DALL·E generated image of shiny new transmission lines tower over rusted pipeline, digital art

HVDC Is The New Pipeline

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For decades, the world has been moving massive amounts of energy around using steel tubes running along the ground, under the ground and under water. The US alone has about 5 million kilometers of pipelines, which have about four years worth of total steel consumption for the country embodied in them.

Now, of course, the owners and operators of those pipelines want to have them become something other than stranded assets that will be yanked out of the ground and scrapped for steel for economy-of-the-future purposes such as wind turbine masts. They make all sorts of claims related to this that don’t stand up to much scrutiny. If reused to move hydrogen, they’ll have to move a lot less energy to remain safe, and of course they come from fields of natural gas, not fields of solar panels and wind turbines next to a good water source, so where exactly is this hydrogen coming from?

Once again, it’s a paradigm and lobbying problem. The easiest way to move energy long distances is in the form of electrons over high-voltage direct-current (HVDC) transmission lines. And it’s not like we don’t know how to build HVDC transmission.

Locations of current, planned and in construction HVDC projects globally from Open Street Maps
Locations of origination points of current, planned and in construction HVDC projects globally from Open Street Maps

The technology was invented in Europe, so it’s unsurprising that there’s a great deal of it there. And it’s equally unsurprising that China has the lion’s share of longer, higher-powered HVDC lines. But as the map shows, it’s present on every continent and projects are being announced regularly.

At that, it’s an incomplete data set this visualization is created from, as it’s difficult to keep up with projects. As I noted recently when asked if there was as good a visual map of the projected HVDC projects as there is for CCS and hydrogen efforts, there isn’t, because unlike hydrogen in pipelines, there isn’t a massive global lobbying, PR, think tank, and industry effort promoting it out of deep fear of becoming extinct.

A few notable projects are worth calling out, especially as they are in places that were considered energy islands that would have to go it alone. Israel, for example, is modeled as an energy island and separate grid in the Stanford 100% renewables by 2050 work that Mark Z. Jacobson leads. But construction is under way for an HVDC interconnector from Greece through Cyprus to Israel. It has a 1,208-kilometer run, mostly under water, a two-way capacity of 2 GW, and is expected to be up and running in 2027.

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What’s an interconnector vs a transmission line? Well, it goes both ways. If there’s a surplus at one end and a deficit at the other, electrons flow that way. If the surplus and deficit reverse, then the flow reverses.

Iceland is another outlier, being 850 km from the tip of Scotland and 1,000 km from Norway across the stormy Northern Atlantic. It’s already doing very well with its geothermal resources, but there’s been an interconnector in the works for a few years to enable it to share in the European energy grid. The Icelink would be over 1,000 km and in the range of a GW of capacity.

The UK, of course, has work underway already to bring Moroccan wind and solar, firmed by storage, 3,800 km north through coastal waters to the country. The Xlinks project will bring 3.6 GW of firmed electricity to the UK 20 hours a day, meaning it will deliver about as many GWh to the UK’s grid each day as the Hinkley Site C nuclear power plant, but at a much lower cost. That effort will become the longest underwater HVDC transmission link, as it hugs the coastline to avoid deep water risks and costs, and in fact required so much HVDC cable that by itself it would have represented 3-4 years of output of European manufacturers. So they built their own HVDC cable manufacturing facility as part of the initiative and are taking orders now for 2025 delivery of their cross-linked polyethylene coated aluminum HVDC cables.

For the political and/or real islands of Asia such as South Korea, Singapore, Indonesia, and the Philippines, there are actually competing proposals for HVDC interconnectors between China’s HVDC Asian Super Grid efforts which are underway and the Association of Southeast Asian Nations (ASEAN) power grid, which is also shaping up.

A proposal for an HVDC cable from Australia to Singapore, Sun Cable, has been hijacked by hydrogen hype, but the likelihood is that a variant of it will return, possibly connecting into the ASEAN and China grids through the relatively close by Indonesia and Philippines.

Japan’s current HVDC connectors between and within its islands block out the country entirely in this visualization. China’s Asian supergrid proposals include interconnectors with Japan. As it’s only 180 km from South Korea, 765 km to mainland China, and 1,700 km from the Philippines, these links are comparatively easy to put in place. However, despite the prevalence of HVDC in Japan, it’s foolishly focused on importing hydrogen and derivatives from Australia and similar sun-drenched locales to power its economy. This too shall pass, but Japan being Japan, will likely take a decade or more longer before energy sanity prevails.

