Author Topic: snowed in, again  (Read 4291 times)

BruceM

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snowed in, again
« on: January 13, 2019, 04:06:22 PM »
More cloudy and cold stretches this winter than we've had in 20+ years, and last night a forecast 0-3 inch now has turned into 8+ and still snowing this morning.  This just after the last snow finally melted.  I'll be on PV and solar hot water snow removal when/if it stops.  An alarming change after over a decade of milder, warmer winters (and hotter summers).   

Lucky for me a friend brought groceries 2 days ago. There's no county maintenance on our dirt roads here, it's DIY all the way.

11:30
Massive PV to the rescue.  With my additional 1500W, despite heavy overcast (though with snow on the ground assist) I've got plenty of power to charge.  By the time I finished shoveling snow, my main battery bank was up to bulk charge voltage. 


« Last Edit: January 13, 2019, 06:12:46 PM by BruceM »

LowGear

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Re: snowed in, again
« Reply #1 on: January 14, 2019, 09:41:52 PM »
Solar power in snow country.  Who would have thought?
NPR Tipper/Dump Truck
Kubota BX 2230
Witte BD Generator
SunnyBoy 6000 + SolarWorld 245

ajaffa1

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Re: snowed in, again
« Reply #2 on: January 14, 2019, 11:00:30 PM »
I would be delighted to have some snow, used to love skiing, bring it on. The effort would probably kill me but it`s got to be better to die doing something I like rather than die thinking about all the things I would like to be able to do.

South Australia has just issued a red alert for a heat wave with temperatures exceeding 45 degrees. We are only forecast to get to 38 by the end of the week, despite being several thousand kilometers closer to the equator. I guess all my solar power will be diverted to the air conditioner again.

My unlucky Brother in Law flew into Melbourne yesterday, for the week. going to be a hell hole there in the heat, expect the grid will fall over again with all those AC units running.

Bob

BruceM

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Re: snowed in, again
« Reply #3 on: January 15, 2019, 12:06:09 AM »
Grid power is for whiny socialist/communist pussies.  Pull the plug. ;)

Seriously, Glort you should think about becoming a distributor of the Ice Bear peak shaving cooling systems.  Your peak power rates are going to get much, much higher.  It's the only way to reduce peak power demands in summer. 

ajaffa1

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Re: snowed in, again
« Reply #4 on: January 15, 2019, 12:22:29 AM »
Oh boy, the numbers are looking very bad again and it`s broad day light, lots of power feeding back into the grid. When that drops off this evening we can probably expect blackouts again. Don`t think the charge in SA`s big Tesla battery is going to last long!

Things are only going to get worse as the population increases and temperatures rise, at some point the idiots in government are going to have to pull their heads out of their arses and put in place some policies that will encourage investment in power generation.

The flows into those diesel generators is frightening, just over eleven litres per second! Guess the oil dealers in Singapore will be having a party this week. No doubt this will lead to a nationwide shortage of diesel, as we no longer have sufficient reserves, allowing the servos to hike he prices. Yet another example of short term thinking by those in charge costing the people money.

My Wife has been in Sydney for the last week and is driving home today, going to be a lot cooler here. Western Sydney forecast to hit 48 today, that`s going to need a lot of AC to cool down.

I`ve got the generators prepped and ready to go at all times due to the shaky grid reliability where we live. Can`t wait for the CS generator to be completed so I can give the bird to both the electric companies and the petrochemical giants not to mention the government.

Stay cool,

Bob

broncodriver99

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Re: snowed in, again
« Reply #5 on: January 15, 2019, 12:29:55 AM »
This one give a different insight, Shows the power being moved around and the price the grid operators are paying wholesale.
When it gets towards $400, you know they are desperate.  Sa, NSW and VIC are already Nudging $300 when at this time of day they would usually be around 60-70.

https://www.aemo.com.au/Electricity/National-Electricity-Market-NEM/Data-dashboard#nem-dispatch-overview


WOW. That's a very interesting site. Does AUS have multiple operators or just one that handles the whole country?

ajaffa1

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Re: snowed in, again
« Reply #6 on: January 15, 2019, 12:35:17 AM »
Like the Ice Bear idea, wonder if it could be reverse engineered to store solar energy during the day to provide air conditioning at night?  Nice little video of the concept https://www.youtube.com/watch?v=F4arHI6Ul90

Bob

BruceM

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Re: snowed in, again
« Reply #7 on: January 15, 2019, 01:32:54 AM »
The right wing mantra of private sector does it better and cheaper has been the power co.s con job since their inception.  It was never true during FDR's time, ala the highly successful TVA project, nor is it true now.

