Coal and natural gas are mainly used for electricity generation, whereas oil is used mostly to power transportation, yet the prices of all these energy sources are linked.

煤炭和天然气主要用于发电，而石油主要用于给运输提供能量，但所有这些能源的价格是相互关联的。

youdao

Others want nuclear, clean coal and natural gas.

一些则喜欢核能，清洁的煤炭和天然气。

youdao

Those prices are too high if solar power is to displace coal and natural gas.

如果用太阳能取代煤和天然气，这些价格显然太高了。

youdao

Does measures seem to low emissions of greenhouse gases by raising the cost of gasoline, coal,natural gas and other fossil fuels.

VOA: standard.2009.12.12

Nick DeIuliis, President of Consol Energy, a coal and natural gas producer based in Canonsburg, Pa.

MSN: Coal producers find themselves in a hard place

These power stations require fuels such as oil, coal and natural gas to operate which are relatively more expensive.

BBC: Tepco seeks more aid as Fukushima clean-up costs rise

So net-net, Yelp saves trees but uses more electricity (and more coal and natural gas, which produce 75% of kWhs).

FORBES: Rating Yelp as a Bellwether of the Social Media Tech Boom