advantage

Universal: The sun shines all over the earth, and there is no geographical restriction, no matter land or sea, no matter mountain or island, it is everywhere. 1. It can be directly developed and utilized, without mining and transportation

2. Harmless: the development and utilization of solar energy will not pollute the environment. It is one of the cleanest energy sources. This is extremely valuable in today's increasingly serious environmental pollution.

3. Huge: The solar radiation energy reaching the earth's surface every year is equivalent to 130 trillion tons of coal, which is the largest energy that can be developed in the world today.

4. Long-term: According to the current rate of nuclear energy produced by the sun, the storage of hydrogen is enough to maintain for tens of billions of years, and the life of the earth is about billions of years. In this sense, we can say that the energy of the sun is inexhaustible.

shortcoming

1. Dispersion: Although the total amount of solar radiation reaching the earth's surface is large, the energy flow density is very low. On average, in the vicinity of the Tropic of Cancer, when the weather is sunny in summer, the irradiance of solar radiation is the largest at noon, and the average solar energy received on an area of 1 square meter perpendicular to the direction of sunlight is about 1000W; According to the average day and night throughout the year, it is only about 200W. However, in winter, it is only about half, and in overcast days, it is only about 1/5. Such energy flow density is very low. Therefore, when using solar energy, to obtain a certain conversion power, it often requires a set of collection and conversion equipment with a relatively large area, and the cost is high.

2. Instability: Due to the limitations of natural conditions such as day and night, season, geographical latitude and altitude, as well as the influence of random factors such as sunshine, overcast, cloud and rain, the solar irradiance reaching a certain ground is both intermittent and extremely unstable, which increases the difficulty of large-scale application of solar energy. In order to make solar energy become a continuous and stable energy, and finally become an alternative energy that can compete with conventional energy, we must solve the problem of energy storage, that is, to store the solar radiation energy in bright daytime as much as possible for use at night or in rainy days, but at present, energy storage is also one of the weak links in the use of solar energy.

3. Low efficiency and high cost: At present, the development level of solar energy utilization is feasible in theory and mature in technology. However, some solar energy utilization devices, because of their low efficiency and high cost, can not compete with conventional energy in economy. In the future, the further development of solar energy utilization is mainly restricted by economy.