Estimation of Weibull Parameters using Graphical
Method for Wind Energy Applications
K. S. R. Murthy
Electrical Engineering Department
NIT Hamirpur
Hamirpur, India
harikella96@gmail.com
O. P. Rahi
Electrical Engineering Department
NIT Hamirpur
Hamirpur, India
oprahi2k@gmail.com
Abstract—Wind power resources are abundant in India; as a
result the wind power industry has entered a period of rapid
growth, and has been facing new challenges currently. Wind
power is environment friendly and renewable in nature. The
wind is caused by an air in motion and is produced by the uneven
heating of the earth’s surface by the sun. The wind speed has
been one of the most significant parameter in the design and
investigation of wind energy conversion systems (WECS). The
objective of the present research paper is to assess the feasibility
of wind power generation for a new site in Himachal Pradesh
using micro-turbines. The major contribution of this paper,
envisages two parameters, i.e., shape and scale parameter based
Weibull distribution model for investigating wind speed
variations and Weibull parameters calculation by Least Squares
Fit Method (LSM) also known as Linear regression model using
graphical method. This research work shows that the hilly site of
Hamirpur in Himachal Pradesh has good wind power potential
and large magnitude of winds have been available for power
generation during the months of March to June suitable for low
wind power generation.
Keywords— greenhouse gases; statistics; weibull distribution;
weibull parameters; wind power density; wind speed.
I. INTRODUCTION
Energy is one of the major inputs for economic and social
development of any country. Energy demand grows due to
population increase, rapid urbanization and industrialization.
The use of fossil fuels for electricity generation has an adverse
impact on environment, especially excessive emissions of
greenhouse gases (GHGs) to atmosphere leading to climate
change and global warming. Renewable energy technologies
are clean sources of energy and are sustainable. Wind is one of
such widely used source worldwide [1].
Major contribution for renewable electricity generation so
far has been from hydro and wind power with small
contributions from solar, geothermal, biomass, waste, and tidal
wave/ocean energy. The government incentives and policies
provide primary support for renewable power generation
programmers [2]. Worldwide wind power generation capacity
978-1-4799-5141-3/14/$31.00 ©2014 IEEE
has reached 282.3 GW in 2012 as per the World Wind Energy
Association (WWEA) [3]. World Wind Energy Report 2012
has shown a 19.2% global growth and the global annual
installed wind power capacity has increased from 1280 MW to
44,799 MW during the period 1996-2012. The cumulative
wind power generation in India has reached 18.4 GW in 2012.
The total renewable energy installations in the country has
reached 26.9 GW in January 2013 which accounted for over
12 % of total installed capacity, and about 6% of electricity
generation by the end of 2012 as compared to 2% in 1995. The
wind power alone accounted for about 69% of total renewable
energy capacity or about 8% of the total installed capacity in
India [4].
Wind turbines are often used in large-scale wind farms in
the countryside or in coastal regions, but there has been a
growing market for micro-turbines. Micro-turbines are defined
as those that are capable of delivering energy at a rate of less
than 50kW [5]. This definition covers a range of turbine sizes,
from blades of half a meter to around 15 meters with 30 meter
tall towers. Small wind farms consisting of large number of
such wind turbines in vast open spaces have also become a
reality. Large wind turbines are now in their seventh or eighth
generation of technology development, while micro-wind
turbines are yet to evolve commercially in India. Micro-wind
turbines can achieve high market penetration especially in
areas with lower housing densities and sufficient wind
resources [5]. The efficient micro-wind turbines for low wind
speed regions with low cut in speeds are required to be
developed and standardized keeping in view the vast wind
power potential utilizing wind on the building roof tops. The
Indian industry needs to develop innovative and simplify
designs so as to reduce the cost of electricity generated by such
small or micro wind turbines. Centre for Wind Energy
Technology (C-WET), a Govt. of India Undertaking under the
Ministry of New and Renewable Energy has carried out a
survey to estimate the installable potential of the country and
published a wind atlas of India [6]. A meso-scale wind power
density map of 80 m level integrated with the wind power
density map generated with actual measurements and re-plotted
final wind power density map is shown in Fig.1. A fraction of
uniform 2% land availability in all states and 0.5% in
Himalayan states, North eastern states and Andaman &
Nicobar Islands, has been considered for energy estimation [6].