I found it interesting that every country with a national grid has pretty well thought out grounding and safety systems, decent rates considering their countries energy assets. They are mostly planning on migrating to renewables in a rational manner. The US system of patched together private systems is a farce, and the MEN grounding system is an abomination.  Hanging "smart meters" on it makes me think of adding GPS naviation on an Amish buggy. As everywhere else, there was no cost savings to the consumer at all, just more increases.  Only Germany was smart enough to look at the data and say no, thank you to "smart" meters.

If you think power should be provided for everyone, it seems to work out better to nationalize and have central planning and less quarterly profit pressure on management and maintenance. 
 
Given the idiocy of most humans regarding power, that may be the best solution. Most guys here could do off grid easily, but this is hardly representative.



BruceM

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Re: snowed in, again
« Reply #8 on: January 18, 2019, 02:43:34 AM »
A moderate summer high for Phoenix, 44C, 111F.
Except for Tasmania's Hydro, Au is almost all coal and little NG.  Are solar-molten salt plants on the way?  They have good carry over to peak times, though not for more than a day or three, depending on molten salt storage capacity.  Beats the heck out of current battery tech.

ajaffa1

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Re: snowed in, again
« Reply #9 on: January 18, 2019, 08:13:44 AM »
Absolutely right Glort, the power companies are rorting the system. They have no interest in generating electricity to support the people and industry of Australia. The capitalist system is all about maximizing profits and shareholders dividends, it has nothing to do with investing in the nations future. I wonder what percentage of the shareholders are Australian and actually live here. I suspect that most of the shares are owned by overseas investment funds that don`t give a sh1t about Australia.

Until the government can put in place some sort of long term energy plan things will only get worse. It is farcical that a country whose economy is based around mining fossil fuels and minerals for export, is afraid of using them to benefit our own population.

We are not the only country with this problem, take a look at this: https://www.dailymail.co.uk/debate/article-6605473/As-Japanese-firm-Hiatchi-scraps-20bn-nuclear-power-plant-ALEX-BRUMMER-says-need-fast.html

Bob

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Re: snowed in, again
« Reply #10 on: January 18, 2019, 01:16:48 PM »
I don't know where the figure of 40000 litres an hour came from they must be enormous diesels. Even the 70,000 hp diesels in the panamax containerships only use about 10 tons an hour (12000 litres).  Might be a bit of an exaggeration or really inefficient diesel or gas turbines.

ajaffa1

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Re: snowed in, again
« Reply #11 on: January 18, 2019, 09:43:09 PM »
Someone needs to build a generator that runs on BS, the stream of effluent coming out of Canberra would power the nation for years.

I worry about your prediction for cascading power failures, I`m OK cos I can fall back on R A Lister. The old, young and sick don`t have that luxury and many could die from heat stroke. The inevitable political fallout won`t achieve anything, they will all just point the finger at someone else as usual. Eventually they will conclude that it`s the peoples fault for using too much power.

Bob

carlb23

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Re: snowed in, again
« Reply #12 on: January 20, 2019, 01:53:03 PM »

 Western Sydney forecast to hit 48 today, that`s going to need a lot of AC to cool down.

I can't see that anywhere but i hope not.
48 is the most I have ever been in in my life, Twice, and it's no fun.

Problem there is when it gets over about 35, most AC starts falling off it's curve pretty rapidly. So do solar panels well before that.

I have a hose on the back of the AC condenser with some garden water mist Nozzles that throw bit of a fog into the coils and cools the intake air.  Makes a HUGE difference to the exhaust air, goes from distinctly hot like a fan heater to quite warm but maybe 20o or more drop.
Allows the machine to do it's job and also not trip out on heat overload.  Nozzles use like .5L water an hour so well worth the benefit.

Nice and cool in here so far and haven't even touched the air.  Will warm up from now on as the sun hits the back of the house.  I'm definitely thinking of getting some shade cloth and clamping it to the gutter all along the exposed back of the house. I think that would make a very big difference to keeping the place cooler.

Of course Mrs would go into orbit about that like every other thing that upsets the look of the place despite the benefit.

I have done my bit for the wildlife this morning.  Got the birdbath I found in the over grown Bushes and put it right next to the grevillia all the native birds are at all day and I can watch from my window.
Might take them a bit to get used to it but if it gets warm enough i'm sure they will soon put their concerns aside for a splash and a drink.  Dad has one and refills it 4 times a day in the hot weather. they know where to find it and make the most of it so hopefully will do the same here.

I suspect in a few short years your  condenser coils will be covered in minerals from the water and become much less efficient  as the air flow becomes restricted and the coils are insulated from the mineral deposits. The coils will begin to corrode in the same time period.   I would not put city or well water over the condenser coils.

