Written by Maria Beck
Everyone’s talking about smart homes – yet while for many this simply means greater convenience, an intelligently networked home can now deliver tangible cash benefits. After all, the potential energy savings that customers can identify and unlock by connecting their electricity, heating and transport energy together ultimately reduces their bills. However, the large number of new applications entering the market has stifled the emergence of any standard for data transfer, which prevents many devices from communicating with one another. We have overcome this barrier with our open VARTA energy storage systems that include an Ethernet interface to enable communication with virtually all networked devices. This frees customers to choose whichever manufacturer they like for their smart home applications.
Before the era of the smart home energy, car fuel costs and heating were supplied separately to private households. Electricity was sourced from energy suppliers or PV systems, heating was generated using a gas boiler, and cars were refueled with gasoline.
However, the trend is moving toward linking these areas with the aim of harnessing synergies. This is largely being achieved through integrated energy solutions geared toward replacing fossil fuels. For example, instead of gas or oil, electricity – ideally from renewable resources – is used for heating. The mobility sector is also being increasingly electrified. While most trains already run on electricity, more and more electric cars are also coming onto the market. This trend is having a positive impact on grid stability, too. For example, the surplus energy generated by PV systems around midday can be used to generate heat as a means of avoiding fluctuations in mains voltage. Without integrated energy solutions, the energy revolution cannot be fully implemented.
These kinds of solutions are also feasible and useful in private households. By networking people’s homes, the electricity supplied by a PV system can be used for heat pumps and electric car charging stations, turning householders into “prosumers”, who both consume and produce electricity. However, if self-generated electricity is limited to PV systems, it can only be used when there’s plenty of sunshine, such as at midday. Yet it is mostly needed in the evening or at night – when electric cars are being charged for the following day, for instance. This is where energy storage systems come in. They are charged during the day with the surplus energy from PV systems and can be discharged during the evening or night, thus supplying clean energy around the clock.
To efficiently integrate electricity, mobility and heating, energy storage systems need to be able to communicate with all sorts of different applications. As no data transfer standard has yet been established, many are locked in with specific manufacturers of smart home applications. This is not the case with VARTA energy storage systems. Their open design enables them to communicate with a wide variety of different devices, without being tied to specific manufacturers. In particular, there are no limitations or obligation to replace any existing brands in the home with compatible devices,* freeing customers to select the device that best suits their own needs rather than those of the manufacturer.
VARTA energy storage systems communicate via an Ethernet interface. Their publicly accessible XML protocol can be used to view the information from energy storage systems, such as charge and discharge capacity. This offers users a continuous overview of production and consumption data – but it does not provide any means of controlling the energy storage systems.
It’s the Modbus protocol and associated loads and generating systems that enable various settings to be made on VARTA energy storage systems – including limiting the charge and discharge capacity so as to enable weather-based charging, for example. The sequence in which individual devices are supplied with energy from the storage system can also be specified. As these kinds of settings can have a far-reaching impact on the functioning of an energy storage system, the Modbus protocol is made available to manufacturers of smart home applications. This ensures that energy is always used economically and efficiently.
For integrating VARTA energy storage systems into cloud solutions, there is also the P-Extra protocol. However, as this controls the consumption from and infeed into the grid, access is restricted to energy suppliers to comply with legislation.
For more information on connecting VARTA energy storage systems in smart homes, please contact our Service Team.
An overview of the energy storage systems can be found here.
* It may be necessary to purchase a control unit.