Journal of Energy Bioscience 2012, Vol.3, No.1, 1-12
10
with better spatial coverage would aid in better
validation of these results apart from removal of
uncertainties such as data gaps, etc. Availability of
more number of reliable wind measurement stations
and detailed analysis of terrain features could facilitate
micro-scale (1~10 km) wind resource assessment in
Himachal Pradesh.
4.3
Small-scale wind applications in Himachal Pradesh
In order to explore the potential of wind technologies
at an increased hub height, hourly surface wind speed
measurements at IMD stations were estimated for 30 m
using power law in Equation 1 and represented in
Figure 11. More than 61% of measured hours in
Nahan, 44% in Bhuntar and 18% in Dalhousie
obtained wind speeds above 2 m/s. Over 29% of the
measured hours crossed 4 m/s wind speeds in Bhuntar.
These finding along with relatively higher wind
speeds (> 2 m/s in high elevation zone) observed in
seasonal wind profiles (based on synthesised CRU
data) are indicative of the prospects of small-scale
wind applications in Himachal Pradesh.
Figure 11 Percentage occurrence of winds above 2 m/s and 4 m/s
from hourly measurements projected to 30 m hub height
With advancements in technology, small-scale wind
turbines functional at moderately low wind speeds are
technically feasible and economically viable (Cabello
and Orza, 2010). Some of these are listed in Table 3.
The Savonius rotor Vertical Axis Wind Turbine
(
VAWT) that can function in wind speeds as low as 1
m/s (Ayhan and Saglam, 2012) is of special interest in
this region.
Wind pump for drawing water is an attractive
small-scale wind technology for rural energy needs
(
Mathew et al., 2002). The agriculture intensive
sub-tropical to wet-temperate zones of Himachal
Pradesh could get benefited by wind pumps that
function at low wind speeds. As seen in Nahan and
Bhuntar, increased hub heights (30 m) could deliver
prolonged winds above 2 m/s.
Table 3 Available small-scale wind turbines (European Wind
Energy Association, 2012,
. wind-energy-the-fa
cts.org/
)
Rated power, P
rated
(
kW)
Rotor swept area (m
2
)
Sub-category
P
rated
< 1
A < 4.9
Pico wind
1
< P
rated
< 7
A < 40
Micro wind
7
< P
rated
< 50
A < 200
Mini wind
50
k < P
rated
< 100
A < 300
(
Not defined)
Wind based space heating systems have been assessed
to be cost effective compared to many conventional
fuel sources like fuelwood and electricity (Jaber et al.,
2008).
The colder alpine zone of Lahaul Spiti and
Kinnaur where the wind speeds are relatively higher,
could meet their space heating requirements through
wind energy. Development of wind energy based
water heaters is promising for such regions
(
Tudorache and Popescu, 2009).
Reduction in wind speeds and duration could be
compensated by hybridizing wind with available
alternative resources. Our assessment of solar energy
potential in Himachal Pradesh substantiates that it
receives monthly average global insolation (incoming
solar radiation) > 4 kWh/m
2
/
day except for the winter
months (December and January). Higher altitude
alpine zone (> 3500 m) receives lower insolation
values but higher wind speeds. This trends inverts in
lower altitude tropical zone i.e higher insolation and
lower wind speeds (Ramachandra et al., 2011;
Ramachandra et al., 2012). Hence wind-solar hybrid
systems could be considered for endured energy
supply in the region. Small-scale wind turbines could
also be used in conjunction with diesel generators
especially in remote areas (Clausen and Wood, 1999),
although not a clean option. Battery charging based on
wind systems supplements the energy requirements
during reduced wind speeds.
4.4.
Constraints
The present study provides a meso-scale
