Post by QuarkingMad on Jun 12, 2012 21:45:13 GMT 9.5
A report was released by Beyond Zero Emissions in mid April detailing the replacement of Playford and Northern Coal fired power plants with 6 Concentrating Solar Thermal plants (based on the Solar Reserve plant at Tonopah) and 95 Enercon E-126 wind turbines. You can find this report here.
Now this report states in its conclusion that a total installed capacity of 760MW of CST and 700MW of wind to produce 4650GWh/yr of zero emissions (operating) energy. No capital or O&M costs were included. The report went into the health benefits, and jobs created (direct 360 operating, 1300 construction).
What piqued my interest was, other than no capex or opex thus no LCOE, the Enercon E-126 turbines. To state these things are tall is an understatement. Hub height is 135m and rotor span is 127m. Max rated power output is 7.5MW at a wind speed of 16m/s. These would be a sight to see. Currently there are 35 Turbines in operation in the world.
The Repowering Port Augusta report notes that for an installed capacity of 700MW with a capacity factor of 30% (p. 24) it will only require 95 turbines. Thus the rated average power output is 7.368MW per turbine. Using Enercon's fact sheet on the E-126 for an average output of 7.368MW you will need an average wind speed of 15m/s. That seemed a bit high for an average, so I decided to work back from the location.
Renewables SA has some great fact sheets on solar and wind data for various locations around SA. Luckily they have a sheet on Pt Augusta. This is the data as follows:
Average wind speed = 4.22m/s @ 10m
Average DNI solar radiation = 236.3 W/m2
Because the E-126 hub height is 135m I needed a wind speed at this height. Using the wind profile power law:
ux = ur(zx/zr)a
Where:
ux = Wind speed @ 135m
ur = 4.22m/s
zx = 135m
zr = 10 m
a = Hellman exponent
For different conditions the Hellman exponent will range from 0.06 for unstable air over water to 0.60 for stable air above urban areas. To determine the conditions at Pt Augusta and surrounding areas I used the standard exponent of 0.143, unstable air over flat coast 0.11, neutral air over flat coast 0.16, and stable air over flat coast 0.4. The following are the respective air speeds at 135m:
a 0.143 = 6.122m/s
a 0.11 = 5.61m/s
a 0.16 = 6.39m/s
a 0.40 = 11.95m/s
Since Enercon provides a power curve the following are the respective power outputs (this is an average over the year and closest output to whole m/s):
a 0.143 = 6.122m/s = 760kW
a 0.11 = 5.61m/s = 760kW
a 0.16 = 6.39m/s = 760kW
a 0.40 = 11.95m/s = 5750kW (5.75MW)
I'll note here that the values between 6 and 7m/s range from an output of 760kW to 1.25MW. Thus for a 700MW installed capacity as the BZE report states these are the following turbine numbers:
760kW @ 700MW = 921
1.25MW @ 700MW = 560
5.75MW @ 700MW = 122
Using data from the SA government, the wind calculation that wind developers use, and data from the company this report appears to have underestimated the turbine requirement from a factor of 9 to 1.3. However I must note that for anyone who has been to Pt Augusta you have the Southern Flinders Ranges to the East, Cultana range to the West, and urbanization at Pt Augusta and thus the Hellman exponent of 0.4 for stable air (no turbulence) on the coast is not indicative of the region. Therefore the estimate is out by a factor of 9 to 6.
On a technical basis, unless someone can point out where I went wrong in the calculations, this report has underestimated greatly.
Furthermore to site 560 to 921 turbines at 199m (base to tip) tall by 127m wide in an area where there are a few nat parks, Cultana range (Defence; Army), and the township of Pt Augusta is a stretch to say the least. According to NREL 560 turbines requires 140 acres, and 921 requires 230 acres. However I don't think this is correct for the E-126. There is a formula, but I am at a loss to find it, help?
For the CSP plant the figures for the Tonopah are as follows:
110MW installed capacity (still under construction)
500 GWh/yr production (CF of 51.8%)
1600 acre (6,474,970.28m2) field size
Pt Augusta DNI radiation on average is 236.3 W/m2, Peak summer midday January 728.4 W/m2, Peak winter midday July 578.3W/m2. The figures are in the Renewable SA report here.
I am unfamiliar on the CSP calculations from mirror to tower W/m2 conversion to power. If someone is feel free to take the details from the BZE report on p. 24 and the data from Solar Reserve.
