Grid in Transition
Renewable energy resources like wind-powered generators or solar panels have the benefit of being emissions-free, but they are not dispatchable, meaning they cannot produce electricity on demand and respond to signals to increase electricity production in the same ways that many fossil-fueled generators can. Electricity produced by wind and solar powered resources are intermittent suppliers, meaning they cannot produce energy when the sun is not shining, or the wind is not blowing. Energy storage can help resolve this challenge by storing excess wind and solar energy and discharging that electricity when needed. But current electricity storage technologies are limited in how much electricity they can store and then supply to the grid when needed. Because of these characteristics, a successful transition to a zero-emission grid means synchronizing the addition of clean energy resources with the retirement of fossil-fuel generators to maintain reliability.
The grid will always need sufficient flexible and dispatchable resources to balance variations in wind and solar resource output. These resources need to be long-duration, dispatchable, and emission-free. Essentially, they must have the attributes of fossil generators (responding quickly to rapid system changes) without the emissions. Such resources are not currently commercially available and may not be for many years.
The retirement of fossil-based resources is outpacing the development of new renewable-based resources and other dispatchable, emissions-free resources. The effect is that reliability margins will thin to concerning levels beginning in 2023, highlighting the need for a careful transition that maintains grid reliability and resilience.
Another factor in this transition is that, during periods of high demand, constraints along key transmission lines can limit the amount of carbon-free electricity that can be delivered from upstate, where generation is predominantly emission-free, to meet demand downstate, where most of the electricity is required. Today, New York City and its surrounding suburbs at times rely more on fossil-fuel powered generation located in the downstate region to serve customer needs.
New transmission investment will be important because of the so-called “peaker rule,” which will require that certain fossil fuel generators meet tightening regulations on smog-forming pollutants beginning in 2023. Many peaker plants are located within “pockets” in New York City and Long Island where the ability to transmit electricity into these areas is limited. To fully meet consumers’ needs in these areas, local supply is necessary. As it does with all generators retiring from serving the grid, the NYISO has conducted reliability studies to understand the impacts of generators retiring in response to the “peaker rule.” While reliability needs have not been identified to date, the NYISO continues to monitor the impacts of these retirements, along with expected levels of electricity demand and available transmission, to identify and take steps to address reliability needs should they occur.
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Addressing Transmission Needs
Like any product, electricity must travel from where it is produced to where it is consumed. Our Public Policy Transmission Planning Process identifies the transmission investments needed to achieve public policy goals, such as increased renewable energy production.
As a first step, the New York Public Service Commission (PSC) opens a public process to examine what transmission system upgrades and additional investments need to be made. Chief among the considerations is where the system is most constrained and, looking into the future, where expected renewable supply will be developed, and where forecasted demand will be greatest. Many parties participate in this part of the process, including the NYISO, making suggestions and putting forward ideas.
Once the PSC identifies specific needs for the power system, we request proposals from developers to meet those needs. The NYISO then evaluates the proposed solutions based on their ability to satisfy the needs identified by the PSC. The proposals are ranked based on design criteria, efficiency, and cost-effectiveness.
Most of the land-based wind generation and large-scale solar electricity production is located in northern and western New York. This is because these regions have the strongest winds to support land-based wind turbines, and where land is more available for solar farms. These regions, which typically have lower demand levels than other regions of the state, have limitations to their ability to transmit electricity. Absent upgrades to the transmission system, renewable resources in northern and western New York would increasingly be bottled. Bottling occurs to renewable resources when they are generating more energy than can be consumed within the region it is produced or can be reliably transmitted to other regions. Existing constraints on the transmission system lead to “curtailing,” or purposefully reducing the output of solar or wind in order to maintain grid reliability.
A historic level of investment in the transmission system is currently underway, with projects that will deliver more clean energy to consumers while enhancing grid resilience and reliability.
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The increase in large scale renewable generating facilities and new clean energy technology is driving a transition of the transmission system. Integrating a high volume of new facilities onto the transmission system can have major implications for reliability and the flow of power across the state.
To address this, the NYISO has an Interconnection Process, which requires proposed new generation and transmission projects to enter an “interconnection queue.” Proposals undergo a series of studies and detailed analysis that serve two key functions on behalf of customers:
- Determinations of whether adding a new resource creates reliability issues on the system; and
- If the project does impact system reliability, determine what system upgrades are necessary to interconnect the project while maintaining system reliability, and the costs of those upgrades.
Under the process, the costs of equipment and upgrades required to connect projects are assigned to project developers, and in some cases, the local utility, not consumers. The interconnection process is required to identify the lowest cost solution to solve the reliability need. The allocation of upgrade costs identified through the process are not subject to negotiation, providing an important element of certainty for developers. This cost certainty is a highly regarded aspect of the New York process.
The interconnection process ensures “open access” to the transmission grid for new supply resources seeking to enter operation and is an essential element in maintaining the performance and reliability characteristics of the electric system on behalf of customers.
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Planning for the Future
The NYISO is constantly analyzing the electric system and its future capabilities by conducting reliability planning studies. These studies identify when and where reliability rules, set by state, federal, and regional entities, will be violated unless action is taken in the form of system upgrades and investments. If a scenario is identified in which the grid may lack enough available supply of electricity or transmission capability to serve future demand, a “Reliability Need” is declared, setting off a set of steps to address the situation.
Four times a year, we conduct a Short-Term Assessment on Reliability (STAR), which focuses on identifying reliability needs up to five years out. For a longer-term approach, our Reliability Needs Assessment (RNA) looks out 10 years. This process cycle runs every two years and begins with the development and publishing of the RNA report. The RNA looks at both the adequacy of energy resources and limitations of the transmission grid to determine whether the electric system will be able to supply enough power to meet demand.
The NYISO’s role in identifying system needs, and finding solutions, is part of the process of planning for the grid of the future.
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