Conclusions

The subject of wind penetration onto the electricity market is vast with too many aspects to examine in a short project such as this. There are issues such as stability of the grid and major outage strategies that were not examined. These areas could well provide different limits to the ones found here. It was expected that hard limits such as maximum storage capacity would be encountered but these were not found, instead the limit is based on the border between variable load and base load. It was decided that with the wind industry being infantile that at this stage it would be too dangerous to encroach on base-load generation with such an unpredictable source of generation. For this reason the wind penetration limit was found to be 40% of the winter peak demand.

The following four points are our projects main 'take away' points.

1. Pumped hydro in Scotland is an under-developed resource.
2. As a backup to wind power, it is more sustainable than conventional generation but is significantly more costly.
3. Overall costs of generation will increase.
4. At 40% wind penetration - winter variable load limit reached.