Why We’ll Need CSP’s Solar Thermal Energy Next


What if we could switch on the energy of the sun like turning on a tap? Concentrated Solar Power (CSP) is the form of solar that can be switched on when it’s needed.

CSP is complementary to the better-known solar. Thermal solar energy (TSE) also known as CSP provides a completely different benefit to the grid than Photovoltaic (PV) solar. That is because CSP can store its solar energy thermally. This means it can deliver power day or night, regardless of whether the sun is out.

Because PV has been so successful and is growing so fast, CSP with storage is needed as the complement to PV in a completely new grid system.

Here’s why the grid is changing to accommodate solar PV. Once the atomic-level engineering is in, a solar panel is like any other mass produced object, with a simple installation process at utility-scale. This revolutionary simplicity of PV is causing its prices to plunge.

The success of PV has created the need for dispatchable power

Because of PV’s simplicity, it is low cost. Because it’s low cost, it is growing fast. But solar PV is not dispatchable: you can’t turn it on when you want it. PV needs to be backed up with a source that can deliver power over the long hours after daylight.

As long as base load power dominated the grid, there was little need for dispatchable power, a flexible form of power that can be delivered on demand. But that’s changed now. Because it is such a disruptive technology, PV is changing the grid from a “base load grid” to a lumpy grid with gaps. The success of PV is creating a new need: dispatchable energy to fill in: CSP.

Initially, backup for intermittent renewables had been the job of natural gas.

We’ll need CSP / STE next because it is dispatchable

Like a natural gas plant, a CSP plant runs a power block. Because it can store its energy, it has a ready supply of fuel to run on. This makes it as dispatchable as a natural gas plant running a power block. The difference is that CSP runs on clean solar energy, not a fossil fuel.

So CSP is the dispatchable form of solar, that can be turned on or off on demand, supplying energy when needed. CSP can use its own thermally stored solar energy to dispatch power any time on demand. CSP is well-suited for covering the recurring gaps in PV generation. The gap that’s growing fastest is the evening peak period after the sun sets.

With PV for daytime and with CSP taking stored solar power into the late evening, most of the hours in a day can be solar-powered. So CSP supplies part of the route to a 100% renewable electric grid, that will include various mixes of PV, onshore wind, offshore wind, hydro, geothermal, landfill gas and CSP with storage.

No one renewable source can do it all. We will need them all. And that includes both forms of solar generation: PV and CSP.