Generation and distribution planning procedure

Power system planning decides the type, size, location and timing of new generation, transmission and distribution facilities so that the forecast demand is met reliably at minimum cost.

Importance

• Ensures enough capacity ahead of demand, avoiding load shedding (Nepal faced up to 18 h/day load shedding due to poor planning before 2016).
• Avoids over-investment and idle capacity or energy spill.
• Coordinates long lead-time projects (hydro takes 5–10 years).
• Gives the right mix of plants (ROR, storage, solar, import) for seasonal and daily demand.
• Supports financing, tariff setting and policy decisions.
• Maintains reliability and quality of supply.

Generation expansion planning procedure

1. Forecast peak demand and energy for 15–25 years (high/base/low).
2. List existing plants, their capacity, firm energy and retirement dates.
3. Identify candidate plants with capital and operating cost, lead time and seasonal output.
4. Fix reliability criteria (LOLP or reserve margin).
5. Form alternative expansion sequences.
6. Simulate operation (production costing) of each sequence.
7. Compare present worth of total cost; choose the least-cost plan.
8. Do sensitivity analysis (demand, hydrology, cost, discount rate) and finalise.

Distribution planning procedure

1. Make spatial (area-wise) load forecast.
2. Study existing feeders and substations: loading, voltage drop, losses, reliability.
3. Set criteria for voltage drop, losses and reliability indices.
4. Plan new or upgraded 33/11 kV substations and distribution transformers.
5. Plan feeders: new feeders, reconductoring, ring/loop arrangements, underground cables.
6. Add capacitors, regulators, automation and smart meters.
7. Evaluate cost and select the best plan; implement in phases and review.