A Review of the Performance of Minewater Heating and Cooling Systems
Round 1
Reviewer 1 Report
The authors reviewed a number of minewater geothermal energy (MWG) projects in Europe and the USA that utilizes the minewater as energy sources for heating and cooling. The manuscript provides detailed description of some systems and their experiences and challenging facedbased on a combination of site visits, interviews and literature reviews.The risks and issues are identified with the MWG projects. I think the article of interest to those who are interested in planning, construction, and operation of the MWG projects.
The manuscript is well organized and written.My major concerns are associated with two seemingly missing points.
Can the authors provide results or discussion on 1) the economic and energy performance of the successful MWG projects and2) the energy potential of the minewater in a global context?
In addition, section 5 is bit of tedious on the detailed description and technical challenges of each MWG project.Could it be summarized further?
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript is well written, easy to follow, with an interesting topic of using abandoned mines as a heating/cooling resource. It gives a good review of projects, whether they are operational or not. Even non-operational projects can be good example for future planning, developing, and using this potential and somewhat available heat resource. The paper also gives good overview of potential issues which every developer should be aware of when considering using minewater as an energy source.
When it comes to technical issues, please provide figures with better resolution. When zoomed in, the text in most of the figures are of poor quality. Also, please check the journals template for paper margins. As I scroll, it seems as the margins are larger.
Line 157: Is the flow of 50 l/s realistic to expect to pump from flooded mines? In that case, what is the expect rate of cold front advancing to pumping point and cooling the minewater, in the case of reinjecting colder fluid, since the volume of the water is somewhat limited?
Line 360: In the case of Dawdon and Abbotsford Road site you state the minewater flow. Is there no data for previous sites (Shettleston, Lumphinnand etc.) and some of the sites mentioned later in the text? Also, since this is a review paper maybe authors should consider giving the data about fluid flow, minewater volume (assumed can also be ok) or the size of the flooded work, just so the reader is given a perspective of the size.
Line 446: Since previous units for fluid flow were l/s, I suggest the authors choose one unit (l/s or m3/hr) and other value with corresponding unit in brackets. It will be easier for a reader to follow and compare obtained data.
Line 638: In Figure 7, Operational issues, you mention MGES. If I am not mistaken, the abbreviation is not stated in the text.
Line 638: In the Construction issue, is there a possibility of a cave-in during the operation of the MWG system? Could a cave-in or a collapse of mine elements (such as pillars) also be an issue?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
