The disadvantages of solar energy
One of the most well known problems with solar energy technology is that energy is only generated when the sun shines. That means that supply can be disrupted at night and on cloudy days.
The shortage caused by this interruption would not be a problem if there were low-cost methods of storing energy. During extremely sunny periods, solar panels generate more energy than they are using. As the world’s solar power capacity grows, nations such as Japan and other global leaders in solar energy technology are focusing on developing sufficient energy storage to address this issue.
Another concern is that solar panels can take up a significant amount of land, resulting in land degradation or wildlife habitat loss. While solar PV systems can be installed on existing structures (like roofs), larger utility-scale PV systems may require up to 3.5 to 10 acres per megawatt, while CSP facilities may require up to 4 to 16.5 acres per megawatt.
This problem can be helped by locating solar facilities in low-quality areas or along existing transportation and transmission corridors.
Scarcity of Materials
Certain solar technologies require the use of rare materials in order to be manufactured. This, however, is primarily a PV technology issue rather than a CSP technology issue.
Furthermore, the problem is not so much a lack of known reserves as it is the inability of current production to meet future demand: Many rare materials are byproducts of other processes rather than the focus of concentrated mining efforts. Recycling PV material and advances in nanotechnology that increase solar-cell efficiency could both help boost supply, but finding more abundant material substitutes could also play a role.
An Environmental Downside
The one disadvantage of solar technology in terms of the environment is that it contains many of the same hazardous materials as electronics. As solar energy becomes more popular, the problem of hazardous waste disposal becomes more complicated. However, assuming that the challenge of proper disposal is met, the lower greenhouse gas emissions offered by solar energy make it an appealing alternative to fossil fuels.