For new solar energy, it has obvious characteristics compared with fossil fuels such as oil, coal, natural gas and nuclear energy.
1? Abundant resources
Solar energy is the most abundant energy source that humans can use. According to the theory of stellar evolution, the Sun can radiate energy at its current power for almost 10 billion more years. Experts deduce that over the past billion years, the sun has only consumed 2% of its own energy, so this will not change significantly over the next billion years. So we can say that the sun can be used permanently. Energy is inexhaustible and inexhaustible. The energy it sends to the ground for 15 minutes is enough for the entire world to use for a year. The energy of solar radiation that reaches the surface of the Earthe each year is approximately equivalent to 130 trillion tons of standard coal. Its total quantity is the largest. the energy that can be developed in the world today. For example, if we compare the different energy sources currently used each year by humans around the world to the energy emitted during the explosion of a grenade, then the energy of solar radiation that reaches the surface of the earth each year and can be used by humans is equivalent. to a hydrogen bomb. The amount of energy released during the explosion varies considerably.
2? Clean and pollution-free
The development and use of solar energy will not pollute the environment. When solar energy is used, it will not emit any substances that have a negative effect. environmental impact. It is the cleanest source of energy in today's world where environmental pollution is becoming increasinglyincreasingly serious, it is extremely valuable and presents an incomparable advantage compared to any other source of energy.
3? Widely distributed
The sun shines on the earth, no matter the land or the sea, no matter the mountains or the islands, there is bright sunshine and it does not require transportation and is easy to obtain. Areas between 50 and 60 degrees north and south latitude, with annual daylight hours of 1,600 to 2,400 hours, are generally thought to be rich in solar energy that can be used provided that an initial investment is made. made to build solar energy. device of use, the energy will continue to flow on its own. Delivered to your door.
1? Low intensity
Although the solar energy reaching the upper limit of the earth's atmosphere and reaching the earth's surface is very huge, its intensity is not high. This energy is too scattered. An incThe disadvantage is that as a source of energy, its density is too low. On average, near the Tropic of Cancer, when the weather is relatively clear in summer, the irradiance of solar radiation is greatest at noon, and the solar energy received on an area of 1 square meter perpendicular to the direction of sunlight is only about 1,000 watts on average if the day and night average throughout the year is only about 200 watts. In winter it only reaches half, and in cloudy weather it is only about a fifth. This energy flow density is very low. Therefore, when using solar energy, if we want to obtain a certain conversion power, we often need a set of collection and conversion equipment with a considerable area, which is expensive.
2? Discontinuity
The greatest weakness of solar energy is its discontinuity. The alternation of day and night causesinterruptions of solar radiation. On average, across most of the planet, almost half of the year is plunged into darkness; the remaining half of the year is spent in darkness. What is the weather like? It is already very difficult to use solar energy on cloudy and rainy days, but it is impossible to use solar energy at night, which seriously limits the application of solar energy.
3? Uncertain
Due to limitations of natural conditions such as day and night, season, geographic latitude and altitude, as well as random factors such as clear, cloudy, cloudy, and rain , arriving at a certain place. Solar irradiation on the ground is neither continuous nor stable, which makes the large-scale development and use of solar energy more difficult.
At the same place, on the same day, the intensity of solar radiation at sunrise and sunset is much less than aroundnoon and in the same place, in different seasons, the intensity of solar radiation in summer is much less; higher in winter. The main reason is that due to the different altitude angles of the sun, the angles of incidence relative to the same horizontal plane are naturally different. The greater the angle of solar altitude, or the smaller the angle of incidence of solar radiation, the more solar energy is received in the same horizontal plane on the ground, conversely, the greater the angle of solar radiation. solar altitude is small, or the larger the angle of incidence of solar radiation, the larger the angle of solar altitude, or the smaller the angle of incidence of solar radiation, the more solar energy is received in the same horizontal plane on the ground. the more solar energy is received in the same horizontal plane on the ground, the less solar energy is received. Everyone must have had this experience when drying clothes: when the flat surface of the garment to be driedfacing solar radiation, it dries most quickly, but when facing sideways to solar radiation, it dries more slowly.
In order to make solar energy a continuous and stable energy source, and thus to make it an alternative energy source that can compete with conventional energy sources, the problem of storage of energy should be well resolved, that is, solar energy radiation on clear days should be It can be stored as much as possible so that it can be used at night or on rainy days, but currently Energy storage is also one of the weakest links in solar energy use.
4? High cost
The current level of development of solar energy use is theoretically feasible and technically mature. However, some solar energy utilization devices have high cost and low efficiency. On the negative side,Overall, the economy cannot compete with conventional energy sources. For a long time, the development of the use of solar energy will be limited mainly by economic costs.
Calculate the total amount of solar energy fixed by producers in a certain marine ecosystem
. The total amount of solar energy fixed by all producers in the ecosystem is the total energy flowing through the ecosystem. When it crosses the first trophic level (producers), the energy passes: part of the producers breathes and part flows to the next trophic. At level , part of the energy contained in producer remains, dead branches and leaves is broken down and released by decomposers.
(1) In marine ecosystems, solar light emission decreases as water depth increases, so light is the main abiotic factor affectingmarine ecosystems. The most abundant producer is mainly algae.
(2) In offshore waters with a water depth of about 10 meters, producers have the most fixed light energy, so the number of producers is the largest.
(3) Below 100 meters of water, there is almost no sun. Animals and a variety of microorganisms mainly live there, so the main components are consumers and decomposers.
The answer is therefore:
(1) LightAlgae (or phytoplankton)
(2) 10
(3) Consumption Decomposition