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photovoltaic vs solar panels

Photovoltaic vs Solar Panels

The difference between solar and photovoltaic panels? The former harnesses sunlight to produce hot water while the latter harnesses solar energy to produce electricity

Solar panels and photovoltaic panels are both technologies that absorb energy through irradiation, but for different purposes. The main difference lies in the utilization of solar energy: solar panels convert it into heat, whereas photovoltaic panels transform it into electrical energy.

Choosing the most suitable panel requires evaluating various aspects. It’s essential to consider the intended purpose, opting for photovoltaic panels for electricity production and solar thermal panels for heat generation. Additionally, one must examine the dimensions and shape of the property, assessing whether the panels adapt to flat or sloped roofs. Finally, the geographical location is another key element, with photovoltaic panels ideal for areas with high solar exposure and solar thermal ones more effective in regions with high temperatures.

To assess all these aspects, innovative software for photovoltaic system design or for solar system design can be useful, guiding you in the design and sizing of elements and providing economic analyses on the actual profitability of the system.

Let’s delve into the difference between photovoltaic and solar panels to fully understand their characteristics.

What is the difference between solar panels and photovoltaic panels?

Often there is confusion between solar panels and photovoltaic panels, using them as synonyms. In reality, the term solar panel is a generic term referring to the solar thermal panel, which harnesses sunlight to produce hot water. The photovoltaic, on the other hand, always utilizes solar energy but to produce electricity.
Other important differences between solar thermal panels and photovoltaic panels include:

  • Material: Photovoltaic panels are primarily made of silicon, while solar thermal panels use a collector to heat fluid substances, usually water;
  • Efficiency: Solar thermal panels have an efficiency reaching 80%, while photovoltaic panels absorb solar radiation with a efficiency ranging between 17% and 25%, depending on the type of panel;
  • Installation: A single solar thermal panel might be sufficient to heat domestic hot water, unlike photovoltaic panels that require larger sizes to achieve equivalent electricity performance. Both require a south-facing orientation, but unlike photovoltaic panels that need ample space, solar thermal ones are more flexible in placement.
photovoltaic vs solar panels

solar thermal and photovoltaic panels

How do solar thermal panels work?

Solar thermal panels are panels placed on the roof of a house that utilize solar heat to produce hot water. A solar thermal system, unlike a photovoltaic system, is a hydraulic system that uses a heat transfer fluid.
This fluid, heated in the panels by solar heat, carries heat to a storage tank. We can envision this tank as a boiler that takes in cold water and outputs hot water at the desired temperature. Heat exchange occurs in this tank: cold water from the network is heated thanks to the heat brought by the heat transfer fluid from the solar panels.

An important aspect of these systems is integration with a boiler that only comes into operation when the demand for hot water exceeds the capacity of the individual solar panels. This approach allows for efficient use of resources, minimizing boiler use and maximizing available solar energy.

Depending on the presence or absence of a pump for water circulation, there are two types of systems: natural circulation solar thermal systems and forced circulation solar thermal systems.

How do photovoltaic panels work?

Unlike solar thermal panels that harness the heat of the sun, photovoltaic panels harness sunlight. Through sunlight rays, the silicon in photovoltaic cells produces the photovoltaic effect.
Photons striking solar-grade silicon (a semiconductor material) excite electrons, creating a potential difference within the cell. This electrical differential between the upper layer and the lower layer of the cell creates electrical current.

The current produced is direct current that can be directly used to power electronic devices or stored in batteries for later use.

Solar Thermal and Photovoltaic Panels: Pros and Cons Compared

As we have seen, solar thermal panels and photovoltaic panels are both technologies that utilize solar energy to produce renewable energy. Below is a comparison of the pros and cons of each technology.

Pros and cons of solar thermal and photovoltaic panels

Pros and cons of solar thermal and photovoltaic panels