Frequently questions asked

Questions were asked during information evenings and via the survey, about among other things, the aquathermia technology, the impact on the ecology and financial aspects. We answer these questions based on current available knowledge. New insights may lead to edits on this webpage.

Technical questions

What are the changes in my house?

The new system enters the house with two pipes. The diameter of the pipes entering the house is approximately 10 cm including insulation. These pipes are connected to the ‘delivery set’ which extracts the required heat from the heat network. The ‘delivery set’ is placed as close as possible to where the heat network pipes come in. This may be possible at the place where the current boiler is installed, since the ‘delivery set’ has approximately the same dimensions. The ‘delivery set’ is then connected to the existing central heating system. The temperature can be regulated with a thermostat in the living room. To measure how much heat is consumed, a consumption meter that is comparable in size to the electricity meter will also be installed with the ‘delivery set’. Because every house is different, the best way to connect to the heat network will be examined for each house.

This is an illustration of a ‘delivery set’ with tap water. It will be placed in an insulated box.

Does the “delivery set” make noise?

No. The only electrical part is the pump. This is comparable to the pump in your current boiler and should not make any noise.

How is the tap water heated?

Two options are currently being considered for hot water from the tap. Option 1 is an individual electric water heater. The choice of the volume and capacity of this water heater is completely free and depends on the needs and wishes of the household. Option 2 is that the ‘delivery set’ is slightly larger (comparable to the picture) and that the heat for tap water is also obtained from the heat network. Both options have their pros and cons. Which of the two options it will ultimately be, will be determined in the near future.

What if the central heat pump of the aquathermal system is not sufficient in a severe winter?

For this purpose, an emergency facility is installed that can provide additional heating on those few days in the year when it freezes very hard. If a fault occurs in the heat pump or when maintenance is carried out, this emergency facility can supply the entire system with heat.

Is water from the Linge stored underground?

No, the water of the Linge and the groundwater never come into contact with each other. Only the heat extracted from the Linge is stored in the groundwater. Groundwater quality and quantity will not change.

Isn’t it a problem to go through the dike?

There are requirements and regulations for this. If these are followed, there is no risk. The Water Board supervises this and does not give permission if there are problems or risks.

Where does the electricity come from for pumping up the Linge water and for the central heat pump?

The electricity comes from the normal electricity grid. So we can choose an energy supplier ourselves.

How will the heat network connect to all the different homes with different existing systems, such as an existing air heating system?

The situation is different in almost every home. We will therefore make an inventory per house. There is also a good solution with high efficiency for air heating systems.

Doesn’t energy (heat) leak into the ground?

Every heat system has losses. However, the soil and groundwater can retain most of the heat. The losses in a heat exchanger are very low; less than 1%. To compensate for the losses in the entire system, heating will take place approximately 3 degrees above the desired temperature (total 73 °C).

We assume that the system runs all year round. This is also necessary to provide us with tap water if we choose this option. However, this still depends on the final technical and financial concept.

Questions about the positive and negative impact of aquathermia on the ecology of the Linge

How much heat can you extract from the Linge, can you do that with impunity?

Consultations with the water board have shown that there are frameworks for the degree of cold discharge in relation to the size of a river. Enspijk’s possible system is expected to remain well within this range. The cold plume from water discharge is resolved after a few hundred meters. The effect this has on the ecology is being further investigated, but the frameworks that the water board works with are intended to minimise the risk of negative effects. To further reduce the risk of negative ecological effects, a monitoring program will also be developed to monitor the impact of the system. We can expect support from the water board and national research institutes.

Will villages downstream be impacted by changes in the water temperature of the Linge?

It is expected that the water temperature along villages downstream will not be impacted, because the water warms up again over time and distance due to the sun, the air and the river floor of the Linge. These influences result in the temperature returning to the same temperature compared to upstream of the DWE installation. Moreover, one of the criteria of the Waterboard is that villages downstream are not restricted in the development of an aquathermal system as a result of the heat extraction by Enspijk.

We don’t get a situation here like in Groningen, do we?

