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The Magazine
Udo Brockmeier: “Siemens solved problems whenever they came up.”

Combined heat and power

“We have a product-led strategy”

In this interview with the Siemens Magazine, Udo Brockmeier, chairman of utility Stadtwerke Düsseldorf in Germany, explains how combined heat and power generation will assure the profitability of his record-breaking power plant, and why CHP will continue to play a key role for Düsseldorf in the future.

Mr. Brockmeier, for years we’ve been hearing that it’s no longer viable to build new gas-fired plants in Germany. Why did you decide to do just that in 2010?

Even back then we were thinking mainly in terms of a product-led rather than a generation-led strategy. In other words, we were asking ourselves what product was relevant for the Düsseldorf market. The answer was heat and power, generated in an environmentally and climate-friendly manner. And in an urban agglomeration it was clear that we’d have to use combined heat and power to generate it.

Even though at the time we were predicting much higher electricity prices for 2016-18, in retrospect we still believe it was the right decision. Especially when we look at the difficult situation other plants generating only electricity find themselves in. There was also an economic dimension to our decision: the fact that the German government is promoting CHP plants alongside its subsidies for renewables.

But what sets you apart from the rest?

Here we run a cogeneration plant that also produces carbon-free district heat, which under the law is equivalent to renewable energy. There is a large and expanding market for this in a city like Düsseldorf. So the heat produced by our plant is not only an important contribution to sustainability, it’s also a key in terms of economic viability. It means that changes in the price of electricity are less relevant for us.

People protested the original plans to build a coal-fired plant here. How did the citizens of Düsseldorf react to SWD’s decision six years ago to construct a CHP plant?

Very positively – despite Düsseldorf’s history as a center of coal. We spent a lot of time talking with politicians, citizens, and the NGOs about what the role of a power plant in a modern city is in the first place.

We wanted to make the plant a component of the urban infrastructure – which also explains the sophisticated architecture of the “Fortuna” block. The idea is that the plant not only supplies the city, but it belongs to the city.

We also had a lot of discussion with people about how the plant can help achieve the climate targets. This protracted phase of open discussion ultimately generated a lot of support for the project. In the approval phase there wasn’t a single objection. That’s very unusual indeed for such a big project in the midst of a city. 

A single stack is the only thing remaining from the old coal-fired plant. The new power plant sets new records in terms of efficiency.


Was there another alternative besides a coal-fired or CHP plant?

The alternative would have been to build nothing at all. But that would have meant we’d have to import electricity from outside. We wanted to make the plant a regional component. This also ties in with our concept of a distributed energy supply, which is a key element of the energy transition. When we say distributed we don’t necessarily mean small-scale. For us, a distributed energy supply is one that’s adapted to the specific structures and needs of the region. In a rural area that might mean a small cogeneration unit. Here in the city it means a CHP plant. It fits our city entirely.

Düsseldorf is a large, densely populated industrial city that has set the target of climate-neutrality by 2050. What does that mean in concrete terms?

In concrete terms “climate-neutral” means that annual carbon dioxide emissions per capita won’t exceed two tonnes. That’s the amount you are allowed to emit without releasing a proportion of CO2 that would in turn lead to a warming of the atmosphere above the maximum targeted by the international community.

In the first year of operation, the new gas-fired power plant in combination with the district heating will save 600,000 tonnes of carbon emissions. By 2025 this figure will have increased to a million tonnes.

The federal government wants renewables to account for 80 percent of energy by 2050. What will the share of CHP, wind, and solar energy be in the future?

The energy supply will continue to rest on two pillars going forward: cogeneration on the one hand, and regenerative resources on the other. In rural areas renewables such as solar installations, pellet heating, and heat pumps will play a very important role. But in an urban area like Düsseldorf that’s not possible. We can’t build wind farms here because the area’s too densely populated. And there isn’t sufficient roof space for photovoltaic installations to cover household consumption. 

Even in 2050 we expect that around 60 percent of electricity will come from our CHP plant.
Udo Brockmeier, chairman of Stadtwerke Düsseldorf


So we’re redefining the federal government’s targets for a city like Düsseldorf in such a way that 80 percent represents the sum of renewable energy and combined heat and power. Even in 2050 we expect that around 60 percent of electricity will come from our CHP plant. Twenty percent will come from wind and solar generation, with the rest from other sources. In our case renewables means a clear focus on wind: 10 percent of renewable energy will come from solar, and 90 percent from wind farms.

What role do the technological configuration and flexibility of the “Fortuna” block play in terms of its economically viable operation?

Given the competition from other producers it’s not always possible to feed electricity into the grid profitably. This is what makes the flexibility of our plant so incredibly important. A gas turbine can be fired up and down very quickly.

But there is a basic disadvantage to CHP plants in that they only achieve high efficiency if you produce combined heat and power.

So what do you do in situations where the demand’s primarily for heat rather than power, or vice versa?

We’re currently building a heat accumulator right next to the power plant. It’ll be 30 meters in diameter and 50 meters high. This will be able to store surplus heat at times when there’s demand for power but not for heat. This substantially increases the time we can cogenerate heat and power. We can release the heat again when the situation reverses. 

The visitor platform at the “Fortuna” power plant provides a great view of nearby downtown Düsseldorf on the other side of the River Rhine.


How did you select a partner for such a big project?

We have many years of experience with Siemens, and based on that have built a relationship of trust. But of course there was first a tender, where the performance and price of the plant were important considerations. Siemens beat the competition.

Our subsequent collaboration worked very well. Siemens kept to our agreements and shared our work spirit, for example the understanding that issues would be resolved immediately rather than postponed. This meant that we were able to remain within our budget and keep to the schedule. An important feature of cooperation is also that there wasn’t a single workplace accident during the construction phase.

Of course the partnership doesn’t end with the commissioning of the plant. We have a long-term service and maintenance agreement with Siemens. 

Moritz Gathmann is a freelance journalist in Berlin.
Picture credits: Siemens AG