Renewable means coming from sources that do not run out — sun, wind and water. Renewable energy, renewables, a renewable source.
Renewables as a plural noun means the whole sector: renewables now supply about half of Britain's electricity in some quarters. The contrast is with fossil fuels, which are finite. Renewable is not the same as carbon-neutral or as sustainable, and the three are often muddled in advertising. Note also the ordinary sense: a renewable contract or licence is one that can be extended.
1adjectiverenewableComing from sources that do not run out.
“Renewable sources supplied about half the electricity that quarter.”
2adjectiveableAble to be extended for a further period.
“The licence is renewable every three years.”
renewable is a quality of not running out.
Proto-Indo-European
*new- (new)
Old English
nīewian — to restore; renovate; renew
Middle English
renewen
English
renew
English, today
renewable
Built from
From renew + -able. renew comes from Middle English renewen, an alteration (possibly on analogy with Latin renovāre) of earlier anewen (“to renew”), from Old English nīewian (“to restore; renovate; renew”), equivalent to re + new. Cognate with Old High German giniuwōn (“to renew”), Middle High German geniuwen (“to renew”), Old Norse nýja (“to renew”).
Etymology from Wiktionary, CC BY-SA