Energy – Wind power

Wind Power

For the past two years a number of sites have been investigated, and a number of installers have been consulted, for likely wind-turbine electricity production. Especially on the western margin of the estate (Woodcock area) conditions seem favourable, open aspects to the west and south-west (the prevailing wind direction).

A turbine installation, although much more expensive than a grid-connection, has two main attractions; it would attract funding from a number of sources (as did the woodfuel boiler system), and it would qualify for (the generation component of) FITs, the government feed-in tariff scheme. Both these factors would improve the (financial) feasibility of the project, but other hurdles remain. What about possible objections from valley residents and/or MoD (Eskdalemuir)? Is the wind resource sufficient? After all, neither funders nor installers would want to get involved in a project which doesn't actually work! To get some results on both these issues, an 18m (60ft) mast was erected on a likely site, and anemometry instruments installed for a number of months, before dismantling and re-erecting on a second site. A separate (static) anemometer was used as a control, to allow for seasonal variation. This temporary mast also allowed an assessment of line-of-sight visual effect.

Initial results have been promising enough to ask for quotations from installers, which were on the basis of an 'island' (ie no grid connection) system. It is normal with such systems to build in a degree of energy storage, to allow for lulls on the windspeed,as it is rare that turbine output exactly matches demand. Storage can be hydraulic (pumped water), dynamic (flywheels) or chemical (batteries). Each is appropriate to a particular scale of project, and costs vary. The standard option in Chisholme's case is for deep-cycle lead-acid batteries. Knowing average demand, 8 hours backup alone (normally design is 24hrs) would need a large battery bank, costing up to £13,000. This bank would also need to be replaced once in a while, as batteries degrade with use. The generators would also need to be maintained for those extended periods of low wind speed.

Of course, the alternative to a battery bank would be a grid connection, which, although costing more (and not as attractive to funders), would enable excess (turbine) electricity to be exported (leading to enhanced FITs payments). As a connection seems to be a necessary first step towards a turbine installation, the former is being addressed as a priority.