Can the battery cover the whole request?
Check the power and energy limits before you offer a delivery window.
The question
You assess a battery delivery request for an Australian storage portfolio. The portfolio lead approves commitments. The starting energy already includes conversion losses. The battery cannot recharge in this window.
| Value | |
|---|---|
| Power ceiling in MW | 30 |
| Starting usable energy in MWh | 72 |
| Energy held back in MWh | 12 |
| Requested power in MW | 24 |
| Requested duration in hours | 2 |
Keep the 12 MWh in reserve when you compare offers.
“Can you recommend the first request? Show both limits and what would remain.”
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A strong answer, step by step
Open each step in turn. This is one strong answer, not the only one.
Step 1: Check both limits
What would you do here? Open the move you’d make.
Check the 24 MW rate and the 48 MWh total.
The strong move. Power sets the rate. Energy sets how long that rate can last.
Approve the request using only the 30 MW power ceiling.
Tempting, but it misses something. The rate fits, but it gives no answer about the energy needed over two hours.
See how a strong candidate says it
“24 MW is below the 30 MW power ceiling. For two hours it needs 48 MWh. The portfolio can commit 60 MWh after holding 12 MWh back, so the first request fits both limits.”
Why it works: Power sets the rate. Energy sets how long that rate can last.
Step 2: State what remains
What would you do here? Open the move you’d make.
Report 24 MWh remaining, with 12 MWh still available to commit.
The strong move. Keep total energy remaining separate from the amount available for a new commitment.
Tell the buyer all 24 MWh remaining can support another commitment.
Tempting, but it misses something. The portfolio holds back 12 MWh from that total.
See how a strong candidate says it
“Starting with 72 MWh and delivering 48 MWh leaves 24 MWh. That includes the 12 MWh we hold back, so another 12 MWh would remain available.”
Why it works: Keep total energy remaining separate from the amount available for a new commitment.
Step 3: Check the longer window
The buyer extends the request to 3 hours at the same 24 MW. Starting energy and the held amount are unchanged.
What would you do here? Open the move you’d make.
Reject the battery-only 24 MW for three hours and give two bounded options.
The strong move. Both options use 60 MWh and keep the held energy in the plan.
Offer the longer window using all 72 MWh.
Tempting, but it misses something. That proposal spends the 12 MWh the portfolio holds in reserve.
See how a strong candidate says it
“24 MW for three hours needs 72 MWh, 12 MWh over the limit. Within the limit we can propose 24 MW for 2.5 hours or 20 MW for three hours.”
Why it works: Both options use 60 MWh and keep the held energy in the plan.
Step 4: Give the buyer an option
What would you do here? Open the move you’d make.
Confirm the buyer’s minimum and ask the portfolio lead to approve the complete offer.
The strong move. The extra 4 MW would cover the gap in every hour alongside 20 MW from the battery.
Promise 24 MW for the full window and find the rest later.
Tempting, but it misses something. The battery alone falls 12 MWh short. The additional supply is unconfirmed.
See how a strong candidate says it
“If the buyer can use 20 MW for all three hours, I’d ask the portfolio lead to approve that offer. If the buyer needs 24 MW throughout, I’d ask the lead to confirm a separate 4 MW for all three hours before we commit.”
Why it works: The extra 4 MW would cover the gap in every hour alongside 20 MW from the battery.
The answer, in short
- Decision
- Offer 20 MW for three hours if the buyer accepts that level and the lead approves.
- Because
- Three hours at 24 MW needs 72 MWh. This battery can commit 60 MWh.
- What would change it
- A confirmed 4 MW companion for all three hours could support the full request alongside the battery’s 20 MW.
Common traps
- Confusing MW with MWh.
- Counting energy held back as available for the buyer.
Check your answer
- I checked the rate and duration.
- I kept the held energy in the plan.
- I recalculated the longer window.
- I gave the portfolio lead a bounded offer.
Last reviewed Nov 11, 2026