Yellowstone

Geothermal energy, heat energy from the earth's interior, is used to generate electricity in a variety of places throughout the world.
No. Scientists agree that drilling into a volcano would be of questionable usefulness. Not withstanding the enormous expense and technological difficulties in drilling through hot, mushy rock, drilling is unlikely to have much effect.
If another catastrophic caldera-forming Yellowstone eruption were to occur, it quite likely would alter global weather patterns and have enormous effects on human activity, especially agricultural production, for many years.
Yes. Over the past 640,000 years since the last giant eruption at Yellowstone, approximately 80 relatively nonexplosive eruptions have occurred and produced primarily lava flows. This would be the most likely kind of future eruption.
There is no evidence that a catastrophic eruption at Yellowstone is imminent, and such events are unlikely to occur in the next few centuries. Scientists have also found no indication of an imminent smaller eruption of lava. 
The diagram below shows that the three largest Yellowstone eruptions emitted much more material than the eruptions of Mount St. Helens (1980), Mount Pinatubo (1991), Krakatau (1883), Mount Mazama (7,600 years ago), and Tambora (1815).
The science of forecasting a volcanic eruption has significantly advanced over the past 25 years. Most scientists think that the buildup preceding a catastrophic eruption would be detectable for weeks and perhaps months to years.
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it.
Earth's heat is released in Yellowstone by two main processes, conduction and convection: