their is a huge difference between the flooding in harvey and irma, harvey was just a huge amount of rain that didn't get more than a foot or two deep in most places, irma caused a tidal storm surge of 6+ feet or more on those isolated islands. More than likely the marathon spc was underwater if not washed away.
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Hurricane Irma
- Thread starter DiamondHands
- Start date
K-MTG
Sunshade Captain of TMC
FPL offers net metering so the expense of a power wall system is hard to justify. Even so, you can power your entire house with powerwall. You just need several or more of them depending on your house size. I've priced it out for my house and it would take 4 power walls to provide entire house power at a cost of $22,700. Other than providing backup power, the power walls offer no other real benefit since we have net metering. You can get a whole house on demand backup generator for less than that.
I've been without power since Sunday 9am. My Honda EU6500 generator is quiet as can be and it runs either of my AC units (one at a time). I've also had it run my pool pump, cooktop range, and water heater. Only needed it for the water heater during the storm as my solar water heater wasn't heating water on account of no sunlight during the hurricane. Of course, the generator can only run one of those at a time but other than some minor power mgmt and refilling of the gas life if pretty much normal for me. Another benefit of having a Tesla is the NEMA 14/50 outlet is now my receptacle for the generator. Works like a dream.
No damage beyond some busted palm fronds.
I strongly recommend this generator for anyone wanting backup power. The new one has EFI and is 7000 watts. Especially if you have a NEMA 14/50 outlet. It's amazing. I haven't turned it off since 9am Sunday. Runs like a top. All of my neighbors have 7000-10000 watt cheap generators and none of them can get it to run their AC units. Honda is doing something right.
If you have solar panels can you run it with a generator?
NigelM
Recovering Member
I've read a report from down there that Marathon was completely underwater, no dry spots whatsoever. We have a couple key life-support-systems people who were allowed to stay on Summerland Key in a designated Cat 5 building and have radio message that they are ok as expected but all comms and utilities are down including cell towers. Big Pine Key was also flooded. Indication is that those islands fared worse than Key West.
Racerx22b
@unplggdd on Instagram
The solar panels do not function without power from FPL. I don't know exactly how it works but there is something on the inverter that detects power from FPL and the inverter only operates when power is coming from them. Otherwise, there is a potential for the solar panels to backfeed the grid and potentially causing harm to a lineman. That is no Bueno.
So to run the generator I turn off the main disconnect before doing anything with the generator then once that disconnect is off I then use the 50amp breaker intended for the NEMA 14/50 outlet as my main disconnect for providing power from the generator. Again, keeping the main disconnect off from FPL prevents me from back feeding into the grid.
So to run the generator I turn off the main disconnect before doing anything with the generator then once that disconnect is off I then use the 50amp breaker intended for the NEMA 14/50 outlet as my main disconnect for providing power from the generator. Again, keeping the main disconnect off from FPL prevents me from back feeding into the grid.
nwdiver
Well-Known Member
Have you looked into AC coupling? A cheap backup system would cost ~$3k and allow you to at least use your panels during the day to conserve fuel. How much gasoline do you use per day running the AC?
My backup system is a Magnum Energy 4400PAE and two 48v banks of golf cart batteries you can get at costco. I technically have up to ~12kW available during the day since the 4kW magnum operates in parallel to the 8kW Grid-Tie. The golf cart batteries cost ~$100/kWh.
You can open your main and trick your inverter with the right equipment
Cyclone
Cyclonic Member ((.oO))
Whew. I was going to quote your prior post and ask to make sure you are doing just that. Glad you knew about that!
Racerx22b
@unplggdd on Instagram
Have you looked into AC coupling? A cheap backup system would cost ~$3k and allow you to at least use your panels during the day to conserve fuel. How much gasoline do you use per day running the AC?
My backup system is a Magnum Energy 4400PAE and two 48v banks of golf cart batteries you can get at costco. I technically have up to ~12kW available during the day since the 4kW magnum operates in parallel to the 8kW Grid-Tie. The golf cart batteries cost ~$100/kWh.
You can open your main and trick your inverter with the right equipment
Good info!! This generator is pretty efficient. I can get about 10hrs of run time on 5gals. I've owned it for 10yrs and it's now finally paying off. This is the first time I've needed it since owning it. Plus I can take it with me if I ever move.
nwdiver
Well-Known Member
That's not bad. I missed the bit that you energized your panel with the generator. Was the breaker to the inverter closed? I'm surprised it didn't try to back feed the generator.
nwdiver
Well-Known Member
There is an AC Powerwall but I don't think it's designed to be used off-grid... at least not 'out of the box'. There are a couple tricks to AC coupling; You need isolation from the grid, you need a way to buffer the output from the grid-tie and you need a way to turn off the grid-tie when the batteries are full. I don't know how the Powerwall would do this.
