Energy
HHNK climate neutral in 2025
By 2025, HHNK wants to be climate neutral. This means not only energy neutral, but alsoCO2 neutral in 2025. To this end, a Climate and Energy Program has been drawn up.
HHNK is North Holland's largest energy consumer 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 household consumption, HHNK consumes as much as a municipality the size of Aalsmeer, for example, with 10,000 households and 32,500 inhabitants. The energy is mainly needed for wastewater treatment, drying sewage sludge and regulating water levels.
We want to achieve our sustainable goals by saving energy, innovating and investing in green energy, such as solar, wind and aquathermy.
Energy Savings
Energy conservation is the cheapest form ofCO2 reduction. Significant energy savings have been made in recent years. These savings have been achieved mainly 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 co-firing.
Sun
Over the past and coming years, we are installing a total of 110,000 solar panels on our treatment sites and building roofs. That accounts for about 35-38% of our total electricity needs. The Map shows where these locations are.
Wind
With wind energy, we could make giant strides toward achieving our 2025 ambitions. Whether and how this could be done is not clear at this time. However, this is being looked at, together with other possibilities for generating energy.
Off the gas
Drying sludge in the sludge drying plant (SDI) in Beverwijk, requires 97% of the gas consumption. However, like the rest of the Netherlands, we want to get rid of gas, which means that the SDI will go out of operation around 2022. Then the Household Waste Plant in Alkmaar will start drying the sludge with residual heat.
Thermal energy
Water is a huge potential source of thermal energy. Theoretically, water in the province of North Holland could provide as much as 98% of the heat. That's 94% from surface water and 4% from sewage. To gain more insight into the relationship between cost and yield, we are adapting a basin pumping station and a sewage system to recover thermal energy.
Biogas
At a number of digesters, we collect sewage sludge from multiple treatment plants for biogas recovery. Partly this is converted into electricity for the treatment processes such as the aeration of sewage and also green gas is produced here for part of the vehicle fleet. The other part of the cars, meanwhile, runs mostly electric and some on blue diesel. This is completely non-fossil.
Area and energy scheme
A software program was developed for Texel that calculates how much water flows through the water system and wastewater system based on precipitation radar images and weather forecast models. The model also calculates how much energy the solar park will generate. This allows the system to calculate how best to use the pumping stations and sewage treatment plant.
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 on Everstekoog for use in the evening.
Innovations
We are always looking for smart, efficient and sustainable ways to keep the management area livable for all users. We do this by innovating. To this end, we work together with knowledge institutions, industry, governments and stakeholders.
Our employees have recently Map 135 innovations. Thirty of these contribute to the energy neutrality of HHNK, such as water intake or pumping away during "off-peak hours.