@okie,
Quote:Solar would be no good at night, so already the capacity of solar is limited to only half a day, plus factor in cloudy days.
It's certainly true that cloudy days play a role. However, that can be mitigated by choosing an appropriate location. (Likewise, you wouldn't build a wind farm in an area that has no steady wind most of the year.)
Apart from that, it also depends on what kind of solar power you have in mind. Photovoltaic generates electricity from sun light, and would require to store the electricity. Concentrated Solar Power (CSP) plants, on the other hand, can produce electricity for a long time after the sun has set.
The Andasol power stations in Spain, for example, use a parabolic trough system - which looks something like this:
The troughs are constructed as parabolic mirrors, with a long tube running along the centre. The mirrors reflect the sunlight and concentrate it on the tube. A fluid runs through the tubes and absorbs the heat from the concentrated sunlight. And after passing through the array, the heat is used to generate steam and power a generator - essentially like in any other conventional power plant.
However, instead of storing the electricity produced from the generator, it's actually more efficient to store the heat generated by the system during the day.
The Andasol plants use a system of liquid salt heat storage. This stores the heat so effectively, that electricity can be generated even 7 ½ hours after the sun has gone down. (
Andasol 1 fact sheet - PDF)