What you should be asking for is an end to the climate alarmism-- the biggest hoax ever perpetrated on humanity. Then, clean burning gas rotating alternators can be again ramped up.
Fundamentally, Inertia is an bidirectional energy store and a quite ineffective one at that. For example a 500MW steam generator might have 4,500 MWs of inertia. If a fault, loss of load or loss of supply causes a 0.5Hz frequency change, the inertia can contribute/absorb 4,500 x (1-(59.5/60)^2 = 74.7 MWs of energy. If it takes 4 seconds to reach the nadir/zenith, the power over the period averages 18.6MW and might peak at 30 MW for a second or so. Power rates beyond 50-60 MW for more than 1-2 seconds would imply rate of change of frequency of 0.3-0.5 Hz/s which would start triggering ROCOF relays and load shedding
Alternatively a 300 MW battery can be supplying 300 MW in 140 ms so over 4 seconds the peak power would be 300 MW and the energy supplied 1,170 MWs. ten times the power and fifteen times the energy.
Further when the fault is corrected, all the inertial energy has to be restored over the next 20-50 seconds or so, as the generator returns to speed, so the net contribution is zero. The battery can be contributing for hours if necessary.
Then there is the question of generator perfomance, there is a lot of talk about the limitations of grid following inverters, however most gas generators on many energy-only grids are also run in grid following mode keeping at their bid power levels, regardless of frequency and voltage. Thus if a major coal unit goes out, there can be a cascading failure across the system as the gas units don't respond See South Australia 2016..
When the central control system wakes up the gas units will take 5-10 seconds to even significantly increase output. In fact because the compressor output is roughly proportional to the cube of the speed, there may well be a dip in the output of the gas turbine, so even if there are adequate "spinning reserves". it can be minutes before voltage and frequency stabilise, let alone return to 60 Hz.
Again there is an assumption that wind and solar can't contribute to fault conditions, this is not true. The lack of mechanical and thermal inertia means that if there is a loss of load wind and solar can be ramped down in 10s-100s of milliseconds with little chance of overvoltage or frequency.
Loss of supply is a little more tricky but a wind turbine with "synthetic Inertia" can use the inertia of the turbine (slightly more than that of a gas turbine) much more effectively because the asynchronous machine can slow down 10-20% without affecting frequency or voltage so say a 500 MW wind farm with 2,000 MWs of mechanical inertia can contribute 550 MWs of inertia whereas a 500 MW gas turbine with 1,500 MWs of inertia could only contribute 25 MWs.
Further just as a coal or gas turbine can only contribute to loss of load if it is running below capacity, it is quite possible to run a wind or solar plant below its instantaneous capacity. In fact that is what happens much of the time in a high renewable grid due to economic or grid constraints. This means that in high sun conditions 2,000 MW of solar farms might have an instantaneous capacity of 1,900 MW but have only bid 1,500 MW into the energy market but can simultaneously bid 400MW into the FCAS raise market. The beauty of that approach is that the solar farm can supply the 400 MW in less than a second, no gas or steam turbine can match that
Perhaps Alberta could repurpose retired or idle synchronous generators as synchronous condensers? I assume it’s not being discussed in an Alberta context because the market design doesn’t have a mechanism to compensate utilities for frequency stability / system inertia.
Manitoba utilizes synchronous condenser(s) from its “semi-retired” Brandon thermal generation facility, I assume that Manitoba Hydro as public crown corporation, has greater agency & flexibility to utilize its existing & retired assets compared to Alberta’s market system.
I must have missed your previous comment, my apologies. Synthetic inertia would definitely be helpful, and this should be valued appropriately in the future market design to ensure we are incenting the attributes we need to maintain reliable operations.
What you should be asking for is an end to the climate alarmism-- the biggest hoax ever perpetrated on humanity. Then, clean burning gas rotating alternators can be again ramped up.
Appreciate the Questions to Consider section
Fundamentally, Inertia is an bidirectional energy store and a quite ineffective one at that. For example a 500MW steam generator might have 4,500 MWs of inertia. If a fault, loss of load or loss of supply causes a 0.5Hz frequency change, the inertia can contribute/absorb 4,500 x (1-(59.5/60)^2 = 74.7 MWs of energy. If it takes 4 seconds to reach the nadir/zenith, the power over the period averages 18.6MW and might peak at 30 MW for a second or so. Power rates beyond 50-60 MW for more than 1-2 seconds would imply rate of change of frequency of 0.3-0.5 Hz/s which would start triggering ROCOF relays and load shedding
Alternatively a 300 MW battery can be supplying 300 MW in 140 ms so over 4 seconds the peak power would be 300 MW and the energy supplied 1,170 MWs. ten times the power and fifteen times the energy.
Further when the fault is corrected, all the inertial energy has to be restored over the next 20-50 seconds or so, as the generator returns to speed, so the net contribution is zero. The battery can be contributing for hours if necessary.
Then there is the question of generator perfomance, there is a lot of talk about the limitations of grid following inverters, however most gas generators on many energy-only grids are also run in grid following mode keeping at their bid power levels, regardless of frequency and voltage. Thus if a major coal unit goes out, there can be a cascading failure across the system as the gas units don't respond See South Australia 2016..
When the central control system wakes up the gas units will take 5-10 seconds to even significantly increase output. In fact because the compressor output is roughly proportional to the cube of the speed, there may well be a dip in the output of the gas turbine, so even if there are adequate "spinning reserves". it can be minutes before voltage and frequency stabilise, let alone return to 60 Hz.
Again there is an assumption that wind and solar can't contribute to fault conditions, this is not true. The lack of mechanical and thermal inertia means that if there is a loss of load wind and solar can be ramped down in 10s-100s of milliseconds with little chance of overvoltage or frequency.
Loss of supply is a little more tricky but a wind turbine with "synthetic Inertia" can use the inertia of the turbine (slightly more than that of a gas turbine) much more effectively because the asynchronous machine can slow down 10-20% without affecting frequency or voltage so say a 500 MW wind farm with 2,000 MWs of mechanical inertia can contribute 550 MWs of inertia whereas a 500 MW gas turbine with 1,500 MWs of inertia could only contribute 25 MWs.
Further just as a coal or gas turbine can only contribute to loss of load if it is running below capacity, it is quite possible to run a wind or solar plant below its instantaneous capacity. In fact that is what happens much of the time in a high renewable grid due to economic or grid constraints. This means that in high sun conditions 2,000 MW of solar farms might have an instantaneous capacity of 1,900 MW but have only bid 1,500 MW into the energy market but can simultaneously bid 400MW into the FCAS raise market. The beauty of that approach is that the solar farm can supply the 400 MW in less than a second, no gas or steam turbine can match that
Perhaps Alberta could repurpose retired or idle synchronous generators as synchronous condensers? I assume it’s not being discussed in an Alberta context because the market design doesn’t have a mechanism to compensate utilities for frequency stability / system inertia.
Manitoba utilizes synchronous condenser(s) from its “semi-retired” Brandon thermal generation facility, I assume that Manitoba Hydro as public crown corporation, has greater agency & flexibility to utilize its existing & retired assets compared to Alberta’s market system.
NREL paper looking at synchronous condenser & smart IBRs to improve stability: https://www.nrel.gov/docs/fy20osti/75848.pdf
I asked this on one of your other posts, thoughts on synthetic inertia?
I must have missed your previous comment, my apologies. Synthetic inertia would definitely be helpful, and this should be valued appropriately in the future market design to ensure we are incenting the attributes we need to maintain reliable operations.
Sell to locals first, then new regions * expand 2-5km per year.