Hi all – I've been reading this 2018 analysis (PDF) by Oak Ridge National Laboratory on ways to reduce the cost of digging vertical loops. Have you seen any drop in cost in recent years? The ORNL report models different tweaks like "thermally enhanced" (TE) pipe, working fluid, and grout. For the pipe, TE means better insulation, and for the fluid, TE means better heat transfer than glycol. Any improvement in these materials is supposed to reduce the necessary loop depth, and therefore reduce cost. Have these improved materials, well, materialized? I can't tell if they're out there in the marketplace at this point. They also go into improved drilling rig technology, like electrohydraulic drilling, thermal-assisted, and water jet-assisted, all of which have the potential to reduce costs by reducing the time it takes to drill to a given depth. Has there been any adoption of improved drilling technology lately? Thanks.