Optimize your self-consumption of PV energy via your KNX bus!
Why think about complex things like energy management in private homes if power comes from the wall plug nevertheless?
Energy rates continue to rise while harvesting own energy with a PV system becomes simpler and cheaper. Furthermore the revenue when feeding the energy back to the public grid is much lower than the price you have to pay. Optimizing the degree of self-consumption is the best way to save money.
And this is what your home energy management does, but with the same comfort and flexibility and without making things too complicated.
Energy management and KNX
instead of a proprietary, vendor-specific solution we incorporate the basics of KNX: different devices from different vendors communicate without any problems.
Charging with surplus power
One of the main private energy consumer is already often the EV. Its need for approx. 20 kWh per 100 kilometers is pretty high, compared to a fridge with around 150 kWh per year. The goal is to charge the EV with your solar energ.
If the stove is turned on to prepare lunch, the energy consumption of the home changes, and so changes the surplus of solar energy.
The SmartMeter measures that change and sends the information on the KNX bus. The EV charge control of the EibPC² adapts to that change by notifying the EV charger to reduce the charge current. After lunch, the limit is raised again.
Out-of-the-box support is included for
Keba KeContact P30 c- and x-series via UDP.
The charge control itself is not limited to a specific vendor. The own requirement is that the EV charger can be controled using one of the supported network protocols of the EibPC².
Those chargers typically offer Modbus TCP, an HTTP-API oder a vendor-specific TCP or UDP based protocol.
Realize your own ideas
The EibPC² is very flexbible, making it fun to implement your own optimization, adapted to your very specific situation. This may include local weather data or the integration of a battery to store energy during the day and use it for charging your EV at night.
»Smartest Home« made a video featuring our EibPC² EV charge control (german only)
When charging for the first time or when you switch to a different car, chose your battery capacity. Then select the current battery fill level in percent as shown by the car, select the charging mode and press »start«. The EibPC² takes over the control. The user-selected maximum current is never exceeded, and max be changed also when charging is active.
Reduce grid feed-in
To optimize self-consumption, the available charge current is computed from the effective power. If no surplus is available, i.e. the effective power in direction of the supplier is positive, the charge current is redurced to the minimum supported by the charger.
Minimize feed-in with time limit
Self-consumption should be optimized, but the car has to be charged after a defined time configured when starting to charge. The charge current is derived from the effective power, but raised to the user's maximum when necessary to fulfill the time limit.
No dynamic current control but use the configured maximum.
Control and visualize
Use any KNX rocker, visualization panel or your smartphone to control the charging.. Or use Enertex® MeTa Premium with its large display to show remaining charge time or the current charge state in percent.
The following KNX group objects are available:
As with conventional KNX devices, read-requests on the status group objects are answerd by the EibPC².
Commissioning is as easy as possible.
As the KNX application of our Enertex® KNX SmartMeter has many features and options, we offer a ready-to-use ETS project for download. Simply copy the SmartMeter device over to your project, preserving the group address connections, and reimport it into EibStudio. Group addresses for our charger controller can also be copied and imported.
EibStudio 4 includes visualization templates for SmartMeter and charger control, and the group objects from the example project are already correctly assigned when you add them to your project after ETS import. Add analysis of energy-, quality and harmonics with only three simple clicks in EibStudio!
Starting at 4:00 min, the video shows where to find the example projects in EibStudio. Click here for downlaoded of the example EibStudio 4 project.