Prospex Energy plc / Index: AIM / Epic: PXEN / Sector: Oil and Gas

17 November 2025

Prospex Energy plc

("Prospex" or the "Company")

Completion of the Statutory EIA Consultation Process

to drill five further wells on El Romeral Production Concessions

Prospex Energy plc (AIM: PXEN), the AIM quoted investment company focused on European gas and power projects, is pleased to announce that that the full suite of Environmental Impact Assessment ("EIA") documentation for the application by Tarba Energía S.L. ("Tarba") to drill five new natural gas wells on the El Romeral concessions was submitted to The Ministry for the Ecological Transition and the Demographic Challenge in Madrid ("MITECO") on Friday 14 November 2025.  The consultation process that Tarba was required to go through before submission has concluded with no objections or adverse comments received from a total of 29 statutory consultees, non-governmental organisations, local stakeholders, local regulators, associations or residents and town councils.  Prospex owns 100% of Tarba Energía S.L.

EIA Highlights

·    Full EIA documentation submitted to MITECO in Madrid on Friday 14 November 2025.

·    No objections received from the 29 statutory consultees.

·    MITECO now has the full EIA documentation to assess and evaluate.

·    Subject to final approval, MITECO can then move to recommend a Ministerial resolution to approve the well permits, the final stage of the permitting process.

·    MITECO states that the timeline for this final step of the approvals process is 90-180 days.

·    Identified resource base of more than 90 bcf^[1] of gas, now 100% owned by Prospex, within El Romeral.

·    The five wells being permitted are targeting the lowest risk structures in the concessions with best estimate contingent and prospective gas resources of 18.2 bcf.

Drilling Preparatory Work

Whilst Tarba has been waiting for the regulatory approvals process to complete, Tarba has progressed key drilling preparatory work, including detailed well design, sourcing essential long-lead items and evaluating the necessary contractors and equipment to deliver the five new production wells.

Seismicity Study

Tarba has also started a project to record the background seismicity across the three El Romeral concessions in order to establish the background seismicity of the area.  This step is a recommendation (but not a requirement) from the EIA process so that Tarba can demonstrate to the regulators that any future extraction of natural gas from the concession areas does not cause a seismic event.

Background on the permitting process

The application to drill five new natural gas wells on the production concessions owned by Tarba known as El Romeral 1, 2 & 3 was submitted to MITECO in Madrid in May 2024 together with the full scientific analysis and assessment of any potential effects that the proposed drilling project may have on the environment.  The EIA consultation was publicly gazetted on the State Official Bulletin on 19 February 2025, (see RNS of 20 February 2025).  Officially, the statutory EIA consultation period was 30 working days (to 4 April 2025), however it has taken until now for certain statutory consultees to complete their review and respond.

Having received all of the mandatory reports including from the Geological Survey of Spain (Instituto Geológico y Minero de España, "IGME") in Madrid, the Hydrologic Public Domain Authority (Confederacion Hidrografica Del Guadalquivir) in Seville and the environmental department of the Sub-delegation of the Government in Seville, the Sub-delegation of the Government in Seville has reported back to MITECO its findings and recommendations.  From this point, MITECO targets between 90 to 180 days for the final review and approval, giving time to gather its internal and final EIA evaluation, together with all the mandatory statutory reports from the public administrations and institutions before it can recommend a Ministerial resolution to approve the well permits to drill the five wells.

The local governmental authority alongside the Department of Industry and Energy of the Sub-delegation of the Government in Seville received no objections or concerns on the environmental impact of the project other than confirmation that mandatory legal obligations that are already included in the EIA reports are to be enforced.  The EIA submitted by Tarba comprised a full suite of documentation as required by law covering every aspect of the environmental impact of drilling the five proposed natural gas wells on the El Romeral concessions.

Background on El Romeral

Tarba generates electricity at its El Romeral power plant from its own natural gas production from the concessions, which in July 2024 were granted a ten-year extension by the central Spanish Ministry to July 2034.  The five wells are planned to target the five optimum structures on the El Romeral concessions, which will produce biogenic gas from shallow subsurface horizons.  The depth of the wells average about 700 metres and will each take no longer than 3 to 4 weeks to drill once a suitable drilling rig has been mobilised after the well permits are secured.

Ongoing Activity at El Romeral - Transformer Replacement

Following a competitive tender process, Tarba has awarded the supply of a new electricity transformer with its unique voltage and power specification, to provide future security of operations for Tarba.  Delivery normally has a lead time of 10 months; however, the Spanish vendor is working urgently to accelerate this to deliver to site in 6 months.  Tarba will do regular quality, schedule visits and Factory acceptance tests at the Vendor's site.

As previously reported, the Lessor of the transformer at the El Romeral power plant removed it on 1 July 2025 on the condition that it be replaced within a few weeks and compensation was agreed to be paid to Tarba for the lost revenue.  The Lessor has failed to deliver a replacement rental transformer and payments agreed for the lost revenue have not yet materialised.  Tarba is seeking recovery from the Lessor.

Due to these unforeseen developments, staffing costs at Tarba have been reduced and other cost saving measures have been implemented.

