Fort Isabella

At Fort Isabella, BuitenStadEnergie supplies renewable energy in the form of heat and cooling for homes and commercial spaces. Your home is also connected to BuitenStadEnergie's energy system. The heat is generated using a heat and cold storage (CHP) system with heat pump. This allows Fort Isabella residents and businesses to heat and cool their spaces carefree with sustainable heat and cold. Upon completion, the entire complex will be "off gas".

How does a CHP system work?

A ground energy CHP system generates heat for heat networks. The CHP consists of two wells about 80 metres deep. In winter, groundwater from the well is used to heat buildings. In summer, cold groundwater is used to cool your home. This water flows through the floor pipes, absorbing heat from your home. The water that returns heated is stored in the ground for reuse in winter. In this way, we make energy available for reuse and ensure that heat and cooling is sustainably available to residents and businesses.

Schematic representation of energy system

In general

BuitenStadEnergie's renewable energy system has several advantages. For example, you can do without a central heating boiler or geyser. This saves noise and space. You will also not have to deal with unexpected expenses for maintenance, repair or replacement. And of course, you benefit from a pleasant indoor climate in summer and winter. Heating and cooling your home with our sustainable energy system does not require burning gas. A large part of the electrical energy needed is generated at Fort Isabella by 1,630 solar panels. The remaining energy is purchased as green electricity. This reduces emissions of harmful greenhouse gases such as CO2 and nitrogen. Therefore, your energy system from BuitenStadEnergie is very environmentally friendly. Yet on average, you pay no more for your heat than if you would have had a gas connection.


As with water, telephony and gas, for heat you pay not only a standing charge or subscription, but also for consumption. Since you cannot choose who you take your heat and cold from, it is important that the price is arrived at carefully.

The price of heat

The energy bill is an important part of monthly expenses for almost everyone. This is true for electricity and gas but also for heat and cold. In your case, there is only one fixed producer and supplier supplying the heat to you, BuitenStadEnergie. This means that there is no price competition and therefore it is important that the price is established carefully. From 1 January 2014, the Heat Act came into force for this purpose.

The Authority Consumer and Market (ACM) oversees the supply of heat and sets tariffs by 1 January each year. These annual tariffs set by the ACM guarantee that the price for heat supplied is never higher than the cost of obtaining the same amount of heat when using gas as an energy source. The price applies for the whole year and does not change in the interim.

The price for the supply of heat consists of a fixed amount and an amount per Giga Joule of heat consumed. For the heat exchanger and the heat meter, together BuitenStadEnergie's Afleverset, you pay a separate metering rate or rental amount, the standing charge. This standing charge also falls within the tariff set by the ACM, which sets it on the basis of reference tariffs.


With BuitenStadEnergie, you only pay a fixed charge for cold. Consumption is free. The amount of the standing charge for cooling is also determined by the ACM. This standing charge for cooling is included in the standing charge item for the Diverter Set.

More on the Heat Act

On the consumer site Consuwijzer you can read more on the Heat Act and the rates. On this site and on the ACM website you can read more on the compensation fee. This compensation is set by ministerial regulation and comes into effect in case of a serious failure in the supply of heat. The regulation deals with reimbursement arrangements if the goods and services provided do not meet the agreed quality requirements. The compensation payment then relates to the heat in the heat network, with certain specific types of individual failures excluded from compensation under the Heat Act.

Advance and final settlement

We charge you a monthly advance. This advance payment consists of the fixed costs (standing charge) and estimated consumption costs. Your consumption depends on many factors. It is therefore impossible for BuitenStadEnergie to accurately estimate your consumption straight away. For newly delivered homes, extra consumption must also be taken into account because there is still 'building moisture' in the home that needs to dry out. It is possible that windfalls or setbacks occur in your final settlement due to incorrectly estimated consumption. You cannot therefore hold BuitenStadEnergie responsible if we have estimated your consumption incorrectly. Over time, it will become increasingly possible to determine an appropriate advance payment for your consumption.

Once a year you will receive a final settlement based on your actual consumption.

  1. Did you pay too much with the monthly advance? Then you will receive money back.
  2. Did you pay too little? Then you have to pay extra.

You will receive the final bill automatically. If you move, you will receive an interim final bill. The final statement is also the basis for a possible adjusted advance proposal for the next period. It is up to you to make use of this or to choose your own advance amount. BuitenStadEnergie's tariff sheet shows a suggested advance amount based on an average situation. Your personal wishes are best communicated via email or use the telephone number to do so.


The indoor system from the delivery set to the indoor installation is owned by the owner of your home. The remaining system, up to and including the delivery set, including consumption meter, is the property of BuitenStadEnergie. Handle the delivery set and consumption meter with care. Do not hang or mount anything on, on, above or below the meter. The place where the meter is located must be and remain easily accessible, for instance for emergencies, malfunctions or for inspection or repair by or on behalf of BuitenStadEnergie. Also make sure that there are no things near the afleverset that could damage it. Is something still damaged or is the seal broken? If so, contact us immediately.

Indoor installation of your residence is no property or responsibility of BuitenStadEnergie

The indoor installation in your home is not the property of BuitenStadEnergie. However, the indoor installation does have a major impact on the functioning of our energy system. You will receive further information about its use. The hot water supply works with an environmentally friendly heat pump, connected to the heat network. The domestic hot water supply is the property of the home owner. Before the completion of your home, you will receive the formal contract documents from BuitenStadEnergie. This will also include contact details for delivery and fault service.