Weighing Pros and Cons of Energy Storage Technologies
Last time we made the argument that advanced energy storage has a demonstrable track record of positive environmental and economic benefits. Now let’s look at some of the energy storage technologies available in today’s marketplace:
Dynamic Power Resources (DPR)
- Ramp Rate Control: DPRs monitor output from a renewable generation source on a microsecond basis and automatically responds by either absorbing renewable output or supplying additional power so that the grid receives smooth, clean power at a desired MW/minute rate.
- Firming/Shaping: Coupling a DPR with a renewable generation forecast allows the utility to organize other generation resources to meet expected demand based on its guaranteed day-ahead renewable output schedules, as well as reshape output to deliver power during peak demand times regardless if the renewable asset is generating power or not. If a forecast is inaccurate, the DPR automatically supplies or absorbs power on a microsecond basis to ensure the day-ahead output schedule is met.
- Curtailment Mitigation: if there are times when the utility needs to curtail renewable output, the DPR can take advantage of all of the as-available fuel by storing curtailed power and redistributing it at other times throughout the day, whenever the grid needs excess energy.
- Ancillary Services: the speed and accuracy of the full four-quadrant DPR are unparalleled to that of typical generation resources.
- Voltage Support: the DPR has the ability to supply and absorb reactive power (VARs) while simultaneously supplying real power (Watts). This allows the system to maintain a target power factor while continuing to provide other functions that require real power management such as services mentioned in this section.
- Frequency Regulation: the DPR can respond to both AGC signals and/or frequency deviations with sophisticated control algorithms to help maintain nominal grid frequency. The DPR is capable of providing the frequency support during loss of generation or system disturbance, as well as address less severe frequency deviations due to normal grid operations throughout the course of each day.
- Spinning Reserve: the unique sizing scheme of the DPR allows the customer to add more energy storage (MWh) and act as a back-up power reserve for extreme generation trip scenarios by providing power while offline generation units ramp up to replace lost generation.
- Transmission and Distribution Upgrade: Deferral: instead of undertaking costly T&D upgrades, utilize DPRs to supply power for incremental increases in load, as well as to enhance grid reliability for weak and/or congested T&D lines.
- Peak-Shaving/Load-Leveling: Similar to ramp rate control, but for longer periods of time, a DPR can absorb and provide power, charging during off-peak times for use during on-peak times. Peak loads are lessened, which ultimately enables traditional generation to run more efficiently.
James Holler is founder of Abidance Consulting.