Valuation Reports for PV Systems and Battery Storage

How we value: technology, yield, value

Every report follows the same chain. Value follows from yield, and yield follows from technical condition.

1. TechnologyWe inspect the system on site: modules, inverters, mounting structure and cabling. Drone thermography, electroluminescence and IV curves reveal degradation and damage. From this we derive the remaining useful life.
2. YieldWe compare the actual yield from meter data with the expected yield and add revenue from the feed-in tariff, direct marketing, PPAs and self-consumption as well as running costs.
3. ValueFrom technology and yield we determine the asset value, income value and market value, and where needed the residual value at a later date.
4. TransactionThe report is tailored to the occasion: purchase, sale, financing, M&A, insolvency or court. Every assumption is disclosed and verifiable.

Which valuation do you need when?

Which factors go into a valuation report?

We weight more than 20 individual factors for each system. The most important ones:

Asset value and income value

Module prices have fallen sharply since 2010. As a result, the income value of a working system with a high feed-in tariff is often well above its asset value. Used systems of this kind can cost more than a comparable new system.

Which documents do we need?

• Yield dataFeed-in statements from the grid operator and monitoring data for recent years.
• ContractsCommissioning record, direct marketing or PPA, roof lease, maintenance, insurance.
• System documentationData sheets, string plan, acceptance record, entry in the market master data register.
• OperationMaintenance and inspection records, faults, repairs, replaced components.
• Battery storageBMS data, cycle history, temperature logs, revenue records.

If anything is missing, we agree in advance how to close the gap.

Which valuation methods are there?

• Income approach (DCF)Standard for PV systems and solar parks. Present value of future surpluses after replacement investments and decommissioning.
• Asset valueReplacement cost less ageing. Important for insurance and self-consumption systems.
• Comparative valuePrices paid for comparable systems. Published transactions are rare, so it is mostly used as a plausibility check.
• Scenario analysisContinued operation, repowering, adding storage or decommissioning compared. Shows which option has the highest value.

Valuing battery storage (BESS)

For storage, cell ageing is the key variable. The chain stays the same:

1. TechnologyState of health (SOH) from capacity measurement and BMS analysis, cycle history, thermal stress, calendar life remaining.
2. YieldRevenue from balancing services (FCR, aFRR, mFRR), arbitrage and self-consumption optimisation.
3. ValueIncome value (DCF) over the remaining life, pending replacement investments.
4. TransactionBankability for financing, purchase and sale.

The basis is IEC 62619 and IEC 63056, and VDE-AR-N 4110 and 4120 for the grid connection. More on the BESS assessment page.

Rooftop, self-consumption or solar park

For self-consumption systems on private and commercial roofs, asset value and saved electricity costs carry more weight. Solar parks and large rooftop systems are valued using the income approach. There, tariff term, operating costs, lease, grid connection and permits determine the value.

What does a valuation report cost?

The price depends on scope and occasion. The main factors:

• System size and number of sites
• Scope of the on-site inspection
• Measurements such as thermography, electroluminescence and IV curves
• Rooftop system, solar park or battery storage
• Private report or court report
• Time pressure, for example in insolvency or price negotiations

You receive a free fixed-price quote in advance. After your enquiry we usually get back to you within 24 hours.

Who prepares valuation reports for PV systems?

PV systems are valued by photovoltaic experts, technical assessors and valuation firms specialising in energy assets. A reliable result needs technical inspection, yield analysis and economic valuation in one report.

At PV-BESS-Assessor, both come from one source. We are TÜV-certified experts and value systems of every size in Germany and Europe. Every report is based on an on-site inspection with measurements and a calculation for that specific system. We do not use flat-rate depreciation tables. Our reports have stood up in court proceedings and transactions. More on our qualifications.

Want to calculate it yourself first?

Our value calculator estimates the income value of your system in two minutes. It works with fixed assumptions. Solar market values, interest rates, component prices and demand for existing systems change continuously. We determine the value at the market conditions on the valuation date in a valuation report.

Frequently asked questions