As the electricity grid transitions towards intermittent renewable sources of electricity generation, there will be a growing need for large-scale energy storage. There is general agreement that current options, namely lithium-ion, will not be sufficiently low-cost for long-duration storage. Thermal energy storage is a growing area of interest because of its low cost per energy (CPE) and scalability. One such variation of this is the Thermal Energy Grid Storage (TEGS) concept, which uses advancements in thermophotovoltaics (TPVs) and liquid tin pumping to create an ultrahigh temperature (>2000°C) graphite-based thermal energy storage system. Such a system is projected to be extremely low cost (<$20/kWh) and moderate round trip efficiency (50%), meeting necessary criteria to be economically competitive in potential decarbonizing grids. However, it remains to be tested how the system will perform when these tested subsystems are combined. Potential issues, such as deposition of gasified contaminants onto the TPV active surface, the erosion and clogging of graphite piping due to changes in solubility of carbon in tin with temperature, and management of tin vapor, have the potential to derail the scaling of this technology. In this work, we construct a laboratory-scale prototype of this technology with the aim of testing the system up to its maximum operating temperature (2400°C). By doing so, we can validate modeled heat extraction from the storage medium to the TPV heat engine and identify and overcome system integration challenges.