Every renewable source has a scheduling problem. Solar clocks off at sunset, wind does whatever the weather feels like doing that afternoon, and grid operators spend real money papering over the gaps.<\/p>\n
Tides do not have that problem. The whole pattern repeats on a 17.6-year cycle, and the tables are printed years in advance.<\/p>\n
Britain has been staring at that fact for a century. The first proposal to dam the River Mersey for electricity dates to 1924, and the Liverpool City Region Combined Authority has spent the last decade turning the idea into a 700-megawatt barrage it says would be the largest tidal power scheme in the world.<\/p>\n
The design is drawn. The flythrough video is out. What has not happened is anything that would let a contractor pick up a shovel.<\/p>\n
Two dates on official registers have now quietly gone past. One was the decision on where in the estuary the barrage actually sits. The other was the date the Planning Inspectorate<\/a> still lists for the application landing on its desk, which was last month. And in the three weeks since, most of the government Liverpool has been negotiating with has been replaced.<\/p>\n Tidal range works on height, not current. You close a structure across an estuary, let the difference between high and low water build up on one side, then let it through turbines.<\/p>\n The Mersey gives you a lot to work with. The tidal range at Liverpool reaches 33 feet (10 metres), which is among the largest in Britain and second only to the Severn’s 46 feet.<\/p>\n The current design puts 28 turbines rated at 25 megawatts each into a barrage between Liverpool and the Wirral. That is 700 megawatts of nameplate capacity. The consenting envelope filed with the Planning Inspectorate is wider, describing a power generation system of up to 1 GW, which is why you still see the gigawatt figure floating around in older coverage.<\/p>\n Alongside the turbines sit sluice gates to dump water fast when the estuary needs it, and marine navigation locks, because the Port of Liverpool is still a working port and cannot be walled off. The barrage would also carry the first walking and cycling route across the river.<\/p>\n It runs one-way or two-way, using the incoming flood tide, the outgoing ebb, or both, which allows up to four generating windows in 24 hours. There is a pumping mode to top up the upstream basin when the head difference gets thin.<\/p>\n Construction is estimated at seven to 10 years, built either inside a temporary cofferdam or from concrete caissons floated out and sunk into position. Design life is 120 years.<\/p>\n Two tidal range barrages of any real scale exist. France opened La Rance in Brittany in 1966 with 24 turbines and 240 megawatts, and it held the world record for 45 years. South Korea took the title in 2011 with Sihwa Lake, which threaded 10 turbines into a seawall built in 1994 for flood control and irrigation.<\/p>\n Sihwa is 254 megawatts and generates on the incoming tide only, sluicing the outflow away. The Mersey scheme would be close to three times its capacity, which is the entire reason nobody has done this yet.<\/p>\n Liverpool has been borrowing homework from the people who did. The Combined Authority extended its memorandum of agreement with K-Water, the Korean state utility that runs Sihwa, for another two years last November. K-Water is planning its own follow-up barrage at Saemangeum.<\/p>\n Everywhere else in the sector, the pattern is smaller machines going in faster. Wales has consented 240 MW of tidal stream turbines off Anglesey<\/a>, and Scotland’s MeyGen has had machines sitting on the seabed for seven years without a repair<\/a>. Those are turbines you can lift out with a boat. A barrage is a civil engineering project the size of a motorway bridge, and it either exists or it does not.<\/p>\n Here is the part that has not been reported anywhere. The project team has been running something called the Barrage Scheme Options Appraisal, which scores potential locations and configurations inside the estuary. The output of that work was supposed to be a recommendation to the Combined Authority on the development area to carry into the planning application.<\/p>\n That item was scheduled for the Combined Authority meeting on 12 June 2026. On the authority’s own decision register<\/a>, it is still logged as awaiting determination. Other items from the same forward plan, including ones dated 17 July, are already marked as approved.<\/p>\n So the scheme that has renders, a flythrough, a public consultation and a ten-year political campaign behind it does not yet have a confirmed line on the map. Four candidate grid connection points are still live too, at Birkenhead, Capenhurst, Lister Drive and Breck Road substations.<\/p>\n None of that is unusual for a Nationally Significant Infrastructure Project. It does mean that when Liverpool calls this thing shovel-ready, it is describing 2028 at the earliest.