11 WIND TURBINES


A Encraft Warwick Wind Trials Project


This report summarizes the full findings from the Encraft Warwick Wind Trials Project, covering 168,950 hours of operation of 26 building-mounted wind turbines from five manufacturers across the UK during 2007–2008. These turbines were mounted on sites ranging from theoretically poor (single-storey urban buildings) through to theoretically excellent (45 m tall exposed flats in isolated settings on hilltops).


Objectives


The objectives in setting up the trial were to see how grid-connected micro wind turbines perform on a variety of building types, and to see if any patterns emerged that could provide a helpful guide to potential purchasers, and also help manufacturers and installers direct their sales and marketing efforts appropriately.


Results Average energy generated per turbine per day = 214 Wh = 0.85% capacity factor.


Average capacity factor of larger turbines on free-standing sites in good areas = 10–30%.


The best-performing site generated an average of 2.382 kWh per day. The poorest site generated an average of 41 Wh per day, which is less than the energy it consumed to run the turbine’s electronics.


Notes 1 Turbines on our high-rise sites were able to generate as much energy in one month as other turbines in the trial achieved in one year, but these high-performing turbines had to remain switched off for the majority of the trial, following complaints about noise from the building residents.


2 The findings of this report apply only to currently available models of building-mounted wind turbines, designed for connection to the national grid. The findings of this study cannot be generalized to larger-scale wind turbines, nor to free-standing wind turbines of any size mounted on poles or masts well away from obstructions.


This is an edited excerpt from a report on a public field trial of urban micro-wind turbines by consulting engineers Encraft. B Rotor Rotor diameter (D) Gearbox Generator


Hub height


Tower Guy wire Gearbox HAWT VAWT 91 Generator Rotor Tower


Hub height


Rotor height (H) Rotor diameter (D)


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134