Sunny is one of the climatic factors observed by the length of time, it has close relation with solar radiation and is directly governed by the amount of cloud. The number of sunny hours is the number of hours the intensity reaches or exceeds a certain value, is burning the sunshine. The number of sunny hours in the coastal plain ranges from 1,800 - 1,820 hours, mountainous areas from 1,500 ÷ 1,520 hours. The total number of sunny hours in the coastal plains is larger than the mountains.

The sunny period with over 100 hours of sunshine / month lasts from March to the end of October every year. In particular, the most sunny months are the months of V, VI and VII with the number of sunshine hours reaching 215 ÷ 260 hours / month, ie about 7.2 ÷ 8.7 hours of sunlight / day, of which the month has The highest sunny hour is October

The period with relatively little sunshine in the year is the winter months, from November to February next year, reaching less than 100 hours of sunshine per month. The month with the lowest number of sunshine hours is December (coinciding with the apparent movement of the sun), only about 62 ÷ 73 hours of sunshine, ie about  2,2 to 2.6 hours of sunshine / day. Particularly in the mountainous area because there are many fogs in February, the total number of sunshine hours this month is the lowest. During the year, the number of sunshine hours increased most rapidly in April and May and decreased relatively quickly from October to November, as these were seasonal seasons.

Table 3: Monthly sunshine hours and average annual years (hours)

Based on the radiation data as well as the number of sunshine hours, geographic location and the size of the land area for project construction, the results of on-site field surveys as well as assessment of characteristics Natural and socio-economic, the location is expected to exploit solar power in the area of ​​the waste treatment plant in Ly Trach commune, Bo Trach district with a capacity of about 1.0MW connected to the grid combined with electricity generation capacity. of the waste treatment plant of the project on sorting waste treatment, biogas production and organic mineral fertilizer.