Overview

Project Aims

The aim of this group project is to set scenarios of wind power penetration (10%, 20%,.....50%) in Scotland, and then to highlight and assess the various obstacles that are associated at various levels of penetration. It was envisaged that limiting factors would need to be taken in to consideration-- limits that were either hard or soft. Modells were developed that project when certain limits are likely to come in to effect, and ultimately the costs associated with the development of greater levels of wind power penetration.

Background

The building environmental pressure from the Global community to reduce fossil fuel consumption and greenhouse gas emissions is providing the high level drive towards greater renewable energy exploitation. In the case of the UK and in particular Scotland these pressures have materialised as government policy, which has set the UK renewable energy penetration targets.

Considerations

The domain of wind power has developed over the decades into a well established technology and industry. This project could not possibly consider all aspects of the domain in the time available. However, a broad spectrum of issues were considered, which enabled the project to achieve focus and a sense of context.

The broad spectrum of issues included a review of the past and present wind power technologies, allowing us to appreciate the realities and possibilites of wind power. We also reviewed the present electricity network, not just in Scotland but the UK as a whole. This review looked at the operational procedures and constraints of conventional thermal generators; it looked at the fundamentals behind an interconnected power supply system; it also looked at the moves and motivations being made by the private power companies to facilitate the renewable energy targets.

There were many other aspects and issues that were identified as being important, such as the availability of suitable wind farm sites; government legislation and incentives; climate and weather data. One of the major considerations was economics, as such we made cost a central issue in the model.

Limits

It was envisaged that at various levels of wind penetration there would be certain barriers resisting a progression to higher levels of penetration. These barriers/limits were classified as being either hard or soft. A hard limit is defined as being an insurmountable, definitive limit; whereas, a soft limit is problem to overcome. Examples of limits include: availability of wind farm sites, pumped storage resource, grid connectability, spinning reserve, cost and others. The factors that were taken into consideration in this project were classified as soft limits.  

Storage Model

A storage model was constructed using mathematical modelling. Consumption data for a typical winter was analysed and storage requirements for a worst case scenario, calculated using a Matlab programme specifically for this purpose.

Cost Model

The cost of wind power is the major driving force that controls wind penetration in the UK. It was determined that such an important driver to wind penetration warrants detailed analysis and modelling. Therefore, a cost model was derived. The four main areas of cost analysis were: Present and future cost of wind generation; Present and Future cost of pumped storage; Future cost of grid upgrade; Present and Future cost of conventional generation. The outputs of the model suggested that increased wind penetration would incur unavoidable cost increases to the price of electricity. There would also be extra costs associated with the requirement of pumped storage at higher levels of penetration. The actual price would vary depending on the time to reach targets.

Conclusions

It was expected that hard limits would be encountered but instead a range of soft limits were met. The project concluded that a soft penetration limit of 40% could be reached in Scotland before any major problems would be encountered. This limit applies only within the scope of the issues examined.