CSP vs. PV is a wrong approach. Isn't it?

Jorge Alcauza
CSP-World
23 March, 2013

Like probably most of you, I have seen some articles published in the past weeks claiming about PV winning over CSP. But after taking a look at some of them, my findings can be summarized in some questions about what do they mean about ‘winning’.

Is the winner the most widely deployed? The cheaper? The easiest to install? The one with highest performance? The most bankable? The most supported with public funding? In conclusion, I think it’s not so easy –or should I say impossible- to claim one technology is winning over the other.

Firstly, some considerations, PV is a technology that suits for both, domestic and utility-scale, while CSP makes sense mainly for large projects. While PV has been supported since decades ago, CSP has ‘just’ taken off. As of 2006, when CSP was reborn after 15 years of not even a MW installed, since the 354 MW of the SEGS plants in the US, there were roughly 10 GW of PV worldwide, that’s almost 30 times more.

Thus, the total power installed cannot be a criteria to compare both technologies, obviously, PV will lead this race, at least for now, one never knows.

In economic terms, renewable –and non-renewable- energy technologies have been able to drive down the costs thanks to economies of scale, which, in turn, is a result of a strong governmental support. That’s how Nuclear did and how Wind and PV are doing now to drive down their costs, and this is how CSP will do, there is no other way.

There are some facts that could make us think PV is a better choice: it’s easier and faster to install –you can put a PV module almost anywhere-, it’s suitable for low solar radiation areas –although with poor performance-, it’s highly scalable –from some kW on your rooftop to solar farms of GW size-  and, for now, has lower costs of operation and maintenance.

But, by contrast, there are some facts that make it not so suitable for large grid-connected solar farms. It’s highly unstable and intermittent due to its ‘direct’ conversion from sunlight to electricity, what makes the grid operator to struggle with peaks and holes in its production as clouds go and come.

Thanks to its simplicity and a large track record of previous small projects since decades ago, a PV solar farm is more bankable than a CSP plant, and this has made grow the overall capacity of PV in the world. For the CSP case, as I said before, it has just taken off and banks and governments are more reluctant to provide funds until the first projects are complete and running.

What about performance, stability, reliability, dispatchability? In this case CSP is the best choice. The current commercial technologies in operation are capable to generate electricity for many hours further from sunlight availability, thanks to energy storage systems and hybrid plants with other fuels –renewables or not-, CSP is a stable and reliable source of energy to be easily integrated to the grid. Furthermore, its ability to dispatch energy when necessary, leads us to think about it as both, a base-load and a peak source of electricity.

A Concentrated Solar Power plant can be configured in many ways, to meet the requirements of each location. Base-load, peak, back up, … something that PV or Wind can’t afford.

PV and CSP will be installed depending on the requirements of each case, if you need a 10 kW off-grid installation to be used during daylight hours, you’ll choose PV, but if you need a 50 MW power station to run almost 24 hours a day, you’ll have to choose CSP with storage or an hybrid plant.

As I was told in my early years of school, you cannot compare pears with apples, they are both fruits, yes, but they are different. However, above all, one thing that we all should bear in mind is that trying to compare PV and CSP and talk about a winner is one of the stupidest things we could do. Who needs a winner?, what we really need is a world fueled by renewable energy sources. Thus, if you still need a winner, think about the environment and the mankind as the only possible winner -or looser-.

Source : http://www.csp-world.com