Thomas Koch, DEG
Climate protection

Climate protection

Leading by example

Global warming requires immediate action. Thomas Koch, who works for German development finance institution DEG, has assumed responsibility and reduced his carbon footprint to a minimum. How did he get to that point? It all started with a visitor to his home.

Thomas Koch, DEG

Thomas Koch outside his home in Bonn. Solar panels on the roof, the geothermal system under the lawn, the tablet in his hands that he uses to control electricity generation and consumption.

The panorama from the living room window is impressive. From up here, Thomas Koch looks out over a forest on the edge of the Siebengebirge mountains, over the Rhine Valley, over the former capital of Germany. And over the climate crisis. It would be easy to succumb to the idyllic vista. But Thomas is no longer deluding himself. “We’re looking northwest right now,” he says, pointing towards the horizon. There in the distance, the smoke rises from the Garzweiler coal-fired power station, fed from the gaping holes dotting the Rhineland mining district. There, too, is the Hambach Forest, a symbolic landscape that has been fiercely contested.

“I know all about it,” says Thomas, “and I don’t approve of what’s going on.”

Koch, 60, may be slowly approaching his professional retirement. But by no means is he coasting along. For several years now, he and his wife Claudia have been busy rebuilding their lifestyle from the ground up. A trained economist, Thomas has been travelling the world for a long time and is director of strategic projects at KfW subsidiary Deutsche Investitions- und Entwicklungsgesellschaft (DEG) in Cologne.

“I’ve seen so many of the dramatic impacts of climate change unfold that we haven’t fully got to grips with yet here in Europe,”

Koch says. This spurred the couple to change their behaviour, including how they generate electricity, heat their home and commute to work.

A genial soul, Koch is clad in a blue checked shirt and a jumper over his shoulders. His voice is clear and calm. He greets his visitor outside on the driveway of the detached house in the Holzlar district of Bonn, on which construction was completed in 1965. A few yards further ahead is the black Volkswagen e-Golf, with which he started the journey into this new life around five years ago. The electric car has more than 100,000 kilometres on the clock. “I’m one of the people they’d call an early adopter in marketing jargon,” Koch says. “I can tell you from experience that a car like that really works.” He adds that he will never have to stop at a petrol station again, which has changed his life for the better.

The burning of fossil fuels is part of the catastrophic picture that the Kochs saw for themselves when they visited the Hambach open-pit mine – and that Thomas experienced when he was checking up on project financing. He describes El Niño and La Niña in Peru and Colombia, the symbols of a changing climate that strike unpredictably and harder than before; salty soils left behind by rising sea levels in Bangladesh, which are depriving millions of their livelihoods; the drought in Tanzania, which is driving smallholders from their homes – and, in turn, has brought a renewable energy project to a standstill.

“I’ve seen some of the top ten countries heaviest hit by climate change. That sort of thing sears itself into your mind and stays with you forever.”

From the electric car to the photovoltaic system

The Kochs have a comfortable life. It is around 20 degrees Celsius when they sit down for a chat around the wooden table in their open-plan kitchen. Despite the rain falling outside, it is bright indoors. The coffee comes from a machine that leaves only compost behind and has just replaced the pod machine. “We’re taking things step by step,” says Claudia Koch, who now has an e-bike to commute around eleven kilometres to her workplace in Bonn city centre, weather permitting. The two describe it as a process of their consciousness being awakened, more and more things being called into question, then changes being made. “There’s always extra room to build,” says Claudia. They eat seasonal vegetables from the garden and organic meat from the farmer – plus “a currywurst, on occasion, when we’re in town,” Thomas says in a sheepish tone, making his guilty conscience readily apparent. But he is not interested in encouraging people to give up on consumption: “As a development banker, I can sense the disruption when people’s local incomes are threatened – after coffee or avocado purchases completely dry up, for instance.” The question is always how sustainably the process is managed.

There are lots of moving parts. Simply giving up on things is not a solution, if the Kochs’ lifestyle shift is anything to go by. You have to change the way you live your life. In the Kochs’ case, this started with the renovation before the family moved in in 2011. The steps they took seem unspectacular: a solar power system for heating support on the roof, triple glazing, roof insulation, an exterior insulation finishing system. Once the e-Golf was parked outside the garage, it was time for the next step: a photovoltaic system. 91 modules have been installed on the property since 2015, with state-of-the-art digital monitoring technology from Israel.

power supply

With their way of life, the Koch often supply more electricity than they consume - especially in summer.

