Modelling and comparing the seasonal and diurnal components of electricity demand, wind speed, wave height and wave period; for the Isles of Lewis and Harris

摘要

The location of the Isles of Lewis and Harris, off the west coast of mainland Scotland, is favourable for the generation of renewable electricity from both the wind and ocean waves. However the islands’ position on the UK electrical grid’s periphery, with restricted local network capacity and only a limited connection to the mainland, makes it more challenging to capitalise on this advantage. This study sought to explore the relationship between the local wind and wave resources and consider how they track the islands’ indigenous demand for electricity. This was accomplished by using a mixture of Fourier analysis and auto-regressive techniques to model and de-trend local electricity demand data gathered over a 365 day period; and similarly process the wave and wind parameters associated with renewable generation, obtained from Hebridean metrological measurements recorded over the same interval. Results confirm that due to the partially complimentary relationship between wind and wave power, balancing generation across these sources is more likely to be efficient at matching customer demand, rather than a reliance on electricity from wind power alone. This would seem particularly significant for relatively isolated networks with only limited local network capacity and modest quantities of conventional generation available to balance any fluctuations in renewable supply. In conclusion, for the Isles of Lewis and Harris over the 365 day period studied, where grid capacity is restricted and such resources are available, it appears advantageous in terms of network efficiency to combine generation from wind and wave sources.