How Lenders Should Value Solar and BESS Collateral Before Financing a Project

Date :

16/9/2026

When a lender finances a $50 million solar or battery storage project, there are really two assets being underwritten.

The first is the project's ability to generate cash
The second is the physical equipment sitting behind the loan

Most project finance models spend considerable time on the first. Revenue forecasts, PPAs, DSCR, operating expenses, production assumptions, tax benefits, and counterparty risk are modeled carefully. But the second question can be surprisingly difficult to answer:

If the borrower defaults, what is the collateral actually worth?

For solar PV and battery energy storage systems (BESS), the answer should not simply be the project's original construction cost minus depreciation. Equipment prices change, technology changes, battery condition changes, secondary markets change, Commodity prices move and even recovery options develop.

The result is that the value sitting behind a renewable energy loan can look very different from the value assumed when the project was originally financed. For lenders, that makes solar and BESS collateral valuation an underwriting question, not simply an appraisal exercise.

Why Renewable Energy Collateral Valuation Is Becoming More Important

The amount of renewable infrastructure entering the financing market is growing rapidly.

U.S. utility-scale battery storage capacity reached nearly 52 GW by June 2026, after averaging approximately 70% annual growth during the previous three years, according to the U.S. Energy Information Administration.

Solar is already operating at a significantly greater scale. Total U.S. solar photovoltaic capacity reached approximately 209 GW in 2025, including utility-scale and small-scale installations.

More assets mean more construction loans, term loans, refinancing transactions, portfolio acquisitions, tax structures, and private credit facilities where renewable equipment ultimately forms part of the lender's collateral package. But greater deployment does not necessarily make the collateral easier to value.

In fact, rapidly changing equipment markets can make historical project costs less useful. The International Energy Agency reported that solar PV prices fell approximately 20% during the first half of 2024 alone, while grid-scale battery storage prices declined almost 10%.

For a lender, this creates an important distinction: What the borrower spent building the project is not necessarily what the collateral is worth today.

The Problem With Using Project CAPEX as Collateral Value

Imagine a project cost $100 million to construct. That number includes far more than recoverable equipment.

Project CAPEX may contain:

EPC margins
engineering and design
development expenses
permitting
interconnection costs
construction labor
financing costs
site preparation
taxes
logistics
developer overhead
modules, batteries, inverters and other equipment

Some of those costs contributed to creating the operating project. They do not necessarily represent assets that a lender could sell or recover after default.

Even the physical equipment itself may no longer command pricing comparable to its original procurement cost. Berkeley Lab found that utility-scale solar installed costs declined roughly 75% between 2010 and 2023, averaging approximately a 10% annual reduction over that period.

A depreciation schedule applied to historical CAPEX therefore does not automatically produce a current market value. It produces an accounting assumption. Those are not the same thing.

So, What Value Should a Lender Actually Use?

There is no single renewable energy asset value that answers every lending question. A lender should understand at least three different values before relying on the equipment as collateral.

1. Replacement Cost New

Replacement Cost New (RCN) estimates what it would cost to replace the existing equipment with an equivalent asset using current market pricing. RCN can help lenders understand the current economic scale of the equipment and is particularly relevant when reviewing insurance coverage and replacement exposure. But replacement cost should not automatically become collateral value. A lender facing default generally will not purchase new equipment to replace the collateral.

The lender needs to understand what can actually be recovered from the equipment already installed.

That brings us to market value.

2. Current Market Value

Market Value estimates what the existing equipment is worth under current market conditions. This requires more than applying an annual depreciation percentage.

A useful solar or BESS market valuation should consider factors including:

manufacturer and model
equipment vintage
remaining useful life
operating history
physical condition
technical specifications
current equivalent equipment pricing
secondary-market demand
technology obsolescence
location
removal and transportation economics

For BESS assets, the analysis becomes even more asset-specific. Battery chemistry, state of health, remaining capacity, cycle history, warranty position, system configuration and technology generation can materially influence what another buyer might pay for the equipment. That means two battery systems with the same original CAPEX and commissioning year may not carry the same collateral value.

3. Salvage and Recovery Value

The third number lenders should understand is salvage value.

This asks a different question: If the equipment cannot economically remain in service or be resold as operating equipment, what value can still be recovered?

Depending on the asset, recovery pathways may include:

resale
reuse
refurbishment
component harvesting
recycling
commodity recovery
scrap

This number becomes especially important when lenders model severe downside scenarios. A project may stop producing the cash flow assumed in the underwriting model without its physical equipment becoming economically worthless.

That distinction matters. Assigning zero residual value may appear conservative, but it can also obscure real recoverable collateral value and distort the economics of a financing decision.

Replacement Cost, Market Value and Salvage Value Are Not Interchangeable

Consider a simplified example. Suppose a solar project originally cost $80 million. A lender reviewing the project several years later might encounter three very different numbers:

Valuation

What It Answers

Replacement Cost New

What would equivalent equipment cost today?