Nothing is taken from the soil or added. There is therefore no chance of the soil sinking. Moreover, we ourselves become the owners of the system. In the unlikely event that problems arise, we can therefore immediately come up with a solution ourselves and we are less dependent on large influential bodies such as the NAM.

Questions about costs

The construction of a heat network in Enspijk requires an investment of many millions. The Coöperatie DWE cannot afford this, so a lot of subsidy and funds from other financiers is needed. Other municipalities have already proven that this is possible and feasible. It is our ambition that we, the residents, do not or hardly have to invest in the construction of the heat network.

What is the price per gigajoule?

The aim is to achieve the lowest possible heat price for the inhabitants of the village center of Enspijk. We also try to remain equal as or lower than the gas price at that point applicable. This depends, among other things, on the net costs (after deduction of subsidies) of the installation and the heat network. Developments are currently underway regarding subsidies. The subsidy measures are being expanded. On the other hand, prices are subject to inflation. As a result, we cannot estimate exactly what the final costs will be for the installation and operation of the system. We are a non-profit cooperative, which means that we can limit the price for heat compared to commercial parties.

If we have such a delivery set in house, do we have fixed costs or usage costs?

The starting point now is to be able to make the ‘delivery set’ available to the owner of the building free of charge. The unit remains the property of the supplying party (just as the gas meter currently). It is not yet clear whether this will succeed or whether a “fixed fee” per month will be charged for the “delivery set”. In any case, this will not exceed the fixed costs for a gas meter.

It is quite a drastic cost to renovate homes built before 1980, is it feasible?

Insulation costs and other sustainability measures can be reduced through our collective purchasing and moreover, it is expected that more subsidy will be possible if we jointly apply for this.

The aim is to ensure that part of the insulation costs (to be mapped out per home) are not borne by the owner of the building by making optimal use of subsidies. The remaining costs are for the owner of the property. DWE may only assist in obtaining the subsidy. It is therefore up to the owner whether he makes this investment.

A lot of subsidies will become available for the insulation of homes. This already reduces the costs to a certain extent. In addition, you can borrow money for insulation at a very attractive low interest rate. For the first few years, you pay off that loan with the savings on your energy bill, after which you will have a relatively lower energy bill.

The best solution is still being sought for financing the adaptations to the homes for connection to the heat network. You can assume that the starting point is to keep costs as low as possible. These are included in DWE’s budget.

What are the costs for a customer to terminate your contract if you are not satisfied?

In principle, you will have to sign up for a multi-year contract, since we need to guarantee continuity in the collective heat supply network and the financial exploitation. No decision has yet been made on exit costs upon termination.

Questions about participation and the powers of the board of Coöperatie DWE

Can the board make decisions on its own?

The board can indeed take decisions itself, but is accountable for this in the members’ meeting. The articles of association and the internal regulations serve as a starting point for the policy and in this way the board implements the policy of DWE. Changes can be made to this. However, these must first be approved in accordance with the articles of association during a members’ meeting.

Questions about support base

What to do if you are already thinking about your own initiative, an individual solution?

Everyone is free to choose an individual solution.

If you have plans, we would like to be involved to think along. DWE has also considered the possibility of using individual solutions in the Action Plan, but this has quite a few drawbacks. A collective solution is therefore preferred. We need about 150 connections for a profitable network.

Has a poll been conducted among the residents?

A survey was recently conducted among the residents. This is not yet completed.

Is Kleurijk Wonen supporting the initiative?

The housing industry supports the initiative.

What is the opinion of the Waterboard?

The Waterboard has to deal with the consequences of climate change like no other. It is therefore self-evident that they cooperate in this, they have confirmed this. Certain national frameworks will have to be taken into account for this, but the starting point is yes, unless. Preventing negative ecological effects is very important in this respect. All in all, the Waterboard is in favour of this initiative.


Comment from a resident: As a member of the cooperative, do I also have to purchase heat?

As a resident of Enspijk you can always join as member of the cooperative. There is no obligation to purchase heat.