This research will calculate the extended LCOE of internal hydrogen production and stor- age in offshore wind turbines at remote locations and will be done in collaboration with Van Oord. Van Oord is a global offshore marine contractor which is focused on dredging, land infra-str
...
This research will calculate the extended LCOE of internal hydrogen production and stor- age in offshore wind turbines at remote locations and will be done in collaboration with Van Oord. Van Oord is a global offshore marine contractor which is focused on dredging, land infra-structure, offshore wind and oil gas infrastructure.
To test the competitiveness of this technology a test location is selected; Grenada in the Caribbean. Grenada is selected because of its suitable conditions: the island is remote, which makes energy supply from outside the island not feasible. The current energy is generated with diesel generators, whereby the diesel is transported from onshore. This makes the elec- tricity relatively expensive and creates excessive carbon emissions compared to sustainable energy systems. This high electricity price also makes renewable energies competitive in an early stage of development. Lastly, the location conditions are favourable for wind energy; high average wind speed, high capacity factor and water depths which are suitable for fixed bottom wind turbines.
To calculate the LCOE of this technology, first a base load calculation is made with the wind speed data from one year. The output of this calculation is the input for the technical com- ponent selection of the hydrogen system. The overproduction of the offshore wind turbine is used to produce hydrogen with an electrolyzer. For this process, fresh water is required, which is produced by a desalination system. The hydrogen is pressurized with a compressor and stored in a storage tank. If the wind turbine is not able to produce the required energy, the hydrogen is reconverted into electricity. All these components are located inside the foundation of the offshore wind turbine. The LCOE is calculated with the hydrogen com- ponent cost and the cost overview of the the wind turbine. This design is tested for the Grenada location, with various base load scenarios and number of wind turbine generat- ors (WTG’s). A sensitivity analysis on these input variables will show their impact on the LCOE and makes design optimization possible. The extended part of this LCOE analysis is the carbon emission decrease calculation between the current non-sustainable diesel gen- erated energy and the offshore internal hydrogen wind turbine system. This sustainable impact is converted into financial input values which shift the financial competitiveness of the technology.
With the base load and LCOE models the following results are obtained. The extended LCOE for an internal hydrogen production and storage system depends on many variables and therefore is given as a range. The LCOE of the Grenada scenarios ranges between †604.03-246.53/MWh. If electricity is supplemented with diesel generated power, at the current energy price, the LCOE can drop to †230.09/MWh. For a single structure with gen- eralized system design, Grenada location input, without the use of overproduction and a base load of 1.5 MW, a LCOE of †501.32/MWh is calculated. If this energy is used, this LCOE will drop to †390.46/MWh. With the addition of the hydrogen system, the security of supply of a traditional wind turbine is increased from 68% to 76%. Depending on the configuration and number of WTG the security of supply can increase to 100% for low base loads. The extended analysis of this LCOE calculation is the sustainable impact of the tech- nology. According to the calculations, the assumed carbon emissions can be reduced up to 96% for a wind turbine system supplemented with diesel energy and up to 99% if the energy production is only generated with wind turbines. If carbon certificates need to be bought, the competitive financial break-even point of this technology will shift. For Grenada, the price of these certificates ranges between †42.03/kg tonnes of CO2 up to †489.86, depending on the selected base load and configuration.
From the sensitivity analysis the influence of the parameters on the lCOE are obtained; an increase in base load, Number of WTG’s, power output or storage volume will de- crease the LCOE. However the LCOE will increase if the energy losses, discount rate, OPEX, CAPEX, decommissioning cost or growth rate are increased. Most of these variables are inter-depending, which requires iterations to decrease the LCOE.
Many stakeholders are involved in the roll-out of new electricity technology. For Grenada as remote location, the stakeholders are the electricity provider, electricity consumers, gov- ernment, investors and secondary stakeholders. The competitiveness of a technology is not only depending on the LCOE, even with a sustainable impact analysis, but also on the im- plications for these stakeholders. Examples of these additional factors are view pollution, political incentives and benefits from byproducts.
Due to the early stage of development, many assumptions and simplifications have been made. These assumptions can be divided in four categories: technical, financial, location specific and stakeholders. Examples are; the foundation is assumed to be feasible for this technology, the carbon emissions are only based on the direct diesel emissions and the car- bon emissions of the wind turbine and the base load calculation are based only on a data set of 2020. Therefore future research is recommended for detailed analysis on this technology.