Type of CHP system: Grate fired boiler

Plant owner: The CHP biomass plant in Dresden-Niedersedlitz is owned by STEAG Saar Energie AG in Saarbrücken.

Commissioned : 2004

Status of plant: Commercial

Contractor details:

Boiler: Kablitz

Burner: Ray

Turbine: Alstrom

Generator: LDW

Power generation: Steam turbine

Main fuel: Wood chips

The biomass plant uses appr. 50000 t/a of treated and untreated wood (national standard: A1 to A4).

Nominal capacities & efficiencies:

Total thermal input, incl. fossil fuels: 25,4 MW (without back-up boilers)

Gross electrical output: 7,07 MWe

Net electrical output: 7,07 MWe

Heat output: 17,5 MJ/s

Electrical efficiency, gross: 27,8 %

Electrical efficiency, net: 27,8 %

Overall efficiency, gross: 82 %

How is plant controlled: The unit is controled by the amount of fuel input and limited by the heat demand in the disrict heating network.

Heat backup: Oel-fired boiler

Heat usage: Heating only

Energy usage:

The company will partly use the heat for own purposes. Furthermore a district heating system with one industrial client, 20 business customers and one heating supply company are under contract.

Intern net-temperature: 110°C/70°C

DH-net-temperature net (4,3 km):  110°C/ 70°C

DH inlet temperature: 110 °C

DH return temperature: 70°C

Heat storage size: 2700 m3

Hours of full load that the heat storage can meet: appr. 120

Fuel storage: The biomass plant storage facility has a capacity of max. 750 t. This corresponds to roughly 120 hours of full load operation.

Waste water: Waste water will not be treated; disposal in the public sewage system

Ash discharge: The ash (appr. 1000 t/a) will partly be used for the production of mineral-bound building materials. The rest of the ash will be deposited without previous treatment.

Plant description:

The Biomass-CHP unit in Dresden was built by the STEAG Energie Contracting (SEC) at the location of an old district heating station.

The first start up of the new biomass unit was planned for December 2003.

Fuel feeding system: Mechanical loading system

Steam data:

The maximum steam capacity is approx. 30 tonnes per hour (65 barü, 425°C).

secundary cycle (water): 13 bar, 110/75°C

primary cycle (steam, condensation): 1 bar, 120/90°C

Flue gas cleaning:

The flue gas of the CHP-biomass unit in Dresden is cleaned by a centrifugal force cyclone, followed by a fabric filter. HCL will be prevented by a dry sorption and a fine dust filter. SO2 will be prevented by a corresponding lime dosing and a fine dust filter. NOx will be prevented by a selective non-catalytiv reaction.

Staff: Appr. 7 full-time persons during day-time, 2 persons in the night

Electricity sale info:

The German biomass-CHP plants, which feed the generated electricity into public grid, get a fixed amount of allowances per kWh (according capacity and year of commissioning) by legal restrictions – EEG -. This allowances decreases every year and is guaranteed for 20 years.

Data collected and quality assured by: Institute for Energy and Environment.

Contact person: Janet Witt