Scottish onshore windfarm to be repowered

[smegal]

I ws looking at the Ripple webbsite and found this (a bit late (Aug '22) but it seems relevant.) https://octopus.energy/blog/repowering- ... -turbines/ with

An illustration of an octopus extending a turbine blade... Preliminary sketch of the blade-lengthening process


The process to build any new energy generator can be long and difficult. Everything from upgrading the local networks to getting planning permission can take ages. It typically takes seven years for a new turbine projects to get fully operational. Actual construction can be completed in a year: most of the time is taken up by lengthy planning and grid connection processes.

Tuning up our existing turbines can take far less time. We already have the most spot on data for wind speeds on site and local topography. Consultations with the local community are far quicker because they've already had a turbine in their neighbourhood – we're just adjusting what's already there. Because a lot of the most time-consuming work is already done, we can get more green electrons down the wires in months, not years.

It seems that raising the tower is an integral part of it, but no mention of re-equippingthe actual generator?
A

The way I read it (plus other info elsewhere) is it takes many years to get a new wind farm (seven years), but even though we have to go through the whole planning process again and re-build most things.

1) The local grid access point is there as it was before, so minimal grid work required.

2) The locals already have been used to the old windfarm so far less hostile to a new one so far easier to get the planning permission.

I believe these two aspects are the longest and hardest to get an otherwise greenfield wind farm operational from the drawing board.

One of the smaller (relatively speaking) wind turbine manufacturers was targeting repowering existing sites. In the example they gave, they targeted replacing a 275 kW turbine,l with their ~900 kW unit, and simply derating their turbine to 275 kW to keep the grid connection (and FiT) the same.

[AE-NMidlands]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

[Joeboy]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

It would be good if the turbines could just output at their design capacity and the fit paid on 30% generation only with the remainder being bought on another contract. Its only paperwork... if the remainder of the site components can take the extra load.

It would be interesting to hear how it plays out?

[AE-NMidlands]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

It would be good if the turbines could just output at their design capacity and the fit paid on 30% generation only with the remainder being bought on another contract. Its only paperwork... if the remainder of the site components can take the extra load.

It would be interesting to hear how it plays out?

I took it that "derating their turbine to 275 kW to keep the grid connection (and FiT) the same" was the crucial bit - avoiding the complications of any paperwork at all, let alone re-engineering!

[Joeboy]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

It would be good if the turbines could just output at their design capacity and the fit paid on 30% generation only with the remainder being bought on another contract. Its only paperwork... if the remainder of the site components can take the extra load.

It would be interesting to hear how it plays out?

I took it that "derating their turbine to 275 kW to keep the grid connection (and FiT) the same" was the crucial bit - avoiding the complications of any paperwork at all, let alone re-engineering!

Fair enough. I just like to see stuff running flat out!

[Countrypaul]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

I suppose it depends on how they are derating the WT. If they are fitting smaller blades so that output peaks at 27kW, the results could be very different from furling the blades to limit peak outpu at 275kW,

If FITs are paid, would increasing the WT to 900 from 275 mean that only 275/900 worth of output is eligible for FITs similar to fitting more PV panels at home?

[nowty]

If FITs are paid, would increasing the WT to 900 from 275 mean that only 275/900 worth of output is eligible for FITs similar to fitting more PV panels at home?

Yes, I just checked the latest FIT guidance doc, the pro rata'ing of the FIT rate (on a extension) is not in the specific PV rules section. Therefore its common to all FIT generation technologies.

[smegal]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

I suppose it depends on how they are derating the WT. If they are fitting smaller blades so that output peaks at 27kW, the results could be very different from furling the blades to limit peak outpu at 275kW,

If FITs are paid, would increasing the WT to 900 from 275 mean that only 275/900 worth of output is eligible for FITs similar to fitting more PV panels at home?

The derating of the turbine is on the electrical side. The mechanical bits such as the blades would be unaltered.

[AE-NMidlands]

I guess this is like having massively over-sized panels and ignoring the summer excess going unused so that you have enough further into the shoulder months, i.e being able to supply the permitted amount of electricity to the grid even as the wind drops away far below the point where the smaller turbine would have stalled.
Effectively multiplying the CF by 900 over 275?

I suppose it depends on how they are derating the WT. If they are fitting smaller blades so that output peaks at 27kW, the results could be very different from furling the blades to limit peak outpu at 275kW,

If FITs are paid, would increasing the WT to 900 from 275 mean that only 275/900 worth of output is eligible for FITs similar to fitting more PV panels at home?

The derating of the [bigger] turbine is on the electrical side. The mechanical bits such as the blades would be unaltered...

... so that your bigger blades can continue delivering 275kW down to a much lower windspeed. As I said, isn't that like massively boosting the CF?

[smegal]

I suppose it depends on how they are derating the WT. If they are fitting smaller blades so that output peaks at 27kW, the results could be very different from furling the blades to limit peak outpu at 275kW,

If FITs are paid, would increasing the WT to 900 from 275 mean that only 275/900 worth of output is eligible for FITs similar to fitting more PV panels at home?

The derating of the [bigger] turbine is on the electrical side. The mechanical bits such as the blades would be unaltered...

... so that your bigger blades can continue delivering 275kW down to a much lower windspeed. As I said, isn't that like massively boosting the CF?

Yes, significantly boosting the CF.

Max power would be at around 7 m/s instead of 15 m/s. Cut out wind speed would be unaltered.