20分～～Adventage and disadventage about Solar power

Advantages:

The 89 petawatts of sunlight reaching the earth's surface is plentiful compared to the 15 terawatts of average power consumed by humans. Additionally, solar electric generation has the highest power density (global mean of 170 W/m2) among renewable energies.

Solar power is pollution free during use. Production end wastes and emissions are manageable using existing pollution controls. End-of-use recycling technologies are under development.

Facilities can operate with little maintenance or intervention after initial setup.
Solar electric generation is economically competitive where grid connection or fuel transport is difficult, costly or impossible. Examples include satellites, island communities, remote locations and ocean vessels.

When grid connected, solar electric generation can displace the highest cost electricity during times of peak demand (in most climatic regions), can reduce grid loading, and can eliminate the need for local battery power for use in times of darkness and high local demand; such application is encouraged by net metering. Time-of-use net metering can be highly favorable to small photovoltaic systems.

Grid connected solar electricity can be used locally thus minimizing transmission/distribution losses (approximately 7.2%).

Once the initial capital cost of building a solar power plant has been spent, operating costs are low when compared to existing power technologies.).

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Disadvantages:

Polysilicon Solar cells are costly, requiring a large initial capital investment, and silicon shortages raise prices. Costs are expected to come down, however, due to increased manufacturing, economies of scale and Balance of System planning. Thin film technology uses less silicon; and Lease/Rental options* are currently being introduced.
Limited power density: Average daily insolation in the contiguous U.S. is 3-9 kW·h/m2 usable by 7-17.7% efficient solar panels.

To get enough energy for larger applications, a large number of photovoltaic cells is needed. This increases the cost of the technology and requires a large plot of land.
Like electricity from nuclear or fossil fuel plants, it can only realistically be used to power transport vehicles by converting light energy into another form of stored energy (e.g. battery stored electricity or by electrolysing water to produce hydrogen) suitable for transport.

Solar cells produce DC which must be converted to AC when used in currently existing distribution grids. This incurs an energy loss of 4-12%.