Photovoltaics · 4 min read

Tax Treatment of Photovoltaic Direct Investments: Securing Returns, Optimising the Tax Burden

This guide refers to German law and the German tax system. It is a translation of our German original and does not replace individual tax or legal advice.

More and more private investors are discovering photovoltaics as a stand-alone investment or as a complement to property investments. The appeal is obvious: stable income over decades, predictable costs and the opportunity to generate calculable cash flow through state-guaranteed feed-in tariffs (Einspeisevergütung). Yet however attractive the economic opportunities may be, the tax treatment is decisive for long-term success. In Germany, photovoltaic systems are classified as a commercial activity for income tax purposes as soon as electricity is fed into the public grid for payment.

This raises questions about profit determination, depreciation and VAT, the answers to which vary depending on the size and use of the system – self-consumption or full feed-in. Those who structure their system correctly for tax purposes can noticeably reduce their tax burden while securing returns within their private assets. For many investors, photovoltaics is therefore not only a contribution to the energy transition but also an instrument of targeted tax optimisation.

Feed-in tariff: a source of income with tax implications

For most private operators, the feed-in tariff makes up the main component of income. It counts as business income and is therefore subject to income tax. This means that the tariff is added to taxable income, while business expenses such as maintenance, insurance or meter rental can be offset against it. What matters is that only the net amount counts as taxable income if the operator opts for VAT and claims input tax deduction (Vorsteuerabzug).

Since 2023, small systems of up to 30 kWp on single-family houses have been exempt from VAT. The rule is intended to reduce bureaucracy and promote investment. For investors, however, it can still make sense to waive the small business regulation (Kleinunternehmerregelung) and opt for standard taxation, particularly when acquisition costs are high and input tax deduction improves liquidity. An individual assessment with a tax adviser is worthwhile here.

Self-consumption and special tax features

Many private investors combine feeding into the grid with self-consumption. Self-used electricity reduces the amount of energy purchased from the utility, but for tax purposes it counts as a withdrawal from business assets (Entnahme). This withdrawal is usually valued at cost or at the market price per kilowatt hour. This increases taxable profit, although in practice the effect remains small, as self-consumption at the same time reduces the household's energy costs.

Anyone who uses a system primarily for self-consumption should, however, pay attention to the so-called hobby threshold (Liebhaberei). If there is no sustained intention to make a profit – for example, if the system makes permanent losses or is too small – the tax office (Finanzamt) can classify the activity as a hobby. In that case, the losses are no longer recognised for tax purposes, and acquisition costs or depreciation may no longer be claimed. A realistic income forecast is therefore indispensable.

Depreciation as a central tax advantage

The acquisition costs of a photovoltaic system can be depreciated over the standard useful life of 20 years (Section 7(1) of the German Income Tax Act, EStG). This straight-line depreciation reduces taxable profit by 5% of the investment costs each year. Alternatively, in certain cases there is the option of special depreciation under Section 7g EStG, provided the system is operated as part of a small business activity and the income threshold is observed.

In addition, investors can immediately deduct up to 20% of the investment costs as special depreciation in the year of acquisition if they meet the relevant requirements. This can be particularly useful in a year with a high tax burden, in order to offset income from other types of income (e.g. letting or capital income). Photovoltaics thus becomes a strategic tax instrument within private assets, with a clearly measurable relief effect.

Profit determination and tax classification

Taxable profit is usually determined using a cash-basis income statement (EÜR, Einnahmen-Überschuss-Rechnung). Here, all income (feed-in tariff, electricity sales where applicable) is set against business expenses (depreciation, interest, maintenance, insurance). The remaining surplus is subject to income tax. Filing a separate tax return for the photovoltaic system is mandatory as soon as feed-in revenue is generated.

Important: interest on financing the system is also deductible as a business expense. This allows investors to cushion the initial years with high financing costs for tax purposes and to secure liquidity. Ideally, a tax loss arises in the first few years that can be offset against other positive income – a legal and frequently used method of reducing the tax burden in a targeted way while building wealth in the private sphere.

Transferring the tax burden into private wealth with Neo Capital

The greatest advantage of a private photovoltaic investment lies in its tax transparency. Income flows directly into private assets without any additional taxation at company level. This makes the investment ideally suited to building wealth in a tax-optimised way while generating predictable energy income. What matters, however, is classifying the system correctly from the outset, particularly with regard to the intention to make a profit, the depreciation period and use (self-consumption vs. feed-in).

Those who make use of the scope for tax planning can achieve more with a photovoltaic system than just producing electricity. The combination of income, depreciation and liquidity advantages leads in many cases to noticeable tax relief. It is important to keep all documents such as invoices, maintenance contracts and income forecasts in full, in order to demonstrate the economic sustainability of the investment to the tax office.

Conclusion: properly planned for tax, economically well positioned

In 2025, photovoltaics is far more than an ecological investment; it is a highly interesting tax instrument for building wealth in the private sphere. Those who know the rules on profit determination, depreciation and self-consumption can manage their tax burden in a targeted way and secure income over the long term. Especially at times of high income tax burdens, the combination of stable returns and tax advantages is hard to beat.

Experience shows, however, that errors in tax classification or inadequate documentation can cause considerable disadvantages. Individual advice from experts helps to choose the optimal operating structure, avoid hobby-classification risks and exploit the full tax potential of a photovoltaic system. In this way, the energy transition becomes a personal return and tax advantage.