Energy demand, output and competing priorities
Distinguish annual output from capacity and assess costs, reliability and emissions.
Energy demand, output and competing priorities
Original fictional unfamiliar-resource pack. Work across the resources; each describes the same teaching scenario. This is not an official examination paper or a real project forecast.
Capacity, output and land
| Project | Capacity (MW) | Capacity factor (%) | Annual output (GWh) | Capital cost (£ million) | New land footprint (ha) |
|---|---|---|---|---|---|
| Wind | 20 | 38 | 66.58 | 18 | 24 |
| Solar roofs | 15 | 14 | 18.4 | 12 | 0 |
| Small hydro | 10 | 41 | 35.92 | 19 | 8 |
Resource description
Annual output = capacity × capacity factor/100 × 8,760 hours ÷ 1,000. Capacity is a power rate; output is an energy quantity.
Demand and emissions
| Measure | Value | Unit |
|---|---|---|
| Annual local demand | 90 | GWh |
| Wind: lifecycle emissions intensity | 12 | g CO₂e/kWh |
| Solar roofs: lifecycle emissions intensity | 35 | g CO₂e/kWh |
| Small hydro: lifecycle emissions intensity | 24 | g CO₂e/kWh |
Resource description
Fictional lifecycle intensity estimates use the same boundary. They are not operational emissions only; output timing, storage and grid losses are omitted.
Management alternatives
| Option | Capital cost (£ million) | Benefit | Limitation |
|---|---|---|---|
| Wind | 18 | Estimated annual output 66.58 GWh; Lifecycle intensity 12 g CO₂e/kWh | Variable generation and landscape effects; Operating costs and grid connection need separate assessment |
| Solar roofs | 12 | Estimated annual output 18.4 GWh; Lifecycle intensity 35 g CO₂e/kWh | Seasonal generation and roof agreements; Operating costs and grid connection need separate assessment |
| Small hydro | 19 | Estimated annual output 35.92 GWh; Lifecycle intensity 24 g CO₂e/kWh | River ecology and low-flow constraints; Operating costs and grid connection need separate assessment |
Resource description
Available capital budget: £20 million. Options are alternatives; their benefits cannot simply be added. Operating costs are separate.
Options
Wind
Capital cost: £18 million
Estimated annual output 66.58 GWh
Lifecycle intensity 12 g CO₂e/kWh
Variable generation and landscape effects
Operating costs and grid connection need separate assessment
Solar roofs
Capital cost: £12 million
Estimated annual output 18.4 GWh
Lifecycle intensity 35 g CO₂e/kWh
Seasonal generation and roof agreements
Operating costs and grid connection need separate assessment
Small hydro
Capital cost: £19 million
Estimated annual output 35.92 GWh
Lifecycle intensity 24 g CO₂e/kWh
River ecology and low-flow constraints
Operating costs and grid connection need separate assessment
Stakeholder statements
Grid operator: We need output when demand occurs, not only a yearly total.
Resident: Local environmental effects and affordability need consideration.
Climate adviser: Compare lifecycle boundaries consistently.
Limits of this resource model
- Capacity factors are fictional assumptions.
- Annual balances do not represent hourly security or whole-system cost.