Why creating system integration in the North Sea?
Renewable energy capacity in the North Sea is going to grow strongly, whereas domestic fossil fuel production will be declining in the decades ahead. These macro trends are linked to large investments. A reservation of 7 billion is already made in the Netherlands to cover for the decommissioning costs of wells and infrastructure; more than half of this is for the offshore. At the same time, the development of an offshore electricity transport infrastructure to connect new wind parks and other sources to the Dutch shore will also require billions of investment coming from industry and society. An electricity grid capable of transporting 3.5 GW of wind energy is expected to cost 4 billion. Long-term plans in the Netherlands consider a massive deployment of offshore wind in excess of 100 GW and potentially the creation of an offshore supergrid with large scale interconnectors between countries. In total, investments amounting to several hundred billion will be probably necessary. Existing infrastructure, however, can reduce these costs by finding new roles to its physical and logistical assets. Coupling the sectors of offshore wind and offshore hydrocarbon production offers great opportunities. For example, excess offshore wind energy available at times of little demand could potentially be stored and transported to shore through the existing gas pipelines, whose energy transport capacity is much larger than that of electrical cables. A joint vision for the North Sea is necessary for strategic spatial planning, safety, environment, logistics, and asset maintenance.
Most useful system integration options
We have found a number of interesting system integrations options in the North Sea, considering both technical as well as economic aspects.
Existing offshore assets power themselves by burning hydrocarbons in their turbines and engines, thereby creating CO2 and other pollutants. These engines can be replaced by electrical drivers powered by sustainable power generated in neighbouring wind parks. Therefore, the asset can reduce its emissions virtually to zero; the overall system efficiency also increases. The current estimates tell us that, every year, 1 million tons of emitted CO2 can be avoided if the current offshore gas and offshore wind infrastructures are coupled and power can be exchanged. These estimates are based on the most energy demanding platforms currently operating in the North Sea, when all of their heating and power demands can be switched to power. More detailed studies are ongoing within the program to improve these estimates.
Power to Gas
Renewable power can be converted to energy carriers in which the energy is stored or transported via the gas infrastructure. The greatest advantage of this concept is that large volumes of energy can be transported over long distances with the gas infrastructure. Additionally, the challenge of accommodating large peaks in supply to our electrical grid coming from sustainable sources can be eased. Storage of these energy carriers is also possible for later use, as well as their use in the chemical industry as feedstocks.
A recent example of this option is hydrogen production at platforms from offshore wind parks: the revamp of the infrastructure for this purpose is technically possible, and can be economic in some circumstances.
Gas to wire
This concept considers the direct generation of electricity from almost depleted and stranded gas fields. In combination with CO2 capture and storage (CCS), this electricity would be produced from gas with little to no CO2 footprint. Eventually, the power is sent to shore through the available capacity of the offshore electrical grid.