Learn Me: Whole-Home Generators vs Solar and other options

So as I'm typing this, we're in the middle of the 5th day that we don't have line power to our house- my 12-year-old Harbor Freight generator is chugging away out in the garage powering our internet hardware, computers, and the space heater that is keeping it somewhat livable in the house despite it still being in the mid-30's outside. The last nearly week since a massive windstorm knocked out power to large swaths of our city and state have not been a lot of fun, compounded by the fact that the loss of electricity meant that our basement ended up with about an inch of water on the floor due to the sump pump not having power (once things settle down we will be having one with a battery backup system installed regardless of anything else). All things that would not have been an issue if we had some form of alternate/backup power for the house, which I've debated for a while now but figure that after this experience I am much more enthusiastic about following up on.

So, I'm curious what experience others have with either whole-home generators (our house thankfully has natural gas, which has been a blessing through this since we can still use the stove and take hot showers) or solar systems with battery backups (like the Tesla PowerWall). If I'm missing anything else, I'm interested in hearing about that as well. I've had a medium-sized HF generator for a good while and it has made things much more bearable, but it can't cover everything, can't be run constantly (due to safety, noise, and having to shut it down to refuel), and isn't an automatic start/switchover (which mattered here, since we weren't at home when the basement started to flood due to the sump not having power). 

From what I can tell, the breakdown of the comparisons between them goes something like this:

Whole-Home Generator

Pros:

• Lower up-front cost (don't have exact quotes for either yet, but $10k seems to be what is predicted)
• Will run off our existing natural gas lines
• Should not be affected by high winds like we had
• If properly maintained, should have indefinite life
• The generator iteslf could likely be unhooked and moved to a new house when we move

Cons:

• If we never had another power outage, it's effectively wasted money since it doesn't do anything most of the time
• Dependent on natural gas service still working- I've never had natural gas not work during an outage, but it's not impossible
• Noise- should be far quieter than my cheap HF generator, but will still also not be quiet
• Additional cost from the natural gas used to power it

Solar Panels + Battery

Pros:

• Useful all the time and not just during a power outage, offsetting our power bill
• In theory better environmentally
• Independent of external services (electric and gas lines could be cut and still function)
• Silent

Cons:

• Higher initial cost (hard to get a real bead on without an actual quote and knowing what rebates we'd qualify for)
• Panels & Batteries would degrade over time and have to be replaced
• Roof-mounted panels could be damaged by winds
• Would be difficult and likely impractical to move to another house

I suppose I should put this here as well since it's technically an option...

Battery Backup System

This would basically involve getting some of the batteries the solar system would use and having them installed so they'd kick in and power the house in the event of an outage.

Pros:

• Probably the cheapest option
• Could be moved to a new house, or potentially used if we decided to go full solar down the line

Cons:

• Limited run time with no direct way of replenishing them, so for longer events (like this one...) they'd likely be drained before long (though they could potentially be recharged using a smaller generator like we have now during the day)
• Would degrade over time
• Also not really getting anything back from the cost except during an extended outage

So, as I said- I'm interested in what others who have (or have firsthand knowledge/experience with) these setups have to say about them. 

As a final aside- yes, I realize that in theory this is a very rare event and it's likely we won't ever really need any of these... this is the first time in the nearly a decade we've lived here that the power has been out for more than an hour. But I also expect that more extreme weather events like this are going to become more commonplace so being better prepared for them will be a good idea.

Batteries are the biggest expense.  Are you willing to roll your own say using a Tesla battery?  That can lower the expense greatly.  Is there a used solar reseller near you like https://www.santansolar.com/?  If you do the work yourself and get creative you can do a solar/battery system for less that that $10k generator.

In reply to Stampie :

I'm generally unafraid of doing work myself- but I'm at the same time want to make sure that everything is safe and going to hold up and not have the potential of going out/doing damage due to my not getting something right. It will be interesting to see what the solar installer(s) come back with as what the system(s) will cost installed...

Ashyukun (Robert) said:

As a final aside- yes, I realize that in theory this is a very rare event and it's likely we won't ever really need any of these... this is the first time in the nearly a decade we've lived here that the power has been out for more than an hour. 

Ashyukun (Robert) said:

Solar Panels + Battery

Pros:

• Useful all the time and not just during a power outage, offsetting our power bill

I think this is the most important part for a financial decision like this.

Two completely different things with different use cases as you identified.

Power goes out at 6PM in a rip-roaring storm and overcast skies for the next 3 days and 100 degree temps or below zero temps?  Generator for sure.  

House has excellent solar potential and you want to try some independent power?  Solar would be the way to go.

For emergency backup power I would go generator every day of the week.  There are also tri-fuel options that can run off propane, natural gas, or gasoline.  

If the sump pump is your primary concern and you are on city water, you can get a water powered pump that needs no electricity.  

My sister is in the mountains of CA that has been out of power for a while because of recent weather.  She just had a Tesla power wall installed for backup, but it now down to 40% and cannot be charged until the power goes back on.  She uses a pellet stove for heat, so does need electricity to heat the house.  She has a generator, but it will not charge the Powerwall.

This does not help you much, but confirms some things.  I am not sure how her generator is setup, but I would think if it powered both legs of the fuse box, it should be able to charge the Powerwall (?)

So, a battery and a generator might be an option?  This would give you short term full backup, and the ability to extend if needed with a generator, without needing to run it at night.  As you noted, long term outages are going to be (hopefully) uncommon.

I stopped reading here:

my 12-year-old Harbor Freight generator is chugging away out in the garage powering

Please, DO NOT run a generator inside your garage. That is a recipe for disaster! 

In reply to Ashyukun (Robert) :

How rare are power outages in your location? Both here in MS & for most of our lives back in IL it was common to have power go out multiple times per year, although rarely for a day or longer. 

