SMA HM-20 - Load Control; Background Information; Types of Loads

12 Load Control
SMA Solar Technology AG
Operating manualHM-20-BE-en-1970
12 Load Control
12.1 Background Information
12.1.1 Types of Loads
A load is a device in a household that is operated with electrical energy.
The goal of the open-loop control is to have the SunnyHomeManager switch the load so that PV energy is mostly
used, if possible, and thereby, or by selecting a suitable time window, minimize the energy costs for operating the
load.
Loads suitable for control by the SunnyHomeManager are those that are to be switched on and operated for a
defined period of time (e.g. washing machine) or have a flexible time of use (e.g. heat pump, charging station for
electric vehicles).
Loads that are only switched on when they are needed immediately afterwards (e.g. television, toaster, lamp, or
vacuum cleaner) are not suited for being controlled by the SunnyHomeManager.
A distinction is made between the following types of loads that are suited for being controlled by the
SunnyHomeManager:
• Indirectly communicating loads that are integrated via switching devices:
– Program-controlled loads
– Non-program-controlled loads
• Directly communicating "intelligent" loads
Loads controlled by switching devices
Program-controlled loads
A program-controlled load runs through a preset program during operation. The program is typically selected by the
user prior to operation and started by pressing the start button on the load. Once the program has started, the load
should no longer be switched off.
Sunny Home Manager can only control a program-controlled load if, after an interruption in the power supply, the
load's program picks up at the point where the power supply was interrupted.
Typical program-controlled loads include washing machines, dishwashers and clothes dryers.
Non-program-controlled loads
The load must be able to switch on and off as needed and have a flexible switch-on time.
The SunnyHomeManager can select one or more periods within the user-defined time frame in which it can switch the
load on or off.
Typical non-program-controlled loads include heating rods in hot water storage tanks, pool pumps, or charging
stations for electric vehicles.
Directly communicating loads
Directly communicating loads exchange their data directly with the SunnyHomeManager via an SEMP or EEBus
interface. The exchanged data can change several times a day depending on the needs of the load. In comparison to
a self-configured indirectly communicating load, directly communicating loads offer you better system efficiency and a
higher potential for savings.
The load connected via Ethernet or Wi-Fi sends the SunnyHomeManager information about the load type, the
planned energy requirement, and the preferred operating time period. The SunnyHomeManager factors this
information into its load planning, takes the configured optimization targets for the load control into account, and
sends the appropriate start and stop signals to the load.