Solar cells harness the sun's energy and convert it into electricity. However, the cost of this clean energy is much higher than the cost of energy produced using fossil fuels. What development might reduce the prices of solar energy?

A) The use of more wind energy.

B) The discovery of new coal deposits.

C) The expansion of off-shore drilling.

D) The invention of cheaper solar panels.

Answer: Option D

Solar panels contain a very expensive element, i. e. silicon. This element is able to convert the solar energy into electric energy. The cost of the solar panel gets expensive because of this rare element. It is found in limited areas of the world. That’s why option D is correct. Coal is not used in solar panel, so option B is incorrect. Neither is wind energy, so option A is also incorrect. Water is also not used for exploiting solar energy, which makes option C a wrong answer.

D is the correct answer.