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

22 January 2026

Prospex Energy plc

("Prospex" or the "Company")

Tarba - Rental Transformer Enables El Romeral Production Re-start

Prospex Energy plc (AIM: PXEN), the AIM quoted investment company focused on European gas and power projects, is pleased to announce that Tarba Energía S.L. ("Tarba") has signed a contract for the rental of a transformer at the El Romeral gas to power plant in Andalucía, Spain, enabling the plant to resume electricity generation and sales.

The transformer is to be delivered on site and installed before the end of January 2026.  The rental transformer will be on contract until the delivery of the new electricity transformer which was ordered from a supplier in Spain last November.  Tarba is in dialogue with that supplier on the progress of the new build.

Mark Routh, Prospex's CEO, commented:

"The Company is pleased to have sourced a rental transformer for the El Romeral plant.  The transformer, which has an almost unique voltage and power specification is expected to be installed this week allowing Tarba to resume the production of electricity before the end of January.

"We remain confident in the value and development potential of the El Romeral asset and are pleased that the permitting to drill five new natural gas wells is in its final stages.

"The El Romeral power plant can reach full capacity from production from just two of the proposed five new 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.

"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 have started the process of optimising the funding of the wells by seeking potential debt funding and farm-in partners."

Rental Transformer Contract

Tarba has been unable to procure a rental transformer which fits the almost unique voltage and power specifications required to meet the export requirements to deliver electricity from Tarba's gas engine generators to the high voltage grid connection.  Therefore, as reported in the RNS of 17 November 2025, in mid-November 2025 Tarba ordered a brand-new transformer, which is estimated to be delivered by Q3 2026.  This new rental transformer has been procured from the same contractor that rented a transformer to Tarba in February 2025.  As previously reported, that company asked to replace the original transformer with a smaller unit at a reduced rental cost on 1 July 2025, but owing to unforeseen events the replacement transformer was not delivered as agreed, resulting in the cessation of production and gas generation at Tarba's El Romeral plant since that date.  A claim for compensation for lost production was agreed but that claim was subsequently referred to the rental company's lawyers and payment did not occur.  In order to sign an agreement for the immediate supply of the new rental transformer, Tarba has had to waive its €76,000 claim for compensation.  This however will allow the resumption of production and sales at El Romeral as soon as possible.  Tarba took the decision that the legal costs and time required to pursue the claim in the Spanish legal system would outweigh the value of the claim and further delay resumption of production. 

Tarba sells its generated electricity on the spot market and prices can vary hugely each day and within day on account of solar power and wind turbine power dominating the markets.  Recent within day electricity prices have been recorded between €0/MWh at midday and more than €200/MWh in the nighttime hours.  It is Tarba's intention to generate electricity from the remaining gas reserves in El Romeral during the overnight hours when prices exceed €100/MWh.

5-Well drilling Permitting Process

As advised in the RNS of 17 November 2025, the full suite of Environmental Impact Assessment ("EIA") documentation for the application by 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.  That documentation was forwarded internally to the to MITECO's Environmental Department 5 December 2025.  MITECO's timeline for this final step of the approvals process is 90-180 days.

The El Romeral concessions, now 100% owned by the Company through Tarba, has an identified resource base of more than 90 bcf^[1] of gas.  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.

Seismicity Study

In December 2025, Tarba completed 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 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 MITECO 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.

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.

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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.