  The challenge in solar energy today is not the cost of photovoltaic (PV)
electricity generation, already competing with fossil fuel prices, but rather
utility-scale energy storage and flexibility in supply. Low-cost thermal energy
storage (TES) exists but relies on expensive heat engines. Here, we introduce
the concept of luminescent solar power (LSP), where sunlight is absorbed in a
photoluminescent (PL) absorber, followed by red-shifted PL emission matched to
an adjacent PV cell's band-edge. This way the PV cell operates nearly as
efficiently as under direct illumination, but with minimal excessive heat. The
PL-absorber temperature rises due to thermalization, allowing it to store the
excessive heat, which can later be converted into electricity. Tailored
luminescent materials that support an additional 1.5kWh PV-electricity for
every 1 kWh of (virtual) heat engine-electricity, with a dynamic shift between
the two sources are experimentally demonstrated. Such an ideal hybrid system
may lead to a potential reduction in the cost of electricity for a base-load
solution.