A few other proposed and under construction links are worth mentioning in this context. Canada’s Quebec has massive amounts of hydroelectricity and the largest wind farm in Canada (something most Canadians don’t know) and has been supplying New England and New York with clean electricity through high-voltage alternating current (HVAC) lines since about 1980. There are two HVDC lines, one to New England and one to New York state, under way. The 545 km, 1.25 GW line to New York is under construction today and expected to be turned on in 2025. The New England one ran into NIMBYs and was in court this week to get it going again, with the jury agreeing unanimously that objections were specious and that it could go forward.

Europe’s energy crisis has led to a large uptick in projects beyond the ones mentioned so far. I was on a call yesterday with Simon Ludlam, currently CEO of the MaresConnect Interconnector, the third UK-Europe HVDC interconnector project he has underway. It’s hard to keep track of how many HVDC lines the UK has in operation between North Seas wind farms, connecting its islands, and connecting it to Europe.

In the other direction, a 1,200 km subsea cable has been greenlit to bring renewable energy from far east in the Caucasus, linking Georgia to Romania. To the south, in addition to the Israel link, a link from Tunisia in the Maghreb to Sicily has been greenlit. I’m engaged in a small way with the early days of a proposal to link Canada and Europe with a trans-Atlanic, 6 GW set of 3-4 cables, something which sounds absurd until you realize that the first sub-sea trans-Atlantic cable for telegraph signals was connected 165 years ago along much the same route from Newfoundland to Ireland.

And in the other, other direction, China has proposed a polar HVDC super grid to connect all northern hemisphere continents, something entirely technically feasible, if not politically. It would be cheap at about $2 trillion, given the benefits. Pity about the politics for the next 20 years, but politics typically pass.

Aren’t these projects, especially the sub-sea ones, deeply risky megaprojects?

Flyvbjerg cost overruns table
Flyvbjerg cost overruns table

Well, no. Professor Bent Flyvbjerg’s data set of over 16,000 megaprojects includes transmission. While running underwater is higher risk than running over land, it’s still lower risk than most other categories in terms of cost and schedule overruns. Among other things, no one runs anything along sea beds without vast amounts of planning.

Links in all directions to different wind, water, and solar regimes enables vastly broader sharing of low-carbon electricity and results in lower storage requirements in most places. HVDC is the technology for those links. Tubes of steel carrying molecules need not apply.

UPDATE: We reached out to Xlinks about the Morocco – UK Power Project with the following question:

Q: What are the key barriers still remaining for the Morocco-UK HVDC transmission link, and is it an interconnector or a one-way flow?

A: The connection from the generation site in Morocco to transmission in the UK is a one-way, exclusive flow of power to the UK. Like any large development project, we have many stages to complete before it is finished, however we are confident on achieving our targets and delivering 8% of the annual UK energy requirements through renewable energy sources from Morocco.

UPDATE: We reached out to Hitachi Energy with the following question:

Q: How many HVDC construction projects is Hitachi Energy currently supporting and delivering around the world?

A: Hitachi Energy is current executing more than 20 HVDC projects worldwide, including several recently announced major developments in the United States.

In the north, we have projects that will bring enormous quantities of hydropower from Canada to New York. The Champlain Hudson Power Express, connecting Quebec to New York City, is expected to decrease CO2 emissions by an average of 3.9 million metric tons per year, equivalent to removing 44% of passenger vehicles from New York City. Whilst the Châteauguay HVDC system will enable the transmission of up to 1,500 megawatts (MW) of power across the border.

Plus, in the west, our technology will be sending huge amounts of renewable electricity towards the coast. With the SunZia link transmitting power from the new windfarm in New Mexico, which will generate enough electricity for 3 million Americans, and the Intermountain Power Project is great example of the energy transition, where our customer will retire an existing coal-fueled generation plant in Utah and introduce new generating units capable of using CO2-free green hydrogen.

Of course, many of our projects are underway on the other side of the Atlantic, not least of which is the €13 billion (around $14 billion) agreement to connect 12,000 MW across six offshore wind projects in Europe as part of TenneT’s 2GW Program.

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Michael Barnard

is a climate futurist, strategist and author. He spends his time projecting scenarios for decarbonization 40-80 years into the future. He assists multi-billion dollar investment funds and firms, executives, Boards and startups to pick wisely today. He is founder and Chief Strategist of TFIE Strategy Inc and a member of the Advisory Board of electric aviation startup FLIMAX. He hosts the Redefining Energy - Tech podcast (https://shorturl.at/tuEF5) , a part of the award-winning Redefining Energy team.

Michael Barnard has 722 posts and counting. See all posts by Michael Barnard