Switchgrass
		amount	units	comments
		18	Gj/tonne	claim(1)
	*	1,000,000,000	Giga	conversion
	/	3,600	j/wh	conversion
	=	5,000,000	wh/tonne
	/	1,000	kwh/wh	conversion
	*	10	tonne/ha	claim (1) (2)
	=	50,000	kwh/ha/yr	net energy captured by switchgrass
	*	3,413	btu/kwh
	/	5,800,000	btu/barrel
	=	29	barrels equivalent/ha
		Compare
	est.	4.00	kwh/m2/day	approximate sunlight to ground
	*	10,000	m2/ha	conversion
	*	365	days/yr	conversion
	=	14,600,000	kwh/ha/yr	total sunlight
	*	0.33%		24 hr efficiency of photosynthesis
	=	48,180	kwh/ha/yr	net energy captured by photosynthesis
		4%		difference
		Sanity Check
		5,000,000	wh/tonne	see above
	/	3.413	btu/wh	conversion
	=	17,065,000	btu/tonne
		1,000	kg/tonne	conversion
		17,065	btu/kg
		2.2	lb/kg	conversion
		7,757	btu/lb
	est.	8,000	btu/lb	approximate energy content of wood
		-3%		difference
		Potential using all cultivated land
		In terawatts
	est.	150,000,000	hectares	Cultivated Land USA
	*	50,000	kwh/ha/yr	net energy captured by switchgrass
	/	1,000,000,000	twh/kwh
	=	7,500	twh/yr
	/	8,760	hrs/year
	=	0.86	tw equivalent
		In barrels of oil equivalent
	est.	150,000,000	hectares
	*	29	barrels equivalent/ha
	/	1,000,000,000	barrels/billion barrels
	=	4.41	billion barrels equivalent
	1	McLaughlin, S., J. Bouton, D. Bransby, B. Conger, W. Ocumpaugh, D. Parrish, C. Taliaferro, K. Vogel, and S. Wullschleger. 1999. Developing switchgrass as a bioenergy crop. p. 282–299. In: J. Janick (ed.),  Perspectives on new crops and new uses. ASHS Press, Alexandria, VA.
	2	+200 kg of N/ha