What is Solar Energy and how does it work?

Solar energy represents the primary resource of renewable energy available on the planet. The most well-known system for harnessing solar energy is undoubtedly the photovoltaic system, capable of converting solar radiation into electrical energy.

The efficiency of a photovoltaic system depends mainly on the insolation of the location where it’s installed, along with other variables like the orientation and tilt of the panels, energy losses, etc.

To precisely determine the insolation value based on the installation location, I suggest using specific photovoltaic software, which estimates photovoltaic solar production from concrete solar insolation data, available for many locations in Italy and abroad.

Let’s delve into the characteristics of solar energy, how it’s utilized, and the advantages and disadvantages stemming from its use.

What Is Solar Energy?

Solar energy is the primary source of renewable energy on Earth. It’s an inexhaustible and completely clean source, as it doesn’t produce either carbon dioxide emissions or fine particles into the atmosphere.
The applications of solar energy are diverse, and harvesting this energy has become increasingly simple and accessible over the years.

How to Harness Solar Energy

Solar energy can be harnessed through photovoltaic, thermal, and thermodynamic energy:

• Photovoltaic energy: Photovoltaics master the photovoltaic effect, where solar radiation converts into electricity through photovoltaic panels. Here, semiconductors, struck by solar light particles, generate direct current, later transformed into alternating current for use, fed into the public grid, or stored for use when the system isn’t producing;
• Solar thermal energy: In this case, solar energy is used to heat water or spaces, both residential and commercial. The thermal collector is the main component of a solar thermal system, tasked with heating a liquid, called a heat transfer fluid, which then moves within the system, carrying heat to the desired areas;
• Thermodynamic energy: Couples a heat pump with the solar thermal system, ensuring continuous operation throughout the day and year, even when solar energy isn’t directly available. The system can operate without limitations, regardless of weather conditions.

Solar Energy: Advantages and Disadvantages

The use of solar energy presents some positive and negative aspects. The main advantages are:

• Availability: The sun represents an inexhaustible source of renewable energy, accessible even in the most remote regions;
• Cleanliness: Utilizing solar energy generates clean energy, helping to reduce CO2 emissions and protect the environment;
• Costs: Solar energy is cost-effective as it doesn’t involve production, transportation, or supply costs. Given the rising costs of electricity, this solution could help reduce bills;
• Investment amortization: Despite the initial investment being significant, it’s amortized over time, with a return on investment within a few years;
• Savings on bills: With a photovoltaic system with storage, energy savings of up to 90% on the electricity bill are achievable, allowing the use of appliances even at night.

As for the disadvantages, these include:

• Low efficiency of solar installations: Currently, photovoltaic and thermal installations only produce a fraction of the sun’s potential energy;
• Lack of space: Given the low concentrations of solar light, solar installations require rather extensive areas. This entails a landscape or economic impact, as it takes away useful land for other purposes (e.g., agriculture);
• Resource intermittency: Solar radiation isn’t constant due to the day-night cycle and weather events, necessitating solutions like photovoltaic systems with storage to ensure a continuous energy supply.

Solar Energy: The Numbers

Solar energy has made significant strides in recent years.
Renewable sources are surpassing electricity and gas production. Countries like Austria and Sweden are at the forefront of the energy transition, with clean energies covering over 75% of the electricity demand.