Bridging cars and buildings

Bridging mobility and buildings for the future

Bridging cars
and buildings

In the past, houses were the place we parked our cars in front of. Today, the two communicate with each other. In the future, electric vehicles and intelligent buildings will exchange both information and energy as they increasingly merge into one digital entity.

Experts Veit Rohrberg, Head of Development of Smart Charging at Audi AG, and Ulrich Reiner, Advanced Energy Solutions Manager at Hager Group, discuss the inevitable breakdown of the barriers between house and car.

Veit Rohrberg is Manager Smart Charging at Audi AG. Since 2010, Mr. Rohrberg has dealt with electromobility and topics such as manufacturing processes for electric vehicles, charging systems and vehicles intelligently networking with their environment.
Ulrich Reiner has worked for Hager Group since 2012. For his doctoral thesis, as an electrical engineer, he wrote about the integration of electric vehicles into the energy infrastructure. And this is what he is responsible for today in the Department of Corporate Strategy in the area of Disruptive Innovations at Hager Group.

Mr. Rohrberg, what interested you in the field of electromobility?

Mobility is simply of great value to people, and when they drive an electric vehicle and experience how agile it is, they instantly fall in love with it. On the other hand, it’s a question of sustainability and replacing finite resources. And it’s a whole lot of fun when industries such as the automotive industry, energy suppliers and now even those the building services industry – in other words, industries which, until now, had so little to do with each other – work together on the mobility of the future.

In 2003, when I first came across this topic, electromobility was still a niche area and a tiny market. Back then, all you had was a kind of electrified reclining bicycle with a range of less than 40 kilometres. Today, we are on the way to a mass-market product which will leave a lasting mark on us, and is now finding its way into building infrastructure in much the same way as the electric meter did decades ago. This is why, Mr. Rohrberg, our two sectors are working more and more together.

That’s how we see it, too. Right now, we’re integrating the customer’s digital experience into our cars, so networking the vehicle with its environment is, in principle, nothing new for us. The energy management system of buildings is adding another important element.

The other major topic is the energy revolution. Right now, rooftop photovoltaic systems, energy storage devices and electric heat pumps are being used in households and their production and consumption need to be managed. This requires intelligent management systems capable of managing energy flows and costs. The Home Energy Management System (HEMS), which Hager Group is now developing, manages the optimal charging speed scheduling for electric vehicles. This prevents customers from overloading their home power grid and enables them to reduce their ecological footprint and energy costs.

It is well worth it.

Indeed. If you charge your electric vehicle with current from your home’s own photovoltaic system, you can save money.

A few months ago, the European Union spoke out in favour of dynamic electricity tariffs. But if different electricity prices are billed at different times of the day, it suddenly becomes worth filling up your car at the lowest tariff, or even for free, if possible. In periods of strong wind or high photovoltaic power generation, electricity is offered almost free of charge. It’s great if you can use electricity and also preserve the climate!

By 2050, the EU aims to reduce its greenhouse gas emissions by 80 percent; in Germany, buildings are expected to be climate-neutral by this date. This has far-reaching consequences as we expect the electricity consumption of a household to be doubled by an electric car. In conjunction with electric heating, the demand for electricity triples. And this energy must be managed and distributed throughout the building securely and flexibly.

427 km
4 hours
49 mins
0 charges

Hager Group headquarters in the Saarland, 22,400 inhabitants


Audi AG headquarters and home to the second largest automobile factory in Europe, 135,000 inhabitants

In your opinion, does an HEMS make sense if you do not have a photovoltaic system on the roof?

It is with the HEMS that the consumer can make use of the advantages of dynamic electricity tariffs. An HEMS ensures that electricity is preferred and consumed when it is plentiful and cheap. Added to this is the fact that an appliance using the HEMS, such as a washing machine, electric vehicle or heat pump, can be turned on and off depending on the supply of electricity, provided that these electrical appliances communicate using KNX or the new EEBUS protocol.

How will HEMS interact with the smart meters of the future?

