I've had a pretty rough year for electricity at my house. Seems like after every rain shower, someting elecronic stopped working. In addition, about once a month, power flicks off just long enought to set every piece of gear with a clock a-blinking. After hurricane Isabel knocked out my power for 15 hours, I've decided to finally look for a whole-house backup system.
To take care of the momentary outages and brownouts, a huge battery-type UPS that was connected to the whole house would be ideal (it seems.) There is actually a company (Banner Electric -
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that makes such a system and actually markets it as replacements to generators - but I'm not sure exactly how long they would keep a house running (even with loads minimized) plus there is reference to a system costing $20,000 on their web site (ouch...)
I'd like to get the thoughts of anyone out there about the wisdom of connecting the whole house to a big UPS. It seems to me like the ideal system would have an automatic generator for extended outages but a battery to handle short outages and to keep power flowing while the generator started.
This is not a new idea, just new marketing. We have been running computer rooms and other facilities that can not tolerate any power outages on systems such as this for 20+ years. It works well, but it is not cheap. Besides the initial cost, the batteries have to be replaced every few years, the inefficiencies inherent in the system will raise your electric bill, and the system itself can fail and require repairs. The amount of time you get on a system depends on the power required and the number and size of the batteries. There are all sorts of variations, but some of the facilities I am familiar with have 20-30 minutes of battery power, which is sufficient to start the backup generator or to shut down the equipment gracefully. It does not seem to make sense for the average homeowner.
My suggestion for most homeowners is a partial cutover panel. Only certain circuits are brought over. DIY it could be as low as $1000 including the right sized generator. Professional install should not take it over $1600-$2000. Its fairly easy to retrofit. With that you end up with a portable gas generator. The local wire jocks have been installing this one
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And
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gives you some idea of prices of it and others. Home Depot/Lowes also carries them. The meters are a very useful feature. I installed the 7500 model in my home
Next step up is a whole house cutover. That is done at the mains level. A bit more expensive and installation really should be done by a pro. Generator cost is now much higher or you really have to watch consumption. You be surprised how much devices you forget about can draw (think about the old freezer in the basement when it starts up). There are some nice units in this market designed for permanent outdoor installation. Fuel source is also a consideration. People who I know who have these tend to have an autostart in case of a power failure with critical hardware on dedicated UPS boxes. Costs are really elastic based on type of generator used. This would tend to make more sense in an more remote areas where power outages are more common and more prolonged, or is there are some sort of critical systems in the home (oxygen generators come to mind).
When I finally retire, I may go with the latter kind of system. Either that or an electric start generator. I've pulled way too many starter cords today.
telephone central offices have 2 separate banks of batteries and a (diesel generator). they are setup to stay functional for at least 8 hours during a complete power loss.
for home use, you may google (hydrogen) fuel cells.
Whole house would likely be prohibitive. On my smaller clocks, they often take a 9V battery. Or I just suck it up and reprogram the time (the new clocks set themselves - handy for a guest room where I'll sometimes move the clock around and put it back when guests come.
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I've also done very very large power systems. For data centers. We lose power and it will take easy 24 hrs to get machines up and recovered right. UPSs cover us for maybe an hour, then the generator gets kicked on. A second mortgage, and you'll be set :) It's uncheap.
Go for a reasonable in between. mom (in ma) loses power for 2-3 days at a time. Between the gas stove for cooking, wood stove for heat (not a special purchase, just more useful in when the icestorms take down 4 miles of power and the main furance fails), she charges flashlights and a flourescent lantern at work.
She and a friend of mine both got smallish generators. They power the circuit with the fridge, kitchen lights, the well pump (showers) and have enough to run an extension cord from the kitchen ciruit to the TV and DVD (cable usually dies with the power. stupid trees). That means she's not lost power since she got this :)
A friend has many solar panels. They charge a pair of excessively large batteries. Said batteries can power the important parts of the house for a couple days of no power and no sun. His meter usually runs backwards in the day and forwards at night. Net metering means his annual power bill costs a bit less than a nice dinner.
Bottom line: You likely don't need the whole house "on". If you live with essencials and perhaps want to ponder generating your own power for extras (think how much a windmill would have done yesterday!), you can do the generator thing. It's not even that rare in homes to have a cutover for a critical couple ciruits. A small generator can be affordable (tho loud and smelly). They were pretty cheap after y2k didn't pan out as a crisis.
I think after the dust settles, I am going to look into a generator in the 3500 to 5000 watt range. Porter Cable makes one with a Honda engine and brushless generator for under a grand.
At least that will allow me to alternatively run the fridge, or laptop, or TV, to keep from going crazy.
Might be useful for blackouts or terrorism-related stuff, too.
Yikes!! whole house on batt backup?? way too expensive. The install, batteries, replacing them every 4 years would kill your wallet! and even with that.. how long would the batts last??
