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Mast Energy Developments PLC

(Incorporated in England and Wales)

(Registration Number: 12886458)

LEI :213800HFVHGJ9YGO9F71

Share code on the LSE: MAST

ISIN: GB00BNG90H86

('MED' or 'the Company')

Dated: 9 September 2025

Mast Energy Developments PLC

("MED" or the "Company")

Holiday Parks Power Supply Exclusive Joint Venture

& Exercise of Warrants

Mast Energy Developments PLC is pleased to announce that it has signed a comprehensive head of terms for an exclusive joint venture to develop, construct, and operate power supply solutions for holiday parks, the highlights and details of which are outlined below.

Joint Venture Key Details:

· The UK has around 4,700 holiday parks, most of which require power and heat supply security outside of the national grid in order to provide uninterrupted services to its customers throughout the year;

· The MED management team have identified this gap in the market and formulated a new additional growth strategy to benefit from this opportunity, which will complement its existing strategies, being i) acquiring existing sites needing limited overhaul, ii) new-builds, and iii) AI datacentre power supply;

· MED will partner with holiday park developers and owners to provide the holiday park with power and heat supply security, by way of a private wire PPA;

· The benefit to the holiday park is power and heat supply security, at a lower tariff compared to the retail market, and the benefit to MED is two income streams (power and heat) via a long-term PPA at a fixed tariff and attractive margin;

· In addition to the PPA revenues, the power supply site can also partake in the Capacity Market for additional guaranteed income;

· To bolster this new strategy, MED signed an exclusive joint venture ("JV") head of terms with Avanti-E Ltd ("Avanti"), a UK company with strong connections and a proven track-record in the UK energy industry (see below for more details about Avanti);

· Under the JV, MED and Avanti will exclusively work together to develop, construct, and operate power supply solutions and applications for holiday parks;

· The JV will establish MED as an early mover and power supplier in the holiday park industry, to gain maximum benefit;

· The short-term goal is to develop c. 25 MW of holiday park power supply projects, and scale to 100 MW in medium term;

· MED and Avanti are already in discussions with one of the UK's largest holiday park developers and owners to supply power and heat to its holiday parks, with a first holiday park needing c. 5 MW already identified;

· This new strategy will complement and is expected to significantly grow MED's existing portfolio and the Company's goal to build a portfolio of 300+ MW; and

· MED and Avanti intend to enter in a binding definitive JV agreement shortly.

Pieter Krügel, MED CEO, commented : "MED have identified the need of holiday parks for power and heat supply security as an ideal opportunity to expand MED's business model and complement our existing strategies to build a portfolio of 300+ MW. We are thrilled to join forces with Avanti-E in rolling out our new strategy, as they are an ideal JV partner with their strong connections and a proven track-record in the energy industry in the UK.

We are planning to progress this new strategy at some pace, and look forward to updating the market with further positive developments over the coming weeks."

About Avanti-E:

Avanti-E was co-founded by Sean Foley, having spent 30+ years in the UK energy. Avanti-E are experts in the development of power projects in the UK. For more details, visit Avanti-E's website here - https://avanti-e.co.uk .

Stay up to date with MED's latest news and updates by joining our emailing list and social media channels, as follows:

MED general enquiries - https://www.med.energy/contact

MED email alerts - https://www.med.energy/rnsannoucements-1

MED LinkedIn page - https://uk.linkedin.com/company/mast-energy-developments-plc

MED X (formerly Twitter) handle - @mastplc

Exercise of warrants

Capitalised terms used in this part of this announcement have the same meaning as those given to them in the 23 May 2025 announcement unless otherwise defined.

MED has received notice of exercise of Prepaid Warrants, issued pursuant to the Equity Fun d raise announced on 11 July 2025, for a total of 4,957,000 ordinary shares in the Company . MED has also received notice of the exe r cise and the associated cash proceeds of Cash Wa r rants, issued pursuant to the Equity Fundraise announced on 11 July 2025 , for a total of 1,875,000 ordinary shares in the Company of 4 pence per ordinary share.

Application will be made for the admission of the 6,832,000 new ordinary shares to trading on the LSE ("Admi s sion") pursuant to the authorities approved by shareholders at the General Meeting on 8 July 2025. The shares will rank pari passu with the existing ordinary shares and it is expected that Admission will become effective at 8.00 a.m. on 1 1 September 2025.

Following Admission, the Company's issued share capital will consist of 23,735,927 ordinary shares with voting rights. MED does not hold any ordinary shares in treasury. This figure of 23,735,927 may be used by shareholders in the Company as the denominator for the calcul a tions by which they will determine if they require to notify their interest in, or a change to their interest in, the share capital of the Company under the UK Financial Conduct A u thority's Disclosure Guidance and Transparency Rules.

Following Admission, the beneficial holding of Paul Venter, non-executive director and chairman of the Company, will change from 11.59% to 8.25% interest in the issued share capital of the Company. Further, following Admission, the beneficial holding of Riverfort Global Opportunities PCC Ltd will change from 10.09% to 7.18%.

ENDS

This announcement contains inside information for the purposes of the UK version of the Market Abuse Regulation (EU No. 596/2014) as it forms part of United Kingdom domestic law by virtue of the European Union (Withdrawal) Act 2018 ('UK MAR'). Upon the publication of this announcement, this inside information is now considered to be in the public domain.

For further information please visit www.med.energy or contact:

Pieter Krügel

[email protected]

Mast Energy

Developments PLC

CEO

Guy Wheatley, CFA

+44 (0)74 9398 9014

Fortified Securities

Corporate Broker