Disinfecting a sample of water includes generating a current using an array of photovoltaic cells, using the current to power an array of light emitting diodes, wherein the array of light emitting diodes emits a germicidal wavelength of radiation, and exposing the sample of water to the radiation. Another method for disinfecting a sample of water includes placing the sample of water within a container, wherein the container includes an array of photovoltaic cells encircling an exterior wall of the container and an array of light emitting diodes encircling an interior wall of the container, placing the container in a location exposed to solar radiation, converting the solar radiation to a current using the array of photovoltaic cells, and powering the array of light emitting diodes using the current, wherein the array of light emitting diodes emits a germicidal wavelength of radiation sufficient to disinfect the sample of water.