Energy
HHNK climate neutral by 2025
HHNK aims to be climate neutral by 2025. This means not only energy neutral, but alsoCO2 neutral by 2025. A Climate and Energy Program has been drawn up to achieve this.
HHNK is the largest energy consumer in North Holland after Schiphol, Tata Steel, and Google. Our annual consumption amounts to 15 millionm³ of gas and 86 million kWh of electricity. If we convert this to domestic use, HHNK consumes as much as a municipality the size of, for example, Aalsmeer with 10,000 households and 32,500 inhabitants. The energy is mainly needed for wastewater treatment, drying sewage sludge, and regulating the water level.
We want to achieve our sustainability goals by saving energy, innovating, and investing in green energy sources such as solar, wind, and aquathermal energy.
Energy savings
Energy saving is the cheapest form ofCO2 reduction. Significant energy savings have been achieved in recent years. These savings have mainly been realized in the water chain, for example by removing nitrogen more intelligently and using pumps more efficiently. But also by installing a new turbine at the sludge drying installation (SDI) in Beverwijk, which eliminates the need for additional fuel.
Sun
Over the past and coming years, we will install a total of 110,000 solar panels on our treatment sites and building roofs. This will cover approximately 35-38% of our total electricity needs. The map shows where these locations are.
Wind
Wind energy could enable us to take giant strides toward achieving our 2025 ambitions. Whether and how this could be achieved is not yet clear at this stage. However, this is being investigated, along with other possibilities for generating energy.
Off the gas
Drying sludge in the sludge drying installation (SDI) in Beverwijk accounts for 97% of gas consumption. However, like the rest of the Netherlands, we want to phase out gas, which means that the SDI will be decommissioned around 2022. The household waste incineration plant in Alkmaar will then dry the sludge using residual heat.
Thermal energy
Water is an enormous potential source of thermal energy. Theoretically, the water in the province of North Holland could even provide 98% of the heat. That is 94% from surface water and 4% from sewage water. To gain more insight into the relationship between costs and returns, we are adapting a drainage pumping station and a sewage system to recover thermal energy.
Biogas
We collect sewage sludge from several treatment plants at a number of digesters for biogas recovery. Some of this is converted into electricity for treatment processes such as sewage aeration, and green gas is also produced here for part of the vehicle fleet. The other part of the fleet now runs mainly on electricity and partly on blue diesel. This is completely non-fossil.
Area and energy regulation
A software program has been developed for Texel that uses precipitation radar images and weather forecast models to calculate how much water flows through the water system and the wastewater system. The model also calculates how much energy the solar park will generate. This enables the system to calculate how the pumping stations and sewage treatment plants can best be utilized.
Flow battery on Texel
A flow battery has been put into operation on Texel. This battery stores part of the electrical energy produced by the solar park at Everstekoog so that it can be used in the evening.
Innovations
We are always looking for smart, effective, and sustainable ways to keep the management area livable for all users. We do this through innovation. To this end, we collaborate with knowledge institutions, the business community, governments, and stakeholders.
Our employees have recently identified 135 innovations. Thirty of these contribute to HHNK's energy neutrality, such as letting water in or pumping it out during off-peak hours.