Potential of Solar Energy in Nepal - Smart Solar Nepal

Potential of Solar Energy in Nepal

Solar energy (in the form of electromagnetic radiation) enters the earth’s surface. The wavelength of solar radiation entering the earth surface varies from 0.3-3 micrometer. Air molecules, aerosols and clouds absorbs and scatters the incoming solar radiation after it strikes the earth atmosphere. Out of the total radiation entering the earth’s surface about 70% of incoming radiation is engulfed by the atmosphere.

Looking back to the energy consumption patterns of the 50 years, the energy demands of the world has tripled because of advancement in technology and increase in number of developing countries. If the energy consumptions patterns remain same, in the next 30 years the energy demands would triple again. The current energy consumptions pattern has increased the energy crisis and would create problem in the energy security. So, the use of the renewable energy has been emphasized by most of the country. Germany, by the year 2020, had planned to meet its 20% electricity usage and 10% of their energy demand with the renewable resources. Many countries are making improvements in the renewable’s fields. Switching the energy consumption patterns from non-renewable to renewable energy would help in energy security and also reduce the carbon footprint and energy crisis.

The rate of consumptions of petroleum products in Nepal is increasing at the rate of 10% per year (source: NOC,2011).  Nepal lacks its own sources of petroleum and coal due to which its dependency with other country has increased, resulting the trade deficit. From the past six years regularly the price of the fossil fuel has been hiked. To break this dependency, promote long-term economic growth, tackle climate change, enhance global energy security and to assists in the development of the renewable field, it is essentials to make the use of solar energy. Solar radiation could be a major source of fuel in Nepal. Various research has been carried out to know the actual potential of the solar in Nepal. In Nepal, there are no continuous or long-term solar radiation results. However, the Royal Nepal Academy of Science and Technology (RONAST), in partnership with JICA, Japan, has conducted short-term solar radiation monitoring and utilization. In 1992 and 1995, they constructed 4 kW prototype and 40 kW solar photovoltaic panels for water pumping at Sunderighat, Kirtipur, and Bode Bhaktapur, respectively (Bhandari, 1996).

The total energy consumptions of the Nepal in fiscal year 2008/09 was found to be 410,000 TJ. According to the MOF, out of the total energy, 85% is covered by the traditional resources, 14% by commercial sources (coal-3%, grid electricity-2% and petroleum products-9%) and about 1% by alternative sources (solar power, wind, biogas and micro/pico hydropower). In average the global solar radiation varies from 3.6-6.2 kWh/m2 day in Nepal. In a year, for about 300 days, sun shines. The number of sunshine hours amounts almost 2100 hours per year and average insolation intensity about 4.7 kWhm-2 day-1 (=16.92 MJ/m2 day). In the world, Nepal is located in a favorable insolation zone. From 2008 to 2012, monthly sum global solar radiation for six sites is shown in the table below:

NOV 345.10505.50334.70389.50501.80436.80
DEC317.40438.50 311.00360.90436.50366.10

Monthly sum minimum global solar insolation was reported as 285 MJ/m2 in January for Biratnagar, 242.33 MJ/m2 in August for Lukla, 311.00 MJ/m2 in December for Kathmandu, 360.60 MJ/m2 in December for Pokhara, 436.50 MJ/m2 in December for Jumla and 366.10 MJ/m2 in December for Simikot, according to the data provided in above table. According to the above results, the lowest values of global solar radiation were reported in November, December, January, and February, which correspond to shorter days, the earth’s greatest distance from the sun, cloudy skies, and foggy days. The lowest value of minimum global solar radiation was 169.90 MJ/m2 in June 2008 at Kathmandu, which has the haziest, gloomy atmosphere, and rainy conditions (average rain fall 7.34 mm per day) (Source: DHM/GoN) of the Kathmandu Valley. The months of April to July have the highest solar insolation, while January, February, November, and December have the lowest. Jumla was discovered to be the place with the greatest amount of global solar energy. Nepal has a national average solar insolation of 4.66 kWh/m 2 day (16.776 MJ/m2 day). This value is higher than the 4.39 kWh/m2 day calculated by the Solar Energy Research Laboratory, Department of Physics, Silpakorn University, Thailand for Lao PDR, but lower than 5.1 kWh/m2 day, which represents selected high-potential Nigerian sites. According to the Solar and Wind Energy Resource Assessment (SWERA), solar energy is available in Nepal at an annual average of 4.7 kWh/m2/day (SWERA, 2006). According to this report, Nepal has a lot of solar energy. Plenty of the places in Nepal are solar radiation-friendly, which means that Nepal receives a lot of global solar radiation. As a result, Nepal has a high insolation level and a high solar energy capacity when compared to other countries. As a result, solar farming is strongly recommended in this country to address environmental, economic, and energy issues.

More from Us


Renewable energy, also called alternative energy, usable from replenishable sources such as the sun (solar energy), wind(wind energy)river(hydroelectric energy), hot…


Significant energy disparities exist in the world, both between and within individual states as well as between affluent and poor…

Solar PV in Nepal: A Bright Future For Clean Energy 

Around 20% of Nepal's total energy consumption is made up of modern energy sources including electricity, petroleum, and renewables, and…