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Enel is seeking novel methods to economically extract lithium and other minerals from brines produced in geothermal power plants.

This is a Reduction-to-Practice Challenge that requires written documentation and experimental proof-of-concept data.


The global demand for lithium salts, the raw material for lithium-ion batteries, has increased significantly in recent years as a result of technological advancements in electronic devices and electric cars requiring high energy-density batteries. Traditional sources of lithium are quickly being depleted and alternative supplies must be explored. One potential source is the fluid used in geothermal power plants, known as geothermal brine, but extraction of lithium from such fluids has proven challenging due to several factors including the presence of other salts in the brine (that can be valuable as well). Enel is looking for novel methods and technologies to economically extract lithium and other valuable minerals.

This Challenge will be run in two phases. Enel will evaluate submissions to this first phase and choose the top Solvers to be invited to participate in the second phase. Solvers invited for the second phase will be required to sign and return a Non-Disclosure Agreement (NDA) as well as provide proof of identity in order to participate in phase 2 of the Challenge. The deadline for phase 1 is 11:59 PM (Central European Time) December 31, 2019. Detailed information regarding the deadline and additional requirements for phase 2 will be provided to the invited Solvers who return the requested documentation.

This Challenge provides contribution to the following Sustainable Development Goals:

  • SDG 6: Clean water and sanitation
  • SDG 9: Industry innovation and infrastructure
  • SDG 12: Responsible consumption and production
  • SDG 15: Life on land

For questions about the challenge and your proposal you can contact EnelOpenInnovabilityChallenges@innocentive.com

See Q&A in the description below




Geothermal brine is a byproduct of geothermal power plants, produced when geothermal fluid comes out in the wellhead from deep water dominated reservoir. The steam phase is separated and sent to a turbine for electricity production, the remaining water phase (brine) is sent back in the underground reservoir through reinjection wells. These brines are typically rich in high-value minerals such as lithium and silica, and may be a significant alternative source of these minerals to supplement or replace traditional mines.

As worldwide consumption of lithium salts rises sharply in response to increased use of lithium-ion battery containing products from mobile phones to hybrid and electric vehicles, traditional sources of lithium are rapidly being depleted. New sources must be found and developed in order to keep pace with the ever increasing demand. One such source are the geothermal brines described above. As a part of ongoing studies into the economic use of geothermal fluids, lithium recovery from geothermal brine is gaining interest from research institutions and industrial start-ups.

In the past tentative extraction processes were set up based on unit operation like liquid-liquid extraction, membrane filtration, and crystallization etc., but none showed competitive advantages with respect to traditional mine extraction. More recently, the increased use of lithium combined with the depletion of traditional supply sources have turned lithium extraction from brine strategically and economically attractive. In particular, the presence of silica is a critical issue in the management of brine reinjection due to its tendency to precipitate and clog wells. However, these problems represent a valuable opportunity to enhance the extraction of minerals from geothermal brine: solutions that will integrate the extraction of lithium with other minerals (in particular silica) will be evaluated as a plus.



Enel is searching for novel methods or technologies to economically extract lithium from geothermal brines. These brines are typically at elevated temperatures (150 °C – 250 °C) and pressures (10-15 bar) and contain many other dissolved minerals. Composition of geothermal brines differ from site to site and feed to feed because of geological features of the reservoir. Information about the specific compositions of the brines of interest will be made available to Solvers chosen for phase 2 of this Challenge.

General composition information for these brines is as follows:

·      T°C: 150

·      SiO2 ppm: 500-1000

·      H3BO3 ppm: <3000

·      Li ppm: 10-50

·      Sb mg/l: <50


Submissions must meet the following technical requirements:

  1. Able to extract lithium from geothermal brines in the presence of silica, stibnite and boric acid in the concentrations listed above.
  2. Extract lithium from brines containing from 10 to 50 ppm of lithium
  3. Able to operate without constraint to the geothermal power plant’s operations.
  4. Support Enel’s commitment on SDGs (Sustainable Development Goals) with specific emphasis on 6, 9, 12 and 15


In addition, the following qualities are highly desired but not required:

  1. Simultaneously extract other minerals as well



The submitted proposal should include the following:


Phase 1 – this Challenge

  1. Detailed description of the novel method or technology to extract lithium/other minerals from geothermal brines (including efficiency, energy consumptions, raw materials, etc.)
  2. A bibliography of relevant literature (e.g. journal articles, patents, trade materials) that support the proposed solution
  3. Additional documents containing supporting information (file formats such as .doc, .jpg, .pdf, .ppt) may be uploaded as attachment


Phase 2 – For invited Solvers

  1. Preliminary equipment design that illustrate important aspects of the design (e.g. electrical, mechanical, visual, functional) and how it would be installed in a power plant setting
  2. Scale up criteria
  3. Experimental proof of concept data at a minimum of Technology Readiness Level 4 (TRL 4)
  4. Additional documents containing supporting information (file formats such as .doc, .jpg, .pdf, .ppt) may be uploaded as attachment


The proposal should not include any personal identifying information (name, username, company, address, phone, email, personal website, resume, etc.) or any information the Solvers may consider as their Intellectual Property they do not want to share.