Smart meter gateways represent the communication modem between the meter box at home and metering station operators. They are essential in enabling the HEMS to create optimal consumption conditions for electricity consumers and use the cheapest electricity tariffs available. Smart meter gateways are secured in accordance with military standards to ensure that no private data is leaked. And, of course, they require additional infrastructure costs to start with. However, operating costs in the renewable energy future will, generally speaking, be very low. Today, as an electricity consumer, you still have to pay for gas, oil and coal. Wind and sun, however, are free of charge. The bottom line is that the power supply for the end customer is probably not much more expensive. In your opinion, what difference will charging technologies make?

One thing is clear, charging must be as easy as possible. Today, the customer still has to connect their vehicle manually. In the future, we will not need to do this thanks to technologies such as inductive or automated charging. Another important question is how to re-charge quickly on long journeys. In the future, we want to offer charging power of 150 kW. This means that you will be ready for a long journey within 30 minutes. We are also committed to the Ionity joint venture, which is working on a Europe-wide expansion of the quick charge network. As a result, the range of electric vehicles will soon no longer be an issue.

Let’s look a few years into the future and imagine that a few tens or hundreds of thousands of electric vehicles are docked at stations. Each vehicle battery can store about as much energy as an average household uses in a week. In other words: electric vehicles will suddenly make huge sources of decentralised storage capacity available. Our two industries can make a major contribution to the success of the energy revolution.

In Germany, there are currently around 40 gigawatt hours of pumped storage hydroelectric power available. At Audi we have set ourselves the target of electrifying a third of the cars we bring onto the market by 2025. Including the ambitions of our corporate brands, this corresponds to a capacity of around 150 gigawatt hours of new energy storage capacity on the market every year.

…or more than three times the storage capacity currently available in Germany. More-over, here at Hager Group, we have just completed the takeover of the energy storage specialist E3/DC, and we are planning interesting developments with them when it comes to storage technology. And what about 10 or 20 years into the future: What role do you see for electromobility then?

The app gives the current charge status of the electric vehicule.

It will be a widespread form of transport. And electric vehicles will be an integral part of the energy landscape. It is likely that batteries will be so sophisticated that we will be able to use electric vehicles as mobile energy storage devices to store energy temporarily and, if necessary, return it to the power grid.

I agree. From the point of view of building technology, I would also like to add that you can automatically transfer convenience settings from your building’s home automation system to the vehicle. In the future, the two will complement each other perfectly, and driving will be a new experience. I am looking forward to working together.

So am I! It’s a really exciting time for our industries. If we can create cross-industry networked solutions, things that were once considered unthinkable will become possible. To the benefit of the environment, climate and consumers alike.

Home Energy Management System

Balances electricity consumption and production according to forecasts

Photovoltaic panels

Provide self-generated electricity to the home network, buffer storage or electric vehicle battery

Electric vehicle

Charged according to electricity tariffs and energy demand & production in the home


Supplies energy required or feeds it back into the grid; electric vehicles could be used for flexible storage in the future

What is an HEMS?

Home Energy Management Systems (HEMS), currently being developed at Hager Group, will soon be found in intelligent buildings. These buildings will no longer simply consume energy; they’ll store it too – for example from the battery of an electric vehicle or stationary storage unit – as well as generating their own with rooftop photovoltaic systems. Large controllable appliances will be included with heat pumps and electric vehicles simultaneously. The building will go from being an energy consumer to a ’prosumer’ that also produces energy. And the HEMS manages all of these energy flows.

Its most important tasks include anti-tripping (i.e. the avoidance of overloading and power failures), photovoltaic optimisation (maximum owner use of the self-generated green electricity) and the intelligent charging of electric vehicles (with a view to using the self-generated current and benefitting from the current cost of mains power). An intelligent HEMS like that of Hager Group also takes into account the expected energy demand of a household coupled with the expected power generation of the building’s photovoltaic system, controlling power consumption accordingly. This enables a Home Energy Management System to protect the environment, the climate and your wallet all at once.

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