SAN FRANCISCO (MarketWatch) — Hammered by tanking oil prices, shares of solar and renewable-energy companies fell sharply Friday, along with conventional-energy stocks.

Cheaper oil can translate into cheaper energy costs, which can hurt the economics of installing solar panels and other alternative energy sources.

Top losers among renewables included solar-panel maker Canadian Solar Inc. CSIQ, -0.44% and renewable oil maker Solazyme Inc. US:SZYM

The selloff in renewables followed news the Organization of the Petroleum Exporting Countries on Thursday decided to stand pat on oil production.

Crude prices traded around their lowest since May 2010 before recovering some ground on Friday.

Markets were split on whether OPEC would cut output to help boost crude prices at its meeting Thursday, or keep production the same to defend its market share.

OPEC’s decision to stand pat on output will keep the world awash in oil — analysts said Friday the surplus for next year would hover around one million barrels a day.

The Guggenheim Solar exchange-traded fund TAN, -1.17% was poised to end the week down more than 5%.