Ripped off - again - solar power in Australia

[augustinetez]

Well, they're at it again.

Owners of rooftop solar are going to be charged to export power to the grid, because of the greedy power companies lack of foresight and short-sightedness when it comes to investing in upgrading the power network to handle renewable energy.

While we supposedly have until 2025 before this comes in to force, they'll spend much longer than that arguing between themselves about how much they can rip off the consumer to maintain the plush life styles of the top executives - greed is alive and prospering in Australia.

https://www.abc.net.au/news/2021-08...-solar-owners-for-exporting-to-grid/100368588

 

[Diver300]

As I see it, the government is allowing distribution companies to alter the rates given to solar generators depending on the demand at the time. So when there is an excess, the price will be less.

I can't see how it can be fair to pay generators for electricity that isn't wanted at that time.

All large generators have variable prices paid to them. Wholesale prices for electricity have often gone negative when there is excess wind and nuclear power. It's nothing new. Pump storage schemes like Dinorwig in the UK, built in the 1970s, only exist because the price of electricity varies so much.

 

[augustinetez]

I understand that, but we (as private individuals with solar panels) will be charged for our excess that is fed in to the grid as opposed to them paying us which is the current case (and is a pittance anyway - 6 cents a kwh).

Our electric bills already have a supply charge on (a little under $2 a day) them which is supposed to cover the cost of maintenance and upgrades to the network, now they want more.

 

[Visitor]

Australia has had times when 100% of the power being used has been provided by solar. That's fantastic, you think. The dream of renewable energy achieved! That's a good thing, right?

Actually, it's a bad thing for utilities and the electric grid. Most of the solar panel arrays operate autonomously. When the sun is out, they put power into the grid, with no ability to control how much power goes into the grid. The power grid is a complex beast, but there is one overriding truth. You must put into the grid exactly what you take out of the grid. You can't put 110 watts into the system if only 100 watts are being used. Traditionally, there is a complex control network in place to adjust how many generators are online and the power they produce minute by minute. Generators are started up and shut down to keep [power in] equal to [power out]. With thousands of uncontrolled solar arrays pumping power into the grid, when the energy they are supplying approaches or exceeds 100%, there's a problem. Too much input raises the voltage on the grid; at some point, damage begins to occur.

I believe that Australia is going to require remote control of I dependant solar arrays. The ability to say "No thank you. We don't need your contribution right now." The utilities are also developing storage methods to store the excess power when a available, and supply it back to the grid when needed, but this is an expensive proposition.

Control systems would give the utility the ability to refuse excess power. So let's say exactly 100% of the power supplied to the grid is solar. If we control it at 100%, that's a good thing, right? But what happens when a storm comes in, and some percentage of solar power production is lost? The utility has milliseconds to make up the shortage. A rotating generator can't be started instantly from a dead stop. Somewhere in the system, turbines are rotating generators so that [power in] = [power out] can be maintained. Virtually instantly. As more storage systems are brought on line, the elasticity of the system is improved, but at some point, eventually traditional power plants must be spun up to keep the lights on. Plants have to be staffed and maintained to be ready to go at a moment's notice.

 

[Nigel Goodwin]

Control systems would give the utility the ability to refuse excess power. So let's say exactly 100% of the power supplied to the grid is solar. If we control it at 100%, that's a good thing, right? But what happens when a storm comes in, and some percentage of solar power production is lost? The utility has milliseconds to make up the shortage. A rotating generator can't be started instantly from a dead stop. Somewhere in the system, turbines are rotating generators so that [power in] = [power out] can be maintained. Virtually instantly. As more storage systems are brought on line, the elasticity of the system is improved, but at some point, eventually traditional power plants must be spun up to keep the lights on. Plants have to be staffed and maintained to be ready to go at a moment's notice.

Further above ' Dinorwig ' was mentioned, which is a stored water power station in Wales - it's also a tourist attraction, a hollowed out mountain that you drive in to on a bus.

I went round it a number of years ago - basically during excess demand they pump water from the lake at the bottom to a lake at the top, then when they need extra power they let the water back down.

Now if the turbines aren't spinning it takes a fair while to start generating power (a few minutes perhaps? - it's many years since I visited, so I can't remember exact figures) - so when demand is expected they have the generators spinning ready. It then only takes ten seconds to go from zero output to full power - but that's still ten seconds. While it's in 'standby' with the generators spinning it also draws 10MW from the grid, so it's not something you keep running 'just in case'.

The classic example would be a football match (world cup final or whatever), half time is at a specific known time - so they will have it spun up ready for everyone plugging their kettles in to make a tea or coffee.

It's certainly a tricky business trying to run an electrical grid.

 

[Visitor]

Speaking of storage solutions in Australia....

Tesla’s Megapack Battery Burned For Days In Grid Storage Fire

Lithium rechargeable batteries have been heralded for their high-density energy storage, enabling all manner of technologies to come to fruition. From drones to practical electric cars to large-sca…

hackaday.com

 

[augustinetez]

Interestingly on the news this morning, one of the big electricity suppliers made a $2 billion + loss (supposedly because of renewable energy) and is now calling for coal fired power stations to be closed down.

And to be replaced with what? - renewable energy of course.