<\/p>\n The blocker is not planning and never has been. It is the money to write the full business case, which is the document that would let a Treasury sign off on the thing.<\/p>\n The Combined Authority’s report to its 23 January meeting<\/a> put it plainly: after a year of talks with the energy department and other ministries, no development funding had been secured. The target for a final investment decision moved from 2028 to 2030 in that same paper. New Civil Engineer has put the construction cost at around \u00a33.5bn and the job count at 3,300.<\/p>\n The policy scaffolding is mostly there. Tidal range is named in the national energy policy statement, and the energy department published formal criteria for a well-developed tidal range proposal<\/a> back in December 2023, complete with an inbox to send it to.<\/p>\n What is missing is a revenue mechanism. The national grid operator published its first whole-system study of tidal range in over a decade<\/a> last October, and found it could shave roughly \u00a3120m a year off wholesale energy prices between 2037 and 2060, while concluding that more work was needed on how to finance it. The British Hydropower Association called the modelling flawed and asked for it to be rescoped.<\/p>\n France knows this feeling. A six-turbine tidal farm in Normandy has every permit signed, \u20ac95m committed and a shipyard waiting, and it still cannot start because one enabling document has not been published<\/a>.<\/p>\n On 20 July, Andy Burnham became prime minister. Two days later, Miatta Fahnbulleh replaced Ed Miliband as Secretary of State for Energy Security and Net Zero<\/a>, with Miliband moving to the Foreign Office.<\/p>\n That matters here for a specific, unglamorous reason. The energy secretary is the person who ultimately decides a Development Consent Order for a project this size, and the energy department is one of the departments Liverpool has spent a year asking for development funding.<\/p>\n The politics are hard to miss. Burnham spent nine years as mayor of Greater Manchester arguing that Westminster should hand money and powers to metro mayors, and Steve Rotheram has run the Liverpool City Region on the same argument since 2017. On 21 July, Rotheram and the other northern mayors sent the new prime minister an open letter asking for a devolution-first approach<\/a>.<\/p>\n No government has said anything specific about the Mersey barrage since the reshuffle. What has changed is who picks up the phone.<\/p>\n Public opinion locally is not the problem. Liverpool’s first consultation drew 3,039 responses, and 84% backed the project<\/a>, with 1,238 people turning up to ten drop-in events.<\/p>\n The birds are a different conversation. The Mersey Estuary is a Special Protection Area, a Ramsar wetland and a Site of Special Scientific Interest, and the RSPB says it supports more than 100,000 non-breeding waterbirds. The charity has published a casework page opposing the scheme<\/a>, describing itself as deeply sceptical that a barrage can be built without serious damage. Cheshire and Lancashire Wildlife Trusts have made similar arguments.<\/p>\n Liverpool’s counter-argument is flooding. Updated Environment Agency maps published in 2025 showed significant numbers of properties and critical infrastructure in the middle and upper estuary already exposed to storm surges. Factor in sea level rise of 0.8 to 1.2 metres over the next century, leave the existing defences alone, and the authority’s modelling says the number of properties at risk trebles.<\/p>\n A barrage can hold the incoming tide down inside the basin. That is why flood protection was written into the project’s core objectives in January rather than sold as a side benefit.<\/p>\n Everything about this project is long. The pre-application stage alone runs two to three years, examination and determination another two, construction seven to 10. Liverpool’s own paperwork calls it a solution for 2150.<\/p>\n Against that, a planning date slipping from 2026 to 2028 barely registers. What does register is that the specific piece of hardware holding up 700 megawatts and 120 years of predictable generation is not a turbine, a caisson or a bird survey. It is a funding decision, and it has been the same funding decision since 2019.<\/p>\n Liverpool now has a prime minister born in the city, an energy secretary three weeks into the job, and a barrage that still has not been told where to stand. The Planning Inspectorate page, for what it is worth, has not been updated either.<\/p>\n","protected":false},"excerpt":{"rendered":" Every renewable source has a scheduling problem. Solar clocks off at sunset, wind does whatever the weather feels like doing … <\/p>\nThe machine is 28 turbines and a wall across a shipping lane<\/h2>\n
Nothing this size has ever actually been built<\/h2>\n
The barrage still does not have an address<\/h2>\n
What Liverpool actually needs from London is a development cheque<\/h2>\n
Whitehall changed hands three weeks ago<\/h2>\n
The estuary gets a vote too<\/h2>\n
A century of output stuck behind a signature<\/h2>\n