Tom Lombardo posted on January 04, 2015
It was a good year for solar power in the USA, with over six gigawatts of photovoltaic (PV) capacity and more than one gigawatt of concentrated solar power (CSP) being added in 2014, bringing the nation’s total solar power capacity to more than 17 gigawatts. That’s a 41% increase in solar power capacity in just one year. While PV gets most of the attention due to it being more flexible, concentrated solar power is beginning to shine on a large scale. Let’s take a quick look the advantages and disadvantages of CSP and then check out the utility-scale CSP plants that came online in 2014.
Photovoltaic vs Concentrated Solar Power
Photovoltaic technology converts light directly into electricity. PV panels produce DC, which needs to be converted to AC before being placed on the grid. PV panels work best in direct sunlight when they’re pointed perpendicular to the sun’s rays, but they also work reasonably well in diffuse light, even when not pointed directly at the sun. This makes them inexpensive and suitable for rooftops, since solar tracking isn’t required. PV also works in climates that aren’t particularly sunny; Germany gets less sunlight than the northern US, and yet it has a large portion of its power generated by PV.
Concentrated solar power, on the other hand, requires direct sunlight and solar tracking. CSP focuses the sun’s energy and uses the resulting heat to create steam that drives a traditional turbine generator. Even better, the heat can be stored – usually in the form of molten salts – so the CSP plant can generate electricity even when the sun isn’t shining. Because CSP relies on direct sunlight, it’s most suitable for very sunny locations like the American southwest. Here are two popular types of CSP: trough and tower.
Images: US Department of Energy