Nij Smellinghe pioneers: completely off gas by 2027 with revolutionary heat battery

Nij Smellinghe is taking a big step in energy transition. We are the first hospital in the Netherlands to use a heat battery on a large scale. The PowerStove converts sustainable energy into heat and then into steam for sterilization, pharmacy, kitchen, air humidification and peak demands for heat and tap water, among other things. This will allow us to completely get rid of gas by 2027 and be carbon-neutral on energy. A unique, innovative and revolutionary solution that contributes to a sustainable world for our patients, staff and society.

2027 off gas

“We want to be part of the solution, not part of the problem. The hospital runs 24 hours a day and needs a lot of energy. We have already taken many steps to become more sustainable and reduce our energy consumption. But some of it still comes from natural gas. We want to change that. By 2027, we will no longer use fossil fuels and emit CO₂ for energy. In this way we not only take care of our patients and employees, but also of a sustainable world,” says Arno Vredevoort, manager of Technical Management and Maintenance at Nij Smellinghe.

“The PowerStove gives us energy security and makes us agile in a challenging energy market. This heat battery delivers steam to our existing infrastructure via a steam generator. As a result, the gas-fired steam boilers will soon no longer be needed. Only for emergencies will they still be on standby, running on biodiesel. This offers many advantages and is the final step for Nij Smellinghe to go completely off gas.”.

What makes the PowerStove unique

• First application on this scale in an existing hospital running 24/7
• Stores energy for an extended period of time, several days to weeks possible
• Energy available when needed
• Storage of heat up to 360 °C
• Fits existing infrastructure (steam, hot water, cooling, hot air)
• (Fire)safe, circular, proven technology, lifespan of at least 30 years
• Manufactured from sustainable, circular materials of European origin. Fully recyclable with no harmful emissions
• Savings for Nij Smellinghe of 285,000 m³ of gas per year. That is equal to the annual consumption of approximately 275 households

How does the PowerStove work

The PowerStove is a thermal battery that converts locally and sustainably generated energy into heat and then stores it for long periods of time. Green electricity is used to heat thermal oil, which transfers heat through heat exchangers to magnetite (iron ore) in a well-insulated container. This enables the battery to retain heat up to 360 degrees Celsius for several days to weeks.Appropriate to Nij Smellinghe's consumption and wishes, the heat is retained for an average of three days. When the hospital needs steam, for example for sterilization, pharmacy, kitchen or humidification, this heat is used to make steam and distributed through the existing infrastructure. This ensures energy security even at times when there is little sun or wind or the energy grid is overloaded.

Why steam in a hospital

Hospitals use steam for processes that require temperatures above 100°C. Such as the sterilization departments, the kitchen, the laboratory and in humidification.Steam kills bacteria and germs on medical instruments and rids them of harmful microorganisms. This is a safe alternative to chemical agents. Steam is also indispensable in the kitchen for preparing meals and cleaning dishes. Good humidity is important in the hospital for a healthy working environment, and steam is used for that. The PowerStove converts renewable energy into heat and, via the steam generator, into steam.We can use the steam at any time through our existing infrastructure.

Preserving and reducing energy consumption

In Nij Smellinghe we have already done a lot to make our energy consumption more sustainable and lower. On our roofs and solar carports, solar panels generate 3 million kWh of energy annually. Comparable to the consumption of about 1,200 households. We have two Thermal Storage Systems (CHP), insulated facades, a lithium battery and a smart Energy Management System (EMS) that automatically adjusts the use of systems, such as charging stations and batteries. The final step to going off gas is with the heat battery. The PowerStove replaces gas-fired boilers, which means we will no longer use gas by 2027.

Collaboration and future

Heatwacht is the developer of the PowerStove and our collaboration partner. “With this heat battery we show that sustainable energy storage is also possible on a large scale. Nij Smellinghe dares to pioneer and sets an example for other hospitals and large-scale users.