Abstract
This study quantifies the potential power system benefits that the UK stands to gain through the deployment of marine energy technologies (wave and tidal stream) in domestic waters.
These system benefits are primarily due to the temporal and spatial offsetting of wave and tidal resource with other, more established variable renewables, such as wind and solar. Wave and tidal generation can be available at times of low wind or solar resource, helping to balance the overall renewable power profile. It has been found that a more diverse generation mix including marine energy is consistently more available and better able to meet demand than a renewable generation mix comprising of only wind and solar.
This study focuses on a 2050 net-zero compliant scenario for the power system of Great Britain. System benefits from marine energy are quantified over a range of metrics: increased renewable dispatch, decreased peaking generation and fossil fuel dispatch, decreased storage requirements and decreased dispatch costs.
This work is founded on deployment scenarios, where cost, performance, and systematic conditions are defined by the 2030 levelised cost of energy (LCOE) targets in the Strategic Energy Technology Plan for Ocean Energy. Deployment modelling obtained from the Energy Systems Catapult (ESC) forms the basis of the 2050 future energy scenarios used in this analysis. Scenarios both with and without marine energy are included, in order to compare the impact of including marine energy within the future generation mix.
The resultant deployment scenarios for 2050 have then been modelled using the EVOLVE Great Britain economic dispatch model. This model computes the least-cost supply-demand balance over a full year of electricity dispatch, at an hourly timescale, representing perfectly competitive wholesale market operation.
Results are also presented over a range of sensitivity analyses: five separate years of variable resource and demand profile input data are used to show the sensitivity of the results to particularly high or low wind years; and three gas price scenarios are used to show the sensitivity of the results to future gas price assumptions.
Results from this work can be summarised as:
- Energy planning modelling projects 6.4GW of wave and 6.2GW of tidal stream deployments in GB by 2050, if the SET Plan targets are reached by 2030.
- Previous work has shown that the resultant value to the UK economy from these deployments would be up to £8.9bn Gross Value Added.
- This study shows that the potential power system benefits of this 12.6GW deployment of marine energy would be up to £1.03bn reduction in dispatch costs per annum.
- This cost reduction comes from a higher dispatch of renewable energy – by up to 27 TWh (+6%), and thus a lower requirement for expensive peaking generation – by as much as 24 TWh (-16%) when wave and tidal generation are part of the electricity mix, compared with a scenario without marine energy generation.
- Additionally, the scenario which includes marine energy demonstrates a higher ability to meet domestic (GB) demand with domestic generation, as it requires 5 TWh less (-65%) battery use and 3 GWh less (-6%) energy imports over interconnectors.
Several sensitivity analyses have also been performed, and it has been found that the general trend in results is consistent between every sensitivity scenario, that is: a higher penetration of marine energy results in lower dispatch costs, higher renewable dispatch, lower peaking generation and flexibility requirements.
It should be noted that the scope of this work is the GB grid (comprising Scotland, England and Wales). The whole of Ireland is a separate power system and market, and so Northern Ireland, although part of the UK, does not fall within the geographical scope for this study.
This analysis is particularly meaningful as there are very few studies that quantify the system benefits associated with including marine energy within country-scale power systems. These results will be of interest to various stakeholders across the sector: technology and project developers, academic and industrial researchers, and grid operators and policy makers looking to develop future decarbonised systems whilst maintaining security of supply.
It should be noted that these system benefits to the GB power system are only achievable if focused investment in marine energy technologies enables a reduction in LCOE in line with the SET Plan targets. This results from performance improvements and cost reduction both through innovative step-changes in research and development and through learning from continues successive deployments.