Author Topic: Power outages  (Read 6043 times)

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #15 on: November 29, 2018, 09:39:45 PM »
You'll see a lot of PCM or ice freezing A/C assist cool storage systems in the near future.  The power co.s will push peak power rates so high you'll do anything to avoid them.  It's going to get ugly, and the Power Co.s will do anything they can to keep the status quo.

For off grid, freezing/PCM  to store cool is clearly the way to go.

Sydney's climate is pretty mild.
https://weatherspark.com/y/144544/Average-Weather-in-Sydney-Australia-Year-Round

If this is correct, a super insulated home would likely need very little cooling if any.  Little enough that cooling the water for the in-floor pex could do it, as I plan to do and which is very well proven. The cooling could be during the sunny (PV) day. 

In the past, mild climate homes get little or no insulation, and owners just throw energy at the problem.  Those days will be coming to a close in the next 30 years. 




« Last Edit: November 29, 2018, 10:01:54 PM by BruceM »

ajaffa1

  • Hero Member
  • *****
  • Posts: 1725
    • View Profile
Re: Power outages
« Reply #16 on: November 29, 2018, 10:26:22 PM »
So the Australian power grid won`t be able to meet demand if it gets hot in the summer. When was the last time we had a cold summer? The energy companies need to wake up to reality and make the much needed investment in new generating capacity. Something they are not going to do until the politicos stop fighting among themselves and introduce a long term energy plan.

The idea that we should all switch from internal combustion engines to electric vehicles is plainly nonsense. I`m sure there must be scientists and engineers that know this, so why are we all being lied to?

Definitely need to get a wriggle on with my CS project. One of the questions I have is about my grid tied inverter. When there is a power outage there is no 50 Hz signal to drive it so it produces nothing, would the output from a generator be stable enough to provide that 50 Hz? My second worry is that the output from said inverter would then reduce the demand on the generator, would the governor react quickly enough to prevent over voltage or would I end up cycling the two against each other and blow something up?

Perhaps I should be looking at a second stand alone inverter and array with generator backup. If I did that the grid tied system could export it`s entire production and the electric company would end up having to pay me money!  :laugh:

Bob

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #17 on: November 29, 2018, 10:38:01 PM »
As you suspected, Bob, you will need a stand alone inverter.  The grid tie inverter won't do the job. There are some new models that do support a backup power mode when the grid is down.
If you hook it to a generator, the poor bugger will try to pump power back onto the generator, which will then overvoltage and turn off the inverter almost immediately. 

All inverters should have at least a dual stage common mode choke filter on inputs and outputs.  Dirt cheap health insurance.

ajaffa1

  • Hero Member
  • *****
  • Posts: 1725
    • View Profile
Re: Power outages
« Reply #18 on: November 29, 2018, 10:52:14 PM »
Thanks Bruce, thought that would be the case, I`ll start looking for a decent second hand stand alone inverter. Wonder if I should get more panels or put a diverter switch on the panels I have?

Bob

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #19 on: November 30, 2018, 01:32:45 AM »
Yes, PCM is phase change material.  For a cooling system just water freezing at 0C is OK, but for colder temperatures, other materials can be used or a bit of antifreeze added.

Your bigger temperature swings don't change the situation regarding super-insulation.  The peaks don't really matter; I have temps over 100F regularly in June, but the house stays around 68-71F.  Cool night time air, with open windows is all I need to drop it back down to 68 overnight. I occasionally get tricked by late clouds and a warm night, but not often.

As long as the total demand for cooling isn't too high, and the humidity isn't high, the in floor pex for heating can be used for cooling, with water temperatures around 55-60F.  If the water is too cold, or house is too humid, you get condensation on the tile floor.  A higher volume pump would help avoid cold spots.

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #20 on: November 30, 2018, 01:38:42 AM »
Bob, I can't remember the big picture of your homestead power. One of the dual use inverters might be good for you, with a modest battery bank which could be augmented with Lister power.

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #21 on: November 30, 2018, 05:11:32 AM »
Good advice Glort.  Auto batteries do very well for the "ballast" since they are designed for (and good for) very high discharge rates, and high charge rates too.