Market Value

What is the existing equipment worth in today's market?

Salvage Value

What could be recovered through resale, recycling or other disposition pathways?

None of these numbers is inherently the "correct" value. They answer different questions. For lending, the objective should be to understand the collateral across several scenarios rather than forcing every decision onto one number.

A Better Framework for Solar and BESS Collateral Valuation

Before financing a renewable energy project, lenders can evaluate collateral through six layers.

Step 1: Build a Component-Level Asset Inventory

Start with what actually exists.

For solar projects, this may include modules, inverters, trackers, transformers and related balance-of-system equipment
For BESS, the inventory may include battery cells or modules, racks, enclosures, PCS equipment, thermal management systems, transformers and control infrastructure

Manufacturer, model, quantity, capacity and commissioning year should be identified wherever possible. A $100 million project is not one asset. It is thousands of individual assets with different recovery characteristics.

Step 2: Establish Current Replacement Economics

Determine what comparable equipment costs today. Historical EPC contracts can provide context, but they should not substitute for current market intelligence. Renewable equipment pricing can move significantly during the life of a loan. That means collateral analysis should be tied to today's market rather than yesterday's procurement environment.

Step 3: Determine Current Secondary-Market Value

Next, evaluate whether the equipment has an observable resale or reuse market.

The analysis should incorporate actual market evidence where available, including transaction data, dealer markets, secondary equipment pricing and comparable equipment. This is where generic depreciation schedules become particularly weak. Equipment does not lose economic value in a perfectly straight line. Technology, condition, demand and market liquidity all influence the curve.

Step 4: Model Salvage and Recovery Pathways

If resale is not viable, what happens next?

The lender should understand alternative recovery pathways and their economics. That includes recycling and commodity recovery, but also refurbishment, reuse and component resale where applicable.

The question is not simply: What is the asset worth if everything goes right?

It is also: What could still be recovered if things go wrong?

Step 5: Apply Asset-Specific Risk Factors

Solar and BESS should not be treated as interchangeable collateral. For solar assets, relevant considerations can include module degradation, inverter condition, equipment compatibility, technology vintage and remaining project life.

The U.S. Department of Energy notes that a typical photovoltaic system performance period is approximately 20 to 30 years, but individual equipment condition and remaining economic life still need to be assessed. For BESS, valuation may need to incorporate state of health, cycle count, chemistry, degradation, warranty coverage and technological obsolescence.

This is why a simple "$/MW" benchmark is rarely sufficient for a defensible collateral valuation.

Step 6: Stress-Test the Recovery Scenario

Finally, lenders should ask what happens under different outcomes.

For example:

Base case: The project continues operating normally
Refinancing case: The borrower refinances or sells the project before maturity
Distress case: The project continues operating but requires restructuring
Liquidation case: Equipment must be sold into the secondary market
Recovery case: Equipment cannot be resold economically and must be refurbished, recycled or scrapped.

A lender that understands collateral across these scenarios has a much clearer view of downside exposure than one relying on a single depreciated project value.

Why BESS Requires Its Own Valuation Logic

Battery storage deserves particular attention because the U.S. BESS market is expanding exceptionally quickly. Nearly 52 GW of utility-scale battery storage was operational in the United States by June 2026, and operators reported plans for another 54 GW over the following two and a half years.

But rapid deployment also means rapid technological change. A battery system's collateral value can be influenced by:

battery chemistry
system architecture
state of health
remaining usable capacity
cycle history
warranty coverage
manufacturer support
safety history
augmentation requirements
replacement battery pricing
secondary-market liquidity
commodity recovery value

The original purchase price tells a lender relatively little about many of these factors. A BESS valuation therefore needs to follow the actual asset, not simply the accounting schedule attached to it.

Collateral Value Should Not Stop Moving After Closing

There is another problem with traditional renewable energy collateral analysis. It usually happens once.

An appraisal is completed during underwriting, the loan closes, and the valuation enters the credit file.

But the market keeps moving
Solar equipment pricing changes
Battery pricing changes
Commodity markets move
Assets degrade
Secondary-market liquidity develops
New technologies enter the market.

For a five, ten or fifteen-year financing facility, the collateral value at origination may tell the lender relatively little about recovery value several years later. Renewable energy collateral should therefore be monitored throughout the life of the loan, particularly around refinancing, covenant reviews, portfolio reviews, restructurings and material market changes.

How Buckstop Helps Lenders Value Solar and BESS Collateral

Buckstop is built specifically around the valuation problem facing renewable energy lenders. Instead of relying solely on historical project costs, generic depreciation schedules or fragmented equipment research, Buckstop's Valuation Studio gives lenders market-backed renewable energy asset intelligence across three core valuation workflows:

Replacement Cost New: Understand what equivalent equipment would cost in today's market.

Market Value: Estimate the current value of existing solar and BESS equipment using market intelligence and secondary-market evidence.

Salvage Value: Understand potential recovery through resale, refurbishment, recycling and commodity pathways.

