From citrus peels, seaweed and slurry to biogas

Date: 18 September 2014

Seaweed smells and residues from industry production are typically regarded as waste. But why not transform it to biogas for heating and electricity instead? That is precisely what the municipality of Solrød, Denmark is doing.

In 2015 the upcoming biogas plant in Solrød, Denmark will produce about 5,4 million cubic meters of methane gas for 25,4 GWh of electricity and 28,5 GWh of district heating. The sources of energy are 79,400 tonnes of organic industry by-products from companies CPKelko and Chr. Hansen, 52,800 tonnes of animal residues from nearby farms and 22,000 tonnes of seaweed from the beach.

More than four years of preparation has not only ensured a biogas solution that is economically sound, it also reduces the smell from seaweed on the beach, cuts CO2 emissions by 40,500 tonnes, meets reduction requirements for phosphorus by 100% and 72% for nitrogen as well as improving the water quality in the bay area.

The biogas plant has received EUR 480 million in EU support from the Mobilizing Local Energy Investments program (MLEI), which is part of the umbrella program Intelligent Energy Europe, based on utilising seaweed as a source of energy. Total costs have been budgeted at EUR 11,42 million.

Lessons-learned, step by step
Based on experiences and lessons-learned from the preparation phase, four important aspects have been highlighted in relation to the realisation of the project:

1) Project Management
Ensure that management of the project identifies and includes all relevant stakeholders, and establish a project committee of relevant experts. The steering committee behind this project consisted of representatives from the municipality of Solrød, suppliers of biomass as well as purchasers of the produced biogas.

2) Organising citizen involvement and regulatory processes
Realisation of such a biogas project necessitates a strong involvement of the citizens living in the municipality. Typically, biogas projects are subject to citizen resistance due to fear of smell, noise and other disturbances. The municipality of Solrød have not received any complaints so far, just as all decisions have been passed by a unanimous city council. Notable factors behind this count many initiatives for citizen involvement, a high level of transparency and putting great effort into communicating the economic, technical and environmental perspectives of the project.

3) The technical aspects
Involve the experts from the beginning. For instance, the project group behind this project is represented by the municipality of Solrød, the University of Roskilde, Solrød District Heating Plant and a technical advisor Gascon. Broad involvement of stakeholders ensures high professionalism and insights into all details of the project.

4) Ensure multiple benefits
Upon realising projects of such nature, it is important to ensure multiple benefits, both direct and indirect, so the investments generate as many environmental outcomes as possible. It benefits the project and increases understanding and citizens acceptance.

 Source: State-of-green