The Offshore Green Energy Chain

In this article, I am going to go through one chain of events that the green movement has started in the US. The recent demand for wind power in the northeastern US market has trickled a chain of events that grew other sectors tremendously and grew local economies significantly.

Due to the green energy demand, many US utilities and business developers have been moving away from fossil technology as a source of energy and shifted toward cleaner energy. Recently, the northern eastern part of the US has seen a spike in wind turbines construction of offshore platforms (in the sea). These platforms are being built tens of miles away from the shore, and in some of them, their distance for the shore exceeds one hundred miles.

To bring the generated electricity to land from these wind turbines, we need to connect all of these turbines’ outlet connections to one main electrical connection. Then, we need to connect a High voltage cable from this connection, lay it down on the ocean floor and run it all the way to a substation on land. 

If the distance between the turbines and the land is significant, the energy transferred through a cable will diminish due to voltage losses.

In this case, an HVDC (High Voltage Direct Current) platform would be built in the sea to transfer the electricity to shore.

The HVDC platform purpose is to convert the AC (Alternative Current) from the turbines to DC (Direct Current).

Direct current does not have the same significant losses as it travels through a long cable the same way the alternative current does.

Once the DC voltage arrives to shore, it will be connected to another HVDC onshore platform that will convert the DC back AC. Afterwards the AC current is transmitted to another electrical onshore substation that transmits the electricity to the market.

As a summary, the need for green energy sparked the installation of wind turbines onshore and offshore.   To transfer the energy from the offshore wind turbines, a cable is needed between the turbines and the offshore/onshore platforms. The monetary value of a turnkey project that includes an HVDC project is around one Billion Dollars, and the cable in between is a few hundred of million dollars.

These values are pertinent to one project only. The northern eastern US and European market have in their forecast many of these projects.

The economy created with this technology is a serious energy paradigm shift.     

There is also a new energy that has been making the hype recently which is Hydrogen. The combustion of Hydrogen does not emit pollution as Gas does. Hence there is a push in the industry to shift from Gas to Hydrogen to decarbonize the fossil fuel industry.   Hydrogen is created by electrifying water in the Electrolysers using DC power, the water molecule H2O gets separated into Hydrogen and Oxygen. The Hydrogen is filtered, compressed, and stored for industry utilization.

The HVDC onshore infrastructure provides a great opportunity for the electrolyzers to be built near these platforms to generate clean Hydrogen. It is called clean because the source of the electricity that was used in the electrolyzers is coming from green energy (wind) and not a combustible polluting energy. 

Here is the chain of events: Offshore wind turbine -> submarine AC cable-> HVDC offshore platform-> DC submarine Cable-> Onshore HVDC platform -> AC (Alternative current) to substation and DC (Direct Current) to Electrolyzes. This chain creates more electricity for the grid and Hydrogen for combustion or industrial processes. 

The monetary value of one project of this sort can be easily around two Billion dollars.