With the help of Smart Energy Logics, various conditions can be defined for when an additional load is to be activated, for example at a certain surplus level. Different devices can be used to physically switch on the appliances. Depending on the specific purpose, the Solar-Log™ potential-free internal relay, a Smart Plug, the Smart Relay Box or the Smart Relay Station can be used. An appliance can be controlled via the internal relay of the Solar-Log 1200, 1900 and 2000. The relay can switch devices with a maximum voltage of 24 volts at a current up to 2 amps. The Smart Relay Box provides eight additional relays for the Solar-Log™ to use. Up to three appliances can be switched on and off with the Smart Relay Station; additionally, the Relay Station records the consumption via an internal meter.