With an AC couple inverter you can tie to any grid-tie inverter including micros. Ideally the off-grid should be ~30% larger than the grid-tie. I break the rules a bit by using a 4.4kW off-grid tied to an 8kW grid-tie but if I have to use the grid-tie I'll pull 2 of 3 fuses so I'm only on 3.5kW of panels to prevent overloading the off-grid. When the batteries are full the AC couple raises frequency to ~61Hz. Nothing in your house would notice such a small change but the grid-tie will trip off as required by UL1741.
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AFAIK, it's the only one, isn't it? Didn't they cancel the DC powerwall?
It'd seem to be a big design oversight if it didn't, given that they're designed as "all-in-one" solutions. That doesn't mean that it is set up that way, but it'd seem to be a big oversight if it wasn't; acting as a "backup generator" would be a massive selling point for powerwalls.
nwdiver
Well-Known Member
The Powerwall might be designed to work with a specific inverter. The on/off thing isn't an ideal solution. It would be A LOT better if the Powerwall could 'talk' to the grid-tie and tell it to reduce it's output instead of being either on or off. Of course this means the Inverter would need to speak the same language as the Powerwall.
I understand that this is the case with the Powerwall 2.
For Racerx22b, a key point is that he's had access to plenty of fuel. (And I'm happy to know that his household and property are in good shape.)
One difference between hurricanes in Florida and natural disasters in the West (earthquakes and wildfires) is that you obviously have much more advance notice of an approaching hurricane, thus affording an opportunity to stockpile fuel for generators. That would increase the attractiveness of a good generator relative to the Powerwall 2.
Here in the California mountains, I'd just rather not have to bother with fuel, as the only machine we own that can use it is a Prius, and that's slated to be replaced with a Model 3. On the other hand, if I had a generator and a bunch of stockpiled fuel (with an expiration date), I could give away fuel to my neighbors from time to time. Absent our state subsidies on home batteries, and with no electric rate arbitrage opportunities, that might be a more cost effective approach. This all assumes an outage that doesn't exhaust fuel supplies.
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nwdiver
Well-Known Member
That's why I went with good 'ol lead acid. I don't need a high cycle life to keep me powered in an emergency. Golf Cart batteries are perfectly happy being kept on a float charge for years. I cycle them 2-4 times a year just to test the system. I'll get a Powerwall when the price comes down a bit but until then it's hard to beat $100/kWh golf cart batteries....
NigelM
Recovering Member
Solar panels CAN provide you with some power when the grid is down. Sunny Boy inverters (I have them installed and used them this week) have a system called 'Secure Power Supply' so that when they sense the grid is down they cut off power flow back to the grid and divert to a switched outlet:
I installed four of these inverters on my solar arrays more than three years ago. My guess is that other brands of inverters probably have the same feature.
Racerx22b
@unplggdd on Instagram
For me, if I have backup power I want whole house backup power. A few 120v outlets isn't gonna cut it. AC units have to work. If I have to switch one power hungry 240v device off to use another that's fine but when doing it legit they don't typically give you that option. You have to size the backup power according to what your house is capable of using. They don't trust you to use your brain. I've had my generator running 3.5 days now and I've yet to trip it's on board breaker.
But now the wife is over refilling the gas (I had to leave town for work) and she wants an on demand system w a buried LP tank. This is gonna cost me a lot of money.
gg_got_a_tesla
Model S: VIN 65513, Model 3: VIN 1913
On a different note, wanted to check with Florida locals on good charities that are helping with the hurricane relief efforts on the ground?! I know the likes of American Red Cross are simpler choices to contribute to but, would like to help (and get my and my wife's companies to match) smaller charities that don't get as much and which also have smaller admin overhead.
IMHO the red cross is probably the poorest choice for your charity dollars, I'm sorry i cannot provide a better option but I would seek out a local charity, possibly the salvation army which has much less administrative costs and puts more of the money they collect to work.
Racerx22b
@unplggdd on Instagram
No breaker for the inverter. It taps into the feed from grid before the main disconnect (which is off when on generator power).
Interesting for this conversation that Musk just tweeted this article about powerwall + solar serving as backup during Irma.
Might want to reconsider that.
America's Top 50 charities: How well do they rate?
92% of red cross money goes to aid. 84% of Salvation Army goes to aid. Salvation Army is also heavily into using their charity work for evangelizing (unless you're into that, wherein, by all means support that).
BTW, the salaries don't tell the whole story. The Salvation Army owns a lot of high-end real estate ($4B total) which houses its officers:
Salvation Army is part church, part charity, part business
It's hard to analyze in too much detail because it hides most of the information about its finances - something it's able to do because it's registered as a church. That "84%" number is a "take us at our word" figure.
Might want to reconsider that.
America's Top 50 charities: How well do they rate?
92% of red cross money goes to aid. 84% of Salvation Army goes to aid. Salvation Army is also heavily into using their charity work for evangelizing (unless you're into that, wherein, by all means support that).
BTW, the salaries don't tell the whole story. The Salvation Army owns a lot of high-end real estate ($4B total) which houses its officers:
Salvation Army is part church, part charity, part business
It's hard to analyze in too much detail because it hides most of the information about its finances - something it's able to do because it's registered as a church. That "84%" number is a "take us at our word" figure.
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