Living in a powerhouse

Fly over most western cities these days and the proliferation of solar panels, or photovoltaic cells, on private homes is as commonplace as a car in the driveway. For Audi manager, Bernd Ritter, his ‘solar journey’ began some years ago and he and his family have become very accustomed to Producing, storing and managing energy sourced from the sun.

Ritter has been with Audi for 20 years and is currently a project manager working with the Audi e-tron models. But the trained engineer takes his passion for his work home with him, and since 2014 he has been adapting his home to be powered by the sun. Ritter has spent around €73,000 on having a household power plant installed in four stages with a system that currently consists of solar cells with a power output of 15.5 kilowatt peak (kWp) on the roof and two batteries in the cellar with a total capacity of 27.6 kilowatt hours (kWh). “The sun is always there and has enough power to supply us with the energy we need. Why shouldn’t we use it?” Says Ritter. 

“I do realise I’m in the fortunate position of being able to afford a household power plant. Other people might spend that kind of money on a sports car, but to me, this project is more exciting. It’s important to me to do my part in helping energy move towards renewable sources.”

Thanks to their household power plant, the family can supply home-produced electricity to the house and their vehicles, which until recently included an Audi Q7 e-tron quattro. “The Audi Q7 e-tron quattro was a great experience and loads of fun to drive.” He now drives a plug-in-hybrid – the Audi A3 Sportback e-tron – as well as a fully electric vehicle, the VW e-Up! . 

The example he has set outside Ingolstadt shows how the elements in this kind of modern concept intertwine. The household power plant is augmented by charging devices for the Audi vehicles, with charging made easy thanks to a specially installed industrial power socket and the Audi Wallbox that goes with it. The vehicles’ batteries are charged up overnight – using solar power produced during the day. The charging station knows when batteries are full and automatically stops the charging process. An Audi A3 Sportback e-tron needs around 3.5 hours to charge fully using a regular domestic socket, and around 2.5 hours using an industrial one.

“The household power plant’s battery discharges during the night if the power’s needed for things like household appliances – fridge and washing machine, for instance – and for charging the cars. As soon as the sun starts shining again in the morning, the household power plant’s battery charges up again,” says Ritter. 

How much solar power is generated depends of course on the weather and season.

“Our house is very well positioned. Its roof pitch faces an ideal south, so we get a very good energy yield.” 

Sometimes more electricity is produced than the family needs for everyday use, and when that happens, surplus power is fed into the mains and sold to the power company. Selling may be an important economic aspect of amortisation, but his family doesn’t have to worry about being plunged into darkness, because the system is programmed intelligently. “The system follows the following supply rules: number one priority is supplying the house including charging the vehicles. Priority two is charging the battery in the cellar. Lastly, any surplus electricity produced is sold. 

But because of the weather where he lives, things aren’t always quite so sunny for Bernd Ritter and his household power plant. In winter, when the days get shorter and the skies are often cloudy and even full of snow, power yields can drop. The system responds appropriately by connecting to the mains and obtaining ‘outside power’ to cover lean periods before a deficit occurs. Ritter can use his battery manufacturer's customer website to analyse when his household and vehicles are being supplied with solar power – surfing on the green wave, as it is known – and when electricity has to be bought. 

“I’m interested in the statistics, of course – per day, per month, per year. Consumption and production are really easy to track this way. Yesterday for instance, I didn’t need any extra electricity, I was 99 percent autonomous. The system has to tune in now and again because of the frequencies, so it’s normal to miss a percent or two,” says Ritter. 

Home is naturally a fixed point within this self-made energy supply world, but travelling and being mobile is a major part of family life too. Being able to charge up at your own property is a key to the benefits of electric mobility. The Audi A3 Sportback e-tron can cover up to 50 kilometres in electric mode, while the Audi Q7 e-tron quattro manages up to 56 kilometres. 

“I drive an average of 20 kilometres a day, for which I charge up at home and at work,” Ritter says. It’s a range that allows him to commute without producing emissions locally using the electric mode of his e-tron. And without producing much noise either.

“I don’t listen to the radio any more. Music’s great, but driving without any sound and no engine noise or vibration – just enjoying the peace and quiet – that’s another level,” he says. Ritter uses every possible charging opportunity whenever he stops, and he has enhanced his driving style to achieve his aim of driving as far as possible in electric mode. “If you want to make efficient use of the benefits of electric driving, you have to adjust your driving habits after driving a combustion engine. On my daily routes I know exactly where I can ease off the pedal and coast. The motor just turns off on its own accord.”

Ritter and his family have comfortably adapted to life powered by the sun and the advent of the all-electric Audi e-tron, with its 400km range just takes the equation to a whole new level, says Ritter. As charging infrastructure increases in markets with growing electric vehicle populations, and EV model’s range increases, so too will the acceptance and adoption of purely electric mobility for the future.