As per usual, these 'people' have known for more than 10 years this has been coming and done what - sweet FA.

All this talk of investment cost, getting your money's worth from that already invested etc etc means that the investment in new technology is going to be many times more than it would have cost if they had just gotten off their arses and done something about it in the first place.

 

[sagor1]

For solar systems feeding the grid, do you not have contracts with the utility? Contracts are binding, and if they have excess energy, that is their problem, not yours. That said, if they disconnect you somehow, that may be a "back door" for them to bypass the contract terms.
Currently I have a 20 year contract with my hydro supplier, based on captial costs and expected capital recovery period of approximately 10 years (more like 11 years based on what I see). If they violated the contract, my capital costs would be legal issues with them...
With no contract, you are subject to the whims of the utility

 

[Visitor]

The utilities do have a method of controlling excess production at the current time. They black out neighborhoods producing excess power. If they don't do that, and excess power is pumped into the grid, the voltage will (must) rise. Damage will be the result.

 

[Pommie]

I'm not sure about now, but in the UK in the 80s the frequency varied as demand varied. As the load increased the generators ran slower resulting in a lower frequency. I assume that a turbine running slower would produce a lower voltage but higher current hence reducing (or balancing) the load. They constantly adjusted frequency so that it was correct over a 24 hour period.

Mike.

 

[Visitor]

Yeah, but.....

The problem in Australia has been that home solar installations have supplied greater than 100% of the need. That have been times when there have been no conventional sources on line, with no way to control production.

 

[Pommie]

They're planning a pumped water scheme (Snowy River II) but I'm not sure it will be completed in my lifetime.

However, allegedly, it'll be complete in 2025. See here.

Mike.

 

[augustinetez]

However, allegedly, it'll be complete in 2025

Oh, look, a pig just flew past the window.

 

[Pommie]

I nearly added "and the pigs are fully fuelled and ready for takeoff."

Mike.

 

[KeepItSimpleStupid]

What I learned is, you start grouping power and they each have their niche/

1.Nuclear - bulk - slow to turn off
2. Hydro - free, bulk
3. Wind - If it's there you have to take it; rather random
4. Coal - poluting
5. gas/diesel - easy to throttle up/down (the requlator of the grid)
6. Solar - peak shaving (Air Conditioning is on when sun is shining)
Inverter technology - local power factor correction
7. You can have a Toyota
Prius generate electricity too. Look up Pre-UPS

 

[Pommie]

The idea that wind and solar HAVE to be used is not necessarily true. Turbines can be feathered and can't you just not use solar and it goes to waste?

Mike.

 

[KeepItSimpleStupid]

Your correct, solar you can turn off, which is, I guess the problem in Australia. the utility needs to be able to turn them off generation.

Not sure what feathered is? I hear that unloaded wind turbines can get out of hand.

Any inverter technology can be used for local power factor correction which is cool.

The one think that you MIGHT be able to do is pump water, but wind is generally located off shore.

I set up for some research to be done in what was called "Demand side management". I think one of the results was the ability to turn off your AC unit and water heating.

Demand side management has gotten fancier in that the power company can control your thermostat, so they don;t have t turn it off/

Solar generally peaks when electricity demand is needed the most for AC.

We have "peak energy savings days" where our rewarded if you use less electricity than you normally do.

It might mean delaying wash or running a dishwahher or lowering the t-stat for cooling.

 

[Visitor]

The idea that wind and solar HAVE to be used is not necessarily true. Turbines can be feathered and can't you just not use solar and it goes to waste?

Mike.

The problem, which is starting to be addressed, is that home solar arrays have no OFF switch that the utility can control. The present options are take it and deal with it or disconnect neighborhoods making sizable contributions to the grid (grid-tied solar arrays only work when the grid is connected, so a home-owner can't use their solar array if the grid is down).

Wind farms operate under utility control – the utility can regulate the power it's receiving from wind farms.

There are options for direct electricity storage – batteries and pumped hydro storage probably the biggest potential. But other options are being explored, like using your electric car as a storage reservoir. Charge it doing the day, and then use some amount of the stored energy during the evening and night.

Other storage possibilities don't store electricity directly – they store the products of electricity. For example, during the day, lower the air conditioner temperature lower than you normally would to chill the house down. Then at night, increase the temperature back to the normal point or even a little higher. You might be able to run through the night without the air conditioner even running and stay be comfortable.

 

[KeepItSimpleStupid]

But other options are being explored, like using your electric car as a storage reservoir. Charge it doing the day, and then use some amount of the stored energy during the evening and night.

See this: **broken link removed**

 

[augustinetez]

The idea that wind and solar HAVE to be used is not necessarily true ........ can't you just not use solar and it goes to waste?

Mike.

Unless the inverter is the type that can be turned off by 'command central', which most of the older ones can't, means that to stop them feeding in power the grid voltage has to be raised.

The problem comes from, the more they raise it, the higher the voltage goes in the older inverters until the limits are reached and the grid goes in to free fall.

As of about 4 years ago, new inverters had to have the ability to be turned off built in.

Now if the 'powers that be' were smart, one of the easiest and cheapest ways to solve the problem is to pay for all the older consumer inverters to be changed to the new type.

Unfortunately, 'smarts' are in short supply at the top end of town.