Photovoltaic in the bill: complete and operational guide

The photovoltaic system on the bill is an innovative formula that allows the installation of a solar system without bearing the entire cost upfront, by paying monthly installments directly integrated into the electricity bill. A simple, accessible, and sustainable solution, designed for families and small businesses wishing to reduce energy costs and contribute to the transition towards renewable energies.

Differences compared to direct purchase, leasing, and operational rental

Unlike direct purchase, it does not require initial capital; compared to leasing or rental, it guarantees the transfer of ownership at the end of the contract, without additional interest or perpetual constraints.

When is it correct to talk about payment on the bill

The term “photovoltaic on the bill” is only used if the installments are included in the energy invoice and not in a separate financing: a single bill thus includes both consumption and the share of the system.

Technical-contractual aspects

The energy supplier also becomes the payment intermediary, offering clear contracts on installments, duration, guarantees, and included services. It is not a traditional bank loan, but a complete energy package with integrated installation and management.

Who is responsible for the design and installation

Electricity and gas supplier, installers, and owner of the system

The first actor is the energy supplier, who proposes the photovoltaic contract on the bill. They bill the installments together with the electricity consumption. Next to them is the installer, the company that carries out the survey, design, and installation of solar panels. Finally, there is the customer, who becomes the user of the system and progressively becomes the owner.

Who manages installments, energy, and additional services

The supplier manages the charges and often also handles the bureaucratic procedures. The installers take care of the technical aspects: installation, testing, guarantees, and maintenance. Some contracts also include additional services, such as insurance against damages or failures and monitoring of energy production via app.

Responsibilities regarding the design and installation of the photovoltaic system

The responsibility for correct design lies with the installer. They guarantee that the panels are properly sized, that the inverter is adequate, and that the system complies with CEI regulations. The supplier, on the other hand, is responsible for contractual transparency and the correct application of the installments on the bill.

Eligibility requirements

Type of customer: residential, condominium, or small business

The photovoltaic system on the bill is primarily aimed at families and small businesses. In some cases, it can also be extended to condominiums, but this depends on internal regulations and the availability of suitable surfaces.

Building conditions: roof, solar exposure, urban planning constraints

It is not enough to have a supply contract: the building must be suitable. The roof must have optimal exposure, preferably south-facing, without shading. In areas subject to urban regulations, special permits may be required to install the panels.

Required documentation and technical feasibility checks

Before signing the contract, the supplier requests recent bills, land registry documents, and photographs of the roof. A technical survey follows, which is essential for verifying space, inclination, and stability of the covering. Only after this phase is the definitive offer made.

How it works, step by step

From the quote to the survey for solar panels

The process begins with a request for a quote, often online. After the preliminary analysis, a technician visits the dwelling to assess the conditions. This phase allows for estimating the annual production and potential savings.

Monthly installment plan integrated into the electricity bill

If the offer is accepted, a plan for monthly installments is defined. The amount varies based on the power of the system, the duration of the contract, and the included services. The installments appear in the electricity bill, along with the items related to consumption.

Installation, testing, and activation of production from renewable sources

The installer proceeds with the mounting of the panels, the connection to the inverter, and the connection to the electrical grid. A technical test follows to certify safety and compliance with standards. Once activated, the system starts producing energy immediately.

Transfer of ownership of the system at the end of the contract

Upon the expiration of the installment plan, the system becomes the property of the customer. This means that, from that moment on, the energy produced is entirely free, net of ordinary maintenance.

Cost structure and bill reading

The photovoltaic system on the bill is based on a monthly expenditure made up of two main items: the cost of the electricity actually consumed and the installment for the photovoltaic system. In this way, the bill becomes a unique tool that encompasses both energy expenditure and investment in the system.

• Implicit initial investment and savings → there is no immediate outlay, but the installment incorporates the costs of modules, inverter, installation, and ancillary services. At the same time, self-production reduces withdrawals from the grid and thus the amount of the bill.

• Spending breakdown → suppliers clearly distinguish between the consumption share and the system installment share, making the reading of the invoice transparent. Some operators attach examples or monthly simulations to help customers monitor the benefits obtained.

• Additional costs → these may include bureaucratic procedures, installation of the bidirectional meter, or insurance, depending on the signed contract.

• Practical reading of the bill → invoices show not only the electrical consumption but also self-consumption and withdrawals from the grid. This helps to understand how much is saved thanks to the panels and how much still comes from the national grid.

Contractual models compared

Fixed installments on the bill vs. variable installments linked to the kilowatt-hour cost

In some contracts, the installments are fixed and independent of the energy price trend. In others, however, they are linked to the cost of the kilowatt-hour or to market indicators, making the expenditure less predictable.

Typical duration and early exit clauses

The average duration of these contracts varies between 8 and 12 years. In the case of early withdrawal, penalties or payment of the remaining installments may be provided.

Redemption options and long-term economic benefits

Many suppliers provide the possibility of redeeming the system early by paying the remaining balance. This option is interesting for those who, after a few years, have liquidity and want to immediately reduce the installments.

Integration with incentives and national mechanisms

One aspect that makes photovoltaic on the bill even more interesting is the possibility of combining it with incentives and benefits provided at the national or European level. Each country has specific tools to promote the spread of renewable energy: in some cases, these are incentive tariffs for energy fed into the grid (feed-in tariff), in others tax bonuses or grants for the installation of solar systems.

An additional advantage comes from direct self-consumption: the energy produced and consumed on-site reduces the need for electricity purchased from the grid, lowering the bill. Where production exceeds consumption, the excess can be fed back to the national electricity system and valued according to local market rules.

