Too much solar???

[Joe Blake]

Australia appears to be running into a problem with too much solar power being generated. The authority in charge (AEMO) wants to be able to switch it off.


https://www.abc.net.au/news/2024-12-02/aemo-demands-emergency-backstop-to-switch-off-solar/104670332

The body responsible for keeping the lights on in Australia's biggest electricity grids wants emergency powers to switch off or throttle rooftop solar in every state to help it cope with the daily flood of output from millions of systems.

In a report to be released this morning, the Australian Energy Market Operator said it urgently needed "emergency backstop" powers that would give it the ability to turn down – or off – solar installations in extreme circumstances.


Yet our Parliamentary Opposition wants to build nuclear power plants. :wacko:

[Rob Beckers]

This has been a thing over here for some time as well. Code has changed for solar inverters to require a mechanism for the utility to switch or limit the inverter if they so choose.

It is a real issue though: The electrical grid is not inherently stable, demand and supply have to exactly match at any point in time. When there is too much supply the Voltage will rise (and with it loads will start using more power, think of an incandescent light bulb shining brighter when the Voltage goes up). That can only go so far though, the Voltage is supposed to stay within fairly narrow limits up or down. With solar or wind the power output of the inverter will change all the time, depending on how much sun or wind there is, or if a cloud drifts in front of the sun. That makes keeping the electrical grid a challenge. It gets worse when demand is low and there is lots of solar power coming into the grid. That is why utilities have a real need to be able to limit PV output power (same for wind).

On the demand side of the grid there are of course also continuous changes, as people switch things on or off, or if it's hot and the A/C is switched on in the afternoon. It used to be that smaller natural-gas fired electrical plants would ramp up or down to meet these quick changes in demand (and they still do in most places).

Regarding nuclear, and this is my own personal opinion, I used to be opposed for most of my life until recently. But at this time I do not see any other way to generate the electrical demand for the world without it, at least not if we don't want to emit more greenhouse gasses making electricity. Much as I'd like it to, solar, wind, or water are just not going to cut it. Too many reports have come out showing this. They can help, but we have a need for stable base-load power; electrical power generation that provides a substantial percentage of the loads and that does not ramp up or down all the time. Maybe in the future we can use renewables and batteries to do this, but in the next decade or two this just won't happen, and it is still dubious if we can do this further down the road.

There you have it!
Comments of course welcome (as long as we keep this civilized).

-Rob-

[Joe Blake]

Whilst Nuclear power may be a solution for Canada, Australia is not Canada. Apparently Canada averages 143" of snow per year. In Australia if snow falls in a major city that is likely to make the headlines. Most snow falls on mountain tops for the skiers.

Without wanting to get too much into Australian politics, the leader of the Opposition has used Canada as an example of why nuclear power should be built in Australia. However ...

https://reneweconomy.com.au/ontarios-huge-nuclear-debt-and-other-things-dutton-doesnt-understand-about-cost-of-electricity/

In Oz we generally suffer from a surfeit of energy, and as has been pointed out, storage is our problem. In what could only be called suspiciously well timed*, the Govt has legislated to allow electric vehicles to operate Vehicle to Grid, which will ameliorate the problem somewhat.
(*We are due for a Federal election early in the New Year).
https://www.drive.com.au/news/australian-government-to-announce-electric-vehicle-to-grid-household-standards-today/

A bit about storage.

Australia: How has battery energy storage capacity in the NEM hit 3 GWh? - YouTube

https://www.energycouncil.com.au/analysis/battery-storage-australia-s-current-climate/

From a more personal perspective yesterday (3 Dec 24) I commissioned my own storage system. In 2017 I purchased a second hand 2012 electric scooter (ie sit-down, not stand up), and a couple of years ago the batteries (LiFePo) were on the way out, so I purchased a new set. In 2022 I asked an elec engineer friend if he could take these batteries and add them to my SLA batteries on my rooftop solar, and via a Daly BMS he accomplished this. In the meantime the scooter itself died and I was stuck with a pretty new set of batteries, and a very old (2004) off-grid set up with flooded lead acid batteries. With over 15 months of success from my initial experiment, we got together and after recycling the FLA's, which were on their last legs, I bought some replacement 12 volt solar panels, an MPPT controller, a few Anderson plugs and have now got an off-grid back up system (which only runs three 12/24/240 volt freezers) which I've tested sporadically over the past fortnight by disconnecting from the grid via the house power board circuit breakers. Despite having some rain for the last 3 days, I've been able to get everything fully charged before midday. So whilst it's not my intention to go off-grid I now know that, at least in summer time, I am not relying on the grid at all.

