The Difference Between Solar Panels and Solar Collectors

In this article, Sef Gojo discusses two significantly different technologies.

Solar Collectors Vs PV Solar Panels

What is the difference between Solar PV Panels and Solar Collectors (Solar Thermal Panels)?

When using solar energy, these two terms occur most often. They represent two different technologies and therefore differ significantly from each other. Some need one, and some need the other. We compare them so that you can make the best possible decision!

What is a solar cell (PV Panel)?

The solar cell utilizes solar energy in the form of electrical energy. As a result of the photovoltaic effect, it can produce electricity that any electrical device can use.

What is a solar collector?

It utilizes solar energy in the form of heat. The sun heats the liquid in the solar collector, which is stored in a tank and used when needed. The container is naturally insulated to keep the liquid inside warm for a long time.

Solar panel or solar collector — What’s the difference?

Although both utilize the sun’s heat, the two technologies significantly differ. The solar panel produces electricity, and the solar collector heats the liquid, which can be used for heating.

The solar panel must feed the energy back into the grid because it is only worthwhile to store it when there is no nearby electrical grid. In this case, we are talking about an island solar system. In all other cases, the electricity produced by the solar panel must be used immediately or fed back into the grid.

The solar collector heats the liquid, and that energy can be used later. However, maintenance due every 2–3 years must be considered. The PH value of the liquid must be checked, and the pressure must be adjusted, so the system must be maintained. In the case of the solar panel, this is not necessary. At most, it should be cleaned occasionally.

The use of solar cells is broader since it is possible to operate several devices with electrical energy. The water heated by the solar collector can only be used for heating, bathing, and cooking.

In short, a solar collector (or solar thermal panel) is a device that transforms the radiative energy from the sun into heat – usually used to heat water. A PV solar panel converts the same radiation into electricity.

Solar panel types

Solar cells are usually distinguished according to their manufacturing technology. This significantly determines the properties of the solar cell. It affects its efficiency, performance, and to a certain extent, its appearance. According to production technology, we distinguish:

• Monocrystalline solar cell
• Polycrystalline solar cell
• Thin film solar cell

According to the aspect of feeding into the network, we distinguish between the following:

• Grid-feeding solar panel systems
• Island solar systems

Types of solar collectors

In the case of solar collectors, we can talk about several types. There are also different types within the two major technologies.

• Vacuum tube
• Plane

We still differentiate within vacuum tube technology

• Heat pipe
• U-tube
• Direct flow
• Absorber plate technology

Solar panel advantages

• The risk of failure is much lower
• Lower maintenance costs
• All electrical consumers can be operated with it

Disadvantages of solar panels

• Works with less efficiency
• A larger surface area is needed, and more support structures need to be built

Advantages of a solar collector

• Works with higher efficiency
• Less is needed to utilize the same energy
• It takes up less space (fewer panels)

Disadvantages of a solar collector

• It also contains moving parts, so the chance of failure is greater
• Its construction is also more complicated
• Need to spend more often on maintenance

A summary

Of course, the two types of technology can complement each other, so both can be used in the case of a household.

If I only choose one, I’ll take the time to assess the options, think about what I need specifically, and make accurate calculations about which decision is expected to be financially better. I also assess the expected costs in 5–10–20 years.

Sef is the author of SolarLab.ph. A blog about solar energy where I share information about solar energy, how much it costs to install solar panels, components of a solar panel, inverter, batter, and much more.