Buckstop's valuation methodology combines real-world transactions, secondary and scrap markets, technical specifications, economic context and recovery history. The platform currently includes more than 1.3 million assets, uses 22+ commodity and secondary-market data sources, and has analyzed more than 3,000 MW of solar and storage capacity.

For lenders, this means collateral assumptions can be supported by current market evidence rather than static assumptions.

When a Certified Appraisal Is Required

Not every financing decision requires the same level of documentation. For initial screening, portfolio analysis or ongoing monitoring, an on-demand market valuation may provide the intelligence a lender needs.

For credit decisions where the valuation needs to be independently documented and defended, lenders may require a formal appraisal. Buckstop also provides USPAP-compliant Certified Appraisals for solar PV and BESS assets, backed by current market intelligence and professional appraisal review.

Certified appraisals can support:

project financing
underwriting
collateral analysis
refinancing
credit committee review
portfolio transactions
financial reporting
distressed asset situations

Buckstop delivers certified renewable energy appraisals in approximately 10 business days, while maintaining the underlying market intelligence required to support the valuation.

What Lenders Should Ask Before Financing a Solar or BESS Project

Before approving a facility backed by renewable energy assets, credit teams should be able to answer several questions:

What is the current replacement cost of the equipment?
What is the existing equipment worth in today's market?
What secondary markets exist for the equipment?
What could realistically be recovered after default?
What is the salvage value if resale is not viable?
How does equipment condition affect the valuation?
How quickly could the collateral be liquidated?
How sensitive is the valuation to equipment and commodity prices?
What evidence supports the valuation?
How will the collateral value be monitored after closing?

If those questions cannot be answered, the lender does not yet have a complete picture of the collateral.

The Bottom Line

Renewable energy project finance has historically been built around forecasting what a project will earn. Lenders increasingly need equal visibility into what the underlying assets could recover.

For solar and BESS projects, historical CAPEX, book value and generic depreciation schedules cannot fully answer that question. A stronger collateral assessment separates Replacement Cost New, current Market Value and Salvage Value, then tests those values against real recovery scenarios.

That gives lenders something much more useful than another number in the underwriting model. It gives them a defensible view of what sits behind the loan.

Before financing your next solar or BESS project, know what the collateral is actually worth.

Buckstop's Valuation Studio provides market-backed replacement, market and salvage valuations for solar and battery storage assets, with traceable data and confidence-scored outputs built for lending and project finance decisions.

Get your first valuation free and evaluate the collateral before capital is committed.

Frequently Asked Questions

How should lenders value solar project collateral?

Lenders should evaluate solar collateral using current asset-level market data rather than relying only on historical project CAPEX or accounting depreciation. A complete assessment should consider Replacement Cost New, current Market Value, secondary-market demand and Salvage Value.

How is BESS collateral valued?

BESS collateral valuation considers equipment specifications, battery chemistry, state of health, remaining capacity, cycle history, warranty status, technology vintage, current replacement pricing, secondary-market demand and potential recovery value.

What is residual value in renewable energy project finance?

Residual value is the economic value that remains in solar, battery storage or other renewable energy equipment over time. Depending on the asset and scenario, value may be recoverable through continued use, resale, refurbishment, recycling or commodity recovery.

Should lenders use replacement cost as collateral value?

Not by itself. Replacement Cost New estimates what equivalent equipment would cost today, while collateral analysis generally also requires understanding what the existing equipment could sell for or recover in a distress scenario.

Why is historical CAPEX not enough to value solar or BESS collateral?

Historical CAPEX includes costs that may not be recoverable, such as development, engineering, construction and financing expenses. Equipment prices and technology also change over time, so original project cost may differ materially from current asset value.

What is the difference between market value and salvage value for renewable energy assets?

Market Value estimates what existing equipment may be worth in the current market. Salvage Value estimates the amount that may be recovered through alternative disposition pathways such as recycling, scrap, component recovery or other end-of-life options.

How often should lenders revalue renewable energy collateral?

Collateral should be reviewed when material changes occur in equipment pricing, asset condition, secondary markets, commodity prices or the borrower's credit situation. Long-duration facilities may also benefit from periodic portfolio-level collateral monitoring.

Can solar panels and BESS equipment retain value after project default?

Yes. Depending on condition, technology, location and market demand, equipment may retain value through resale, reuse, refurbishment, recycling or commodity recovery. The appropriate recovery pathway should be evaluated using asset-specific and current market data.

Do lenders need a certified appraisal for solar and BESS financing?

Requirements depend on the financing structure, institution and transaction. When an independent, formally supported valuation is required for underwriting, credit review or another regulated decision, lenders may use a certified renewable energy appraisal.

What does Buckstop provide for renewable energy lenders?

Buckstop provides solar and BESS valuation intelligence for lenders and capital providers, including Replacement Cost New, Market Value and Salvage Value. Lenders can use Valuation Studio for on-demand valuations and portfolio monitoring or request a certified appraisal when an independent formal valuation is required.