Hydro scheme progress

Thanks to the generosity of Marcus Worthington, and of all those members who responded to the appeal in the last Newsletter, and to the patient fund-raising skills of Peter van Zeller, we have secured sufficient funding to order our waterwheel generator.  Because public funding would disqualify us from the benefits of Feed-in Tariff, all the money is from private sources.

The suupliers are two Cumbrian firms, Smith Engineering of Maryport and Border Hydro of Lorton, near Cockermouth.  The steel girder framework has been manufactured, galvanised and painted.  On  9-10 September it was transported to the mill and has now been installed in its final location. The motor and gearbox have been ordered, and the machining of other component parts is planned.  Smith Engineering have arranged for the specially shaped buckets to be laser-cut and shaped. The control panel design is complete and the parts have been ordered.

Joiners are assessing timber requirements for the launder (the trough that will carry water from the existing mill leat to the top of the ‘overshot’ waterwheel).  The timber used will probably be European larch and perhaps some green oak. Whilst ensuring that the required flow rate is maintained, water must be fed as slowly and calmly as possible into the buckets.  Otherwise, air gets trapped in the flow and, being much less dense than water, would reduce the efficiency of the waterwheel.  The design of the buckets gives them capacity to develop more power in future, should it be decided to move to a 3-phase electrical system.  They are carefully shaped to hold the water as far out as possible on the radius of the wheel, thus developing the maximum torque (turning force).  A trench will be dug, away from pathways, to take the power cable to the location of the controls for the generator.

We are on track to be generating power by the end of 2015, well within the limit of one year from the approval date allowed for installation and commissioning of the generator, thus qualifying us for the Feed-in Tariff under the government’s renewable energy initiative.  The boost to the mill’s normal income will begin at the same time.

The similar waterwheel built by Smith Engineering and Border Hydro at Skelwith Bridge, in Great Langdale, has now been operating successfully and very efficiently for almost a year, giving us confidence that the generator will serve our purpose well.  It is designed to produce a maximum 3.5kW of electricity, given a water supply of at least 100 litres per second.  That should be available in all but the driest periods, which used to occur most often in late spring and early summer; but who knows what to expect in the next 25 years ?  If we are able to keep the equipment running for most of the time, say 75% of the year, then at the kilowatt-hour tariff rate of 25 pence per kWh we should earn around £5,000 per annum, provided the efficiency of our wheel and the one at Langdale are the same.