The chief limitations of solar energy include an inability to generate power at night, an inability to ramp up power production to meet demand, and the cost of solar panels. Transferring the electricity from areas where solar is more efficient to other areas of the planet is also a problem.
The generation of solar electricity produces no carbon emissions and the power is free after the cost of equipment, but its limitations make it a poor choice for base-line energy generation. Power stations that use coal or natural gas and nuclear plants can adjust their output to generate more electricity as needed, while a solar panel produces a set amount of electricity depending on the intensity of the sunlight that strikes it. Desert areas are best suited to the generation of solar electricity, but transmission losses make it difficult to transport that electricity into regions without suitable solar intensity.
While solar panels do not generate power at night, concentrated solar power is one solution to the reliability problem. These plants focus the sun's heat onto a central tower filled with molten salt, and use the heat of that salt to create steam and generate electricity. The temperatures generated are high enough that a concentrated solar plant can produce usable steam well into the night, and in some cases may be able to operate 24 hours a day solely on solar energy.