  Efficient storage of solar thermal energy is still one of the major
bottlenecks in realizing dispatchable solar thermal systems. Present work is a
significant step in this direction, wherein, we propose, thermochromism
assisted photon transport based optical charging for efficient latent heat
storage. Seeding thermochromic nanoparticles into the phase change material
(PCM) allows for dynamic control of PCM's optical properties - aiding deeper
penetration of photons and hence significantly enhancing the
photon-nanoparticle interactions. Moreover, carefully tailoring of transition
temperature near the melting temperature allows for efficient non-radiative
decay of the absorbed photon energy and that too under nearly thermostatic
conditions. In particular, the present work serves to develop a mechanistic
opto-thermal theoretical modelling framework to compute melting front
progression, latent heat storage and sensible heat discharging capacities
pertinent to thermochromism assisted photon transport. Moreover, to truly
assess and quantify the benefits of the aforementioned charging route, a host
of other possible charging routes (viz., thermal and non-thermochromic optical
charging) have also been dealt with. Detailed analysis reveals that relative to
the thermal charging route, thermochromism assisted optical charging offers
significant enhancements in terms of melting front progression (approximately
152%) and latent heat storage capacity (approximately 167%). Overall,
thermochromism assisted photon transport is a synergistic approach which allows
for simultaneous collection and storage of solar energy at accelerated rates
without requiring the PCM to be heated to high temperatures.
