Home Backup Power Systems

[ponytug]

Man…no way i want my backup to depend on internet…much less a 3rd party screw up. I had no idea the powerwall had external control.

Yes, it sounds bad, but it is not really that bad.

The internet loop is data from the local system to the cloud storage, and from the cloud storage to the control app, so the local system doesn't need the cloud for operation. However, like all IOT items, there is the risk that the company would dump support for the model, or go belly up, which is why none of our backup generators have WiFi on them, and all can be easily manually started.

You can control the Tesla Powerwall locally in the event of an internet outage, but the process is different, and not the easiest. OTOH, one would only need to do that to adjust the control settings, almost all of which are irrelevant in an outage, e.g. no need to adjust backup reserve, nor the times that you want to "peak shave" time of use loads, etc.

The one time it acted up for us had more to do with Tesla's lack of documentation on how its remote CTs functioned and how they were connected to the master control unit. The documentation required one network setup, but I discovered that network configuration is used only at power on. It uses a different communication method in normal function, one that has some special requirements. In the end, the lack of cloud interaction was ok, but silence from our remote CT was not. As so much of Tesla's setup is software and software control, plus Musk's known dislike of supporting customer service means that the Tesla documentation is rarely complete, even for installers, and installer configuration software is a moving target. There is a really good 3rd party app, NetZero for complex control automations and for extensive data analysis and configuration setup. It's way better in my opinion than the Tesla's app.

However, I'm not looking a gift horse in the mouth. The system was 1/10th the cost of competing systems, and it has always backed us up when needed, like last evening when we had a really "terrible storm" event (sunny, 68F, still air, no ice or snow) and the power kicked out. (Based on what died, I am pretty sure genius at the utility hit the wrong switch for the umpteenth time and knocked our whole distribution circuit off line. Yes, I am of the opinion that the local crew couldn't arrange a piss up in a brewery, based on their performance history. There are some great people there, but organization is beyond dysfunctional in my opinion. It took me three or four months of my complaining for them to admit that they had an overvoltage issue here and to fix it. At the very end, I spoke with a nice tech, who had all the data proving and supporting my complaint. It turned out that they had three minute voltage reads from our smart meter going back years, so they should have been able to acknowledge the overvoltage issue on the first call, or before that. Inability to arrange a piss up in a brewery competence.)

All the best,

Peter

 

[QRTRHRS]

Can anyone educate me on military surplus generators? We did not lose power but this current winter blast has me concerned. I am thinking that something trailer mounted or something that I could set on a trailer to take with me would be the way to go. Years ago, I often lost power at another location. I had an 8500 watt construction generator set up with ten manual circuit switches that worked well overall. I had oil heat and it would start my well pump, just no oven. My current home has a heat pump so I need a lot more generator. We don't venture far so a manual transfer switch is just fine.

 

[ponytug]

Can anyone educate me on military surplus generators? We did not lose power but this current winter blast has me concerned. I am thinking that something trailer mounted or something that I could set on a trailer to take with me would be the way to go. Years ago, I often lost power at another location. I had an 8500 watt construction generator set up with ten manual circuit switches that worked well overall. I had oil heat and it would start my well pump, just no oven. My current home has a heat pump so I need a lot more generator. We don't venture far so a manual transfer switch is just fine.

I'll give it a shot.

Have you worked out how many kW you need to run your heat pump? I would go through the house energy budget and figure out what the minimum power you need to run the heat pump plus a few other items.

Military surplus commonly come in 10, 15, 30kW and higher, but starting at the 15kW level and larger they switch from split phase (120/240) capable to 3 phase only. A few of the larger generators (especially the 12 lead models), can be rewired to split phase, but not every version, and not always without a loss of capacity, and a loss of many of the control functions. At some level of complexity, it is easier to go 3 phase to DC to AC, which has the advantage that you can splice in a battery to charge while supplying the house. With a battery the DC to AC inverter can be much larger to deal with things like the well pump kicking in while the heat pump is running. Yes, it is more complicated.

The military sets are overbuilt, like proverbial tanks. So they are bigger, heavier than civilian units.

The drawbacks? Well, you aren't likely to have a @grsthegreat down the road who will come service it for you and many of the parts may be rare mil-spec parts, not all of which have civilian replacements, but if you are fairly handy, you can often find a work around. Buying a "certified used" generator from somebody who buys and resells military generator can get you a source for advice and parts. Some of the newer surplus generators come with computer controls that don't have declassified manuals, but many people get them to work.

Almost all military generators are diesel. So, it is good to figure your fuel plan, and how you are going to keep your diesel clean, dry, and ready to go. I think that as a generator energy source, propane has a lot going for it in the store forever category. Diesel not so much. I wouldn't count on natural gas in a big emergency.

