Home > Post > The Difference Between Solar PV and Thermal

The Difference Between Solar PV and Thermal

When people hear ‘solar energy’, it’s easy to just imagine blue solar panels sitting on rooftops. But there are two types of solar power contributing to energy grids around the world.

These are:

  • Photovoltaic Solar: also known as PV power.
  • Concentrating Solar Power: also known as CSP or solar thermal.

But what’s the difference? Our Trusted Solar experts explain below.


Two Types of Solar Power

Solar power refers to energy created from the sun. Currently, PV and CSP are the two most popular ways to do this. While they’re both in the same category of renewable energy, their processes are very different.

How PV Power Works

The PV process uses semiconducting materials like silicon to absorb sunlight and create direct current (DC) electricity. This occurs in the many solar cells that make up a panel. Households and energy grids use alternating current (AC) electricity, so an inverter changes the DC to AC before it powers anything.

How CSP Works

Simpler than PV solar, CSP focuses on the raw heat of the sun. A large array of heliostats (mirrors that follow sunlight) are placed in circles to reflect sunlight into a tower at the centre. Salt runs through the tower and, when it’s heated, turns into a molten state.

In its fluid form, the hot salt is stored in a tank at the base of the tower. When it’s needed, it moves to the steam generator along with water, creating immense pressure that powers turbines – this creates electricity. The steam condenses to be recycled as water and the salt cools, to be heated again.


The Biggest Differences

CSP is a modern twist on old-fashioned technology – using a standard steam turbine. PV solar, on the other hand, continues to evolve and change as the technology and materials used get more efficient. The biggest differences between PV solar and CSP include:

  • Current Potential – The largest PV solar park has a capacity of 1,550 MW, compared to the largest CSP station that has a capacity of 392 MW.
  • Difficulty – Melting salt may be simpler than producing the Photovoltaic effect, but aligning thousands of heliostats is an incredibly difficult task.
  • Storage – PV batteries can store solar energy, but the tanks of molten salt in CSP systems can store heated fuel for hours – providing energy 24/7.

While both PV solar and CSP are used commercially, only PV is used residentially. That’s because solar panels can be placed almost anywhere, even at your home. If you’re interested in capturing solar energy yourself, get in touch with our Brisbane solar panel installers today and we’ll send you an obligation-free quote.