If you have natual gas there are nat gas powered generators whcih will eliminate fuel storage tanks too. that can run for days if necessary
Natural gas gens work great as long as there is natural gas. What would it take for the source of natural gas in your area to loose pressure in the pipe? I agree, battery backup for the house will be in the 10's of $1,000.
Rather than connecting the entire house to yet another monolithic system that may create yet another single point of vulnerability, consider a carefully designed, _distributed_ backup system.
Consider each power need separately and creatively. For example, it is much less expensive to replace an electric range/stove with a natural gas or LP range/stove than to provide battery backed UPS for an electric range/stove as you seem to be entertaining.
One part of that system could consist in a DC power network for devices that intrinsically run on DC and have AC->DC converters built such as computers.
I have set for myself the goal of an independent 48vdc whole-house wiring system, using an off-the-grid supply with battery and 120VAC "backup", to power the ever-growing number of PC's, SBC, subsystems, and other HA accoutrements.
The motivation stems partly by the need to improve the grounding system for these devices so that they don't fail during lightning events, and partly out of embarrassment of how little truly _necessary_ function these devices provide for the amount of electrical energy and other resources they consume ...
There are many sources of 12vdc- 24vdc- and 48vdc-input ATX-style supplies for computers.
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to name a few
HTH .. Marc snipped-for-privacy@nothydrologistnot.com
It occurs to me that some thing in the middle would work. A couple of UPS for the clocks and computer, and then a generator you can hook up if the power cut lasts longer.
You've had some great advice from the other writers.
Last I knew, propane-powered generators still used carburetors. (This may have changed in the last decade). Propane-powered generators may need more than 1.5 times the rated steady-state KW of a generator powered by a diesel or other fuel-injected engine to have the same resistance to voltage sags from the start-up of heavy loads like refrigerators, AC, heaters and so on. These sags can cause your electronic gear to reset.
My experience was that this problem was not solved for continuous use by conventional, small UPS's because the sensitivity of UPS's was such that they tripped excessively and wore down their batteries more quickly than they could be recharged.
The solution in my case was to use a diesel generator with a large flywheel and UPS's with built-in magnetic conditioning (Ferrupps) and adjustable sensitivity to voltage and (especially) frequency variations.
A different solution, which I would implement now, would be the one I suggested in another post to this thread, viz: fit PC's and HA and other electronic equipment with DC->DC power supplies.
HTH ... Marc snipped-for-privacy@nothydrologistnot.com
In article snipped-for-privacy@4ax.com, snipped-for-privacy@nothydrologistnot.com ruminated:
What makes gasoline-powered generators such a PITA is the fact that they have a float bowl from whence gasoline is drawn up by vacuum pressure, rather than having a simple jet where already-pressurized propane can be fed into the carburetor. The float bowl and associated jet immersed in said float bowl is the primary culprit in reliability problems caused by old fuel oxidizing into varnish. Propane does away with that problem. In addition, propane burns more cleanly than gasoline, making the oil last longer.
Propane-powered generators are also a helluva lot cheaper than diesel, though. If you don't expect to run electronic gear during an outage, that may be a major factor in choosing propane over diesel.
The best way to save money on power is not to add solar panels or wind or hydro - it's to reduce usage first.
This is relevant here because I'll presume, before you power a house, that the fridge is a highly efficient fridge. Not perhaps propane (virtually mandatory for off-grid setups), but very highly rated per energy star and installed well (heat can escape, etc).
I'm told that empty is less efficient than full. We used to keep milk gallons of water in a spare fridge at some point. Keeps all the cold when from leaving open the door? I dunno.
That light you'll be powering in every room? I presume it's fluorescent. Perhaps 48VDC for direct powering from batteries?
The TV, for best power use, should be an LCD.
Computers? Absolutely laptops! Macs are lower power than PCs (Intel chips suck power, where PPCs are relatively efficient.
In work places, an LCD monitor will pay for itself over a CRT monitor in under a year in power and cooling requirements (not to mention disposal - anyone need some 14" monitors?).
For clocks and not resetting them: self setting clocks are no longer a novelty (and my VCR finally started taht). And most clocks radios of the last 15 years take a battery. $2 for a battery is a lot cheaper than wiring a genny in to power every circuit in the house. And it's a lot cheaper than getting a genny that large.
If you are BUILDING the house, you get to run low voltage DC power for some of the lights. I live in earthquake land, so there are a couple (fluoresent) flashlights that plug into the walls (with wall warts) that go on automatically if power goes. They tend to last many many hours. For long outages, they take a 12VDC input to recharge and stay on.
Using DC: bulbs supposedly last longer, 48VDC doesn't require the fat wires that 12VDC wants, batteries and solar can easily provide
48VDC. AC can be derived from the batteries with an inverter.
You can do the whole house thing, but the money best spent is spent lowering consumption FIRST. In emergencies, you can just leave things off, not hit the fridge often, etc.
Additional note: At least in calif, off grid installs are NOT eligable for the rebates. And the rebate is lowered if you self install. One of the goals is to jump start the businesses and contractors; I can't really disagree.
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