Photovoltaic systems: what they are and how to save money

Even with the photovoltaic systems there may be wasteBy getting the cost-benefit ratio wrong, building an appropriately sized system, or choosing obsolete technology. These are reasons why, when choosing photovoltaic systems, you need to know exactly what options are available and understand how to save money.

WHAT ARE THE VARIOUS TYPES OF PHOTOVOLTAIC SYSTEMS?

Naturally, there are more than one type of photovoltaic system available on the market, each with different characteristics. The main ones that can be installed are the following:

• Stand-alone photovoltaic system (also called "off-grid"). This is an autonomous system, completely independent from the electricity grid. This means that it uses electricity generated at the moment to operate. Or when needed, if it is collected in a energy accumulator which it may or may not be equipped with.
• “Network-connected” system (also called "grid-connected"). As is easy to deduce, this is a type of system connected to the electricity grid, meaning it operates in a two-way exchange regime with it. In this case, the energy produced is used for self-consumption, and any unused energy is fed into the national electricity grid.
• “Hybrid” stand-alone systemThis type of system remains connected to the electricity grid, but primarily uses its own sources. It can also use a combination of these, for example, combining photovoltaic and wind power. It usually uses a battery. If none of these sources are available, it uses energy distributed by the electricity grid.

Photovoltaic systems are made up of silicon photovoltaic cells 99% pure. Based on the different types of the latter, the following three types can be distinguished:

• Monocrystalline silicon panelsThey are recognizable by their dark blue, black color and are characterized by excellent performance and efficiency. The average power of a standard module is around 150-180 watts.
• Polycrystalline silicon panelsThese cells are iridescent blue in color and are cheaper to produce. However, they perform well and are similar in efficiency to monocrystalline cells, but their cost is lower.
• Amorphous silicon panels: they are characterized by a lower yield of approximately 30%. Performance and efficiency are lower than the first two, but they boast good adaptability to high temperatures.

Recall that the efficiency of a photovoltaic system It depends on at least two factors, namely the actual production of the system on the roof and the ways in which the energy produced is used (which is often a mix between consumption ed grid entry (of energy that is not self-consumed). And that the actual yield is influenced by the power of the system, the physiological deterioration of the panels' performance over time, the orientation and inclination of the latter as well as the place of installation.

ALSO READ: Balcony photovoltaics: costs and performance

HOW TO SAVE MONEY WITH PHOTOVOLTAICS

Photovoltaic systems produce electric energy taking advantage of the sunlightThey capture it and convert it into electricity that can be used at home. Mount the solar panels allows you to generate renewable electricity, even if the cost of installing a photovoltaic system is certainly not cheap, and in fact the saving It's in the long run. Although sunlight is free, the initial investment must be taken into account. Therefore, savings must also include the cost of installation.

That being said, electricity costs will actually be reduced. Not only that: combining the photovoltaic system with other renewable technologies – solar systems for hot water or heat pumps, for example – costs will be further reduced. Finally, whatever type of system you decide to install, at certain times the electricity generated will be greater than that used or stored. Therefore, you can choose to export the electricity to the grid. surplus and get paid for it.

HOW MUCH CAN YOU SAVE PER YEAR WITH PHOTOVOLTAICS?

The savings resulting from the use of a photovoltaic system are essentially equivalent to the cost of all the energy you can self-consume. However, considering that not all self-produced energy is self-consumed, the economic return deriving from the system must also be taken into account.export of excess energy to the grid.

That said, if we start from the assumption that each kilowatt hour of self-produced electricity is a kilowatt hour that is saved on the bill, if a user's requirement is 12 kWh per day and, with his photovoltaic system, he manages to produce or consume them, then it means that the cost of the electricity bill will be equal to 0.

Let's take a 3 kW system as a reference and assume that the average annual energy produced by it is approximately 3.272 kWh and the average annual consumption is approximately 2.880 kWh. Furthermore, let's assume that the average annual energy exported to the electricity grid is just under 1.728 kWh and self-consumption is equivalent to approximately 40% (with a savings of approximately €400), while the sum received from the Electricity Services Manager is €215,00. Well, the total savings will be approximately €610This figure could be even higher if the system is located in Southern Italy and is used for self-consumption for 70%.

WHAT DO YOU PAY ON YOUR BILL WITH PHOTOVOLTAICS?

Once the photovoltaic system is installed, this should lead to a reduction in energy withdrawal from the grid. This reduction is followed by a reduction of energy costs and therefore an immediate saving in bill. In essence, in bill Only the cost of energy purchased from the grid is covered (deducted from the unused energy produced by photovoltaic panels). This is thanks to the collaboration between photovoltaic and energy companies. In this regard, since customers not only have the full right to freely choose their energy supplier, but also to choose the best contractual conditions, a Guide to changing your electricity supplier, which turns out to be a much simpler operation than you might think.

HOW LONG DOES IT TAKE TO RECOVER THE INVESTMENT IN PHOTOVOLTAICS?

This depends on a number of factors. First and foremost, the size of the solar panel system installed, self-consumption (and the resulting savings on your bill), and the money earned by exporting excess energy to the national grid. And, of course, the initial investment for its installation. Based on an average calculation, without benefiting from tax deductions, the costs incurred for the system's construction they pay for themselves in approximately 7-10 yearsIf you have taken advantage of the available benefits, the timeframe is reduced to between 4 and 7 years.

WHAT ARE THE TAX INCENTIVES FOR PHOTOVOLTAIC SYSTEMS?

Among the building renovation interventions planned for access to the tax benefits This benefit also includes the installation of a photovoltaic system on the roofs of houses. This benefit, which consists of the possibility of deduct 50% from personal income tax All taxpayers subject to personal income tax are eligible for the reimbursement of costs incurred (including VAT) for the construction of a photovoltaic system. The maximum expenditure limit is €96.000.

In addition to being able to benefit from the 50% home bonus, in certain cases, such as when other specific jobs are already being carried out, you can enjoy the superb 110% as “pulled” work. The new Budget Law has extended the deadlines of the Ecobonus, extended until December 31, 2024, and also there credit transfer and invoice discount, which allow for a 50% or 65% reduction in bill costs, which can be benefited when installing photovoltaic systems, storage systems, solar thermal systems, or heat pumps.

ALSO READ: Solar panels, the best solutions for saving. A turnkey home solution.

PHOTOVOLTAIC PROS AND CONS

Wanting to examine the pros and cons of a photovoltaic system For the sake of completeness, we can state that the advantages associated with this include:

Pro

• Source renewable energy
• Reduction in the cost of electricity bills
• Tax and bureaucratic benefits
• Various applications
• Low maintenance costs
• Technological development
• Reducing your environmental impact

While the disadvantages that must be considered include:

Cons

• Cost (installation)
• Dependence on weather conditions
• Cost of solar energy storage
• Using a lot of space

HOW TO SAVE ENERGY AT HOME:

• How to save on heating by adjusting your thermostat correctly
• App to save energy at home, monitor and keep track of consumption and avoid waste
• Smart metering: how it works to reduce waste and save on electricity bills. The Open Meter system provides real-time consumption information (photos)