It was not just on his travels afar that Thomas had a moment of clarity – another wake-up call took place in his home town. It was in late 2017 when the global climate conference, COP 23, met in Bonn. At that time, a climate activist from Guinea was staying over at the Koch residence. He made the Bonn-based banker a member of his country’s delegation. Koch observed the diplomatic goings-on at the event and still appears dismayed to this day.

“I was under the impression that none of the government parties were really sticking to the climate agreements.”

While the guest from Guinea admired the solar power set-up on Koch’s roof, the man with the short grey hair was thinking about his skeleton in the cupboard: the oil heating system that burned up 3,000 litres year after year. Koch had expert assessments written up and holes drilled in his front garden. “Are you drilling for oil?” the neighbours asked in jest. But nothing could be further from Koch’s mind. Since 2018, the family has been operating a geothermal heat pump that starts up on chilly days and delivers compressed heat.

Thomas Koch enjoys his technology. He heads through the cellar, pointing out his battery, bidirectional meters, water pipes, pumps and controls. According to the homeowner’s calculations, this spares the atmosphere eleven tonnes of carbon emissions each year when compared with the old equipment – an enormous amount – thanks to a combination of photovoltaic systems, geothermal energy and electric vehicle use. Koch points to his iPad and laptop. How are things looking right now on the electricity front? It may be raining, it may be cold, it may be grey, but there are at least 200 watts coming from the roof at this moment, enough to power the fridge and the lights inside the house. He pulls up the app for his heating system, which he can use to see and control the temperature for each room in real time. Koch’s next idea? A small wind power system on the roof. “How’s the wind?” he asks the virtual assistant. 0.6 metres per second today, an app reports – a fairly tame breeze.

Thomas Koch and his wife on their bicycle

Claudia and Thomas Koch often leave the car at home and drive their tandem to the nearby bio market.

A long breath and a good sensation

Step by step, the Kochs have increasingly been able to declare their independence and go off the grid, meeting over 60 percent of their own needs for the entire zero-emission household, including the electric car. They often generate more electricity than they consume. But during the winter months in particular, when the heating system needs electricity for the heat pump, the solar power goes missing in action. Wind could be a solution to this problem, Koch notes. He has been collecting wind data since early 2019 and wants to make a decision by 2020.

Koch is a finance man, an analyst. He knows that money needs to be spent to protect the climate and states that his investments have been based on sound calculations. It cost around 20,000 euros for the roof-mounted solar system – 6,000 from the Kochs’ own savings, the rest from loans and a redemption grant. The heat pump required an investment of 30,000 euros – 10,000 euros of which went on drilling alone. The Kochs chipped in a third from their own funds, as well as taking out loans and benefiting from promotional funds. Both investments have definitely been worthwhile, Koch says. Playing the role of power plant operator, he reports seven to nine percent profitability per year over the systems’ entire service life. “But the most important thing is that I’m able to feel good. That’s priceless.”

Thomas and Claudia are not ascetics or saints. There is still room for improvement with their carbon footprint. The long-haul business flights produce huge amounts of CO₂ emissions, although his employer is able to compensate for these through climate protection projects. The Kochs now offset their holiday flights, too, with Atmosfair certificates. In the past, however, travel to marathons in New York, Boston or Beijing was a regular occurrence. Thomas has run the 26.2 miles on 24 separate occasions. In the process, he left behind an impact on the climate that still plays on his mind. But while running, he also learned what it means to hold out for the duration.

The Kochs are not deluding themselves. Climate change is inevitable. Politics is stuck in an old paradigm, shaped by interests and traditions. “It will go on until there’s a shift in mindset,” Thomas believes, especially since the climate in Germany is likely to be less adversely affected. But the consequences will be global, and Koch hopes to see rules that reflect this, such as significantly higher carbon pricing. But he also knows that the political world will be slower than it should be. So the Kochs pass on their passion to friends and neighbours who are interested in the battery in the cellar or the photovoltaic modules on the roof. Thomas thinks of his son and his son’s possible children, whose future he does not want to spoil. And he thinks of the civic association in Roleber, where he lives. He was invited to its annual general meeting to explain what he hopes to achieve. Needless to say, he accepted the invitation immediately. Koch will talk about the urgent need to save the climate – patiently, calmly, convincingly. And as he speaks, no doubt, those in attendance will notice that he is enjoying himself.

Published on KfW Stories on 6 September 2021.


All United Nations member states adopted the 2030 Agenda in 2015. At its heart is a list of 17 goals for sustainable development, known as the Sustainable Development Goals (SDGs). Our world should become a place where people are able to live in peace with each other in ways that are ecologically compatible, socially just, and economically effective.