Practice Test Geeks(CEA) Certified Energy Analyst Practice Test
← All CEA Flashcard Decks

Energy Storage & Grid Integration Flashcards

7 cards from real CEA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Energy Storage & Grid Integration flashcards as text

  1. A 100 MWh battery discharges at 50 MW for 2 hours, then must recharge. If round-trip efficiency is 85%, how much energy (MWh) must be input to fully restore the battery?

    Answer: 117.6 MWh

    Energy in = energy out / RTE = 100 MWh / 0.85 ≈ 117.6 MWh must be charged to recover 100 MWh of usable capacity.

  2. What is 'time-of-use (TOU) arbitrage' in the context of energy storage?

    Answer: Charging storage during low-price periods and discharging during high-price periods

    TOU arbitrage captures the price spread by charging when electricity rates are low (off-peak) and discharging when rates are high (on-peak).

  3. Which type of energy storage technology is most suitable for seasonal (multi-month) storage due to negligible self-discharge?

    Answer: Compressed hydrogen

    Hydrogen produced via electrolysis can be stored for months in tanks or geological formations with minimal energy loss, unlike batteries or flywheels.

  4. In the context of grid services, what does 'spinning reserve' require of a storage resource?

    Answer: The resource must be online and able to increase output within 10 minutes

    Spinning reserve requires resources that are already synchronized to the grid and can ramp up to full capacity within 10 minutes to cover sudden generation loss.

  5. What is the primary function of a Battery Management System (BMS) in a grid-scale BESS?

    Answer: Monitor cell voltage/temperature and balance cells to protect battery health

    The BMS monitors individual cell conditions and performs balancing to prevent overvoltage, undervoltage, and thermal runaway, extending battery life.

  6. How does FERC Order 2222 differ from FERC Order 841 regarding energy storage?

    Answer: Order 2222 enables aggregations of distributed resources (including storage) to participate in wholesale markets

    FERC Order 2222 extended market access to aggregations of distributed energy resources, allowing small behind-the-meter storage to participate in wholesale markets as a fleet.

  7. What is 'capacity factor' for a pumped hydro storage facility, and why is it typically lower than for conventional generators?

    Answer: It measures the ratio of actual output to maximum possible output; storage assets operate only during peak demand windows, not continuously

    Capacity factor = actual MWh generated / (rated MW × 8,760 hrs); storage is dispatch-driven and may sit idle for many hours, reducing its annual capacity factor.