CONCLUSIONS
Goa and Mangalore receive global solar radiation in the range of 5.5-7.5 kWh/m2/d during the November-May period. During June-August and September - October the solar radiation received is in the range of 2.5-5.0 and 3.5-6.5 kWh/m2/d. These analyses show that solar potential at Goa and Mangalore is in the range of 5-7 kWh/m2/d for about 9 months a year and 3.5-5 kWh/m2/d during the monsoon season. Dense cloud cover for about 10-12 days, on average, in July and 5-6 days in August are the lean periods for solar energy in this region. Computed global radiation using Eq. (6) (linear relationship between global radiation and sunshine hours) and observed values of global radiation vary within the range 2-7%.
In order to improve accuracy using the available data, we have attempted to estimate global radiation using parameters such as sunshine duration, temperature, relative humidity, specific humidity, and rainfall (25 years of data collected at Goa and 20 years at Mangalore). Based on the high correlation coefficient and minimum standard error of estimate, we conclude that Eqs. (11) and (13) are appropriate. It is found that observed and computed values of solar radiation agree within +or- 5% of the observed values. With this experience, we have computed GR at Honnavar, Karwar, and Bhatkal based on climatological data of 50 years at Honnavar, 39 years at Karwar, and 15 years data at Bhatkal (Shirali) using Eqs. (11) and (13).
Karwar has a GR range of 5.5-6.5 during January-May and is in the minimum range of 4-5 during the monsoon months, July-September. While at Honnavar, the GR range during January-May is 5.47-6.5 kWh/m2 and minimum during the monsoon months. Thus this study of the coastal area of the Western Ghats region demonstrates that good solar energy potential is available in this region during most months of the year.
The amount of solar energy that could be harnessed by utilizing 5% of the present wasteland in coastal taluks as solar collection areas is found to be of the order of 95.72 mkWh/yr from coastal belt (40.90 mkWh/yr at Karwar, 21.98 mkWh/yr at Ankola, 22.60 mkWh/yr at Kumta, 4.176 mkWh/yr at Honnavar, and 6.045 mkWh/yr at Bhatkal). This constitutes 32.55% of present electricity demand from various sectors of Uttara Kannada.
