Why I want to be Off-Grid

http://www.cpsenergy.com/Services/Power_Outages/Outage_event_020211.asp

Power Emergency – Conservation CRITICAL–Rotating Outages Have Begun

The Electric Reliability Council of Texas (ERCOT) has instructed utilities to begin rotating outages to compensate for a generation shortage due to numerous plant trips that occurred because of the extreme weather.

Rotating outages are controlled, temporary interruptions of electric service, typically lasting 10-45 minutes per neighborhood. The locations and durations are determined by the local utilities. Critical need customers such as hospitals and nursing homes are generally not included.

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UPS is on battery power.
[Wed Feb 2 06:46:42 CST 2011]

UPS is on battery power.
[Wed Feb 2 09:49:15 CST 2011]

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Funny thing is, it was 80° last weekend...I ran the air conditioning for a couple of hours on Sunday to work down the humidity. Ma Nature's having hot flashes again...

To continue to have house power when the grid goes down:
1. during the day when the PV system is producing enough power
2. at other times when the PV system is producing little or no power

What does one need to add to a typical Grid-Connected PV system that uses something like a SunnyBoy (SMA) Inverter (one that shuts down if Grid-Loss is detected)?

Is there something simple, assuming that one can split their breakers between a Main panel and a 2nd "Survival" panel:
1. Heavy, unnecessary loads would remain in the Main panel, powered "by the Grid". This would include the Dryer, A/C, Oven, etc.
2. "Survival" circuits would move to the 2nd panel, some lights, the refrigerator, ... possibly a computer, etc. that might total less than 500 watts, less in "Sleep" mode, and maybe twice that in "Evening" mode.

Five 100 amp-hour 12v batteries would provide 6000 watt-hours, or perhaps enough run the house's Survival circuits over-night.

So, SunnyBoy makes a very flexible (and probably very good) "SunnyIsland" controller, but it is a bit expensive.

Any "better" suggestions?

Probably not "better", but another approach: We have an RV, that we never use any more, because I'm trying to break my gasoline habit. So it is just sitting on our property, but it makes a nice emergency shelter - you know, for when "the big one" hits. This is earthquake country, after all. Anyway, back to the point, I've mounted two solar panels on the roof that feed four 6-volt marine batteries (series/parallel). That gives us lights, refrigeration, and a water pump for the onboard tank in case the water main goes. We can even power a computer or TV with satellite access through a 12v-120v inverter. We do have to depend on the RV's propane tank for cooking. (Unless, of course, we want to <shudder> crank up the generator and run the microwave.)

Obviously I'd never buy an RV for that purpose, but since we happen to have one lying around from our younger more profligate days, why not?

If you want to do solar off-grid (charging batteries), you generally need about twice the PV as you normally would to cover charge/discharge losses.

Maintenance of the battery pack is a must and depending on how hard you work the pack, be prepared for costly battery replacements every 3-5 years.

Much more cost effective would be to get a generator and use that for the short periods you are out of electricity.

There are grid-tied inverters that let you use a battery pack basically as a UPS so you get the best of both worlds - but again - you need a pretty big battery pack depending on how long you want to be able to remain powered up while "off-grid". These types of installs aren't that common, either, so finding the expertise to properly design and install such a system can be tough to come by.

Edison Batteries- A company in China was making the cases and sent the electrolyte in bags to be mixed on site. They last about 70 years or more, can do deep cycling, need no equalization, etc. 20kwh was not to expensive relatively. There is a way to use the solar in the day when power is down but for occasional outages a generator on LPG is easy and no gasoline fuss. I have one client on a fuel cell on nat gas. Some folks in SF use $5-10K of electric every month

Damn you engineer types - get out of your head and stick your feet in the ice on my back porch! :lol: It's supposed to be snowing later today - who's coming over for South Texas Snow Angels?

Besides, the problem's solved. Let the Midnight special shine it's light on me...

http://homepower.com/files/webextras/midnight.pdf

Oh drees - you really don't think a lithium guy is going to use lead, do you? Half-cycling some large format LiFePO4 should give me more than 10 years with no watering. And the blasted things are about the same price as some of the big monsters from Surrette and Rolls.

Anyway, my point is just that the 6th largest city in the country, in a state run by 'RED' folks that are all about business, can't seem to keep the lights on when it gets cold. Poor babies. I'd much rather be in a position where I didn't rely on these Bozos for water, gas, or electricikles. Sigh.

