Hi all,

We are planning to setup a basis for tagging ATES systems: aquifer thermal energy storage. I'm looking for other interested community members to contribute in a Working Group.

This type of system is quite common in The Netherlands and surrounding countries. Typically, these are "open" systems with at least one "hot" and one "cold" groundwater source. Wikipedia link

First topics to tackle would be:

• scoping: type of systems to cover: closed loop systems and/or open well systems
• scoping: inlcude/exclude the heatPump equip
• scoping: include/exclude "regeneration" equip (e.g. water to air condenser, surface water, ..)
• who will champion this WG

There are some topics this WG probably will touch and we'll need some haystack expert help:

1. heat exchangers, these are principal components and there is a need to accurately define temperatures and flow on both sides of one or more heatExchanger equips
2. overall setup: defining a single high-level ates equip or subdividing in separate equips (heatExchanger, energy meter, well pump, etc.)
3. compliancy with Haystack 4.0 - do we need to think about tagging differently with haystack 4.0 in mind?

At the moment, we are working on a starting document together with another company in NL. We are hoping to share this in the coming weeks. Anybody interested in joining: feel free!

HI Jaap - thanks for taking the lead on this working group. I'm going to promote this topic to WG status and you can take it from there.

I agree with Jaap that we need tagging for ATES systems so I would like to join in as well.

Jaap, Great idea, we would like to contribute to this WG.

Hi Jaap,

As we also are collecting a lot of data from ATES systems I would also like to contribute to this WG.

Hi Ronald, Patrick and Coen,

Great to have you join our WG!

I'll contact you offline to set things up and get started.

• Jaap

Hi Jaap and other members,

DWA are collecting data from ATES systems for 20 years. We have created our own tagging model, but we miss the integration with the BMS systems.

I am also the founder of Monavisa/Simaxx but now I have returned to DWA where we are working on artificial intelligence and the next step of analyzing energy systems.

I think it is good to develop a widely supported model that can help data integration one step ahead

Thanks for joining Siem, and Leo and Bas also. I've sent you an invite to contribute offline. When we have a first draft, we'll upload it here on the forum for review.

An update from this WG: we have exchanged some ideas offline and have scheduled a meeting soon to discuss the proposal. We plan to submit a draft for review on the forums mid-December.

The WG members have written the following proposal to contribute to Haystack and would like to move this topic to review. It is quite a challenge to make this proposal for these quite complex systems simple and easy to understand and to use as much of the existing Haystack standard as possible. We hope that we succeeded, and we look forward to hear from the Haystack community and to move this tagging schema to the next level.

The scope is for ATES systems: aquifer thermal energy storage (see wiki link in first post), with specific aim for the "open" type of systems that actually pump groundwater between wells to extract energy. Geothermal energy systems are NOT in scope but can be added later.

In this proposal we introduce a couple of new tags for equips and points. To clarify the proposed tagging schema, we have created an attachment that visualizes the generic concepts, includes a list of new tags and includes several ATES plant schematics for different subtypes. See this link.

Main equip structure:

• ates equip
  • well equip
  • heatExchanger water equip
  • flowInverter equip
  • thermal meter equip

All underlying equips have an equipRef to the ates equip.

Each ates equip has a specific permit with legal requirements that we want to keep track of. Also there is a number of different types of ATES sytems and we need a method to distinguish between those. There is a number of sensors that will be direct children of the ates equip, e.g. system flow and pressure. With this in mind, ates equip specific tags are:

• a single marker tag to define the subtype of ATES system: mono / doublet / doubletPaired / unidirectional / closedLoop (only 1 tag possible, required)\

To clarify these types:

• mono: the ates equip has only one physical well, which is deep enough to penetrate two ground water layers.
• doublet: the ates has one or more pairs of a separate warm and cool well.
• doubletPaired: as a doublet, but with specific warm and cool wells that are linked together and do not exchange water with other wells.
• unidirectional: similar to a doublet, but water always flows in the same direction from the extraction to the infiltration well
• closedLoop: a system that uses closed piping to transport a water/glycol mixture through the ground to exchange energy. The system works like a heat exchanger; there is no ground water transported.

Any other equip that receives water / energy from the ates equip can refer to it using the atesRef reference tag. For example a hot-water-plant that is supplied with warm water from the ates equip.

