%0 Journal Article %T Solar Potential in the Himalayan Landscape %A T. V. Ramachandra %A Gautham Krishnadas %A Rishabh Jain %J ISRN Renewable Energy %D 2012 %R 10.5402/2012/203149 %X Estimation of solar energy reaching the earth¡¯s surface is essential for solar potential assessment. Solar radiation data based on satellites provide higher spatial and temporal coverage of regions compared to surface based measurements. Solar potential of the Indian hill state of Himachal Pradesh has been assessed using reliable satellite based global horizontal insolation (GHI) datasets validated based on its complex terrain. Solar maps representing regional and temporal resource availability in the state have been generated using geographical information systems (GIS). Spatial analyses show that the state receives annual average GHI above 4.5£¿kWh/m2/day and a total of 99530395 million kWh (or million units, MU). The regional availability of GHI in Himachal Pradesh is influenced by its eclectic topography, seasons as well as microclimate. The lower and middle elevation zone (<3500£¿m) with tropical to wet-temperate climate receives higher GHI (>5£¿kWh/m2/day) for a major part of the year compared to the higher elevation zone (>3500£¿m) with dry-temperate to alpine climate (4¨C4.5£¿kWh/m2/day). Results show that Himachal Pradesh receives an average insolation of 5.86 ¡À 1.02¨C5.99 ¡À 0.91£¿kWh/m2/day in the warm summer months; 5.69 ¡À 0.65¨C5.89 ¡À 0.65£¿kWh/m2/day in the wet monsoon months; 3.73 ¡À 0.91¨C3.94 ¡À 0.78£¿kWh/m2/day in the colder winter months. 1. Introduction Energy plays a pivotal role in the development of a region. However, energy shortages in recent times, the imminent energy crisis, and threat of climate change have focused the attention for a viable sustainable alternative through renewable sources of energy. Sun being the vital source of renewable energy manifested in different forms in the solar system; it is necessary to understand the mechanism of energy flow involved. The geometry of the earth-sun movements causes large spatial, diurnal, and seasonal variations in the amount of solar radiation received on earth. The 23.5¡ã tilt of the earth¡¯s rotational axis with respect to the plane of orbital revolution causes larger annual variations near the poles and smaller variations near the equator [1]. Due to the variations in the sun-earth distance, intercepted solar radiation fluctuates by ¡À3.3% around its mean value. The variations, due to sunspots, prominences and solar flares, can be neglected as they constitute small fraction compared to the total energy emitted by the sun. The average solar radiation falling on the earth¡¯s atmosphere called the solar constant is estimated to be 1.36£¿kW/m2. The presence of clouds, suspended dust, gas molecules, %U http://www.hindawi.com/journals/isrn.renewable.energy/2012/203149/