ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Parabolic trough systems and their potential – talking storage

Updated on June 27, 2012

Consistent Power

In my hubs about concentrating solar power (CSP) plants I focused on the parabolic trough design. These systems have their place in the power generation market, especially in the multi MW range. They have the oldest and most proven technology. Patents and first designs go back to the early past century. Even though the photovoltaic (PV) effect was discovered in 1839 by Becquerel, it was not until the1950s that the first modern PV cells were developed in Bell Laboratories.

Regions with the most direct normal solar radiation, like Southwestern USA, the North and South Africa region, Southern Spain, or the Middle East offer the most suitable climate for this kind of power plant. But even in the sunniest of regions, clouds can obstruct the sun, and thereby cutting off the heat/power source. Or obviously, the time of solar radiation is limited to day time.

Still, CSP plants can provide a more consistent power output as a result of their capability to store thermal energy . In this article, I would like to talk a little bit about the storage option. Storage systems can buffer the energy during cloudy weather conditions and hours after sunset and give thus the opportunity to deliver power fairly independent of solar irradiation. They can improve economics through heating up the storage media during times of low prices and deliver power during those peak periods when prices are usually high. So it is no surprise that many CSP plants utilize thermal energy storage (TES) systems.

Sunset over Lava

Source

Types and Projects

Most common set ups are two tank direct (same fluid as heat transfer and for storage) and two tank indirect storage system. Types of storage media include the popular molten salt (usually a mixture of sodium nitrate and potassium nitrate), concrete, mineral oil, synthetic oil. Molten salt mixtures seem to offer the best benefit, as they are less pollutant, more cost effective, have a higher heat capacity, are non-flammable, etc. On the other side they are corrosive and require higher system temperatures.

A famous example for a two tank direct system includes the already mentioned SEGS 1 plant. It had two tanks with the heat transfer fluid (mineral oil) as storage fluid and a storage capacity of 3 hours, which was in operation till 1999. The 280 MW Solana plant in Gila Bends, Arizona, will utilize molten salt as storage medium with thermal storage of 6 hours. The 1 MW Saguaro plant facilitates 6 hours thermal storage, using oil. The Hualapai Valley Solar Project in Arizona is a 340 MW plant by Mohave Sun Power, with molten salt storage, with plans to get connected to the grid in 2014.

The Bell Independent Power Corporation is working on a 5 MW demonstration project with a single tank storage in Tuscon, Arizona. They are using a special type of salt, supposedly utilizing more of the stored energy than conventional two tank storage set ups. On the Island of Hawaii near Kona, Keahole Solar Power, LLC built a 2 MW plant ‘Holaniku at Keahole Point’ with 2 h of thermal storage using molten salt as storage medium.

In Europe, the three 50 MW Andasol plants in Spain each include molten salt tanks (indirect storage) with 7 to 8 hours storage capacity. In Italy, the 5 MW parabolic trough plant Archimede is the first plant to use molten salt for heat transfer and storage (storage capacity 8 hours). It is in operation since 2010. Kaxu Solar One in South Africa (Northern Cape) with 100 MW output is planned with 3 h of thermal storage.

Thermal energy storage highly increases the reliability and output consistency of a CSP plant. There is no doubt that parabolic trough systems certainly face lots of challenges, but they are a valuable option for complementing PV technology.

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)