The Debt Service Reserve Account (DSRA) in Project Finance: Save the Lenders, Save the World

Debt Service Reserve Account (DSRA) Definition: In Project Finance, the DSRA ensures that an asset has enough cash on hand to meet its upcoming Debt Service (Interest + Principal Repayments); it ensures that the lenders get paid without an additional contribution from the equity investors for this Debt Service.

The DSRA is typically based on the next few months or quarters of Debt Service.

It is most common for seasonal assets whose cash flows fluctuate significantly, but it can also be useful for assets with irregular cash flows caused by maintenance/repair requirements.

For example, solar and wind plants produce different amounts of power in different months of the year, so their cash flows fluctuate as the seasons change.

The DSRA ensures that even in the “low season,” the asset has enough cash to pay the interest expense on its Debt and repay the required Debt principal.

It’s easiest to illustrate the DSRA mechanics with a simple “cost overrun” example.

Suppose that a newly acquired solar plant requires $22 million of equipment replacements in Year 5.

The investors factor this into the sized and sculpted Debt used to fund the acquisition, and the initial plan looks fine:

But something goes wrong with the asset’s performance, and this new equipment ends up costing $90 million rather than the planned $22 million.

This change reduces the Cash Flow Available for Debt Service (CFADS) from $178 million to $110 million, which is insufficient to pay the lenders, as the total Debt Service is $119 million.

If this happens in real life, the equity investors normally must contribute additional cash to fund the “missing” $9 million.

With a properly provisioned Debt Service Reserve Account, however, there will be enough cash to pay the lenders in Year 5:

The rest of this tutorial describes the concept of Reserve Accounts in Project Finance and walks through the specific formulas used to set up the DSRA shown above.

Files & Resources:

• Simple Debt Service Reserve Account (DSRA) Example – New/Modified Sections in Yellow (XL)
• Debt Service Reserve Account – Presentation Slides (PDF)

Video Table of Contents:

• 0:00: Introduction
• 0:42: The Short Version
• 4:49: Part 1: Why Reserve Accounts in Project Finance?
• 7:14: Part 2: Simple DSRA Formulas and Setup
• 14:43: Part 3: Added DSRA Complexities
• 16:29: Recap and Summary

Reserve Accounts in Project Finance

Reserve Accounts smooth out cash flows and ensure there’s enough cash available to meet upcoming spending requirements.

They are especially important in Project Finance because the Debt is often sized and sculpted based on future cash flows, and a huge expenditure, such as a solar inverter replacement, can significantly reduce the Cash Flow Available for Debt Service (CFADS).

A big drop in CFADS in one period can reduce the total amount of Debt used to fund the project, even if it’s not warranted based on the asset’s performance in all the other years.

Since these replacement requirements are known far in advance, asset owners can set aside cash each month, quarter, or year to pay for them in the future.

To illustrate the problem caused by a huge reduction in CFADS, consider the scenario shown below (for simplicity, this ignores taxes):

If there are no huge cash outflows, and CFADS rises by a fixed $5 million per year, everything is fine.

But now let’s assume there is an unexpected $80 million cash outflow in Year 5:

This creates a problem because the Debt Service Coverage Ratio (DSCR) falls well below the minimum – 1.20x vs. 1.50x – and the Interest Expense alone now exceeds the Max Debt Service in Year 5.

We can solve this problem by allocating $16 million per year to the Reserve for the first 5 years and then withdrawing this balance to pay for the $80 million cash outflow in Year 5.

This reduces the CFADS in the first 5 years but ensures compliance with the minimum DSCR:

In reality, Reserve Deposits and Withdrawals are not part of the CFADS calculation; they normally appear below this line in the “cash flow waterfall” of the model.

However, the basic principle is correct: By “diverting” some of the cash flows from the equity investors in the first few years, the asset has enough cash to cover the cash outflow in Year 5 while remaining compliant with the lenders’ requirements.

How to Set Up a Simple Debt Service Reserve Account

In the example directly above, the generic Reserve Account ensures compliance with a minimum DSCR.

But the Debt Service Reserve Account normally ensures that the cash flows to equity investors do not turn negative, as in the first example in this article.

