Radio monitor for sound and signal reproduction for use in the solar power generation field; photovoltaic inverters; photovoltaic cells; voltage regulator; frequency stabilizer; inverters; power inverters; inverters for power supply; off-grid power and deep cycle battery storage systems comprised of batteries, charge controllers and inverters with integrated LED bulbs and LED light fixtures for photovoltaic system or photovoltaic system power station installations; battery monitors; battery monitoring devices that may be attached to a battery to monitor the performance of the battery and operating software for use therewith, sold as a unit; electronic monitors and monitor modules for monitoring electric current and electrical signals; cut-out switches; thermomagnetic cut-out devices; engine cut-out devices; electric storage batteries; electrical storage batteries; external computer hard drives; external computer hard drives featuring software for energy storage and energy maintenance for operation of photovoltaic systems or photovoltaic system power stations; nickel-cadmium storage batteries; solid state storage, namely, a nonvolatile storage medium that employs integrated circuits; electronic device for monitoring and optimizing photovoltaic arrays; photovoltaic cells and modules; photovoltaic installation apparatus, namely, solar modules for production of electricity, solar thermal and electric receivers, tracking mechanisms and concentrating optics, and control algorithms; photovoltaic solar modules for production of electricity; photovoltaic solar panels for the production of electricity; photovoltaic systems that convert sunlight into electric and thermal energy