Objective
The installation of the 20 kW generating set at Ashfield Mill has two major aims. The first aim is the completion of the reinstatement of the water turbine at the mill. The second aim is the first on-site application and testing of a novel Electronic Load Governor (ELG). The ELG is the first known design which is based on digital/microprocessor electronic circuits and which incorporates a three-phase balancing feature. The anticipated energy production is 124,200 kWh per annum and the simple payback period predicted for this project is 6 years.
The installation first started production of electrical energy in November 1996 supplying a domestic consumer load of approximately 10.5 kW on a daytime only basis. The ELG was not commissioned until the end of June 1997, however the set was able to operate under manual speed control and to produce some energy output. During the period from November 1996 to June 1997 the set ran for 1331 hours and produced 17559 kWh of energy. Thus the total number of hours run from November 1996 to the end of June 1998 is 4430 and the total amount of energy produced is 51420 kWh.
Since commissioning , the installation was in regular operation supplying a consumer load comprising the heating and laundry requirements of the owner's house. The total electricity produced during the monitoring phase was 33861 kWh and at the current cost per kWh of 7.13p the effective revenue generated by the owner is £241430.
The ELG unit itself has performed well throughout the monitoring phase. The unit has always been able to operate when required and the program has operated as designed without any problems. The ELG unit is part of a large system of components which must all work together in harmony. Key elements of this are the rating of the ballast load sections, the inertia of the rotating components and the hydraulic stability of the water column moving through the turbine, draft tube and pipework system. To different extents, all of these elements affected the initial performance of the ELG, however modifications and improvements were undertaken throuhgout the monitoring phase such that by the end of the period, it can be reported that the ELG, and the complete system, is performing satisfactorily.
Despite the problems which did occur, and have been reported, it is considered that the project has been a technical success and that the objectives have been met.
The generating set will be installed in an existing powerhouse and will have the following characteristics :
Gross head - 6.4 m
Net head - 6.0 m
Design flow - 600 l/s
Electrical output - 20 kW
Generator system - 400 V, 3 phase, 50 Hz
The generating set will operate independently from the grid network and will provide energy for private consumption by the owner and developer. The control of the speed of the generating set will be by the innovative Electronic Load Governor (ELG). The digital microprocessor based design of the ELG permits a flexible solution to the Load Governing problem due to the ease in which controlling parameters can be adjusted on-site or re-programmed. This project provides the first opportunity to perform site installation and testing of the new technology.
Economically, the ELG compares favourably with the conventional governor by a factor of about 10, thereby significantly affecting the overall economic success of a micro-hydro installation.
Programme(s)
Topic(s)
Data not availableCall for proposal
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DEM - Demonstration contractsCoordinator
FK15 0JX Dunblane
United Kingdom