Finally, the military sells generators off to surplus because of several reasons; the sets are too old for spares, or something is wrong with it, or they are no longer current, or a combination. So if you buy one at auction, it may or may not run when you get your hands on it. Still, I think the odds are better than trying to buy a used rental generator; most of the rental ones that I see around here are end of life, and I wouldn't count on them in an emergency.

If you get serious about buying a military generator, I would spend some time reading up on appropriately sized generators over on Steel Soldiers. Many of the generators have complete sets of manuals. The bonus being that they were written for any GI, so once you get used to how the manual functions, it will be more complete than virtually any commercial generator, unless you get your hands on the company workshop manuals, which isn't always possible for non-employees.

https://www.steelsoldiers.com/forums/generators.55/

There are more than a few members there who spent 30-40 years repairing and running military generators, including several who are the (retired) military experts for many of the generators. A fair few folks buy a genset, run into trouble, and post asking for help, so you can get an overview of common, and uncommon problems. As many of the sets were worked on by folks learning their trade, sometimes you have to go back to square one and start over not making assumptions.

I like many of the military models, but I would also say that they aren't for everybody. It helps to be a hands on type, who isn't fazed by wading into a previously unknown piece of equipment that is a combination of engines (diesel) and electrical power. I've seen more than a few people who had no clue about one half or the other, and weren't able to get themselves up to speed. There are civilian add-ons that fix some issues the military never got around to fixing (e.g. oddball oil filters in odd locations, or 1960s flakey voltage regulators), and add features like WiFi remote starting and reporting. For most folks, owning a military generator is a labor of love, and something they enjoy sharing, somewhat like TBN.

Does that help?

All the best,

Peter

 

[mark in portugal]

check out 'Deye' hybrid inverters.
I don't know if they have them in the US; probably.
a 15kw unit is just a few grand. There are 3-phase and single phase ones.

Solar in, battery in/out, grid in/out, generator in.
They will run independent of the grid during power failure; not all inverters do that.

They even have an programable generator start relay that will activate when needed.

Generator autostart addon box is available from your favorite Chinese webstores for less that $50. Wire it to your generator (diesel or spark ignition) and it will crank, wait, crank again, for a predetermined number of tries until it starts. Auto shutoff too.

Batteries are still expensive; solar panels are now so cheap that the mounting structure cost becomes a concern.

I'm going electric heat and hot water, 16kw of solar panels, and a 15kw 3-phase Deye inverter. This is economic for me in sunny Portugal.
Backup during grid failure is a happy side effect.
I'll probably add the generator too.

 

[mikester]

Yes, it sounds bad, but it is not really that bad.

Any product that REQUIRES an internet connection to work is an absolute no go for me.

I've been burned too many times buying expensive devices and working equipment that suddenly got bricked because a company goes bankrupt or decides to stop supporting their product.

 

[D&D]

I thought the powerwall sounded interesting until I read it needs an active internet connection to work.

We have more frequent internet outages with starlink than we have power outages.

others rave about how wonderful Starlink is, especially when tied to their Sprint phone service?

 

[ponytug]

others rave about how wonderful Starlink is, especially when tied to their Sprint phone service?

Count me in as a Starlink fan. It is the most reliable home internet that I have ever had.

I am unaware of a Sprint tie-in, at least around here.

@mark in portugal Unfortunately those 3 phase inverters aren't available here. There are some more expensive versions available. 3 phase isn't that common, so most units here are sized for commercial use.

All the best, Peter

 

[QRTRHRS]

Peter, thank you. Your explanation does help. I do happen to have experience with diesel and electronics having went to school for electronics and worked in semi-conductor manufacturing for 20 years. I also have a good amount of electrical experience. I am on municipal water. I do have to sit down an calculate what my needs are.

I have to get with a neighbor to pick his brain on his system. He sourced an old White diesel engine and coupled it to an alternator that want to say was manufactured in Germany. He has it set up in a shed complete with his fuel tank. LOL, set up with a manual switch over, he has to go out to fire it up regardless of time and weather.

I don't plan on staying in my current home forever and all things considered want to keep any system mobile.

 

[D&D]

Count me in as a Starlink fan. It is the most reliable home internet that I have ever had.

I am unaware of a Sprint tie-in, at least around here.

@mark in portugal Unfortunately those 3 phase inverters aren't available here. There are some more expensive versions available. 3 phase isn't that common, so most units here are sized for commercial use.

All the best, Peter

Some of the people we associate with “think” they have to be plugged in 24/7/365 so they show with the new tech, regardless of cost

https://www.t-mobile.com/coverage/satellite-phone-service

 

[ponytug]

Peter, thank you. Your explanation does help. I do happen to have experience with diesel and electronics having went to school for electronics and worked in semi-conductor manufacturing for 20 years. I also have a good amount of electrical experience. I am on municipal water. I do have to sit down an calculate what my needs are.

