Ph.D. (Energy Studies) / The underlying assumption of this thesis is that information is critical for effective energy policy support. The objectives set and attained for this study were to: • assess existing solutions to the problem of supplying energy information; • consider developments in integrated conceptual solutions to the problems; • identify and analyse data structures for providing a single integrated information system as a solution; • evaluate and identify local energy and economic data sources for input to the proposed system; • provide a framework for information outputs in such an integrated system; and • make recommendations on the practical implementation of the conceptual . solution. The concepts underlying the basic assumption, and other parameters were clarified in Chapter 1. In particular, the link between policy formulation, modeling, and data collection, management and dissemination was shown. A study and assessment of existing energy information systems was then carried out. This investigated national systems in South Africa and other countries, and the systems of three international organisations. The structure and management of these energy information systems was assessed, as was the degree to which each provided the necessary support for policy formulation. Legislation was, where applicable, also considered. It was determined from this study and assessment that there were no integrated information systems to provide adequate information for energy policy makers through a single access point. An integrated single access point system was postulated at the conceptual level in Chapter 3. The major contribution to this conceptualisation is the concept of a single standardised referential data set A single referential data set can be used to classify all data at every level of the proposed integrated national energy information system. This integrated approach supports policy formulation and allows for the most efficient use of national resources in maintaining information. The proposed system was considered as a data flow model, to provide an overview of the collection, processing and dissemination of data. Next, a system model was developed. This divided the system into two broad divisions: the central control functions, including the referential data set; and the data modules, which provide the structure for capturing and maintaining the collected data. The final stage in this chapter . was the development of a data model which shows the relationships between the elements of the system model, particularly the relationship between the referential data set and all other data. In Chapter 4, this data model was developed further to identify entity sets and their content descriptions. It indicates in tabular format the structure of the different system components, and then shows diagrammatically the high level linkages between these components; This analysis of the proposed system is the precursor to work by systems analysts who are responsible for the final design specifications for system software. In Chapter 5 the objective was to determine sources of data for input to the national system. The South African energy economy was briefly studied and assessed for both supply and demand side information. Finally in Chapter 6, a set of output templates was developed. Once fully implemented, these will provide system users with all the necessary information to support policy formulation. Desired outputs from a system must be known before the system is designed, and are therefor included.