IDEAS home Printed from https://ideas.repec.org/a/eee/energy/v20y1995i3p209-217.html
   My bibliography  Save this article

The influence of electrical backup element size on the performance of a solar thermosyphon DHW system

Author

Listed:
  • Tully, N.

Abstract

A computer simulation program is used to predict the performance of a solar thermosyphon domestic water heating system. The model has a standard configuration with 4 m2 of solar panels and a 250 l geyser which may be either vertical or horizontal. Typical meteriological year 15 min solar insolation data for the Pretoria area and corresponding ambient and cold water temperatures are used for the simulation input. A daily hot water requirement of 250 l at 55°C is drawn off according to a specified pattern. Electrical elements ranging from 0 to 6 kW are thermostatically controlled to set the temperature of the top 13 of the geyser. It is found that a solar-only system will not provide a reliable source of hot water, but that with a 1 kW element a daily availability of at least 96% of the hot water energy requirement will be provided. Using a larger element will not significantly improve this availability, but will reduce the solar efficiency of the system by up to 3% and increase electrical consumption. In terms of a heating coefficient of performance, a vertical geyser would provide an annual average COP of 3.9 with a 1 kW element, reducing to 3.0 with a 6 kW element: a horizontal geyser is less effective with a COP of 2.1 for the 1 kW element. If solar water heating is to play a role in a national energy-management strategy, the electrical maximum demand imposed on the generating system is of importance. It is found for the specified hot-water draw-off schedule that with a 1 kW element, a maximum half hour demand of 1 kW occurs, predominantly in the 07h00–10h00 and 20h00 periods, while a demand exceeding 1.5 kW is likely if the normal 3 kW element is employed.

Suggested Citation

  • Tully, N., 1995. "The influence of electrical backup element size on the performance of a solar thermosyphon DHW system," Energy, Elsevier, vol. 20(3), pages 209-217.
  • Handle: RePEc:eee:energy:v:20:y:1995:i:3:p:209-217
    DOI: 10.1016/0360-5442(94)00066-C
    as

    Download full text from publisher

    File URL: http://www.sciencedirect.com/science/article/pii/036054429400066C
    Download Restriction: Full text for ScienceDirect subscribers only

    File URL: https://libkey.io/10.1016/0360-5442(94)00066-C?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Jaisankar, S. & Radhakrishnan, T.K. & Sheeba, K.N., 2009. "Studies on heat transfer and friction factor characteristics of thermosyphon solar water heating system with helical twisted tapes," Energy, Elsevier, vol. 34(9), pages 1054-1064.
    2. Rosas-Flores, Jorge Alberto & Rosas-Flores, Dionicio & Fernández Zayas, José Luis, 2016. "Potential energy saving in urban and rural households of Mexico by use of solar water heaters, using geographical information system," Renewable and Sustainable Energy Reviews, Elsevier, vol. 53(C), pages 243-252.
    3. Lloyd, C.R. & Kerr, A.S.D., 2008. "Performance of commercially available solar and heat pump water heaters," Energy Policy, Elsevier, vol. 36(10), pages 3807-3813, October.
    4. Sezai, I. & Aldabbagh, L.B.Y. & Atikol, U. & Hacisevki, H., 2005. "Performance improvement by using dual heaters in a storage-type domestic electric water-heater," Applied Energy, Elsevier, vol. 81(3), pages 291-305, July.
    5. Pan, Tze-Chin & Kao, Jehng-Jung & Wong, Chih-Po, 2012. "Effective solar radiation based benefit and cost analyses for solar water heater development in Taiwan," Renewable and Sustainable Energy Reviews, Elsevier, vol. 16(4), pages 1874-1882.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:eee:energy:v:20:y:1995:i:3:p:209-217. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Catherine Liu (email available below). General contact details of provider: http://www.journals.elsevier.com/energy .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.