Urban Wind Turbines: A Feasibility Study

Transcription

1 Urban Wind Turbines: A Feasibility Study Ben Dymock And Stephen Dance

2 Urbines

3 Urbines: The Issues Urban Wind Turbines Urbines Rooftop installation for energy generation Uncertainty of wind flow and knock on energy production capabilities Noise on site and annoyance to the community Vibration on site and to the residences

4 Urbines London Plan policy 4A.9 "The Mayor will and boroughs should require major developments to show how the development would generate a proportion of the site s electricity or heat needs from renewables, wherever feasible" (GLA, 2004, p13) The Mayor s Energy Strategy proposal 13 "To contribute to meeting London s targets for the generation of renewable energy, the Mayor will expect applications referable to him to generate at least ten per cent of the site s energy needs (power and heat) from renewable energy on the site where feasible. Boroughs should develop appropriate planning policies to reflect this strategic policy" (GLA, 2004, p13).

5 Urbines: Refurbishment of office building Measure: Wind Speed, Direction, Noise and Vibration, Electricity Output

6 Urbines: Specification of Two Turbine Installations in Central London An equation to calculate power in the wind where: P 0 = available power in the wind (W), ρ = Air density (kg/m 3 ), A = Swept area of turbine blades (m 2 ), V 3 = Wind speed cubed (m/s). Norwin 18 kw (STRATA) HUB HEIGHT 135 m 49 m BLADES 5 3 ROTOR DIAMETER 8.5 m 5.6 m RATED RPM Proven 6 kw (LSBU) POWER REGULATION Air brakes / pitch-able blades Mechanical Braking RATED POWER 18 kw 6 kw PREDICTED ANNUAL POWER MWh/annum 6-12 MWh/annum YAW MECHANISM None/fixed YES TOWER TYPE 12.5 DEG tilted custom mast 9 m tapered monopole DESIGN Norwin, custom design Standard design

7 Power (W) Urbines: Specification of Two Turbines Proven Energy Cp Curve Norwin Energy Cp Curve Wind Speed (m/s) Norwin Energy Power Curve Proven Energy Power Curve Wind Speed (m/s)

8 Frequency (%) Urbines: Wind Resource Distributions These assumes an accurate average wind speed but most data taken at airports 0.25 Actual Weibull Rayleigh Wind speed bins (m/s)

9 Urbines: Efficiency vs Surface Roughness Roughness Class Roughness Length m Landscape Type Water Surface Completely open terrain with a smooth surface, e.g. concrete runways in airports, mowed grass, etc Open agricultural area without fences and hedgerows and very scattered buildings. Only rounded hills Agricultural land with some houses and 8 metre tall sheltering hedgerows with a distance of approx 1250 m Agricultural land with some houses and 8 metre tall sheltering hedgerows with a distance of approx 500 m Agricultural land with some houses and 8 metre tall sheltering hedgerows with a distance of approx 250 m Villages, small towns, agricultural land with many or tall sheltering hedgerows, forests and very rough and uneven terrain Larger cities with tall buildings Very large cities with tall buildings and skyscrapers log wind profile law where: V = wind speed at height Z, Z =height above ground level for wind speed V, V ref = known wind speed at height Z ref, Z ref = reference height of known V ref, Z 0 = roughness length

10 Urbines: Wind Resource Modelling A 1 mile radius of London topography centred on the Strata tower

11 Urbines: Focused on the LSBU Campus A 300 m 2 model of the LSBU campus including the tower block turbine site

12 Urbines: Applicable Acoustics Standards BS4142:2014 PPS22 (2004) ETSU-R-97 (1996) ProPG Good Practice Guidance (2017) 'Good Practice Guidance on Noise Assessments of Wind Farms (2013) Additional Guidance (2014) PPG24 NPPF (2012) ISO EN :2003 European Environment Agency in their Good practice guide on noise exposure ad potential health effects (2010) ISO 15666:2003 WHO Environmental Health Criteria 12 Noise

13 Urbines: Rooftop Measurements

14 dba Urbines: Background Rooftop Noise LAEQ LA90 Wind Speed V [m/s] LA eq 1 LA LA eq LA 10 LA 90 Speed Wind LA Wind Speed LAEQ Linear (LAEQ) y = x V [m/s] bins 3 4 5

15 Urban: Operational Rooftop Noise LAEQ LA90 Wind Speed V [m/s] LA eq 1.00 LA eq LA 10 LA 90 Speed Wind LA LA Wind Speed LAEQ y = x V [m/s] Linear (LAEQ)

16 SPL LAeq, db Urban: Operational Rooftop Noise Specta m/s 4-5 m/s 7-8 m/s

17 Urbines: Noise Map: Night Ambient dba Worst Case Wind Speed 6 m/s Typical Wind Speed 3.5 m/s

18 Urbines: Operational Rooftop Vibration

19 Urbines: Operational Turbine Vibration: Wind vs Vibration correlation Coefficient 0.4

20 Urbines: Operational Rooftop Vibration Turbine Mount and Rooftop- No isolation

21 kwh Consumed Urbines: Generated vs Used Electricity Consumed kwh Generated kwh Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec kwh Generated

22 Urban: Optimise Wind Flow 10m high turbine and a proposed 20m high turbine

23 Urbines: Conclusions Site specific atmospheric data is essential CFD modelling is useful for a new build Noise produced is not an issue in Central London Vibration isolation is essential for the mounting Economic analysis needs to include maintenance costs Solution was to increase mast length from 10m to 20m to reduced price per kwh from 40p to 15p based on 30years

24 Thank you for listening! This Research was supported by Brookfield Multiplex and EPSRC