Considering both solar thermal energy conversion to electrical energy and photovoltaic, the following are some disadvantages and how they are being resolved:
1) First, solar energy is only available during day time and effects of climatic changes or geographical location are a big concern. Solar energy availability during the day time only is a hard fact and probably a trade-off considering solar power is freely available to everyone. Power producing plants adjust to this hard fact by utilizing solar thermal energy during peak or non-peak hours of the day depending on weather conditions and power demand. Another option is a provision of thermal storage for
utilization during night time or peak/non-peak hours of the day.
2) Second, energy conversion rates or efficiencies are low compared to other energy sources. Low energy conversion rates to electrical energy in both solar thermal and photovoltaics are being addresed by increasingly stronger research & development activities of key companies to eventually come-up with highly efficient materials and cost-centric solar energy systems or facilities.
3) Third, high capital cost requirement for the procurement or production of materials and installation of solar enery systems or facilities. This high capital cost requirement is being offseted by the following:
a) First, usage of cheap barren lands not frequently affected by climatic changes and that typically have sunny weather conditions throughout the year, and new architectural designs of solar energy facilities and houses to incorporate solar panels in the case of photovoltaic.
b) Second, reduced operating costs given the fact that solar power is free.
c) Third, reduced harmfull effects to the environment (reduced carbon emissions) as compared to using other sources of energy like crude oil.
d) Fourth, reduced dependecy to imported crude oil.
Also, recent developments show that some key companies increased their manufacturing capabilities of solar panels. This will eventually pull down the cost per unit of producing highly efficient silicon photovoltaics.
Regardless of how difficult it is for these key companies to produce solar energy or other forms of renewable energies, the advantages far outweigh the disadvantages. Researchers must hurry to develop solar power further as the world awaits for the big thing to come in energy revolution.