Aug 31, 1988 - erator (WEG) rated at 55 kW and 2.5 kW WEG, specially designed for ... shape parameter k (dimensionless) and scale parameter c. (m/s).
Solar & Wind Technology Vol. 6, No. 1, pp. 91-95, 1989 Printed in Great Britain.
0741-983X/89 $3.00+ .00 Pergamon Press pie
TECHNICAL
NOTE
Estimation of specific annual energy generation from wind in Antarctica JAMI HOSSAIN Tara Energy Research Institute, Jor Bagh, New Delhi-110 003, India
(Received 8 June 1988 ;accepted 31 August 1988) Abstract--It is established that wind is the major source of energy in Antarctica. A Weibull distribution is assumed in energy estimations. Errors in estimations with shape parameters 1. I and 2.9 as compared with Rayleigh distributions are also computed.
2. METHODS OF POWER AND ENERGY ESTIMATION
1. INTRODUCTION Over the last few years there has been an increase in human activity in Antarctica, a continent which was devoid of any earlier human presence. This small presence is entirely constituted by the scientific community from various developed and developing countries. Even during the inhospitable winter months certain manned permanent stations continue to operate. Due to the extremely low temperatures which prevail more or less throughout the year the energy requirements per person per day are enormously high. This problem is further aggravated by the fact that the cold continent is far away from any other centre of civilization. Therefore, the cost of supplying fuel (diesel, oil etc.) to a small human settlement in Antarctica is obviously high by any standards. Although costs incurred on such activities are not a matter of concern, the availability of a local source of energy can go a long way in making the conditions more hospitable. Wind, which seems to be the only locally available source of energy in Antarctica, is characterized by very high speeds (especially more so in the winter months). The average annual wind speed is approximately 12 m/s at Novo, the Russian station [1]. Any location with an average annual wind speed higher than 5 m/s is considered as potentially viable for wind energy generation. Locations with average annual wind speeds higher than 10 m/s are rarely found and a location with a value higher than 12 m/s would perhaps be the windiest location on the globe. In this paper we have attempted to predict the annual energy generation from a conventional Wind Electric Generator (WEG) rated at 55 kW and 2.5 kW WEG, specially designed for Antarctica by Bharat Heavy Electricals Ltd, installed recently at the Indian station "Maitree". The monthly average wind speeds at Novo, the Russian station, are available for a period of thirteen years, i.e. 1961-1973 (Table I), and are used for the purpose of estimation.
A number of studies have been carried out to evaluate the wind speed frequency distributions. It has been found that the wind speeds at any location can be adequately described by the Weibull distribution [2] which is characterized by the shape parameter k (dimensionless) and scale parameter c (m/s). The average wind speed g can be expressed as a function of c and k by the relationship :
= cF(1 +k-').
(I)
As k varies from 1 to 3.5, the Weibull distribution changes from an exponential distribution to an approximately normal distribution [3]. In some cases, the Rayleigh distribution is taken as a representation of a wind speed distribution. The Rayleigh distribution is a special case of the Weibull distribution (i.e. for k = 2 the Weibull distribution reduces to Rayleigh distribution). The energy output E ofa WEG, with a power-wind speed curve P(v) in a wind regime with a frequency distribution f(v) and average air density p in a time period Tis expressed as : vr
/*l/out
E = T | P(v)f(v) dv + TPr | f(v) dr. dv~. .ivr
(2)
Where Vi. is the cut-in speed, Vr is the rated speed and Vo.t is the cut-out speed. The usable power density (Wm-2) Of the WEG is defined by a similar expression : O,
p=
I
O,
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