The major indicators to measure the level of economic development are
1. Net National Product (NNP),
2. Per Capita Income (PCI),
3. Purchasing Power Parity (PPP),
3. Human Development Index (HDI).

(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.

In my locality i found the following environmental problems:
1. Air pollution: As there are a number of vehicles in my area the air pollution in very high Whenever I walk on the road, I could smell the carbon dust emitted from the vehicle.
2. Water pollution: Previously we could get clear water from our taps. Now the water is muddy and polluted.
3. Soil Pollution: Because of the incrase of air pollution we could find the soil polluted in our area.

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.