Still 6 plants at 1600 acres per 110 MW (dependent upon DNI) is a lot of area that basically is covered for no use other than a giant mirror, rough area at 38km2, City of Adelaide council area is 15.57km2. The 38km2 figure will decrease with a higher DNI, but I cannot find the relevant technical details at the moment.
Now this report states in its conclusion that a total installed capacity of 760MW of CST and 700MW of wind to produce 4650GWh/yr of zero emissions (operating) energy. No capital or O&M costs were included. The report went into the health benefits, and jobs created (direct 360 operating, 1300 construction).
What piqued my interest was, other than no capex or opex thus no LCOE, the Enercon E-126 turbines. To state these things are tall is an understatement. Hub height is 135m and rotor span is 127m. Max rated power output is 7.5MW at a wind speed of 16m/s. These would be a sight to see. Currently there are 35 Turbines in operation in the world.
The Repowering Port Augusta report notes that for an installed capacity of 700MW with a capacity factor of 30% (p. 24) it will only require 95 turbines. Thus the rated average power output is 7.368MW per turbine. Using Enercon's fact sheet on the E-126 for an average output of 7.368MW you will need an average wind speed of 15m/s. That seemed a bit high for an average, so I decided to work back from the location.
Renewables SA has some great fact sheets on solar and wind data for various locations around SA. Luckily they have a sheet on Pt Augusta. This is the data as follows:
Average wind speed = 4.22m/s @ 10m
Average DNI solar radiation = 236.3 W/m2
Because the E-126 hub height is 135m I needed a wind speed at this height. Using the wind profile power law:
ux = ur(zx/zr)a
Where:
ux = Wind speed @ 135m
ur = 4.22m/s
zx = 135m
zr = 10 m
a = Hellman exponent
For different conditions the Hellman exponent will range from 0.06 for unstable air over water to 0.60 for stable air above urban areas. To determine the conditions at Pt Augusta and surrounding areas I used the standard exponent of 0.143, unstable air over flat coast 0.11, neutral air over flat coast 0.16, and stable air over flat coast 0.4. The following are the respective air speeds at 135m:
a 0.143 = 6.122m/s
a 0.11 = 5.61m/s
a 0.16 = 6.39m/s
a 0.40 = 11.95m/s
Since Enercon provides a power curve the following are the respective power outputs (this is an average over the year and closest output to whole m/s):
a 0.143 = 6.122m/s = 760kW
a 0.11 = 5.61m/s = 760kW
a 0.16 = 6.39m/s = 760kW
a 0.40 = 11.95m/s = 5750kW (5.75MW)
I'll note here that the values between 6 and 7m/s range from an output of 760kW to 1.25MW. Thus for a 700MW installed capacity as the BZE report states these are the following turbine numbers:
760kW @ 700MW = 921
1.25MW @ 700MW = 560
5.75MW @ 700MW = 122
Using data from the SA government, the wind calculation that wind developers use, and data from the company this report appears to have underestimated the turbine requirement from a factor of 9 to 1.3. However I must note that for anyone who has been to Pt Augusta you have the Southern Flinders Ranges to the East, Cultana range to the West, and urbanization at Pt Augusta and thus the Hellman exponent of 0.4 for stable air (no turbulence) on the coast is not indicative of the region. Therefore the estimate is out by a factor of 9 to 6.
On a technical basis, unless someone can point out where I went wrong in the calculations, this report has underestimated greatly.
Furthermore to site 560 to 921 turbines at 199m (base to tip) tall by 127m wide in an area where there are a few nat parks, Cultana range (Defence; Army), and the township of Pt Augusta is a stretch to say the least. According to NREL 560 turbines requires 140 acres, and 921 requires 230 acres. However I don't think this is correct for the E-126. There is a formula, but I am at a loss to find it, help?
For the CSP plant the figures for the Tonopah are as follows:
110MW installed capacity (still under construction)
500 GWh/yr production (CF of 51.8%)
1600 acre (6,474,970.28m2) field size
Pt Augusta DNI radiation on average is 236.3 W/m2, Peak summer midday January 728.4 W/m2, Peak winter midday July 578.3W/m2. The figures are in the Renewable SA report here.
I am unfamiliar on the CSP calculations from mirror to tower W/m2 conversion to power. If someone is feel free to take the details from the BZE report on p. 24 and the data from Solar Reserve.
Still 6 plants at 1600 acres per 110 MW (dependent upon DNI) is a lot of area that basically is covered for no use other than a giant mirror, rough area at 38km2, City of Adelaide council area is 15.57km2. The 38km2 figure will decrease with a higher DNI, but I cannot find the relevant technical details at the moment.