This study examines the extent to which trees could supply domestic U.S. energy consumption if this energy source were needed. Without crop management annual tree growth would perhaps yield 10° of the current energy consumption. In contrast, whole tree utilization, fertilization, site improvement, and genetic improvements might reasonably raise yields to the point that up to 50° of the total energy supply could be provided from tree growth. Setting aside environmental and aesthetic impacts, the estimated costs for delivered wood chips are between 0.52¢ per thousand kilo-calories ($1.30 per million Btu) at a 5° discount rate and 0.91 ¢ per thousand kilocalories ($2.30 per million Btu) at a 10° discount rate. These costs, although highly tentative, are in agreement with other estimates for wood chips. Because these costs do not include conversion into liquid or gaseous fuels, intensively grown tree crops seem more expensive than current fossil fuels but may impose relatively minor cost penalties when or if it becomes necessary to rely on them.