I just purchased a new heat pump condenser that i will be installing in april.  It a Bosch Bova 5 ton unit with a seer of 18.  its uses a fully modulating inverter driven Mitsubishi compressor and inverter board with bosch coding.  It only draws about 2 amps on startup and then ramps up via a 85 step program as needed based on load.  It can modulate anywhere from 25% to 110% of its 5 ton capacity. It doesn't use any complicated wiring to control the modulation it sets compressor output based or suction line temperature at the condenser.  it is designed for long low power consumption runs as opposed to a lot of start stops.  with a multi stage stat and variable  speed blower you can get as many or as little BTUs as needed based on outside temps. it can perform anywhere between 1.25 to 5.5 tons depending on load.

They also make a smaller 3 ton model.


I expect with its very soft start amp draw it will be very load friendly.

BruceM

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Re: snowed in, again
« Reply #13 on: January 20, 2019, 04:51:07 PM »
These electronically controlled, variable speed motor systems for home A/C and heat pump systems are technically brilliant except for one thing.  They generate massive home power EMI, as bad or worse than typical grid tie inverters.  Bad enough that the power of neighbors sharing your transformer are also affected. A quick check with an AM radio (of the tuner type with static between stations) near home wiring will show that the AM band may be obliterated by the inverter drive and/or GTI.

 It does not have to be this way.  TI has some new Mosfet gate drive components to help control this problem of variable speed drives, by intentionally reducing power slew rates and high frequency gate currents.  Likewise, more and more Mosfets are being fully characterized for linear and semi-linear operation so that better designers, skilled in EMC, can use them more skillfully to control emissions at the source, by slowing down switching speeds.  This does have a modest affect on efficiency and increases heat sinking requirements, and may also best require some redesign for slower switching frequency and the increase the size some power inductors, of so you can understand why marketing pressures would limit it's application. All consumers know about is price, efficiency, and reliability.  In industrial situations, variable speed motor controls are affecting other control electronics so badly that TI (Texas Instruments) felt there was a market for special integrated gate drive components specifically to address the EMI problem at the source.

The independent science showing that EMI and intentional radio/microwaves affects our biology is being ignored thanks to half a billion $ of power co. cigarette science by the EPRI.   Short term profits and reduced liability triumphs over public health, again. Andrew Marino's "Going Somewhere: Truth about a life in Science" explains who we got here.  https://andrewamarino.com/goingsomewherebook/health.html

A passive filter consisting of a couple stages of toroidal common mode chokes and some small differential capacitors can substantially reduce the EMI generated by these variable speed motor controllers and help keep it off of home power.  On a grid tie inverter they should be on both AC and PV sides of the inverter so that the PV wiring doesn't radiate EMI so badly.  PV with microinverters or buck/boost regulators  on each panel make it more difficult to control PV side EMI, since instead of clean DC from the panels, you now have distributed EMI sources at every panel and every panel will need filtering. 









BruceM

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Re: snowed in, again
« Reply #14 on: January 21, 2019, 02:18:40 AM »
Nice weather today, just a bit overcast and high 50Fs.  So I decided to get my backup PV regulator board put together.  I did that, and bench tested it. 

It's a low side linear regulator that takes an analog optical isolator input of 0-5 ma for 0-15 amps charge current. The battery bank controller computes that signal via micropower analog op amp math. The PV linear regulator is powered by 7 ma of nominal +24V from the lowest 24V panel in the 5 panel string.  It was designed for a nominal 120V (220V peak no load) PV array but now that I've changed to 500V linear mosfets, it could do a 230VDC system at half the current.  Mosfets as linear devices are pretty sweet compared to power Darlington Bipolars, there is no base current (called gate for Mosfets) to control them, just gate voltage of around 4 to 10 volts.  Each transistor carries 1/7th of the total demanded current.

The PV regulator is a tight squeeze on the experimenter's bargain board size at ExpressPCB.  On the back you see the solid 14 gauge "jumpers" for power distribution.  For the new build I updated the two quad operational amplifiers  to some newer ultra low offset bias, rail to rail input and output types.  The analog world just keeps getting better.  To use MOSFETs as linear devices in parallel, you must use an op amp for each MOSFET, just as for Darlington transistors.  A 0.1 ohm, 3W shunt resistor for each transistor's output allows current sensing for each.  The op amp drives the gate voltage just enough to get the desired current at the shunt resistor. The world runs on OP amps.

This board gets mounted on a 36"x12"x 5 inch deep finned aluminum heat sink as I don't care for fan motors. 

I do miss out on about 17% power gain of very cold mornings; the linear regulator must piss away the excess voltage on very cold days, unlike a switching buck converter.  It's not all loss, it does help warm up the closed up battery bank shed in the winter.

I am not seriously tempted to do a low frequency, low EMI buck converter version just yet, but I have thought about that design after my success with the inverter project. 
Linear is simple, and I like that.