As the world rapidly pivots towards sustainability, the concept of Firm and Dispatchable Renewable Power (FDRE) is increasingly gaining traction. These cutting-edge power systems are the epitome of reliability and sustainability in renewable energy generation, providing an unprecedented level of control over power output.

Understanding Firm and Dispatchable Renewable Power

FDRE projects incorporate various types of renewable energy, such as wind and solar power, along with Energy Storage Systems (ESS). FDRE power is firm because it’s always available, even when the sun isn’t shining or the wind isn’t blowing. It’s dispatchable because it can be turned on or off, or adjusted up or down, to match grid demand at any given time.

The Rising Importance of Firm and Dispatchable Renewable Power

In the past, intermittent availability has been a significant limitation for renewable power sources like wind and solar. Their energy output fluctuates with the weather and the time of day, which can cause complications with grid stability and energy supply reliability. FDRE solves this problem by integrating storage systems and providing dependable power regardless of weather conditions or time of day.

Solar Energy Corporation of India’s (SECI) Role

SECI, a dedicated organization for renewable energy in India, has been instrumental in encouraging FDRE adoption. One of their recent significant initiatives is a tender for a 500 MW FDRE power supply (SECI/FDRE-I). The tender calls for the development of ISTS-connected RE Power Projects designed to supply power to SECI.

Essential Provisions of the SECI FDRE Tender

The tender highlights that the developer will be responsible for land identification, project installation, connectivity, and obtaining necessary approvals for the ISTS network for power supply. Furthermore, the selection of projects would be technology agnostic, meaning the RE Power Developer (RPD) can choose the type of renewable energy used.

For procurement, a cumulative “Contracted Capacity” of 500 MW is required. This power should come from the project’s solar PV, wind power components, and ESS. RPDs can modify the ESS technology at any point during the term of the Power Purchase Agreement (PPA), under intimation to SECI.

FDRE Configuration and Implementation

To qualify under the tender, projects must be designed for interconnection with the ISTS substation at a voltage level of 220 kV or above. Moreover, project components such as Solar PV, Wind, and ESS can be co-located or located at different locations, taking cognizance of the provision as per Clause 7 of the RfS.

Understanding the Demand Fulfilment Ratio (DFR)

A critical factor in the SECI/FDRE-I tender is the Demand Fulfilment Ratio (DFR). This ratio determines how well the RPD has met the specified demand profile. The RPD is expected to supply power according to the provided demand profile, time-block wise, throughout the month.

Liquidated Damages for Shortfall in DFR

In an innovative approach to ensuring compliance with supply requirements, SECI has instituted a mechanism for liquidated damages against shortfall in DFR. If the RPD’s mean DFR for the month falls short of the guaranteed monthly mean DFR, liquidated damages will be calculated according to the formula provided in the tender document.

The Future of Firm and Dispatchable Renewable Power

With FDRE, we’re on the brink of a new era in renewable energy. FDRE projects offer a powerful solution for the grid reliability issues traditionally associated with renewable energy sources, pushing the boundaries of what’s possible with renewable energy. As a result, FDRE will play an instrumental role in accelerating the shift towards a more sustainable and resilient global energy system.

Understanding Firm and Dispatchable RE Power Supply: A Sample Calculation

Firm and dispatchable Renewable Energy (RE) power supply refers to the reliable and controllable production of power from renewable sources. To help illustrate the concept, let’s explore an example calculation of how RE power can be scheduled to comply with a demand profile and what potential compensations or penalties may apply for the RE developers.

Let’s imagine a solar-wind hybrid project with energy storage is to provide power to an off-taker, such as Solar Energy Corporation of India (SECI), under a Power Purchase Agreement (PPA). In our example, let’s consider that the project is designed to supply 500 MW and the demand profile is outlined for the month of August.

Sample Table for Supply of Firm and Dispatchable RE Power

Date-Timeblock	Power Supplied by RE Developer (MW) (A)	Demand Profile (MW) (B)	Demand Fulfillment Ratio (DFR) (C) = max(A/B,1)
01-Aug 00:00-00:15	467	500	0.93
01-Aug 00:15-00:30	400	500	0.80
01-Aug 00:30-00:45	500	500	1.00
01-Aug 00:45-01:00	500	500	1.00
…	…	…	…
04-Aug 04:00-04:15	150	168	0.89
…	…	…	…
31-Aug 23:30-23:45	400	500	0.80
31-Aug 23:45-24:00	333	500	0.67

Compensation and Penalty Calculation for RE Developers

If the RE developer fails to meet the Demand Fulfilment Ratio (DFR), a penalty may apply. This penalty, often referred to as Liquidated Damages (LD), can be calculated using the following formula:

LD = Total Demand (D) * (Guaranteed Monthly mean DFR (DFRg) – Actual Monthly DFR (DFRa)) * PPA Tariff (P) * 1.5 * 10

For instance, let’s say:

• Total Demand for the month of August (D) = 277.977 MUs (Mega Units)
• Guaranteed Monthly mean DFR (DFRg) = 0.9
• Actual Monthly DFR (DFRa) = 0.86 (Mean of column C in the above table)
• PPA Tariff (P) = Rs. 4.5/kWh

So, the LD applicable for the month of August would be:

LD_Aug = 277.977 * (0.9 – 0.86) * 4.5 * 1.5 * 10 = Rs. 750.5379 lakhs

This amount would be deducted from the payment to the RE developer due to the shortfall in the DFR for the month of August.

This scenario illustrates how RE developers must be diligent in their planning and execution to avoid penalties and ensure they meet the demand profiles outlined in their agreements.