Mark Routh, Prospex's CEO, commented:

"We are delighted to be making good progress in the complex permitting process which has now moved to the final stage.  I also take this opportunity to update shareholders on the El Romeral plant's transformer.  I am pleased to report that we have now placed an order for a new transformer for the El Romeral plant from a Spanish supplier.  The transformer, which has an almost unique voltage and power specification, should be delivered and installed in the first half of next year.  In the meantime, electricity production is suspended but useful work is being undertaken at Tarba in anticipation of the company being back in operation as soon as we are able.

"We remain highly confident in the overall value of the El Romeral asset and its future development potential and are pleased that the permitting process to drill five new natural gas wells has taken a significant step forward.  The process to apply for permission to drill natural gas wells in Spain is lengthy and complex and as we have experienced comes with unexpected delays in recommended timelines.  It is a testament to the professionalism and quality of our team and advisers that the EIA documentation submitted has resulted in no objections or concerns.  The only comments received from the statutory consultees were to confirm that mandatory legal obligations that are already included in the EIA reports are to be enforced.

"The El Romeral power plant will reach full output capacity from production of just two of the proposed five wells.  Any extra gas from the remaining new wells or any future wells drilled on the concessions will support expansion plans at the power plant as well as the ability to supply natural gas directly to the gas grid.  The El Romeral concessions have substantial development potential with more than 90 bcf of gas^[1] now owned 100% by Prospex to be drilled.

"We will continue to keep shareholders updated on the permitting process.  Since we are now in the final stage of receiving the permits to drill these five wells, we can start the process of optimising the funding of the wells by seeking potential debt funding or farm-in partners, or both."

This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("MAR") and is disclosed in accordance with the Company's obligations under Article 17 of MAR.

* * ENDS * *

For further information visit www.prospex.energy or contact the following:

Notes

Prospex Energy PLC is an AIM quoted investment company focussed on high impact onshore and shallow offshore European opportunities with short timelines to production.  The Company's strategy is to acquire undervalued projects with multiple, tangible value trigger points that can be realised within 12 months of acquisition and then applying low-cost re-evaluation techniques to identify and de-risk prospects.  The Company will rapidly scale up gas production in the short term to generate internal revenues that can then be deployed to develop the asset base and increase production further.

El Romeral Gas Reserves and Resources

An independent Competent Person's Report including the gas Reserves and the Contingent and Prospective gas Resources of the El Romeral Licence areas, was prepared by Netherland Sewell & Associates Inc. on 9 October 2019.[1]  In addition to the 2P reserves of 8.5 MMscm (0.3 Bcf) it attributes a total of 142 MMscm (5.0 Bcf) of 2C resources and 2,541 MMscm (89.7 Bcf) Best Estimate Prospective resources to the El Romeral Licence Concessions.

Prospex through its ownership of Tarba now owns 100% of the El Romeral Concessions.

References:

^[1] Source: "Competent Person's Report Netherland Sewell & Associates Inc. 9 October 2019.

NSAI_El-Romeral-CPR-2019

About El Romeral and Tarba

The El Romeral power plant is operated by Tarba, which is based near Carmona east of Seville in the province of Andalucía, Spain.  The El Romeral asset is owned through Tarba by Prospex which owns 100% of Tarba since the acquisition in April 2025 of the shares in Tarba held by Warrego Energy Limited.  Warrego Energy is wholly owned by Hancock Energy (PB) Pty Ltd in Perth Western Australia.

The El Romeral gas and power project in Spain, has gas production wells which supply gas to an 8.1MW power plant near Carmona in Southern Spain.  It can only operate at about 30% of its full capacity because Tarba is waiting on the permits to drill five further infill wells on the concessions to increase production.  Tarba is already categorised as a hybrid energy provider with the successful installation of photovoltaic panels on the roof of the plant in August 2022.  Tarba sells electricity generated from the plant on the spot market in Spain.  The El Romeral licences comprise three contiguous production concessions.

Natural gas continues to play an essential role in Europe's energy security and the ecological transition process.  The production of shallow biogenic gas from the onshore El Romeral concessions will have a carbon footprint which will be a small fraction of the comparative carbon footprint resulting from the importation of natural gas by pipeline, and even smaller when compared to liquefied natural gas imports.

Tarba is pioneering a new hybridisation model that combines natural gas and solar energy as sources for electricity generation in the ecological transition process by developing a project to produce 5MW electricity using photovoltaic solar energy ("Project Helios").

Glossary:

scm                        Standard cubic metres

scm/d                    Standard cubic metres per day

MMscm                Million standard cubic metres

Bcf                         Billion standard cubic feet

MMscfd                million standard cubic feet per day

MWh                     Mega Watt hour

TTF                        The 'Title Transfer Facility' - a virtual trading point for natural gas in the Netherlands.

Qualified Person Signoff

In accordance with the AIM notice for Mining and Oil and Gas Companies, the Company discloses that Mark Routh, the CEO and a director of Prospex Energy plc has reviewed the technical information contained herein.  Mark Routh has an MSc in Petroleum Engineering and has been a member of the Society of Petroleum Engineers since 1985.  He has over 40 years operating experience in the upstream oil and gas industry.  Mark Routh consents to the inclusion of the information in the form and context in which it appears.