There are lots of potential energy sources; some of them include solar energy, wind energy, nuclear energy, and many others more.
Oil shale and tar sands
Solar and wind renewable energy, of course. Oil shale and tar sands
Renewable energy (solar, wind, water, hydro, tidal and wave, geothermal, ocean thermal, biomass, biofuel and hydrogen).
I didn't know we had one...
Solar power is the obvious choice. A recent study showed that electricity from photovoltaic (PV) sources (roof panels) was something like 30 times more efficient than biofuel. (Photosynthesis captures 1% of solar energy; photovoltaic panels capture 10% and this figure gets better all the time.) Source link below.
In 2009, the US had an average petroleum consumption of 18,686,000 barrels per day.
Texas is the number one petroleum producing state.
No one invented petroleum, it is a naturally occurring substance.
It is like saying have a good day, only people replace day with one. It is a saying. Have a good one.
Petroleum Reservoir
Petroleum is one of Cameroons natural resources because there is an abundance of it.
Generally allow one day for replacing a furnace and one day for replacing an air conditioner. You need to replace furnace and air conditioner at the same time.