So getting back to the nuclear issue, in Oz (as in many other places no doubt) there is a shortage of housing, with homelessness increasing, and housing prices are now at an unaffordable level for many people.

https://homelessnessaustralia.org.au/wp-content/uploads/2023/07/Homelessness-fact-sheet-2023-1.pdf

My view is that given that if the Opposition wins government, they've said they'll take 2 years to consult with whoever to allow planning to start building nuclear plants. Given that very few of these builds have finished on time and/or budget, it'll probably be at the earliest 10-12 years to start pumping the first watts into the system. The fly in the ointment is that the plans are to build the nukes on the sites of old fossil fuel plants and/or minesites, but with no definite position on what will replace these plants (which have started dying already, needed taxpayer $ to keep supplying power) in the interim, but already storage batteries are projected to be installed in those sites.

Given the level of homelessness, I don't see how cheap (even FREE) electricity is going to be on any use to somebody who has no permanent accommodation, and that the money to be spent on nuclear power would be better used to build community/ social housing.

[Rob Beckers]

Congrats with the Personal Storage System Joe!
It's something on my "to do" list but as usual "the cobbler's kids go barefoot" (as the expression goes) and while I have PV on my roof there's little 'renewable energy' around my house. Too much to do and too little time! :nuts:

Agreed on the "never on time or budget" comment when it comes to nuclear. I fear that's something that will only get worse, not better. It's not that I'm jumping to see nuclear power take to the stage in a big way, it's with much reluctance, and only with the realization that on a global scale (not just Canada) we're not going to solve the decarbonization issue with renewables alone.

I forgot to mention that this in part comes from seeing much, much safer nuclear power plant designs being available now that do not suffer runaway when suddenly shut down (no more Chernobyl or Fukushima), as well as the hope that thorium will finally be used as a fuel. It is inherently much safer, you can't make weapons from it's waste products (no plutonium), it's nuclear waste is much shorter-lived vs. uranium, and is is actually much more abundant vs. uranium. The reasons why it has not been used have much to do with the fact that you can't make bombs from its byproducts. Such is the world we live in... :cry:

-RoB-

[Dave Hachey]

Thank you for explaining that so well! I'd always wondered why they'd ever want to limit incoming energy from homes/businesses.

I agree with you on the need for nuclear power and it's ability to generate huge amounts of power without harming our environment (from a carbon standpoint at least). I think the new SMR (Small Modular Reactor) plants are the future and in time will be the go to source for clean and safe power generation. Having said that Spain is the first country to ever supply over 50% of it's entire energy consumption via renewables, being solar, wind and water. It can be done!

This has been a thing over here for some time as well. Code has changed for solar inverters to require a mechanism for the utility to switch or limit the inverter if they so choose.

It is a real issue though: The electrical grid is not inherently stable, demand and supply have to exactly match at any point in time. When there is too much supply the Voltage will rise (and with it loads will start using more power, think of an incandescent light bulb shining brighter when the Voltage goes up). That can only go so far though, the Voltage is supposed to stay within fairly narrow limits up or down. With solar or wind the power output of the inverter will change all the time, depending on how much sun or wind there is, or if a cloud drifts in front of the sun. That makes keeping the electrical grid a challenge. It gets worse when demand is low and there is lots of solar power coming into the grid. That is why utilities have a real need to be able to limit PV output power (same for wind).

On the demand side of the grid there are of course also continuous changes, as people switch things on or off, or if it's hot and the A/C is switched on in the afternoon. It used to be that smaller natural-gas fired electrical plants would ramp up or down to meet these quick changes in demand (and they still do in most places).

Regarding nuclear, and this is my own personal opinion, I used to be opposed for most of my life until recently. But at this time I do not see any other way to generate the electrical demand for the world without it, at least not if we don't want to emit more greenhouse gasses making electricity. Much as I'd like it to, solar, wind, or water are just not going to cut it. Too many reports have come out showing this. They can help, but we have a need for stable base-load power; electrical power generation that provides a substantial percentage of the loads and that does not ramp up or down all the time. Maybe in the future we can use renewables and batteries to do this, but in the next decade or two this just won't happen, and it is still dubious if we can do this further down the road.

There you have it!
Comments of course welcome (as long as we keep this civilized).

-Rob-

[Dave Hachey]

Good points! Add to that the fact that Small Modular Reactors (SMR's) are built in a factory so the quality control and efficiencies of volume production come into play, which not only means higher quality but also reduced costs. Ontario is currently installing four of these at the Darlington Nuclear Power Plant, the first installation of SMR's in North America. I think the entire concept is great, a single unit can be dropped into place and power a small town, and when the fuel runs out it just gets swapped out for a new unit, while the spent one goes back to the factory for rebuilding. Pretty cool stuff. It's going to take a bit of everything to get us out of this mess that we've made...

