Installation of a photovoltaic system allows self-consumption of renewable energy with a minimal carbon footprint. This choice translates into energy and cost savings and is quickly becoming a common denominator in the creation of energy communities.
Installation of a photovoltaic system is certainly the smartest way to cut the cost of bills whilst also reducing carbon emissions. For those who have already decided to go down this route, it is important to complete certain crucial steps for solar-panel installation, to guarantee a properly functioning and legally-compliant system. The first prerequisite for installation is that you are the owner of the property or you have authorisation from the owner.
It is essential to consult a qualified technical expert that will guide you through project development. Your technical consultant will perform an assessment and identify the main features of your property. Precise criteria have to be met to ensure feasibility and cost-effectiveness of the installation:
- Roof orientation: a south-facing direction is ideal for solar panel installation on a pitched roof. South-east and south-west facing roofs can also be considered: yields will be lower, but still good. Increased irradiance is also achieved with optimal roof inclination, ideally between 30° and 35° at Italy’s latitude.
- Obstacles to irradiance: there must not be any obstacles present in the trajectory of solar rays that may cast shadows and compromise the system’s yield.
- Roof dimensions: the maximum size of panels is determined by the usable surface area. Generally speaking, a 3 kW system requires around 20 m2, but your technical consultant will advise you on the best set-up for your needs.
- Environmental or visual-impact restrictions: your technical consultant may advise you to check whether the area you live in is subject to environmental or visual-impact restrictions. However, it is your responsibility to obtain further information from your local municipal authority.
Designing the photovoltaic system
Your technical consultant will consider the following when designing the system:
- Characteristics of your home
- Size of your household
- Consumption habits
Based on these factors, the consultant will introduce you to the various types of panels in monocrystalline or multicrystalline silicon or thin-film technologies using cadmium telluride, each with different yields and costs.
Another important consideration is: how do you want to manage excess energy? There are two alternatives: you can either feed it back into the national electricity grid or store it. The second option gives you more independence, even at times when the system is unable to generate energy, by relying on a storage system. This type of investment is becoming increasingly accessible to all users due to the reduction of prices and the presence of incentives and tax exemptions.
You can specify to your technical consultant which type of system you would prefer:
- Stand alone/off-grid: not connected to the national electricity grid and equipped with a storage system (best suited for properties that are not already connected to the national grid).
- Grid connected: connected to the national grid, allowing excess energy to be fed back into the grid in return for a reimbursement on your utility bill, or to be shared with other members of your energy community.
- Mixed: the system is both connected to the grid and equipped with storage systems. This type of system allows both self-consumption of energy generated at any time of day, and also permits sharing of excess energy with other consumers connected to the same transformer substation, if you belong to an energy community.
If you are happy with the design and quoted price, you can proceed by checking the authorisations required by your country regulation.
Installing the photovoltaic system
At this point, you can proceed with installation. The company responsible, together with the designer, will carry out the following activities:
- Preparation of worksite and safety measures
- Installation of support structures and photovoltaic modules
- Installation of inverter, electrical panel and storage system. If you already intend to share your energy with others, perhaps with your neighbours, this is the time to install a controller such as Regalgrid’s SNOCU for:
- Real-time monitoring and management of incoming and outgoing energy flows
- Optimisation and set-up of automatic management for charging and discharging cycles of the storage system
- Active control of all interconnected devices
- Wiring and testing of the photovoltaic system.
You can now go ahead and submit a request to the grid operator for connection to the national grid.
What to do after the installation
It is important to remember that a photovoltaic system has an extremely long lifespan compared to other technology. Annual maintenance helps to keep the modules in good condition, providing a more stable yield. The Regalgrid controller will help you to keep track of yields, better managing energy and monitoring consumption.
With the installation of a photovoltaic system for residential use, average data for self-consumption levels comes in at around 30% nationally, with the remaining 70% sold to the external electricity network. By adding an adequately-sized storage system (read our article on PV installations with storage systems), self-consumption levels around 65% can be achieved, reducing the amount of electricity sold to the external network to 35%. These figures can be explained by taking into account the fact that residential consumption is considerably higher in the evening and at night. To achieve 100% self-consumption for a single home, the battery needed would be so large that it would no longer be economically viable.
The situation is radically changed by the fact that now it is possible to create energy communities here in Italy. In this scenario, the storage systems of various homes, and therefore the solar panels of various roofs, can be part of a single distributed shared system. This is exactly what is achieved by Regalgrid® technology, which allows optimal combined management of multiple photovoltaic systems via communication with the various inverters and control of charging and discharging of storage units. Extremely high levels of self-consumption can be achieved, well beyond 90%. This collective self-consumption approach, no longer a secret, is the basis for energy communities, and Regalgrid plays an essential role.