Gary - I've already played with a grid-tied guerrilla solar install with old micro-inverters (the old OK4U). They need a 60Hz wave to sync with so they think they're still talking to the grid.

EVDRIVER - I'd be interested in hunting down an Edison battery. I'll do some Googling, but would appreciate a link or company name if it's easy for you. Thanks.

When we got solar power I was disappointed to learn that if the grid is down our solar power system is disabled. It was part of the deal of getting the installation rebates from our local power company, APS. There is an expensive backup system with lots of batteries that are allowed. The explanation that we received was that if they did not disconnect us when power was restored on the grid the lack of synchronization would damage the grid.

This seems like a problem that could easily be solved by good engineering. I regard it as a public safety and national security issue. Here in the Phoenix area, it would mean islands of air conditioning distributed throughout the metropolitan area when the grid fails at times of life threatening heat. It would also provide the same islands of power in the face of terror attacks, physical or cyber. This is a problem that can and should be solved by government by mandating devices that allow for safe reconnection to the grid lf all solar installations.

It has been record cold in Texas, I dont think this is very likely to happen again since we are heading deep into AGW due to all the CO2 pumped into the air.. or perhaps we are going into another Ice Age.. Lets ask Algore.

How about a Volt with an inverter that can pump out 15kw of 220v and 110v?.. the genset would be loafing at that power level and the Volt does have a self contained gas tank.. I bet that would sell Volts like pancakes. For maximum efficiency the genset would cycle, recharge the battery at a 40kw setting, shut off and power the inverter from the battery until it was needed again.. the battery could also sustain surges dues to motors starting etc.

A typical grid-tied inverter detects AC in a fairly narrow frequency range, and also wants to see "sufficient" AC voltage. Many will "disconnect" when a "brownout" occurs (the AC voltage falls more than something like 25% or more). Actually, they shut off their AC Generation, but stay connected to the Grid to monitor the AC voltage.

The question is, what do they do if the AC voltage gets too high, and how fast do they react?

Some might continue "pouring" in current even when the voltage is too high. They might assume that the Grid is an infinite "sink" (receiver) for their generated current, without the ability to "throttle back" and do AC voltage regulation. That would make them unable to properly drive variable loads, like the house.

But, I do not know.
Does anybody else?

garygid said:

The question is, what do they do if the AC voltage gets too high, and how fast do they react?

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All UL listed grid-tied inverters will shut off if frequency goes out of spec or voltage. That includes high/low voltage events.

This document from Enphase has a lot of the requirements to meet IEEE1547 and UL1741 requirements.

http://www.enphaseenergy.com/downloads/Enphase_White_Paper_Meaning_of_Utility_Interactive.pdf

There is basically no chance of the grid going away or getting unstable without the inverters shutting down for 5 minutes before reconnecting.

Looks like drees beat me to it while I was digging up links.

AndyH said:

EVDRIVER - I'd be interested in hunting down an Edison battery. I'll do some Googling, but would appreciate a link or company name if it's easy for you. Thanks.

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You probably figured this out already, but they're also known as Nickel-Iron Batteries. There aren't many manufacturers out there - and I don't know how you'd go about buying them. This might be useful though.

And they still use Lithium in the electrolyte so you got that going for you
=Smidge=

Herm said:

It has been record cold in Texas, I dont think this is very likely to happen again since we are heading deep into AGW due to all the CO2 pumped into the air.. or perhaps we are going into another Ice Age.. Lets ask Algore.

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If I'm understanding it correctly, AGW/climate change doesn't guarantee any specific 'local weather' changes, but does result in fewer 'normal' days and more frequent 'bizarre' weather days.

Like 80° on Sunday followed by a 20° Tuesday maybe?

Smidge204 said:

AndyH said:

EVDRIVER - I'd be interested in hunting down an Edison battery. I'll do some Googling, but would appreciate a link or company name if it's easy for you. Thanks.

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You probably figured this out already, but they're also known as Nickel-Iron Batteries. There aren't many manufacturers out there - and I don't know how you'd go about buying them. This might be useful though.

And they still use Lithium in the electrolyte so you got that going for you
=Smidge=

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Thanks Smidge! It's taken me about 35 minutes to finish this post - got sidetracked on Alibaba and BeUtilityFree. Man - these cells are tough!

Oh boy - new toys to add to my 'adult-onset ADD'. :lol:

Herm said:

It has been record cold in Texas, I dont think this is very likely to happen again since we are heading deep into AGW due to all the CO2 pumped into the air.. or perhaps we are going into another Ice Age.. Lets ask Algore

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Anyone that can't 'see' the major climatic changes happening on this planet (too many to list) are either ignorant or have their heads in the sand.

