/sci/ - Science & Math

I want to copy the principles of Concentrating Solar-Thermal Power but instead of directing the concentrated sunlight to a tower to simply boil water and turn a turbine I want to direct it towards a focal point on the ground sublimating any material in its path to create a borehole.
Is there any scientific reason this wouldn't work before I start saving up to create it? would the surrounding earth material just act like a giant heat-sink and dissipate the heat before the material under the focal point sublimates?