Guest article by Cleverson S. Takiguchi
Electric power utilities are working diligently to meet renewable energy mandates enacted by many governments around the world. This massive undertaking demands more widespread deployment of both grid-scale and distributed renewable resources. However, wind and solar energy generation poses significant integration challenges. Wind and solar energy are intermittent resources that can cause serious power grid reliability and stability issues, while also impacting electric service quality for businesses and consumers.
In Africa there is lot of potential in terms of what is called off-grid renewable generation. In that situation, solar, for instance, unlike what is called “grid interactive systems” cannot count on the support of a strong grid and therefore the intermittency effect is even more apparent. Or in some cases connecting to weaker grids can also be problematic especially given the low inertia of this type of generation.
Another concern when the generation surpasses the demand is that there will be the called bi-directional power flow which can further impact grid stability and reliability. Today’s electric power systems were built to handle a one-way flow of power from centralised generators, down transmission and distribution lines to loads.
Distributed energy storage systems, particularly when located in close proximity to renewable resources, are well suited to address the key challenges associated with renewable energy supplies. Variability in output from wind and solar energy generation can create local and feeder-level voltage swings that occur very rapidly, but distributed energy storage can provide fast response to help firm voltage levels and effectively fill in gaps created by large voltage swings and fluctuations. Co-locating storage and renewable energy resources gives utilities a particularly effective way to manage unwanted voltage changes, allowing them to maintain grid stability while also meeting power quality requirements.
Distributed energy storage systems also provide a dispatchable energy resource for utilities, giving them more control to ensure renewable energy supplies are available to meet demand. Renewable energy generated when demand is low is then stored to meet later demand.
Energy storage can be economically deployed in smaller capacity sizes, too, which can help avoid the need to invest in establishing a new plant. Distributed energy storage also supports other grid functions such as peak shaving, which can provide further savings to utilities by reducing the need to maintain conventional generation, and maintaining grid capacity to meet peak demand.
For more information on the latest battery storage technology, come to African Utility Week & Clean Power Conference. The Renewables: Wind & Solar track will have a dedicated session with presentations addressing uses for next generation energy storage on Wednesday 13 May 2015.
For more information on how to register please go to the website: http://www.african-utility-week.com/