Finally, renewable energy communities (REC) and models of collective self-consumption are growing throughout Europe, allowing multiple families or businesses to share the energy generated by a common system. Some suppliers are beginning to offer “on-bill” packages integrated with these solutions, opening new opportunities for savings and collaboration.

Analysis of economic convenience

Calculation of savings on the bill and return on investment

To determine if photovoltaic on the bill is convenient, it is useful to compare the amount of the installments with the estimated savings of the system. In favorable conditions (good irradiation, sustained daytime consumption, well-sized system), a family with about 3,000 kWh/year of consumption could reduce energy expenditure by 30–50%. If the installments are adequate and the design is well done, the monthly bill may be similar to or lower than the current one, with the progressive advantage of acquiring ownership of the system.

Impact of energy prices and household consumption

Convenience increases with rising energy prices. In a context of volatility in the electricity market, having a photovoltaic system allows stabilizing costs over time. The consumption profile is also decisive: those who use energy mainly during the day maximize self-consumption and achieve a quicker return.

Comparison with direct purchase and bank financing

Compared to direct purchase, photovoltaic on the bill has slightly higher overall costs but eliminates the initial barrier. Compared to a bank loan, it offers simplified management integrated into the bill, with less bureaucracy for the customer.

Typical use cases

The photovoltaic system on the bill can adapt to different scenarios:

• Apartment with low consumption → accessible solution, more gradual return but without initial investment.

• Independent house with heat pump or electric car → ideal context to maximize self-consumption and offset the monthly installment.

• Small businesses with daytime activities → stabilization of energy costs and greater predictability in budgets.

• Second home or seasonal residence → lower impact on direct consumption, but possibility of valuing excess energy through net metering or energy communities.

Risks, limitations, and how to protect oneself

Risk of overall costs being higher than direct purchase

The main limitation of photovoltaic on the bill is that, in the end, the total cost of the system may be higher than immediate purchase. This is because the installments can include interest and ancillary services.

Contractual constraints and changing the electricity and gas supplier

Another critical point concerns the freedom to change suppliers. During the duration of the contract, the customer is bound to that specific operator, and early withdrawal may incur penalties.

Guarantees on modules, inverters, and photovoltaic maintenance

It is essential to verify that the contract provides adequate guarantees on the modules (25 years) and on the inverter (at least 10 years). Some packages include ordinary maintenance, which prevents future surprises.

Insurance coverage in case of damage or failure

Many suppliers offer insurance against atmospheric events, fire, or malfunctions. It is crucial to carefully assess these clauses to avoid unexpected expenses.

Essential legal and regulatory aspects

The photovoltaic contract on the bill must clearly specify the nature of the agreement: sale with deferred payment, provision of services or mixed formula. It is essential to establish from the outset when and how the system will become the property of the customer.

The systems must comply with the European directives on energy efficiency and electrical safety, which represent the minimum common standard in EU countries. Suppliers and installers must ensure that the modules and inverters are certified and comply with the regulations in force.

One increasingly relevant issue concerns privacy: monitoring systems and smart meters collect data on consumption and production. This information must be managed in full compliance with the General Data Protection Regulation (GDPR), ensuring that it is used exclusively for energy and billing purposes.

Sizing and technical quality of the system

The technical quality of a photovoltaic system on the bill directly affects the convenience of the investment. During the design phase, it is important to choose solar panels with high efficiency, reliable and correctly sized inverters, and, when possible, integrate storage systems that allow leveraging energy even during evening hours. 

The batteries increase self-consumption and reduce dependence on the grid, while remote monitoring systems allow real-time checking of production and consumption. Even without going into technical details, the message is clear: the better the system is designed and equipped with quality components, the more the customer benefits from tangible savings and a stable economic return over time.

Tax impacts for families and businesses

The tax treatment of photovoltaic on the bill varies from country to country, but across Europe, there are measures of support dedicated to renewable energies.

For families, some States provide reduced VAT rates or tax deductions for those installing a domestic system. Even when payment is made via the bill, the installments are often considered as expenditure for energy goods and services, thereby falling within the expected benefits.

For businesses and professionals, the photovoltaic system represents a capital asset: this means that the cost can be included among depreciation and, in some cases, benefit from tax credits or incentives for energy transition.

The fundamental rule is to check local regulations and always keep documentation related to the contract, invoices with the system share, and technical certifications, so as to access the available benefits without issues.

Checklist before signing

Before signing a photovoltaic contract on the bill, it is essential to carry out some practical checks:

• Key questions to the supplier → clarify total cost of the system, duration of the installment plan, any penalties for early withdrawal, coverage of guarantees, and inclusion of additional services.

• Economic parameters to request in writing → amount of each installment, APR, total cost, included services (insurance, maintenance, monitoring). This allows for an objective comparison between multiple offers.

• Method of comparing suppliers → it is useful to enter data into a spreadsheet with installments, duration, estimated savings, and tax benefits; this way, you get a clear picture of the convenience.

• Contractual clauses to carefully verify → changing supplier during installments, early redemption options, responsibilities in case of failures or malfunctions of the system.

This checklist allows you to reach the signature fully aware, reducing risks and maximizing the economic and practical benefits of the investment.

Conclusions and next steps

The photovoltaic system on the bill represents a concrete alternative to direct purchase: it eliminates the barrier of the initial investment and allows for immediate savings, turning the bill into an investment tool for the future. It is especially advantageous for those who consume a lot of energy during the daytime and want a turnkey approach, while keeping in mind that the overall cost may be slightly higher. The advice is to request savings simulations from several suppliers, carefully evaluate clauses and guarantees, and choose the solution that best fits your energy and economic needs.