More power and lower costs, emissions and grid load at SNB

SNB (Slibverwerking Noord-Brabant / Sludge Processing North Brabant) is the largest sludge processor in the Netherlands. For over 20 years, SNB has been processing sewage sludge, left over after wastewater treatment in sewage treatment plants.

Challenge

Sustainability is high on the agenda at SNB. During the decomposition of sludge, gas is created, which SNB uses to run turbines that generate energy. To meet their own energy demand in its entirety, a 5MW solar park was added. However, SNB was struggling with high monthly reactive power costs. The company was purchasing a significant amount of reactive power and too few kilowatts from the grid operator. The cost of the (excess) reactive power take-up was added to the energy bill.

Objectives

• Obtain more capacity from existing plant
• Fully self-sufficient in energy needs
• Integration of renewable sources
• Reduction of reactive power and costs

Solution

Power Quality Analyzers were used to perform measurements on the outgoing feeder to map the plant’s powers. Each measurement was performed for a representative duration in order to obtain a realistic picture. In addition, a continuous measurement was performed on the incoming power supply at the 10kV distribution station.

After making several measurements and analyzing the results, HyTEPS came up with the best fitting solution: installing five new correctly sized capacitor banks to compensate for the reactive power in the installation. This also improves the Cos φ of the incoming power supply.

Results

The application of compensation allowed SNB to boost the existing plant’s efficiency and capacity.  This ‘inspansion’ not only added substantially more capacity – the ‘reactive power issue’ was solved and the costs were significantly reduced. As a result, the payback period for the entire installation was less than one year. The power operator’s network load is also significantly reduced – 1.75MW, to be precise, comparable to a small industrial plant. Energy losses on the transformers are greatly reduced.

“We have worked with HyTEPS for a long time now,” says Erwin Soeters, plant manager at Slibverwerking Noord-Brabant. “In 2014, they carried out the first project here, related to energy savings on lighting. We are very satisfied with the cooperation with HyTEPS, their expertise and short lines of communication appeal to us in particular.”