| Planned | Joint developerArven Offshore Wind | Development | Continuing 1.8 GW Arven offshore wind development |
| Planned | LiDAR wind measurement campaign sponsorBen Tre - Mainstream - AIT | Project Development | Ben Tre offshore wind measurement campaign |
| Consented | Owner and developerDonghae - KFWIND-A | Owner Operator | Korea Floating Wind projects off Ulsan |
| Consented | Owner and developerDonghae - KFWIND-B | Owner Operator | Korea Floating Wind projects off Ulsan |
| Consented | Owner and developerDonghae - KFWIND-EBP | Owner Operator | Korea Floating Wind projects off Ulsan including East Blue Power |
| Planned | SMart Wind joint venture partnerHornsea Project Four | Historical Development Context | Hornsea Zone original development consortium |
| Planned | SMart Wind joint venture development partnerHornsea Project One | Development | Hornsea Zone and Hornsea One development rights |
| Planned | SMart Wind joint venture partnerHornsea Project Three | Historical Development Context | Hornsea Zone original development consortium |
| Dormant | Development partner recorded in the 2023 portfolioKultje | Historical Development Context | Kultje prospect in Hexicon’s 2023 annual report |
| Planned | Former joint-venture ownerMareld | Ownership History | Mareld floating offshore wind project |
| Planned | Original developerNeart na Gaoithe | Development | 450 MW Neart na Gaoithe development rights |
| Consented | 70 percent owner and co-developer under earlier joint venturePhu-Cuong | Development | 1.4 GW Phu Cuong Soc Trang offshore wind farm |
| Consented | Investment decision and IRC milestone holderPhu-Cuong | Consenting Environmental | First 200 MW of Phu Cuong Soc Trang offshore wind farm |
| Planned | Joint development transaction participantProgression Energy Floating Project | Project Development | Progression Energy Floating Project |
| Planned | Owner Developer · 50%Arven Offshore Wind | Ownership | Arven is developed through a 50:50 joint venture between Mainstream Renewable Power and Ocean Winds. |
| Cancelled | Indirect Parent · 50%Arven South | Ownership | Mainstream Renewable Power participated in the Arven South partnership through UK Mainstream Renewable Power Limited. The project company’s accounts disclose that Mainstream’s participation in governance was limited from 31 July 2025. |
| Planned | Owner Developer · 70%Ben Tre - Mainstream - AIT | Ownership | Ownership relationship |
| Consented | Owner · 33.3%Donghae - KFWIND-A | Ownership | Ownership relationship |
| Consented | Owner · 33.3%Donghae - KFWIND-B | Ownership | Ownership relationship |
| Consented | Owner · 30%Donghae - KFWIND-EBP | Ownership | Ownership relationship |
| Cancelled | Owner Developer · 35%Gippsland Skies | Ownership | The former Gippsland Skies development consortium comprised Mainstream Renewable Power and Reventus Power with 35% each, AGL Energy with 20% and DIRECT Infrastructure with 10%. Feasibility licence FL-003 was surrendered on 5 January 2026. |
| Planned | Owner · 70%Phu-Cuong | Ownership | Ownership relationship |
| In Operation | Developer | Onshore grid assets | Donghae - KFWIND-A · Final Grid Connection Point |
| In Operation | DeveloperIlikwa PV Facility | Solar | Ilikwa PV Facility |
| In Operation | OwnerIlikwa PV Facility | Solar | Ilikwa PV Facility |