Energy demand, output and competing priorities

Distinguish annual output from capacity and assess costs, reliability and emissions.

Resource seedPractice contextExam yearPractice mode

Energy demand, output and competing priorities

Use maps, data and stakeholder evidence to develop a geographical argument. The resources describe one fictional teaching scenario.

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

Original fictional teaching data. These are not observations or predictions for a real place.

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

Original fictional teaching data. These are not observations or predictions for a real place.

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

Original fictional teaching data. These are not observations or predictions for a real place.

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.

1. Calculate the wind annual output in GWh to two decimal places. (1 mark)

2. What percentage of annual local demand could wind output equal, ignoring timing and losses? (1 mark)

3. Explain why annual output equal to a large share of demand does not guarantee a secure supply at all times. (4 marks)

4. Which ratio gives the share of annual demand represented by wind? (1 mark)

Choose an answerWind capacity factor divided by annual demand GWh.Wind annual GWh divided by demand annual GWh.Wind capacity MW divided by demand annual GWh.Wind annual GWh divided by its capacity MW.

5. Recommend an option for energy demand, output and competing priorities. Use at least two resources, compare an alternative and address an uncertainty or stakeholder concern. (9 marks)

Resource assumptions

Capacity factors are fictional assumptions.
Annual balances do not represent hourly security or whole-system cost.

Make an editable teacher pack