Phase 1 (2020)
Inaugural £1bn allocation as part of the Covid-19 stimulus response. Established the Salix-portal application route [Salix].
Phase 2 (2021)
Follow-on £75m phase. Continued the Phase 1 mechanics with refined evidence requirements.
Phase 3a (2022/23)
First sub-phase of the £1.425bn Phase 3 envelope. First-come-first-served queue model [DESNZ].
Phase 3b (2023)
Sub-phase 3b followed 3a with tighter evidence and longer open window.
Phase 3c (opened October 2023)
The £230m sub-phase opened on 10 October 2023 on a first-come-first-served basis and was heavily oversubscribed [Salix]. Demand on this scale fed the move to a targeted-allocation model for Phase 4.
Phase 4 (closed November 2024)
£510/tCO2e maximum Grant Carbon Cost, minimum 12% applicant contribution, and targeted allocation ranking applications by Grant Carbon Cost [DESNZ]. Delivery to 31 March 2028 [DESNZ].
No further funding (from June 2025)
At the June 2025 Spending Review the government confirmed no further PSDS investment beyond currently-awarded projects [Salix]. Phase 4 is the last phase; no Phase 5 has been announced. See Will there be a Phase 5?
Cumulative
More than £3.5bn was issued across nearly 1,400 PSDS grants up to the end of 2027/28, with over £1bn of PSDS budget still to be invested in awarded projects between now and 2028 [Salix]. Funded-project lists are published per phase on gov.uk [DESNZ].