- February 2018
By 5 February we had built a sufficiently well-structured enclosure around the relocated generating machinery to allow us to test its effectiveness in limiting the noise which was of some concern. At the time of writing, the generator has been running for 21 days and it is believed that the objective of reducing noise to an acceptable level has been achieved.
As mentioned in previous Newsletters, the decision was taken to reduce the noise by lowering the generating machinery from waterwheel axle height down to a level deeper into the rock cleft in which the waterwheel is built, and to bolt the machinery upon a concrete block of considerable mass, using anti-vibration mountings. The generator was then to be driven from the waterwheel axle via a massive sprocket and chain, at a reduced speed of rotation. This approach gives a more sedate appearance to its rotation and enables the buckets to be filled more completely.
The generator machinery, gearbox and motor/generator were enclosed by a housing made of two leafs of solid 150mm thick concrete blocks, and the gap between the leafs was packed with acoustic rockwool insulation. The roof comprises horizontally laid, 100mm solid concrete blocks on a steel frame, which is covered with two layers of plastic sheeting and another layer of heavy rubber conveyor belt material. The whole is surrounded by a European larch framing, infilled with river gravel about 50mm deep. The north, west and east walls have been clad in a European larch. The acoustically insulated air intake and exhaust box, needed to ensure adequate cooling of the generator, have been installed in the north wall and door (also on the north face), so as to prevent any sound which may emanate from them being directed towards local houses. Thermocouples have been installed so that the air temperature in the enclosure and that of the generator casing can be measured.
The generator was producing about 3.3 kW for the first 15 days and nights, but with the impending drier weather as we approach the end of February, the power output is falling gradually and may shut down temporarily in the near future. The energy produced so far since commissioning is 1800 kWh, which will realise a Feed-in Tariff payment of about £450, with all but about £100 being earned in the last three weeks.
As this project approaches completion, it has to be said that it would not have been possible had it not been for the most generous financial support of Worthington Construction Ltd, and for the tremendous voluntary efforts of time and expertise of Rod Chilton. A great deal is also due to the excellent working relationship we have with Rod Smith and his company, Smith Engineering (GB) Ltd of Maryport, who designed, manufactured and supplied the mechanics. The Postlethwaite family at Border Hydro Ltd of Cockermouth were of great help with all the electrics and negotiating the Feed-in Tariff paperwork.
The construction part of the project is now very nearly completed, apart from some access steps, a low wall to direct water away from the enclosure doorway, and reinstating the fencing.
Editor’s note : Len omits to mention that the project has depended on his own massive volunteer contribution, often single-handed and sometimes in dispiriting circumstances. The Trust is greatly in his debt.