Classroom #E8: Hybrid Energy Systems
Energy School
(no test, no worries)
Welcome to classroom #E8:
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Key Points
HES explainedHES combines multiple types of energy generation and/or storage or uses two or more kinds of fuel to power a generator. In the past HES have been deployed primarily on islands, which are not connected to the mainland general electric grid. In last few years HES is a valuable method in the transition away from fossil fuel based electric energy and move to distributed renewable solutions. Particularly in the northern countries, where renewable energy sources like sun and wind may be limited in some time periods, backing these up with thermal electric production (Combined Heat and Power, CHP) using local residual biomass, can actually help to expand the use of other renewable energy sources and establish hybrid solution based local micro grid suitable for in rural areas.
Some examples of HES types:
Small HES is presented on the drawing below: An important issue in renewable energy development has been the inability to rely on intermittent renewable sources, such as wind and solar, for base load power. Small, agile HES is one way to allow energy production into the local micro grid more reliably. Generally, at least one source of the fuel used to power a CHP generator is renewable. Such a system is designed to increase the reliability and thus usability of renewable energy sources (increase to more than 50%) by providing redundant energy production from conventional sources or, more efficiently, by providing storage for electricity produced by intermittent renewable sources.
In smarter HES the computer applications automatically increase or reduce conventional generation or battery usage as needed to respond to fluctuations in production from the renewable resources to maximize the amount of renewable energy in the system. In case the larger consumption loads are also controlled, then the HES would form a smart grid. To respond accordingly to peaks and dips in renewable energy production, hybrid systems are best implemented on a small scale because small CHP generators are more flexible. These agile systems can, when possible, be interconnected into the central grid system and function as small power plants. Implementing HES can create also market opportunities for the deployment of energy technologies that are not yet mature. If a particular technology, such as a new type of fuel cell, is not yet efficient or reliable enough to produce electricity in a stand-alone system, it may fit well as an additional component to a hybrid system in which other components can cover possible bumps in the production process. The other option is use of hydrogen as the mean to store the energy for longer periods. As we know the process of electrolysis can produce hydrogen by breaking water into hydrogen and oxygen, it can be stored. In summer period the solar energy available is at its peak, so if the demand and supply is properly checked and calculated the excess energy can be used in the production of hydrogen and can be stored. In sunny and windy days the supply is maximum, and this excess power can be consumed for the manufacturing hydrogen. In winter, the power consumption is high, but the supply is low, and the stored hydrogen can be used in fuelcell to provide the required extra supply. Challenges to using a HES Technical
MicroCHP with stirling engine in fluidised bed The electric energy generating engine's (stirling) head is mounted into the hot fluidised sand, instead of turbulent gases in the conventional burning process. A fluid conducts much better the heat into the stirling head that a gaseous medium. In additions the solution provides many advancements for cleaner burning process and efficiency.
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Class continues..More content in Classroom #E8 is to come.. |
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