Finnish Valmet and Danish HOFOR Energiproduktion A/S have signed a €150 million (US$163 million) contract for development of a state-of-the-art biomass combined heat and power (CHP) plant for Copenhagen, Denmark.
Installation of the Amagerværket plant is scheduled to begin in July next year.
Kai Mäenpää, vice president for energy sales & services at Valmet told Renewable Energy World: “This project is one of the largest biomass-based CHP projects in Scandinavia.”
The plant’s 500 MW biomass-fed boiler will provide district heat capacity of 415 megajoules per second and net electricity production capacity of approximately 150 MW — making the plant the tenth largest in the world by current rankings when it comes online in 2019.
The scale of the plant has prompted unique design considerations.
“The main technology in this delivery is the large circulating fluidized bed boiler,” Mäenpää said. “This 500 MW (fuel effect) Valmet CYMIC boiler is designed to use 100 percent biomass as fuel.
“The boiler will use a total of 1.2 million tons of sustainable wood chips per year. Naturally this sets specific requirements to the boiler technology, [and] this in turn sets challenges for the fuel logistics, storage volumes and fuel handling onsite.”
Detailing solutions to this challenge, Pauli Vanhala, Valmet’s sales manager for wood handling, told Renewable Energy World: “The design flow from storage to boiler is [based around] 2 x 900 m³/h [conveyors]. The storage silos consist of two 175m long, A-framed closed wood chip [structures] side by side, each with a capacity of 52,500 cubic meters. This corresponds to seven days of operation with boiler at full load.”
According to Vanhala, the storage system is able to receive fuel from ocean boats, trucks and from its own chipping plant for round wood.
“There is also a special emergency fuel receiving and feeding line directly into the boiler,” Vanhala said. “Quality of all chips will be controlled and maintained with a separate screening system. The whole wood handling is equipped with advanced IR-technology measurements and follow-up/alarm systems.”
Vanhala added that “high [biomass] availability requires redundant storage and conveying systems. This means that if one of the systems is [for example] under maintenance the plant can still operate with the other system.”
Replacing an existing 600-MW coal-fired plant, the new plant is expected to reduce emissions by some 1.2 million tons annually.
As such, the project fits neatly within the climate plans of the Danish capital, as Carsten Schneider, HOFOR project director, explained: “The city of Copenhagen has an ambition of becoming the first CO2-neutral capital in the world by 2025. This means that we need to move away from fossil fuels and to convert to sustainable CO2-neutral fuels and technologies.”
Schneider said that the new biomass-based CHP plant, BIO4, plays a significant role in the city’s goal, as it will supply approximately 30 percent of the total heat demand of Copenhagen.
As part of the nation’s broader push for clean energy and heating, the new plant will be entitled to state subsidy.
Schneider said that “biomass for heat production is free of energy and CO2 taxes — in opposition to fossil fuels like coal, oil and natural gas. Further electricity generation based on biomass is supported by the state with a subsidy of 15 øre/kWh (fixed prices) — approximately €0.02/kWh.”
A noteworthy aspect to the Amagerværket project — one unconcerned with energy — is its architectural design. Devised by Denmark’s Gottlieb Paludan Architects (a firm with a penchant for sustainable design), the plans adopt numerous striking design features reflecting the sustainable nature of the plant, and its relationship to the natural world.
Image: Illustration of the future Amagerværket heat and power plant in Copenhagen from Gottlieb Paludan Architects.
The firm’s project page presents details on particular facets of the design.