| The proposed system has been analyzed from a technical and economic aspect and will be tested in a real life situation. The research team will be developing and testing a small-scale prototype system that will supply an output power of 50 kW. The prototype can be connected directly to the grid and will be extensively tested under different operating conditions to examine the response of the renewable sources, the interaction with the fuel cells, and the smooth operation of the dc to ac conversion. The research team will perform long term testing in different seasons and under different weather conditions to verify the results of the technical and economic analysis. The results obtained from the setup and operation of the prototype system will indicate whether the proposed method can be implemented for large scale electricity generation from renewable sources with (a) zero CO2 emissions and (b) constant, regulated power output. Therefore, the results of this project will be critical to determine if large scale wind generation (preferably using the proposed novel technology) can be installed in Cyprus. The research team plans to implement the proposed prototype so as to produce electricity during peak hours when the most expensive and most pollution-causing diesel generators are put on-line. The prototype will continue its operation after this project ends since the research team plans to continue its research in renewable technologies and improving even further the techniques developed as well as allowing students to receive training in this type of renewable technologies. | plant |
The System
There are three energy conversion stages in this developing the system. First, wind energy will be harnessed through wind turbines to perform electrolysis of water and store the hydrogen that is produced in appropriate hydrogen storage tanks. Of course, this stage of electric energy to hydrogen conversion is flexible. Other renewable sources and/or methods can be used. However, wind energy is the most appropriate due to the mature technology in this area and its significantly higher capability to produce electricity (as compared for example with solar energy which has a lower efficiency and a significantly higher installation cost).
The second stage of the project uses the stored hydrogen to produce direct current electricity. This is achieved through fuel cells. Fuel cells are now a safe, mature, and reliable technology. Fuel cells use hydrogen as a fuel (or other types of gases) and oxygen (obtained from the air) to produce electricity. The byproduct of this conversion process is water; water can then be reused in the first conversion stage to obtain hydrogen. Therefore, the only byproduct of the electricity generation process will be water and heat.
The third and final stage of the generation process involves the conversion of dc current to three phase alternating current (ac). This is the most novel part of the project. Currently, dc to ac conversion is typically performed through expensive inverters that employ power electronic technology. This technology is very expensive especially for electric powers in the order of 100 MW and more (i.e., a small size power station). We are proposing a new method to convert dc electricity to ac electricity. The research team has performed the required theoretical calculations for the technical and economic analysis of the proposed prototype.
There is no environmental pollution from this process since no gases such as CO2 or NOx are produced. It is a purely environmentally friendly method of electricity generation, while avoiding typical problems of renewable sources such as stability problems due to the intermittency of wind. The system can operate in synchronism with the power grid.