The modern age of CSP can arguably be traced back to the 354MW Solar Energy Generating Systems (SEGS) in the Mojave desert, which now make up the oldest operating plant in the world, as well as one of the largest.
However, recent developments in the industry will see SEGS eclipsed by 5 projects that are scheduled to come online in 2013-14, with a combined total of 1312MW. The five plants in question are Abengoa’s Solana and Mojave projects, BrightSource Energy’s Ivanpah Solar Electric Generating System and finally the Crescent Dunes and Genesis plants being developed by SolarReserve and NextEra Energy Resources respectively.
Recent commentary on the industry agrees that this increase in operating capacity, as well as 1.5GW of projects in planning in the US, demonstrates the strong support for CSP in this region, and there are a number of reasons why it makes sense for the US to pursue leadership in CSP development for years to come. Firstly, the US has ample high-irradiation suitable for CSP development particularly in California, Arizona and Nevada.
Secondly, there are significant economic benefits. The prime materials for CSP plant construction are readily available in the US, in addition to projects generating local employment particularly during the construction phase of a plant.
But most importantly there are a number of reasons why utilities, CSP’s ultimate customers, and grid operators might welcome the technology. As utilities are increasingly being required to introduce renewable portfolio standards, many of the options available, such as wind and solar photovoltaic plants (PV), are challenging because of their output variability. Therefore as PV and wind integration increases, the thermal energy storage capability of CSP becomes a significant feature that will drive projects forward for years to come.
In a recent interview Kristin Hunter, spokesperson for BrightSource Energy, developers of the Ivanpah Solar Electric Generating System, explained to CSP Today that “as energy storage is added to plants, solar thermal becomes even more valuable because stored energy can be used to accommodate the variability of other non-dispatchable renewables, including wind and PV”.
In addition, CSP with storage can modify ramp rates, keeping them more in-line with grid requirements, because plant operators have the flexibility to stop putting solar energy into the grid at a given time, or if needed, put more power into the grid.
Because the addition of thermal energy storage involves additional capital costs for a project, the current perception is that this cost is too high when compared to technologies such as wind and PV. However, in a recent interview with CSP Today, Tex Wilkins the Executive Director of the CSP Alliance, explained that “going forward, storage will not add anything to ratepayers’ cost. It can actually decrease the cost because what happens is you are able to better use the turbine, the generator and all the power block because you are using it for more hours of the day”.
In other words, the turbine equipment will end up operating more efficiently and its effective lifespan will be increased, reducing maintenance and operational costs, ultimately improving Levelized Cost of Energy (LCOE).
To explain the benefits that CSP and thermal energy storage can offer grid operators and utilities CSP Today have released a guide to CSP’s role in the US energy mix. This guide provides data, information and interviews on how CSP and its storage technology can help utilities and grid operators overcome PV and wind intermittency.
In addition the guide gives an introduction to the current thermal energy storage technologies commercially operating in plants, and examines the opportunity to reduce costs for years to come.