To set up this DSRA, the following steps are required:

1) Model Setup – Create “Cash Flow Post-Debt Service” and “Cash Flow Post-Debt Service and Reserves” lines and a separate area for tracking the DSRA, including lines for funding and withdrawals:

2) Calculate the Required DSRA Funding – In each period, this equals the Forward-Looking Debt Service (e.g., over the next month, quarter, or year) minus the Beginning DSRA.

This tells us what we “should” allocate to the DSRA in this period.

For example, if the asset has $100 of Debt Service in the next period, but the DSRA is currently $60, we need to add $40 to the Reserve, so the Required DSRA Funding is $40.

But the asset might not be able to allocate this full $40 toward the DSRA, which explains the next step:

3) Determine the Actual DSRA Funding – This equals the minimum between the Cash Flow Post-Debt Service and the Required DSRA Funding.

In other words, we allocate the maximum possible amount to the DSRA based on the available cash flow:

The MAX(0 is around the formula to handle the case where the CFPDS and Required DSRA Funding are both negative; if this happens, nothing should be allocated.

In this specific example, the Debt Service in the next period is $129, and the Beginning DSRA is $0. Therefore, the Required DSRA Funding is $129.

However, the Cash Flow Post-Debt Service is only $60, so we only fund the DSRA for this $60 in available cash flow.

4) Withdraw from the DSRA If the CFPDS is Negative – This is the entire reason why the DSRA exists.

It’s most elegant to use a MIN/MAX formula to implement this:

First, flip the sign of the CFPDS.

If this “flipped CFPDS” is negative, it means the CFPDS is positive, so we don’t do anything.

The MAX(0 ensures that the Withdrawals are set to 0 in this case, as there is no cash-flow deficit.

On the other hand, if the “flipped CFPDS” is positive, it means the CFPDS is negative, so there is a cash-flow deficit.

In that case, we take the minimum between this “flipped CFPDS” and the Beginning DSRA and use that for the withdrawal.

For example, if the cash-flow deficit is $50, but the Beginning DSRA is $120, we can easily withdraw $50 from the DSRA to cover this deficit.

But if the Beginning DSRA is only $40, we withdraw all $40 but still have a $10 deficit – better than before, but still not perfect.

5) Release Excess DSRA Funding to the Cash Flows – If the Required DSRA Funding (Forward-Looking Debt Service minus the Beginning DSRA) is negative, the Reserve is now too large.

So, we release the excess into the cash flow for the period.

This is based on a MIN(0 function, which ensures that there’s a release only if the number is actually negative:

6) Link Everything in the Cash Flow Waterfall – The DSRA Funding should always be a negative below the CFPDS line, and the DSRA Withdrawals and Excess Releases should always be positives below this:

You may also have to modify other parts of the model, such as the Returns Calculations and the credit stats and yield metrics, such as the Cash Flow Yield.

The normal “Cash Flow to Equity” lines in these schedules should now point to the Cash Flow Post-Debt Service and Reserves line.

The Overall Impact of the Debt Service Reserve Account

The DSRA reduces the Equity IRR because it delays or reduces distributions of earlier cash flows to the equity investors.

Without the DSRA, they would earn the “Cash Flow Post-Debt Service” starting in Year 1.

But because of the need to build up this Reserve, these distributions are delayed:

The DSRA reduces the lenders’ risk at the expense of the equity investors’ returns.

Added Complexities in the Debt Service Reserve Account in Full Models

This is a simple example of a DSRA, but the sky is the limit when it comes to complexity in Project Finance models.

A few additional features that increase the real-life complexity are as follows:

1) Variable Forward-Looking Periods and Non-Annual Models – Some models offer the option to provision for the Debt Service any number of quarters or months in advance, which means that functions such as OFFSET may be required:

Also, the base setup is more complex in these monthly and quarterly models due to the need to modify the standard annual assumptions.

2) Different Trigger Conditions – While the DSRA traditionally exists to ensure that lenders are paid properly, it could be linked to other conditions, such as a DSCR requirement or even something like the Interest Coverage Ratio.

3) Interactions with Other Reserve Accounts – Most real-world Project Finance models have cash flow waterfalls, in which the various Reserve Accounts are ordered and prioritized.

It can be tricky to determine the correct “order of operations” here, as other Reserve Accounts and features like the Cash Trap may also interact with the DSRA: