1. Gaunt ZA Session 5 – Block 2.2 – Paper 5.68 Barcelona 12-15 May 2003 1 LV Network Sizing in Electrification Projects Replacing a deterministic method with a probabilistic method I Ferguson, C T Gaunt – South Africa

2. Gaunt ZA Session 5 – Block 2.2 – Paper 5.68 Barcelona 12-15 May 2003 2 Background Large scale electrification programme. Over 2 million new customers connected, many rural. Need suitable load models and reliable / representative calculation methods.

3. Gaunt ZA Session 5 – Block 2.2 – Paper 5.68 Barcelona 12-15 May 2003 3 Fundamental difference Deterministic methods assume there is a right answer and we can approach it using suitable factors. Probabilistic approach considers a range of possibilities, giving input to the design decisions.

4. Gaunt ZA Session 5 – Block 2.2 – Paper 5.68 Barcelona 12-15 May 2003 4 Testing Load data collection, load models and algorithm were reported at CIRED 1991 and 1999. Concerns about costs and business implications were tested on a recently completed electrification project. Business decision based on results.

5. Gaunt ZA Session 5 – Block 2.2 – Paper 5.68 Barcelona 12-15 May 2003 5 Surprises Designers resist change. Design tools must be benchmarked. Need to revise load forecasting tool for low income communities. Quality control needed of design in turnkey projects.

6. Gaunt ZA Session 5 – Block 2.2 – Paper 5.68 Barcelona 12-15 May 2003 6 New developments Technical development – see papers 5.27 and 5.28 Data and methods are essential for recent/ continuing research into proposed social tariff to support poor households. The probabilistic approach reduces business risk.