More than Megawatts: A Diverse Fuel Mix Supports Grid Reliability
More than megawatts, resources powering the grid must deliver specific capabilities to maintain reliability under dynamic conditions.
Among these critical capabilities are:
- Dispatchability – Resources that provide the real-time ability to turn on, off, increase, or decrease output in response to changing conditions. Dispatchable resources offer highly controllable, reliable, and predictable electricity supply.
- Flexibility – Fast-ramping and responsive resources that can be dispatched through a wide range of operating conditions.
- Multi-start – Resources that can be brought online or switched off multiple times throughout the day.
- Dependable fuel source – Resources that have secure, reliable sources of fuel that can be brought online across a range of operating conditions.
- Non-Energy Limited – Resources that can provide energy for multiple hours and days regardless of weather conditions.
Decarbonizing the Grid Requires Replacing Capabilities from Fossil-Fired Generators
Not every resource on the grid is capable of delivering the full set of critical reliability services. But as long as the grid’s fleet of resources can collectively deliver these capabilities, reliability can be maintained.
While all resources supplying the grid offer some of these capabilities, only hydro and fossil resources deliver the full array of services needed to balance a dynamic grid. Despite the need to reduce fossil fuel use to meet the state’s emissions reduction targets, some level of fossil-fired generation will be needed for reliable power system operations until the capabilities they offer can be provided by other resources.
Existing nuclear energy, in addition to being emissions-free, provides reliable, continuous, predictable supply, however it is limited in its flexibility and dispatchability. Emerging nuclear technologies hold promise for added flexibility and dispatchability, but the commercial availability is uncertain.
Wind and solar resources while being carbon-free, lack dispatchability, dependability, and are considered energy-limited because they rely on nature for their fuel. Battery storage, while offering dispatchability and dependability, is also considered energy-limited because batteries can typically only supply the grid for two to eight hours before needing to be recharged.
Even the capabilities of fossil-fired generators can vary. Generators fueled solely by natural gas are subject to potential fuel disruptions due to pipeline constraints in the winter months. On the other hand, dual-fuel generators that can switch from natural gas to oil are less susceptible to fuel disruptions and offer greater support to power system reliability in cold winter conditions.
Dual-fuel generation is particularly important for meeting downstate energy needs, where it accounts for 74% of the region’s capacity. The availability and consistent contributions of dual-fuel resources are necessary to maintain power system reliability in cold winter conditions throughout the transition toward a zero-emission system.
Simply put, as New York seeks to retire more fossil fuel units in the coming years, it will be essential to deploy new energy resources that collectively replace the reliability attributes provided by fossil generation in order to maintain grid reliability. Advances in new, non-emitting alternatives like hydrogen or advanced nuclear generation can help fill some of these gaps, but until they are developed and commercialized, fossil resources are needed to fill an essential role in preserving reliable grid operations.
