Advantafe:
(1) Universal: The sun shines all over the land, and there is no geographical restriction. Whether it is on land or sea, whether it is mountains or islands, it is everywhere, and it can be directly developed and used 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. Today, when environmental pollution is getting more and more serious, this is extremely valuable.
(3) Huge: The solar radiant energy reaching the surface of the earth every year is equivalent to about 130 trillion tons of coal, and its total amount is the largest energy source that can be developed in the world today.
(4) Long-term: According to the estimation of the current rate of nuclear energy produced by the sun, the storage of hydrogen is sufficient to maintain tens of billions of years, and the life of the earth is also about several billion years. In this sense, it can be said that the energy of the sun is used Inexhaustible.
Disadvantage:
(1) Dispersibility: Although the total amount of solar radiation reaching the earth's surface is large, the energy flow density is very low. On average, near the Tropic of Cancer, when the weather is clear 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; Average year and night, it is only about 200W. In winter, it is roughly half, and it is generally only about 1/5 in cloudy days. This kind of energy flow density is very low. Therefore, when using solar energy, to obtain a certain conversion power, a set of collection and conversion equipment with a relatively large area is often required, and the cost is relatively high.
(2) Instability: Due to natural conditions such as day and night, seasons, geographic latitude and altitude, as well as the influence of random factors such as sunny, overcast, cloud, and rain, the solar irradiance reaching a certain ground is intermittent. Yes, it is extremely unstable, which makes the large-scale application of solar energy more difficult. In order to make solar energy a continuous and stable energy source, and ultimately become an alternative energy source that can compete with conventional energy sources, the problem of energy storage must be solved well, that is, the solar radiation energy during the sunny day should be stored as much as possible for the night or rainy days. Days use, but currently energy storage is also one of the weaker links in solar energy utilization.
(3) Low efficiency and high cost: At the current level of development of solar energy utilization, some aspects are theoretically feasible and technically mature. However, some solar energy utilization devices have low efficiency and high cost. In general, the economy cannot compete with conventional energy sources. For a considerable period of time in the future, the further development of solar energy utilization will be mainly restricted by economy.