Congrats with the Personal Storage System Joe!
It's something on my "to do" list but as usual "the cobbler's kids go barefoot" (as the expression goes) and while I have PV on my roof there's little 'renewable energy' around my house. Too much to do and too little time! :nuts:

Agreed on the "never on time or budget" comment when it comes to nuclear. I fear that's something that will only get worse, not better. It's not that I'm jumping to see nuclear power take to the stage in a big way, it's with much reluctance, and only with the realization that on a global scale (not just Canada) we're not going to solve the decarbonization issue with renewables alone.

I forgot to mention that this in part comes from seeing much, much safer nuclear power plant designs being available now that do not suffer runaway when suddenly shut down (no more Chernobyl or Fukushima), as well as the hope that thorium will finally be used as a fuel. It is inherently much safer, you can't make weapons from it's waste products (no plutonium), it's nuclear waste is much shorter-lived vs. uranium, and is is actually much more abundant vs. uranium. The reasons why it has not been used have much to do with the fact that you can't make bombs from its byproducts. Such is the world we live in... :cry:

-RoB-

[Joe Blake]

The Nuclear Debate ramps up. From ABC (Australia) 7:30 current affairs last night.


https://www.abc.net.au/news/2024-12-09/the-debate-over-australia%E2%80%99s-energy-future/104705168?utm_source=sfmc&utm_medium=email&utm_campaign=abc_newsmail_am-pm_sfmc&utm_term=&utm_id=2466038&sfmc_id=353249868

Looks like coming down to "Who do you believe? Scientists or Politicians?"

[Dave Hachey]

Well that was a good watch! Thanks for sending. I think they're both right in some ways, that the #1 focus should be on renewables but at the same time we'll need another form of abundant and safe energy, with that (to me) being nuclear. SMR's are no longer 'the next great thing that will always be the next great thing' as the one guy falsely stated, they're here right now.

[Joe Blake]

I agree with you on the need for nuclear power and it's ability to generate huge amounts of power without harming our environment (from a carbon standpoint at least).

Whilst I'd agree with your qualification re carbon*, it must be remembered that the first law of thermodynamics ie conservation of energy

https://en.wikipedia.org/wiki/First_law_of_thermodynamics

shows that all the energy created by a non-renewable power plant (including nuclear) will eventually wind up in the atmosphere, whether if be from the "waste" heat in the steam from a cooling tower, losses over transmission lines or at the final destination, whether it be smelting aluminium or cooking the Sunday roast. This would be of particular concern as the conurbations of cities and their suburbs will be generating/ dumping heat, which can contribute to "heat islanding"

https://www.epa.gov/heatislands

which can lead to increased temperatures, resulting in increased consumption of energy eg air conditioning, resulting in more heat and so forth.

As the name implies renewable power generation is using energy which is already extant in the environment, not adding more.


*In considering whether to use nuclear power, one must also consider the energy cost in constructing the systems eg concrete, transportation of materials to the site etc, as well as costs/ dangers linked to storage of dangerous radioactive materials.

[Dave Hachey]

Very good points and some interesting reading there, thank you.

One thing for sure is that there's no panacea when it comes up to the development of energy but at least we're heading in the right direction, although nowhere near fast enough.

We recently converted our home to 100% electric with the installation of a furnace heat pump as well as a hot water heat pump and electric cooktop. The next step is to install lots of solar to offset the majority (or all) of our usage. Say what you want about the Liberals but kudos to them for the Canada Greener Homes Program. It not only covered half the cost of the heat pumps but is also providing us with a 10-year interest-free loan to cover the cost of getting our solar equipment. Doing the installation myself will mean that we will easily cover all the costs and 5-6 years.

[Ralph Day]

Hi Dave
Good to hear about the Greener homes plan. Too little too late for me. Solar and wind put in on my dime, heatpumps put in on my dime...thin edge of the wedge (all originally put in going back 20 years).

Can you get Net metering with your utiilty? Sometimes there's "not enough capacity" for feeding back.

Ralph

[Dave Hachey]

Wow, good for you for being on top of this way before pretty much everyone else! Heat pump technology has come quite a ways over the last decade. A Canadian company called Arctic Heat Pumps have inverter units that offer a cop of 6:1, amazing. I thought about getting one of theirs for our furnace but decided to go with a Bosch unit that runs 3.8:1 because I favored the security of going with a long-term high-end brand like Bosch.

I did however purchase a heat pump pool heater from Arctic heat pumps that runs at 6: 1. And it's utterly shocking at how efficient it is, at all for virtually the same cost as a gas fired pool heater.

We do have net metering but I'm still waiting for a response as to whether we'll be able to hook up. I always wondered why they had limits on this but Rob Beckers posted on this forum an excellent explanation that explain the reason why.