The well equips pose a couple of challenges. Doublet type ATES systems are bi-directional: one of the two wells stores warmer water and the other cooler water. To distinguish between the two we propose to use the marker tag warm or cool on the well equip. An ates equip' can contain 1-n well equip. With this in mind, well equip specifics are:

• Tag type of well with warm or cool tags (pending the discussion about cool versus cold at: https://project-haystack.org/forum/topic/764). This also holds for mono-type systems.
• In unidirectional type ates systems, there is no warm or cool well, but a well that always extracts water from the ground and a well that always infiltrates water into the ground. Add marker tags infiltration or extraction to identify these wells.
• Use an integer number to identify specific wells in a project: wellNum: 1 (Number). If two well equips are a pair in a doubletPaired type ates, they get the same wellNum.

A pump that is placed within a well, will not be defined as a separate pump equip. Any points relating to this pump will reside directly under the well equip. Any pumps under the ates equip (not within a well) will be modeled as separate pump equips.

Any ATES system contains at least one but usually two or more heatExchangers. There is a need to identify the primary and secondary side of the heatExchangers, but also the function. In most designs there is a preferential heatExchanger used for most of the energy exchange, and a second heatExchanger for regeneration. Some ATES systems supply water to several buildings that all have their own set of heatExchangers to their specific hot water and chilled water plant. With this in mind, heat exchanger equip specifics are:

• primary/'secondary' marker tags are used at the point level to indicate either ground water (primary) or building/plant (secondary) side of the heatExchanger
• heatExchangerNum string tag is used to identify (1) which heatExchangers are paired and (2) which heatExchangers have a primary or secondary function. Example: heatExchangerNum: "1.1" is the building 1 primary heatExchanger and "1.2" is the building 1 secondary heatExchanger.

Most ATES systems also have a set of uni-directional valves that are used as a "flow inverter". We propose the equip-level tag flowInverter. This equip can exist either before the heatExchanger on the ground water side of the system, or after the heatExchanger in the building central plant. In both cases this is an essential part of the ATES system and therefore is modelled as a sub-equip of the ates equip. Flow inverter specific tags are:

• active marker tag applied to flow inverters that contain a pump (the active component)
• primary/'secondary' marker tag to indicate the location of the flow inverter as either part of the ground water side of the system (primary) or building plant side of the system (secondary)

This is a great job, very thorough! We'll see if we get additional public feedback, but I think we should start moving towards integrating this into the Haystack 4 website.

From an integration perspective I have a few notes for things we should address:

1. I don't think we want to start down a path of using string patterns for equipment numbers. Making them int tags and maybe using multiple tags is probably going to be easier for applications to consume (such as pump staging control, etc)
2. Using generic names like mono and unidirectional might be difficult. We could give them generic definitions then organize them into a specific choice with extra documentation. Or we could go ahead and coin them as atesMono, etc

To begin, I'll need to get these definitions formally defined as a Haystack 4 defs trio file. And we'll also need a matching prose chapter in markdown. Jaap lets coordinate that work offline if you want to just email me directly

The WG has been working offline together with Brian Frank and updated the proposal above into a new write-up and defs file. We want to invite the community to provide feedback. Note that a couple of tags are relevant for non-ATES systems as well.

After this round of review we will submit the definitions for implementation in the next Haystack build.

Please refer to the first proposal posted above on Jan 24th 2020 first. Contact me if you would like access to the full write-up and a tags.trio definitions file of the proposal.

Notable changes/updates since the last proposal are:

• The type of ates system is now a choice of atesDesign
• The well equip definition is broadened to cover any type of ground water well
• The purge marker tag is added for processes that remove contaminations from a substance by expelling a certain volume of that substance

Notable definitions that may impact other systems:

• The primary and secondary tags are introduced to indicate the side of a system, e.g. a heatExchanger, with primary being the side closest to the (energy) source and secondary closest to the delivery
• The warm and cool tags are introduced for relatively warm and cool sources of energy. The explicit contract with hot and chilled being that it is not actively heated or cooled by a mechanical process and (usually) has a lower energy potential. Also see https://project-haystack.org/forum/topic/764

As of Haystack v.3.9.10, the ATES definitions are included. We don't have any feedback from the community that warrants a change in the definitions so far, so I propose that we move this WG status to closed.

I agree, it is now closed