(i) Solar power is the conversion of energy from sunlight into electricity either directly using photovoltaic cells or indirectly using concentrated solar power.
(ii) Solar panels absorb the sunlight as a source of energy to generate electricity.
(iii) A solar electric system can reliably produce electricity for our home and offices.

(i) NNP - Net National Product
(ii) PCI - Per Capita Income

(i) PPI - Purchasing Power Parity
(ii) HD - Human Development Index.

(i) The Net National Product (NNP) is considered as a true measure of national output. It is also known as national income.
(ii) A rise in per capita income means an increase in aggregate real output. Hence, this is a better indicator than national income for measuring development.
(iii) For measuring a country's development, its income is considered to be one of the most important factors. Countries with higher income are considered to be more developed than those with lesser income.
(iv) So, income itself is considered to be one of the indicators of economic development.

(i) Development refers to the progress of a particular field or a particular person.
(ii) The economic progress of a country is known as economic development.
(iii) Development refers to the improvement in quality of life such as higher income, better education, better health and nutrition less poverty and more equal opportunity.

USE OF NON-CONVENTIONAL SOURCES OF ENERGY:
(i) India depends on thermal and hydro power plants to meet its power needs.
(ii) Both these sources have an adverse environmental impact.
(iii) They emit large quantities of carbon dioxide, which pollute the environment.
SOLAR POWER:
(i) Solar power is the conversion of energy from sunlight into electricity either directly using photovoltaic cells or indirectly using concentrated solar power.
(ii) Solar panels absorb the sunlight as a source of energy to generate electricity.
(iii) A solar electric system can reliably produce electricity for our home and offices.
(iv) It reduces their electricity costs.
(v) Tamilnadu is the state with highest installed solar capacity in India.
(vi) Tamilnadu is one of the leading solar power producing states in India.

(i) Development increases the quality of life.
(ii) People will have higher incomes, better education, better health and nutrition, less poverty and more equality of opportunity.

Human Resource Development means the development of a person's physical and mental abilities through education, health care and training.

Purchasing Power Parity is defined as the number of units of a country's currency required to buy the same amount of goods and services in the domestic market as one dollar would buy in the U.S.

If our thinking turns towards progress and about the ways to achieve the many goals for progress, it leads to development.