrier for wider penetration of wind power. Thus, addressing this problem, the overall objectives of the project are to reduce the financial risk in investment in wind power projects by significantly improving the power performance assessment methods. Ultimately, if this objective is successfully met, the project may also result in improved tuning of the individual wind turbines and in optimisation methods for wind farm operation. The immediate, measurable objectives of the project are: To prepare a review of existing contractual aspects of power performance verification procedures of wind farms; to provide information on production sensitivity to specific terrain characteristics and wind turbine parameters by analyses of a larger number of wind farm power performance data available to the proposers; to improve the understanding of the physical parameters connected to power performance in complex environment by comparing real-life wind farm power performance data with 3D computational flow models and 3D-turbulence wind turbine models; to develop the statistical framework including uncertainty analysis for power performance assessment in complex environments; and to propose one or more procedures for power performance evaluation of wind power plants in complex environments to be applied in contractual agreements between purchasers and manufacturers on production warranties. Although the focus in this project is on power performance assessment the possible results will also be of benefit to energy yield forecasting, since the two tasks are strongly related. (au) JOULE III. 66 refs.; In Co-operation Renewable Energy System Ltd. (GB); Centre for Renewable Energy (GR); Aeronautic Research Centre (SE); National Engineering Lab. (GB); Public Power Cooperation (GR)

[en] A search for δ-Scuti stars and other variables in open cluster is in progress, and we report results for the cluster NGC 6192. At the end the statistics for a number of open clusters on the frequency of variables in the instability strip is presented. We think that there is now increasing evidence for a change with age of the fraction of variables

[en] A CCD-photometry observing program in open clusters has been begun which seeks to answer the following questions about Delta Scuti stars: why is a Delta Scuti star a variable, which modes are observed, and why these modes in particular are observed. Time series of up to eight hours per night are collected for fields of 2 x 3 arcmin. Among seven clusters only two with Delta Scuti stars have been found; and in one of them there is a need to confirm the nature of the variables. It is concluded that a picture is slowly merging which links the frequency of Delta Scuti stars, Ap stars, and active late-type stars to the age of the cluster and possibly to the dynamics during the formation of the stars, which can vary from cluster to cluster

[en] GESMIC (General Equilibrium Simulation Model of the Economic Council) is a general equilibrium model for the Danish economy to be used for analyses of economic political interventions which influence the long term development of the Danish economy. The GESMIC model, inspired by the Australian ORANI model, was developed to be a simple description of the interdependence of investment and capital systems, and the balance between goods and profit and external debt. The publication documents the latest version of the GEISMIC equilibrium model and presents a number of its possible applications. The simulation model is described in detail in addition to the calibration and model closing methods. The effects on environmental and trading policies are also dealt with. (AB) 63 refs

[en] Wind energy will undoubtedly play a significant role in the future energy supply being a nonpolluting energy source, which on a technical basis has proved to be an economically feasible and thus a realistic alternative to traditional power production. This conclusion may be drawn from Danish experiences where energy planning comprises a visible contribution from wind energy. Since 1976 more than 3200 wind turbine units have been installed in Denmark, representing a capacity of roughly 340 MW out of a grid capacity of 8,000 MW. These units are all grid-connected and the unit sizes range from 55 kW to 450 kW. The installed wind energy capacity represents a substantial development of technologies for wind energy utilization during the last 15 years, involving participation from many sides: research institutes, electric utilities, the national energy administration, and private industry. The development has implied a considerable improvement of the technical and economic performance of wind turbines along with increased reliability and durability. The successful development has been strongly supported by comprehensive government programmes, i.e. establishment of a national wind energy research programme, establishment of the Riso Test Station for Windmills and a subsidy scheme for private turbine owners. The improved economic performance is partly the result of a development in rotor size of commercially available wind turbines. In 1981 the largest commercial wind turbine size in Denmark was 55 kW, while today it is close to 500 kW. In the same period the average energy production per installed unit capacity almost doubled, due to enhanced aerodynamic rotor design, increased tower height and improved overall design and production methods. (author) 7 figs., 3 tabs., 13 refs

[en] This paper presents a status of wind power in Denmark and on the technical and industrial achievements. The present total installed capacity is be the end of 1995 approx. 630 MW, and the contribution to the electric energy generation in Denmark is approx. 4%. (author)

[en] Helio- and asteroseismology is the study of the interior of the Sun and other stars by observation of oscillations on their surfaces. The last decade has witnessed a very rapid evolution in the study of the solar interior, to the point where it is now possible to contemplate investigation of the physical state of matter or the details of rotation and other large-scale processes in the Sun. Stellar studies are in some respects at the same stage as were the solar studies a decade ago. However, with the extensive data sets nowadays available for the Sun, solar and stellar observations can be combined to provide tests for stellar models. These proceedings document the wide range of topics covered during the Symposium, from stellar surface properties to internal solar rotation and from current observations to planned large-scale facilities for the study of the exciting field of helio- and asteroseismology. refs.; figs.; tabs

[en] Seeing convolved two-dimensional de Vaucouleurs profiles have been fitted to digital images of the brightest elliptical galaxies in two nearby groups of galaxies and three clusters of galaxies with redshifts in the range 0.06 to 0.15. The digital images were created by scanning electronographic plates obtained by the use of several versions of the RGO electronographic camera. The linear relation between effective surface brightness μ_e and the logarithm of the effective radius r_e, first discovered by Kormendy to be valid for nearby elliptical galaxies, is found to be equally valid for the largest and brightest galaxies in rich clusters of galaxies. The apparent universal nature of that relation indicates that the same type of processes might have been involved during the formation of all ellipticals from cD galaxies in clusters to fainter ellipticals in small groups. It is suggested that the (I_e,r_e) relation is not changed by the expected dynamical evolution of the brightest galaxies in clusters. If the cosmic nature of the (I_e,r_e) relation is confirmed by future observations, we suggest using the vertical position of that relation, derived from the brightest elliptical galaxies in rich clusters, as a new cosmological test, which should be independent of dynamical evolution

[en] The background for uncertainty analysis is summarized, and the theory is employed in the evaluation of uncertainties related to the determination of annual power output from a single wind turbine or a cluster of wind turbines. Because of recent work done under the auspices of the International Energy Agency, special emphasis is put on the error related to power curve measurements and the uncertainty calculation is illustrated by an example. Even when limited to dealing with only part of the general problem (i.e. the power curve), the complexity is considerable. In many cases the uncertainty may be 10-15% on power curve determination and more than 20% on wind resources. In fact, evidence in the form of production statistics from a number of Danish wind turbines indicate that while production forecast on the average fits well, the standard deviation of the difference between the actual and the expected production is of the order 20-30%. The economic implications of the large uncertainty are considerable. (Author)

[en] This article reviews the Danish CGE-model GESMEC and its application to quantifying the macroeconomic impacts of a CO₂ tax. Calculations based on the model indicate that a reduction of Danish CO₂ emissions by 2005 by 25 per cent compared with a baseline by means of a uniform economy-wide CO₂ tax can be achieved at a loss of private consumption of only 0.3 per cent. This result is obtained using standard neo-classical closure, assuming that all markets including the labour market are cleared by fully flexible relative prices. The calculated costs increase considerably if the assumptions of full long-term flexibility are relaxed. (au) 15 refs