Good Friday 2018 is on Friday, March 30, 2018 (in 348 days). Good Friday 2017 has already passed: it was on Friday, April 14, 2017 (2 days ago).
What is solar energy? Solar energy is, simply, energy provided by the sun. This energy is in the form of solar radiation, which makes the production of solar electricity possible. Electricity can be produced directly from photovoltaic, PV, cells.
Visible light such as sunlight carries radiant energy, which is used in solar power generation. In radiometry, radiant energy is the energy of electromagnetic and gravitational radiation. The SI unit of radiant energy is the joule (J). The quantity of radiant energy may be calculated by integrating radiant flux (or power) with respect to time.