Braunschweig on the renewable energy battlefront

If Germany’s “Energiewende” transition to low-carbon energy were compared to a military campaign, the frontlines might well run down Hungerkamp street. There, in the suburbs of Braunschweig, a biomass cogeneration plant supplies electricity and heating to a local police station and several hundred district households.
The essential
Help achieve Germany’s renewable energy and climate change goals.
Convert the district to green electricity and heating.
Veolia's response
Install a renewably sourced district heating system.
Published in the dossier of July 2017

Initiated by Braunschweig’s energy provider and Veolia subsidiary, BS Energy, the Hungerkamp project replaces the previous heating facility and its 34 coal, gas and oil burners, contributing to the country’s renewable energy and climate change reduction objectives. The project’s success reflects a combination of opportunism, creativity and tenacity says BS Energy Project Engineer, Verena Zitterich.

“For the project to be economically feasible, we needed to bring together a number of interconnected components.”

Multi-part solution

The energy transition scaling up in Braunschweig

Produced through an environmentally friendly combination, heat and power are delivered to customers in Braunschweig through its central district heating network. More than 56,000 apartments in Braunschweig and numerous public facilities and companies are connected to the 250-kilometer pipeline network. The network ensures compliance for building owners with legal requirements for structural heat loss, renewable energy and primary energy requirements. Gradually since 2005, Veolia and the city of Braunschweig, which are both BS Energy shareholders, have been gaining small energy transition victories. They are already preparing new plans, such as connecting Hungerkamp to Braunschweig’s large district heating system and implementing an identical concept in the town of Springe, some 95 km away.

Four components, in fact. The complex consists of a cogeneration plant, a wood boiler, a natural gas boiler and two heat storage units. The cogeneration plant is powered with biogas extracted from organic waste. As the waste decomposes, methane is released and used to fuel a generator that produces green electricity. Waste heat generated by the electricity production is recovered and stored in accumulators before being released to customers through a fourkilometer local heat distribution network. Additional heat is supplied during the coldest days of autumn and winter from the wood boiler, which burns locally supplied wood chip waste. The third component, the natural gas boiler, provides peak-load heating capacity and serves as a reserve source of heat when the other two facilities are under maintenance. Finally, supply and demand balancing is ensured through two thermal storage units, with innovative insulation to minimize heat loss.

A concept which became reality, the energy efficient quarter (EEQ) offers a short loop for supplying sustainable energy as needed. This concept is particularly tailored to specific local features. Its advantages include allowing residents to play an active role and control their consumption or take part in a sharing economy (mobility). New features will be possible in the future, such as buying locally produced electricity, profiting from your own organic waste, etc.

Connecting with customers

The Hungerkamp project began with the renovation of the local police station and its old coal- and oil-fired boiler plant. But solving the technical challenges of electricity generation was only one piece of the puzzle. “The economic success of the project hinged on ensuring the consumption of the heat that would be produced,” says Verena. A suitable location was identified for the plant near a high-density residential area with sufficient potential heating customers. Proximity, however, would prove to be only part of the equation. “Convincing the customers to sign long-term supply contracts wasn’t easy,” says Verena. “All had existing functional central heating boilers burning fossil fuel. We spent a considerable amount of time on communications to make sure they fully understood the project and its benefits in order to gain their acceptance.”

Sustainable recognition

BS Energy 250,000 inhabitants kept warm!

A subsidiary company of Veolia in Germany, BS Energy is a regional producer of electricity and heat, as well as the district heating network operator for the city of Braunschweig. BS Energy supplies energy and infrastructure solutions to public and private customers throughout the Lower Saxony region, serving more than 250,000 citizens. Its services include low fixed-price basic energy supplies designed to be environmentally friendly. It provides electricity, gas and district heating as well as drinking water and wastewater treatment services. Other elements of its operations include powering city lighting and traffic lights and operating power networks for electricity, gas, water and glass fiber networks in new construction areas. Prior to the Hungerkamp project, the company implemented another biogas pilot project in 2006, building a 20-kilometer raw biogas pipeline from its biogas plant in Hillerse to its heating station in Braunschweig-Ölper.

Today, the plant serves as a renewable energy-fueled network for the entire neighborhood, with the capacity to produce 9,200 MWh of green electricity and 15,600 MWh of green heat annually. In replacing fossil fuels with renewable raw materials, the project avoids 8,000 metric tons of CO2 emissions per year. The use of different types of fuel, biogas, wood and natural gas as well as its thermal storage allows the system to respond flexibly to fuel price changes and to daily usage fluctuations. The exhaust gases generated during combustion are purified and filtered before being released into the atmosphere and the wood ash is used for fertilizer to create a local circular economy loop. In 2015, the plant was awarded the international “Global District Energy Climate Award” at the Euroheat & Power Congress in Tallinn, Estonia, for its demonstrated leadership in providing a clean and sustainable district energy solution on a community scale. Still operated as a stand-alone system, Hungerkamp may ultimately be extended to connect to Braunschweig’s central distribution network. But, already, it stands as an inspiration of what can be accomplished in the ambitious campaign for a greener tomorrow. One battle at a time. !


Hungerkamp key figures

15 600 MWh heating per year supplying the equivalent of approximately 1,000 households 60% produced out of biogas in the CHP unit 38% from wood chips 2% from natural gas 9 200 MWh green electricity per year supplying the equivalent of 2,300 households produced 100% out of biogas 8 000 T of CO2 per year.

• 2015 Euroheat & Power Global District Energy Climate Award
• 2015 Veolia Sustainability Award

Community benefits
• Sustainable fuels and modern filtering systems
• Lower emissions of harmful substances
• Modular system, flexibly adapted to outdoor temperatures
• Use of regional waste wood supplies
• Use of wood ash as fertilizer