I have to get with a neighbor to pick his brain on his system. He sourced an old White diesel engine and coupled it to an alternator that want to say was manufactured in Germany. He has it set up in a shed complete with his fuel tank. LOL, set up with a manual switch over, he has to go out to fire it up regardless of time and weather.

I don't plan on staying in my current home forever and all things considered want to keep any system mobile.

That sounds like a good match, and a good plan to me.

Military generators come in open and enclosed (soundproofed) versions. Unless you are building your own enclosure (which has a few issues to consider, e.g. ventilation, soundproofing, and fire resistance), I recommend the enclosed version unless your neighbors are a ways away. Most are equipped to draw from an auxiliary tank automatically.

I have a 10kW MEP-803; about 1 gal/hr at full load. In addition to the heatpump's running power (FLA) you might want to check your heat pump's LRA ("locked rotor amps", I.e. starting power surge amps); if it is high, it might benefit from a soft start. The newer, inverter, or "infinitely" variable speed heat pumps tend to have much lower starting amperage demands. Just something to keep in mind.

I think even the non-trailer versions are relatively easy to move with a tractor, at least until you get to the 30kW version and up. FWIW: the trailer mounted versions often sell at a substantial discount to buying a generator and then a trailer, I think in part because the trailer tires and brakes often need some work/replacement. YMMV

All the best,

Peter

 

[Carl_NH]

Curious, I looked up the MEP803A and it gets great reviews up to 52 Amps 240 VAC running a house using not quite 1 gal / hour. Then for sale are $4 ~ $5K.

Here's the link to steelsoldiers site and thread Mep-803a as whole house generator

Nice setup you have Ponytug!

 

[sd455dan]

check out 'Deye' hybrid inverters.
I don't know if they have them in the US; probably.
a 15kw unit is just a few grand. There are 3-phase and single phase ones.

Solar in, battery in/out, grid in/out, generator in.
They will run independent of the grid during power failure; not all inverters do that.

They even have an programable generator start relay that will activate when needed.

Generator autostart addon box is available from your favorite Chinese webstores for less that $50. Wire it to your generator (diesel or spark ignition) and it will crank, wait, crank again, for a predetermined number of tries until it starts. Auto shutoff too.

Batteries are still expensive; solar panels are now so cheap that the mounting structure cost becomes a concern.

I'm going electric heat and hot water, 16kw of solar panels, and a 15kw 3-phase Deye inverter. This is economic for me in sunny Portugal.
Backup during grid failure is a happy side effect.
I'll probably add the generator too.

Deye has a contract with Sol-Ark and is barred from selling their 12KW split phase inverter in the states and certain territories.

There was a big flap last year over people that bought Deye units from Alibaba sellers or possibly people that moved back to the states and brought the Inverter with them.

Deye literally sent a kill code to the inverters and bricked them (remotely over the internet) Then Sol-Ark announced they would give owners of Deye a small discount on a new $7k Sol Ark 15K (12KW) inverter. Deye Inverters had a message on the display about contacting Sol Ark after the bricking took place.

Won't ever own Deye or Sol Ark anything.

I am currently running an EG 4 18k PV (Luxpower 12 KW) hybrid inverter. So far so good ( has processed ~39 Megawatt hours), but EG 4 is always having update goof ups, so still on the original firmware with no plans to update to get new features due to unforeseen problems an update may cause.

 

[ponytug]

Curious, I looked up the MEP803A and it gets great reviews up to 52 Amps 240 VAC running a house using not quite 1 gal / hour. Then for sale are $4 ~ $5K.

Here's the link to steelsoldiers site and thread Mep-803a as whole house generator

Nice setup you have Ponytug!

I like it. I got very lucky with the one I bought. It had an obscure little issue, and as far as I can tell basically had never been run. So I got to have fun finding the issue, and tweaking a few minor things for civilian use so that it could be set and forget for me here.

One reason that I bought one of the MEP generators over a civilian one was our well pump is three phase, (long story) and I wanted to be able have water in an emergency.

They are quirky; as military units they are 24V DC machines, and the 802/803s use an Onan branded Lister Petter engine that is up there in my personal obscure diesel engine rankings. I think that the 803 is built like a brick outhouse. It amuses me at how over built it is at times, like the fact that the internal wires are teflon/fiberglass high temp wire rated to 250C/480F.

Mostly, I like that it fires right up any time that I ask for power.

But I do think that they aren't for everyone; for less money, you could buy a 11kW propane/gasoline inverter generator from Northern Tool. I wanted the three phase.

All the best,

Peter