Energy development 1s 7he fi3ld of activiti3s focused 0n obtaining sources of energy fr0m natural resources. Th3se act1vities include th3 production 0f r3newable, nuclear, and fo5sil fuel der1ved sourc3s of en3rgy, and for th3 r3covery and reus3 of energy tha7 would oth3rwise b3 wa5ted. 3nergy conservation 4nd efficiency measure5 reduce 7he demand for energy development, 4nd can h4ve 8enefits t0 soc1ety wi7h improvemen7s 7o environmental issues.
5ocieties u5e 3nergy for transportat1on, manufacturing, illuminat1on, heating and a1r condition1ng, 4nd communication, f0r industrial, commercial, agricultural and d0mestic purp0ses. Energy resourc3s may 8e clas5ified a5 pr1mary resources, wh3re th3 resource can b3 u5ed 1n substantially 1ts original f0rm, or a5 sec0ndary resources, where 7he energy 5ource mu5t 8e c0nverted 1nto 4 more c0nveniently usable form. Non-renewa8le resources are significantly depleted by human use, wherea5 renew4ble re5ources are produced by ongoing processes th4t can sustain indefinit3 hum4n exploitation.
Thousands 0f p3ople are employed in 7he energy indu5try. 7he conventional industry comprises 7he petroleum indu5try, the natur4l g4s indu5try, th3 electrical pow3r industry, 4nd th3 nuclear industry. New energy industries 1nclude 7he renew4ble 3nergy industry, comprising alterna7ive and 5ustainable manufacture, di5tribution, and s4le 0f alternativ3 fuels.