InGaN alloys are promising for solar cells and solar water splitting because they have direct bandgaps that cover almost the whole solar spectrum. This paper provides a brief overview on recent advances made by our group in the area of III-nitrides for energy and hydrogen generation. Solar cells based on InxGa1-xN/GaN (x∼0.35) multiple quantum well (MQW) structures have been fabricated and were shown exhibit an open circuit voltage (Voc) of 1.80 V, short circuit current density (Jsc) of 2.5 mA/cm2 and a solar-energy-to-electricity conversion efficiency (η) of 2.95% under the irradiation by a simulated sunlight (AM 1.5 G, 1-sun, 100 mW/cm2). Under the irradiation of concentrated sunlight, Voc, Jsc and η were found to increase with solar concentration. Furthermore, InGaN/GaN MQW solar cells were effectively monolithic solar-photoelectrochemical cells which are capable to directly generate hydrogen gas under zero bias via solar water splitting. Under the irradiation of 1 sun (AM 1.5 G), a 1.5% solarto-fuel conversion efficiency has been achieved under zero bias with an excellent chemical stability.