Choosing an Energy Option for a Regional Town
A regional town of 18,000 people currently draws electricity from a coal-fired generator 400 km away via a long transmission line with 7% losses. The town is choosing between two supply options. Option A is a 60 MW solar farm with a 40 MWh battery, built on cleared farmland 8 km from town; it would meet about 55% of annual demand but needs grid backup at night and in winter. Option B is a new gas peaking plant of 25 MW beside the existing substation, which can meet peak demand reliably and has lower capital cost, but locks in emissions for 25 years. The council has a target of net-zero operational emissions by 2040 and a limited budget. Community consultation shows strong support for renewables but concern about reliability during heatwaves, when air-conditioning demand peaks and solar output is high but so is demand.
1. Compare the two options on the criteria that matter for the council's decision, rather than on a single metric.
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The options differ on several dimensions, and no single number settles the choice.
Emissions: Option A produces near-zero operational emissions and is consistent with the 2040 net-zero target. Option B locks in fossil emissions for 25 years, which directly conflicts with that target and would require offsets or early retirement to meet it.
Reliability: Option B is dispatchable and can meet peak demand on demand. Option A meets only about 55% of annual demand and needs backup at night and in winter. The heatwave concern is partly misplaced - solar output is high on hot days - but the risk is real in the evening peak after sunset, when air-conditioning demand persists and the 40 MWh battery provides only limited hours of supply.
Cost: Option B has lower capital cost, which matters given the limited budget, but fuel and carbon costs accrue over 25 years and may rise. Option A has higher upfront cost but no fuel cost and reduces the 7% transmission losses by generating closer to load.
Land and community: Option A uses cleared farmland, avoiding native vegetation clearing, and aligns with strong community support for renewables.
The decision hinges on whether the council treats reliability as a reason to reject renewables or as a problem to be solved alongside them.
2. Recommend a decision and explain how it handles the reliability concern and the budget constraint.
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Recommend Option A plus a targeted firming arrangement, rather than Option B as the default.
The reasoning: Option B resolves reliability but at the cost of the council's own 2040 target and 25 years of emissions, which is a poor trade when the reliability gap is limited to evening and winter periods. Option A meets the emissions target and community expectations and reduces transmission losses, but on its own it does not guarantee supply after sunset.
The reliability gap should be closed explicitly: pair the solar farm with the battery (already included) and contract firm capacity - demand response, a modest amount of storage, or an agreement with the wider grid - sized to cover the evening peak and winter shortfall. This is cheaper than building a 25-year gas plant for the same purpose and can be scaled as storage costs fall.
Budget: the higher capital cost of Option A is the constraint, so phasing is appropriate - build the solar farm and battery first, and procure firming through contracts rather than capital construction. The council should also state the residual risk honestly: if firm capacity cannot be secured within budget, reliability during extreme evening peaks is not guaranteed, and that risk should be reported to the community rather than hidden.