Lets look at the scale of problem:

Current energy usage at 15 trillion watts 86,400 seconds a day for 365.25 days means 475 million trillion joules per year.

Oil provides 33% of this by 31 billion barrels per year, 5,113 million joules per barrel.

Gas provides 24% of this by 3 trillion cubic meters per year, 38.5 million joules per cubic meter. Equivalent of 22.6 billion barrels of oil per year.

Coal provides 26% of this by 5.15 billion tons per year, 24,000 million joules per ton, equivalent of 24.18 billion barrels of oil per year.

Total energy usage from fossil fuels is equivalent of 77.78 billion barrels of oil comprising 83% of total energy.

The total human energy usage is equivalent of 93 billion barrels of oil per year.

For comparison, 6.5 billion humans each consuming 2500 calories per day use 24.93 million trillion joules of energy per year, 5.25% of total energy consumption.

If we want to use bio-fuels of any kind as energy source, we have to look at the fact that the most efficient plant in terms of energy is alfalfa which without fertilizer feed can grow 1600 kg per acre. If we do use fertilizers and pesticides we can boost the output to 4000 kg alfalfa per acre but then it would be energy sink. Assuming we can convert 100% of energy in alfalfa into biofuel it would be 1600 kg * 4000 Calories/kg * 4200 joules/Calorie equal to 26.88 billion joules/acre/yr or equivalent of 5.25 barrels of oil. So to get energy equivalent of 93 billion barrels of oil we have to keep aside 17.7 billion acres just for biofuel production. World's total land area is 37.5 billion acres out of which 15 billion acres produce some kind of food. That includes all forests, orchards, peats, meadows, farms etc. Remember that total food production of this planet is equal to the 2000 calories/day need of 15 billion people, 40% of this is utilized by humans and rest 60% is used by other 4 million species of plants, animals, birds and insects.

If we want to get energy directly by sunlight using photo voltaic cells we must note that per watt PV cell cost is atleast $3 and solar is at best 25% times working rest is when there is night, cloudy days, winter etc and atleast 20% of stored energy is lost in storage. So to have 15 trillion watts we have to have atleast an installation of 75 trillion watts of solar PV cells which cost is atleast $225 trillion dollars even if we ignore costs of installation, costs of conversion of current vehicle fleet to electricity etc.

World GDP is $40 trillion out of which $15 trillion is from industry.