Final answer:
Solar energy's major disadvantage is its dependence on sunlight and reduced efficacy during cloudy conditions. Intermittency issues and high initial investment are also challenges, along with environmental impacts of large installations and PV manufacturing waste.
Step-by-step explanation:
One of the major disadvantages of solar energy is that it is only available when there is sunlight. Solar thermal energy requires direct sunlight and has a lower efficiency under cloudy conditions. Photovoltaic (PV) panels, on the other hand, can still produce electricity even when the sun is obscured by clouds, but the efficiency is reduced. Solar power is also intermittent and comes with high up-front costs. Intermittency can be mitigated with battery storage, yet this increases costs and requires maintenance with periodic battery replacement. Moreover, large solar array installations can impact fragile ecosystems, especially in desert areas, and the manufacturing of PV cells creates some hazardous waste.