| align="center" |110 V <br /> 220 V<ref name="History of Guyana Power and Light">[http://www.gplinc.net/about/history History of Guyana Power and Light] {{Webarchive|url=https://web.archive.org/web/20180430203903/http://www.gplinc.net/about/history |date=2018-04-30 }}. Gplinc.com. Retrieved on 2014-01-01.</ref>
| align="center" |60 Hz<br />50 Hz
|Conversion of 50 Hz distribution to 60 Hz is ongoing<ref>[http://www.stabroeknews.com/2009/news/local/07/10/gpl-converting-parts-of-city-to-60-hz/ GPL Converting Parts of the City to 60 Hz, retrieved 2009 July 31]. Stabroeknews.com (2009-07-10). Retrieved on 2014-01-01.</ref>