LEAFfan said:

Herm said:

It has been record cold in Texas, I dont think this is very likely to happen again since we are heading deep into AGW due to all the CO2 pumped into the air.. or perhaps we are going into another Ice Age.. Lets ask Algore

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Anyone that can't 'see' the major climatic changes happening on this planet (too many to list) are either ignorant or have their heads in the sand.

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Hell, step onto my back porch and they can see, feel, and slide on some of the changes. The good news is that they can't put their heads in the sand here tonight because the sand's frozen... :lol:

24°F tonight...again...and freezing drizzle. I left Michigan for a reason...it's all coming back to me now...

AndyH said:

Herm said:

It has been record cold in Texas, I dont think this is very likely to happen again since we are heading deep into AGW due to all the CO2 pumped into the air.. or perhaps we are going into another Ice Age.. Lets ask Algore.

Click to expand...

If I'm understanding it correctly, AGW/climate change doesn't guarantee any specific 'local weather' changes, but does result in fewer 'normal' days and more frequent 'bizarre' weather days.

Like 80° on Sunday followed by a 20° Tuesday maybe?

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Apparently the definition changes frequently. I get the impression they are just guessing.

The problem with AWG/CC is that everyone is informed by the media, and not the science. The basic concept behind the science is fairly easy to grasp if you know high-school level thermodynamics (and a lot of people don't!) but the devil is in the details as usual... if you can get access to the science journals they're usually a pretty tough read. Al Gore is not a scientist and Time Magazine is not a scientific journal.

But "Climate Change" has been the proper name for it since at least the 1930s. When you cut through the media bullsh*t the science has been remarkably consistent with their data and predictions. There is virtually no real argument among climatologists that the earth is, as a whole, warming ever so slightly - the only debate (and there isn't much anymore) is about what factors are involved and to what extent.

In a nutshell, you get a more unstable climate with a modest increase in average temperature. It might seem tempting to point out the window and say "It's cold global warming is wrong!" but weather is not climate. Nobody credible ever suggested that you'll step outside one day and find your front lawn has turned into a barren desert, or that Greenland would become a tropical resort.

You will get colder winters and hotter summers. When it rains or snows, it will rain or snow more. When there's a dry spell, it will last longer. Biomes will shift and expand/contract. Major storms will be less frequent but more severe... this is the kind of changes we can expect.
=Smidge=

Herm said:

Apparently the definition changes frequently. I get the impression they are just guessing.

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With respect, Herm, I'm not interested in debating climate with you. I'm not here to change your mind, nor are you here to change mine.
Do have a great weekend!

AndyH said:

Damn you engineer types - get out of your head and stick your feet in the ice on my back porch! :lol: It's supposed to be snowing later today - who's coming over for South Texas Snow Angels?

Besides, the problem's solved. Let the Midnight special shine it's light on me...

http://homepower.com/files/webextras/midnight.pdf

Oh drees - you really don't think a lithium guy is going to use lead, do you? Half-cycling some large format LiFePO4 should give me more than 10 years with no watering. And the blasted things are about the same price as some of the big monsters from Surrette and Rolls.
. . . . . . . . . . . . . . snip

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There's a less expensive way. So ... why bother having multiple sets of batteries when you can us an ev / phev / or standard hybrid to do the same thing?

http://priups.com/riddle/answer-1.htm

AndyH said:

Herm said:

Apparently the definition changes frequently. I get the impression they are just guessing.

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With respect, Herm, I'm not interested in debating climate with you. I'm not here to change your mind, nor are you here to change mine.
Do have a great weekend!

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We can get along and have frank and friendly discussions without insults, after all this is not a religion.. What are we here for if not to increase our knowledge?. On the issue of AGW, too many vested interest on both sides of the issue, too much dubious data and no testable hypothesis. Perhaps some mild concern is due, and so study the issue fully but no reason to run around like chickens with the head cut off. How do you feel about mass extinction level asteroid strikes?.. I can see asteroids in my telescopes and astronomical pictures, I know the Solar System has billions of asteroids and comets just orbiting along.

PS: I dont worry about asteroids either.

Herm said:

PS: I dont worry about asteroids either.

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Would you worry about asteroids if there were piles of scientific evidence to suggest there was one big enough to cause an extinction-level even headed right for us?

=Smidge=