16 December 2019 - Q&A

Q: According to the Challenge overview, "the steam phase is separated and sent to a turbine for electricity production, the remaining water phase (brine) is sent back in the underground reservoir through reinjection wells." But in an attached image (see file "Extraction process.jpg" at the bottom of the Challenge description) the liquid water derived from the saturated steam (after turbine and electricity production) is reinjected into the underground reservoir (see the right corner on the image, near cooling towers). I.e. there is shown that pure distilled water is reinjected (and not brine). Please clarify, what is actually reinjected, the brine (which contains silica, Lithium etc.), or purified water which contains no dissolved salts? Or, maybe, both of them are reinjected separately?

A: Both of them are reinjected separately


Q: And, if distilled water is actually reinjected (as shown on the mentioned image), why it is not used in other fields (where distilled water is used), or sold on the market?

A: It is not distilled water but geothermal steam condensed and reinjected back in the underground reservoir. Reinjection helps keep the availability of the geothermal resource constant.


Q: In the Challenge overview it is given "general composition of the brines", and there are data for Lithium, SiO2, H3BO3 and Sb. Are there any other salts which present in the brine (e.g. NaCl, Na2SO4, CaCl2 etc.), what is their concentration, and what is total dissolved solids/salts (TDS) content in the brine? And what is pH of the brine?

A: By regulation these data will be available in the second phase of the challenge, after an NDA signature if the solution proposed will be evaluated in a positive way


Q: Is the extraction process attached the regularly followed method ?

A: No methods for lithium extraction are actually used. The process explains where we have brine availability for lithium extraction according to the geothermal power plant scheme.


Q: Is the proposal for a novel "Extraction unit" as mentioned in the schematic the requirement of this challenge?

A: Yes


Q: Is the Seeker looking for a novel method to extract elemental Lithium or Lithium in any compound form (oxide or carbonates)?

A: Open to different processes: in case another compound form will be proposed, information on usage methods is welcome

Challenge rules


The employees of Enel Green Power who are involved in the organization and management of the Competition or admitted to the Open Innovability Portal back office, as well as their spouses or partners and their relatives up to the fourth degree, are not eligible for participation in this Challenge.

Also, employees of the companies of the Enel Group who have worked in the technical sector of the Geothermal innovation field and that work, in the moment of the competition, on the lithium extraction activities, or their spouses, partners or any of their relatives up to the fourth grade determined according to Italian law are not eligible for the participation to this Challenge.

Without prejudice to the article 5.6 of the Terms of Use, the obligation to grant the IP rights set in this article does not apply if the winning solution is proposed by an employee of an Enel company, unless the employee is the owner of the solution according to the relevant national law.


Challenge, award, IP rights

This is a Reduction-to-Practice (RTP) Challenge that requires written documentation and experimental proof-of-concept data. The Challenge award is $30,000 for meeting phase 2 Technical Requirements and it will be contingent upon RTP evaluation of the submission by the Seeker.

To receive an award, the Solvers will not have to transfer the exclusive IP rights to the Seeker. Instead, Solver will grant to the Seeker a non-exclusive license to practice their solutions.

The final award for this Challenge is contingent upon satisfactory completion of the verification process, including acceptance of the Challenge-Specific Agreement (CSA) that is the regulation for this Challenge (attached below). The verification process includes obtaining the following from the Solver: signed affidavit (based on the CSA), employee waiver (if applicable), and proof of identify.

Attach documents if needed (max 5 files, 25MB total size).



Submissions to this Challenge must be received by 11:59 PM (Central European Time) on December 31, 2019. 

Late submissions will not be considered.

Specific regulation in the CSA attached at the bottom of this page.

What happens next?

After the phase 1 Challenge deadline, the Seeker will complete the review process and make a decision with regards to the top solutions. 

Solvers who submitted these solutions will be contacted and invited to participate in phase 2 of the Challenge after signing and returning a Non-Disclosure Agreement (NDA) as well as providing proof of identity. Detailed information about the requirements of phase 2 will be provided once the requested documentation is received. All Solvers that submit a proposal will be notified on the status of their submissions.

Enel will evaluate the proposal using the following criteria:

  • Overall scientific and technical feasibility of the proposed solution;
  • Economic potential of concept (e.g. Total Cost of Ownership);
  • Business potential for Enel;
  • Novelty and creativity;
  • Potential for proprietary position (i.e., is the technology novel or protectable);
  • User’s capabilities and related experience;
  • Realism of the proposed solution;
  • Maturity level of the proposal.

In case the reward includes “Collaboration with Enel”, once suitable solution/s have been identified, Enel will reserve the opportunity to start a collaboration, by way of example, all or part of the following activities:

  • Test execution;
  • Supply of prototypes (if an equipment);
  • Installation and site tests;
  • Follow up and monitoring of the proposed idea behavior.


Upon completion of the evaluation, you will receive feedback.

In case of success, an Enel contact person will get in touch with you to discuss the next steps.



InnoCentive collaborates with Enel to manage this challenge.

InnoCentive is the global innovation marketplace where creative minds solve some of the world's most important problems for cash awards up to $1 million. Commercial, governmental and humanitarian organizations engage with InnoCentive to solve problems that can impact humankind in areas ranging from the environment to medical advancements.


CSA RTP (Non-Exclusive License) - Brinemine

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Extraction process

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About the seeker Enel Green Power

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