EdDee

  • Hero Member
  • *****
  • Posts: 773
    • View Profile
Re: Power outages
« Reply #22 on: November 30, 2018, 10:46:26 AM »
Hey Guys...

Take a look here: http://www.digipoint.co.za:85 This is basically a battery ballasted system I have running - 48V DC buss on 4Kw of panels, offline inverter/charger... If power goes down at night, the inverter acts as a UPS until the emergency screamer auto-starts, when everyone has woken up from the noise, I start old thumper, then the emergency unit shuts down automatically.... To keep everyone in the neighborhood on their toes, I turn on a bloody great loud siren on the raw mains circuit, this lets us know "subtly" when the grid is back up and running....

Cheers
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

ajaffa1

  • Hero Member
  • *****
  • Posts: 1725
    • View Profile
Re: Power outages
« Reply #23 on: November 30, 2018, 11:42:31 AM »
Thanks guys for that enormous amount of information. I`m off to Sydney for more medical assessments in the morning so I probably won`t be posting until Wednesday/Thursday.

It is difficult to express the horror that I feel about this trip, I don`t want to go but it has been forced on me by the insurance companies and lawyers. I have PTSD and am terrified in motor vehicles, I have no idea how I will cope in an airplane. Guess we will find out tomorrow, if you see some nutcase going postal worker at Grafton or Sydney airport it is probably me. Unofficially my councilor has recommended I dose my self with Valium about an hour before the flight, I`m not entirely sure flying wasted is the best solution but it may be the only option.

How I am expected to cope with Sydney traffic is a total mystery to me, I can`t cope with the traffic in Grafton! Very much hoping this ridiculous exercise isn`t going to induce another heart attack but I can`t help thinking that is all part of the insurance companies plan. Dead men don`t get compensation so lets give this old c*nt the run about and see if we can kill him.

What I find really offensive about this entire exercise is that non of these doctors I am seeing are allowed to make a diagnosis or recommend a treatment/therapy regime that might help me. These guys work for the insurance industry so when I arrive I will have to sign a waver allowing them to share my information with others.They will then determine if I am fit for work or compensation regardless of the wishes and diagnosis of the doctors who are actually treating me. What a crock of shit! Depending on how it goes, I may have to hunt some of these f*ckers down and explain to them the error of their ways. Don`t have a gun licence anymore because I am on anti depressants but I still know where the guns are kept.  :laugh:

While I am away, I would like to know how to rectify 240 volt AC at 15 Amps to smooth filtered DC at around 380 Volts at similar current. I`m hoping this should keep you guys busy and out of trouble till I get back.

Bob

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #24 on: November 30, 2018, 04:16:03 PM »
To take 240VAC to 380VDC with moderate ripple, and intended for a generator requires a large step up transfomer to 385VAC (or a few volts more than your desired DC output), then a well heatsinked bridge rectifier, a large choke of at least 5 millihenries, and at least 10000 uF of HV capacitor.  For less ripple, add a second choke and capacitor.  The chokes and capacitors are going to be large and spendy.  This is how I do it as I loathe switching supplies and their unintentional emissions.  I used this method for my 12 amp 230V AC to 146v DC battery bank charger. It used a surplus 230V to 115v step down transformer plus a motorized variac in series to adjust the charge current.  It's been retired after about 10 years of reliable service since my PV has been increased from 875 to 2375 watts; even on cloudy days I now have plenty of power.

A power factor corrected switching AC to DC supply is the typical modern solution and might save some size and expense...but only if you can find one for a good price. 

A two stage common mode choke filter could be used to knock down the conducted HI frequency emissions to the inverter I'm assuming you're supplying.  The inverter may otherwise have  troubles.

Sorry for your torture at the hands of insurance co. whores. I went though that about 30 years ago, to a very bad result for my health.

Sorry for the PTSD, that's a tough one.  CBD oil alone or pot with 1:1 CBD to THC works for some, according to the AZ veterans support group.  They had quite a fight to get pot approved for PTSD in our state.  I use it periodically for head and muscle pain and for control of complex partial seizures.  Compared to all the 2 dozen anticonvulsants I've tried (on some for 15 years, causing depression and liver, gallbladder, and kidney problems), it's pretty damned amazing.  A good side effect is my depression is improved the next morning from a night time dose which helps me sleep on a rough night. Very small doses below getting "high" work best for me. Too much THC just causes pain and paranoia for me, though I know for some it's very helpful for depression.
My quality of life has improved greatly because of it. 