[Rob Beckers]

Dave, and others,

The reason that in Ontario many are not allowed to do net-metering is a little different from what I was talking about in regard to Australia (and other countries), having too much solar PV, and grid instability. For us in much of Ontario there is a rather artificial limit of 7% where Hydro-One (the local provider of much of this province) draws the line for renewables. So, no more than 7% of the carrying capacity of any point on their grid is allowed in renewables, and once that limit has been reached you get the dreaded "no capacity" message when you apply for net-metering. Vast stretches of the grid have been artificially made inaccessible this way.

Hydro-One's reasoning has to do with a very unusual set of circumstances where maybe, just maybe, with enough renewables on a segment of the grid, those renewables could continue producing power after that segment has been shut down. This is called "islanding", as in creating an island of electrical power apart from the rest of the grid. This would of course be very dangerous for line-workers! For that reason all inverters contain logic that detects islanding and switches the inverter off if it suspects this is happening. There is I believe one documented case where islanding DID happen 'in the wild' that forms much of Hydro-One's case against allowing more. In reality, with today's inverters, this is extremely unlikely to ever happen. Now, there is a limit that is needed to keep the grid stable, but in other (European) countries they allow 50% in renewables and best I know that has worked out just fine.

In reality I suspect that allowing renewables and offsetting one's electrical use is just not part of the business model of the electrical provider...

Unfortunately in our province the electrical providers can in essence write their own laws when it comes to the grid. They are not subject to regular electrical inspections for example, they do their own. And so they get away with this. The only way out would be for the legislature to write laws compelling the providers to allow more, but with the current government that will never happen (and in honesty, the previous liberal government did not do anything regarding this either when they were still in power).

-RoB-

[Ralph Day]

You want to believe it 'Rob
About a Km from my daughter's house is a Hydro 1 transformer station. 1960'sw vintage. It is only now getting upgraded equipment because someone closer (a lawyer) took them to court about the noise level. You can hear the buzz over a km away sometimes.

H1 maintained that they were in an urban setting, not rural. The station is set amongst corn/wheat/bean fields. Rural noise levels are lower than urban. Finally someone got something done.

Ralph

[Joe Blake]

China is really putting the rest of the world far behind installing renewable capacity.

https://reneweconomy.com.au/solar-leads-as-china-adds-210gw-of-new-renewable-capacity-so-far-in-2024/

China has installed 210GW worth of renewable energy through the first three quarters of 2024, an increase of 21 per cent on this period in 2023 and accounting for 86 per cent of all new power capacity added in the year.

Data published by China’s National Energy Administration (NEA) showed that new capacity installed through the first nine months was led by solar, which added 161GW of new capacity added.

A further 39.12GW worth of new wind power, 7.97GW of new hydropower, and 1.37GW of new biomass power rounds out the new capacity added so far in 2024.

At the end of the first three quarters, then, China’s renewable energy generating capacity had reached 1.73TW, a year-on-year increase of 25 per cent.

[Rob Beckers]

Indeed, the rate they are putting up solar is astounding!

Unfortunately, they also are the largest coal-fired power plant installer in the world, adding about 50 GW in 2023 (https://www.carbonbrief.org/china-responsible-for-95-of-new-coal-power-construction-in-2023-report-says/#:~:text='Pivotal%20juncture'%20for%20China,would% 20be%20retired%20by%202025.)...

-RoB-

[Victor Avila]

I am exploring the possibility of using the heat stored in a solar water heating system to convert it, on demand, into mechanical work and subsequently into electrical energy.

Stirling engines, designed to transform heat into mechanical work, are well known for their efficiency, especially when operating under large temperature differences. Small-scale models (around 10 cm) capable of functioning with low-temperature differentials (<100°C or <212°F) are already commercially available. However, there are no large-scale Stirling engines (~1m) designed to operate under such conditions.

This type of engine—large in size and capable of functioning with small temperature differences—would be essential for converting the stored heat from a tank containing a few hundred liters of water heated to less than 100°C into useful energy.

The absence of such a specific Stirling engine seems to be an inherent limitation of scale, making its technical feasibility a challenge. To overcome this issue, I have designed and am currently developing a new thermal engine that, unlike the Stirling engine, does not depend on scale to operate efficiently.

The idea is to harness the fraction of thermal energy that Thermodynamics allows us to extract from the vast amount of heat stored daily by the Sun in large volumes of water. The goal is to ensure a continuous supply of useful energy, both day and night, and for several consecutive days, even in the absence of sunlight.

In summary, this is a thermo-solar system that inherently incorporates an efficient method for storing the collected energy.

I will greatly appreciate any feedback, questions and suggestions.

Victor Avila