A solid state relay (SSR) is an electronic switch, which, unlike an electromechanical relay, contains no moving parts. It is recommended that you use an SSR that turns on and off at the zero crossing mark on a sinewave so that the electrical surges and noise spikes are greatly reduced. Since there are no moving parts in an SSR, they can be cycled on and off many times per second. Key applications include heat/cool temperature control, motors, lamps, solenoids, valves, and transformers. SSRs can be an ideal product if you pay attention to the three important application items; avoid overvoltage (surges), over current, and over temperature. Pyrosales also have available a range of heatsinks to assist in distributing any temperature build up during operation.
Read more about solid state relays here.