Reader CommentsAGL could not reconnect any earlier because the AEMO could not ensure stability of the (repaired) grid!Let’s see how Victorians feel about the gas ban after weeks without power. Nothing like a crisis to sharpen the focus The wifeI'm gathering from the article that nothing at all went wrong with the power station, but the lack of transmission meant it either needed to shut itself off, or did so voluntarily because there was no point being on if the electricity couldn't be sent out. Any electrical boffins that can give us a clearer explanation of what happened?(Edited)At any time generation must match load to maintain the correct voltage and frequency. This is what the AEMO control centre does. If the load is lower than the generation then voltage increases to the point that appliances will be damaged. Hence the generation sources automatically monitor their grid connection and if a sudden change occurs they automatically disconnect from the grid. So a 500kV transmission line goes down that Loy Yang is feeding into, voltage levels change, Loy Yang automatically trips off and will only be switched back on line when AEMO directs.The large NE America blackout in 2003 initiated within the grid (power lines overloaded in Ohio , sagged, there were errors in the protection system, and a huge power surge took out the distribution and power generators within the NE from NY, Ohio to Ontario). What was interesting was the time it took for some areas to restore power - in the case of Toronto it was 40+ hours despite a large presence of hydro-electric power within the system. Some areas electricity was not restored for as long as 9 days). I was recently discussing the Victorian transition to renewables with my cousin who worked for the SEC and then was a Chief Electrical Engineer in oil & gas. Whilst we both expressed a concern about the ability to generate 95% of Victoria's electricity requirements wth renewables backed up by batteries with only 1.5-2.0 hours capacity (Victoria does experience many days of calm winds along its coast and this can extend as far as Flinders & King Islands) his big concern was grid stability and if we lost the Vic grid it would take many days re-establish it as you must first establish a robust 50 Hz and this requires synchronous generation capacity for renewables to synchronise and lock against. The smaller synchronous generation capacity becomes in the grid over time the more laborious and drawn our the the process will become.
During our careers we have experienced our plants being shutdown by electrical events interstate and he is concerned the highly variable renewables output could lead to many such events. We also learnt during our careers when introducing new technology you need to be conservative with plant availability forecasts despite extensive risk assessments. We feel there is a lot of hope a renewables grid can power Australia but risk assessments do not accomodate hope!The main and very critical requirement for a modern economy is to have a full and reliable supply of baseload electricity 24hrs a day, 7days a week (24/7).
Without this blackouts and chaos will happen. To be able to meet this requirement therefor it is equally important that electricity generators have a guaranteed supply of fuel to be able to supply base load electricity to the Grid 24/7.
It is an indisputable fact that solar and wind farms have one fatal fault that makes it TOTALLY IMPOSSIBLE for solar and wind farms to ever provide to the Grid a full and reliable supply of baseload electricity 24hrs a day, 7days a week (24/7).
This is because solar and wind farm operators have no control whatsoever over the limited supply of the weather fuel (sunshine and wind) that their solar and wind farms require each and every day.
Solar panels are fueled by sunshine from the Sun. In Winter the amount of viable sunshine available would be between 8.30am and 4.30pm. This amounts to 8 hours or 33% of the day. On overcast or wet days, it may be reduced to zero.
Because of their lack of fuel, solar panels should never, ever be considered as a viable or economical electricity generator to the Grid.
For Wind Turbines they are powered by a weather fuel the Wind. Because they can only produce electricity, when the wind speed is between 12kms/hr and 90kms/hr. The industry reports that Wind Turbines only produce electricity on average for only 35% of their rated capacity or on average for eight hours per day. Wind Turbines can be becalmed for days. Likewise, if a gale blows for several days no electricity is produced. As wind turbines on average can only be relied on produce electricity on average for only 35% of their rated capacity or on average for eight hours per day.
Wind turbines should never, ever be considered as a viable or economical electricity generator to the Grid.The distributed nature of renewable systems requires far more transmission lines. Another contributor to renewable unreliability.(Edited)My point is that when we get to 2038 and all the coal fired power stations are closed. The wind and solar farms with their unreliable and extremely limited (for solar eight hours per day) fuel supply will in no way be able to provide the reliable power we need even on a normal day.
It would also be very interesting to see how to restart solar and wind farms, without fossil fueled generators to provide the kick start.(Edited)Everything you have stated is correct but the further problem no one ever appreciates is that big storms can totally destroy solar and wind installations. Over a long flying career including with the airlines I have seen lines of thunderstorms hundreds of miles long and extending to great heights. The hail, lightning and strong winds from such weather will destroy so called renewable generation.
Many wind turbines are having gear box and bearing failures within five years all around the world from violent wind change and cannot be designed against the vertical shear which occurs under thunderstorm cells. Unless you have first hand experience operating aircraft when there is wide spread thunderstorm activity, you cannot appreciate the power and turbulence they project.
No storms in Australia in the past 35 years have been extreme and once they develop with tops above 50,000' like they did 40 years ago, that's when the real damage will occur. All thunderstorms have the power to cause significant damage if the cell passes over where you are.
3 phase AC power was never designed to have thousands of generators connected to it because of the technical difficulty of paralleling the generators before they come on line by meeting the frequency, voltage and phase tolerances.