« Last Edit: November 30, 2018, 04:17:58 PM by BruceM »

mikenash

  • Hero Member
  • *****
  • Posts: 955
    • View Profile
Re: Power outages
« Reply #25 on: November 30, 2018, 05:06:36 PM »
Good luck Bob

FWIW my lady friend - she who can only start the easi-start Honda genset - has suffered a life of PTSD as a legacy of ugly childhood abuse stuff and physical damage associated with that

Years before we met, ACC doctors & conventional medicine had left her wheelchair-bound, very unwell, very overweight, and unable to cope with normal social interactions and many physical situations such as your traffic/confinement stuff.  Drugs like Prednisone were slowly killing her

A few years ago she began to research her conditions and situation and to take charge of her own medical processes (after a long struggle to find both a doctor and a pharmacist who "got it")

These days she is fit and active, takes no meds apart from an evening dose of an antagonist, lives independently and enjoys her grandchildren

She is a very smart woman who used the power of her intelligence and the information available in books and the internet, plus her bloody-minded determination, to take back control from ACC (read insurance) doctors and regain her life

It's worth commenting that she did that un-supported, largely, with no $$ at all - just living on something like a sickness benefit from ACC, and in very poor circumstances. Mostly just "determination in action"

I guess I'm saying that "if she can then you can".  Good luck

mike90045

  • Mendocino Metro
  • Hero Member
  • *****
  • Posts: 1594
  • Mmmm BBQ
    • View Profile
    • Mikes Solar PV page
Re: Power outages
« Reply #26 on: November 30, 2018, 07:38:26 PM »
I'd make a screened room, and put Switching Power supplies in it, clean the DC power up as it comes out of the shield room.   Much smaller inductors and caps with high freq switchers (and better power factor) and parts will be avaib in 5 years if it needs rework.    Big 400V computer filter caps are really expensive.


BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Power outages
« Reply #27 on: November 30, 2018, 10:16:00 PM »
The high voltage caps for a simple linear supply are spendy.  The PF for a linear supply with a choke over critical value is nearly perfect.  Switcher's are hardly the robust and long lived solution. Good luck finding an affordable switching supply with good PF, the desired DC voltage, at 15 amps. 

If you are running a generator for the 230VAC source, changing to a 3 phase head and modifying or adjusting an AVR to generate the desired 380VDC or whatever is desired directly might be a nice solution.  Depending on the inverter, just 3 phase rectification alone (no choke or caps) might be all you need.


ajaffa1

  • Hero Member
  • *****
  • Posts: 1725
    • View Profile
Re: Power outages
« Reply #28 on: December 05, 2018, 11:18:34 AM »
Hi Guys, got back today, flights all OK. I had no idea my flight was being stalked by Glort but I wouldn`t expect anything less.  :laugh:

The trip was a total waste of time and the governments money because when I got to see the specialist doctors their information was months out of date. So I have been sent home awaiting another summons to attend the government doctors, once the doctors,lawyers and insurance companies have got their acts together.

I haven`t had time to catch up on all the posts I missed while I was away, I`ll try to catch up in the morning.

Bob

ajaffa1

  • Hero Member
  • *****
  • Posts: 1725
    • View Profile
Re: Power outages
« Reply #29 on: December 06, 2018, 08:52:11 AM »
Hey buddy, this wasn`t a social trip. I would have liked to catch up with you but reason prevailed. I stayed with my Brother in Law who lives in the Eastern suburbs. He very kindly drove me to all the appointments and to and from the airport.

I also got to go and see my Father in Law, he has dementia and is in an aged care facility. I haven`t been able to visit him for over two years. He was a wonderful man before this terrible disease took him from us. Incredibly he remembered me and knew my name, we took him to the beach and fed him ice cream, he smiled and laughed. I guess that`s one thing ticked off my bucket list, hearing my Wife`s Father laugh again.

I`ve still got to pen a stinking email to my lawyers asking why I had to go to Sydney for assessment when my medical issues are still ongoing and undiagnosed/untreated.

Bob