The other downsides of solar are that you'll be generating way less power during winter, and if you have any trees in your yard that cast shade on your panels that will also impact their output significantly. 

Before you go solar, make sure you know what watt-hour usage you'd need, and then plan for the worst case scenario of how many days you could be without power. 

FWIW here in hurricane territory we'd been discussing a whole house generator, but now that we have a 4000w generator in the RV & 4000w inverter in the van I think we're pretty well set. With a full tank in each vehicle that would get us about 3-days of constant use with both of them simultaneously. During Zeta we only had the van & it allowed us to switch between the fridge, freezer, and microwave for 2-1/2 days, but now we should be able to run them all.

In reply to ProDarwin :

It is the biggest reason that solar is a strong consideration- it wouldn't just be thousands of dollars down the drain if the power never goes out again. 

Slippery said:

I stopped reading here:

my 12-year-old Harbor Freight generator is chugging away out in the garage powering

Please, DO NOT run a generator inside your garage. That is a recipe for disaster! 

'Inside' the garage more accurately means 'just inside the garage door so it's shielded from any potential rain with the garage door wide open and the exhaust facing outward'. We started off with it behind the convertible under the 'portable' carport, but since that was 10 feet from a glass door into the house it was just too loud so I moved it and piled tires up between it and the house to serve as noise baffles. 

When scaling these systems, take into account if you're willing to operate at lower power levels during an outage. For example, I'm mostly interested in keeping cold things cold so we don't lose food and being able to run the furnace (hot water) if necessary. I'm less interested in being able to watch Netflix or even charge the EV, those are things I can do away from home.

I've always been interested in solar + enough battery to create a grid. Not a big burly battery that will power the house, but enough to wake up the array and run the refrigerators/furnace during the day. That gets rid of the biggest expense of a battery backup - capacity - and allows us to use the solar array that we installed for other reasons. I haven't dived deep into this yet, but it's my current (har) favorite emergency power concept.

You'll need to get multiple solar quotes obviously, but Project Sunroof might give you a quick idea of the viability of your house based on location, tree coverage, roof area, etc.

NREL also has some decent monthly and annual maps of the US that show how much solar energy might be typical for a given location. Less energy means you'd need a larger and more expensive system to generate similar amount of energy of course.

We added a natural gas generator (Kohler) a couple of years ago.  It is expensive insurance!  Your estimate of $10k is about right.  Ours was more as we had to have a gas line plumbed around the house.  We also had to add an additional panel.  Upgrading the old panel would require all smoke detectors and CO detectors to be hardwired.  

It sure is nice to have when we need it.  

Ashyukun (Robert) said:

lease, DO NOT run a generator inside your garage. That is a recipe for disaster! 

'Inside' the garage more accurately means 'just inside the garage door so it's shielded from any potential rain with the garage door wide open and the exhaust facing outward'. We started off with it behind the convertible under the 'portable' carport, but since that was 10 feet from a glass door into the house it was just too loud so I moved it and piled tires up between it and the house to serve as noise baffles. 

I run mine (only a few times) in the garage also (easy access to 220 with panel locked out).  I added a pipe (conduit pipe works great) to the exhaust and run it out one of the vents.  I also make sure there are thing between the generator and the garage door because of the noise.  It's turned off at bedtime of course.

I don't think there's really a solar option to replace a generator for power outages.  It would be nice if someone were to produce a package that consisted of a bank of batteries, an inverter, and an array of photovoltaic panels to charge the batteries.  Then we could take a particular wattage level and compare costs.  Seems pretty certain that you're not going to be able to get 7500 watts for $500, which is what a cheap gasoline-powered generator is going to cost.

I would be inclined to go with a NG generator.

Yes, it'll be idle most of the time.

Depending on where you live and grid loading, you might be able to work out some sort of load shedding agreement with your power company to disconnect you from the grid during high peak times, getting a discount on power the rest of the time.  Some of the larger manufacturing facilities I work with have co-gen plants for this reason (on a much larger scale).  In that case, you'll want to size the generator to be literally "whole house" including A/C.

Definitely check with the gas company before signing to buy anything. You may need a regulator upgrade to feed the generator, which typically needs more gas than the regulated side of the service can provide. 

Solar has pluses and minuses you've already mentioned, but you would need to have some preliminary design work done to determine if your house has enough roof coverage to provide enough power to run your house during the daytime while also charging batteries to run it at night. 

IMHO, if you live in an area where it gets hot, designing either system that cannot run the house A/C is a waste of money and will offer zero return on investment if/when you sell.  Speaking of that, it seems a generator is more likely to be worth $ to a potential buyer than a solar system. 

Natural gas outages do happen, but they're a lot more commonly caused by earthquakes than by storms.  This is more of a consideration for California than most other states.

Does it snow where you live?  Solar panels don't do you much good if they're covered in snow, and climbing up on the roof to clear them is a significant undertaking.

The whole home generator will be the least expensive, and provide backup power the longest. But like you said, doesn't do anything unless you need it. It's purely an insurance policy. Which can be a benefit too, not worrying about losing power has a benefit even if you aren't using it. 
 

Solar is more expensive, but pays for itself over time depending on how much you electricity bill is. If you have big bills, payback is shorter. Small bills, it will take many years to recoup. This is assuming net metering. Off grid takes forever to pay back, and isn't really about cost savings- unless it's cheaper than running a service to, like a cabin in the woods. 
 

Batteries are more expensive than generators, and have limited capacity for long outages, without increasing battery sizing and cost. The only time they can have a cost benefit is if your utility bills you by time of use. If your utility charges you 3x as much when you are home from work from 5-9 as they do from noon to 5, then you can store the cheaper power and use it later. This applies with and without solar. 
 

My recommendation- if you have low bills but want long term emergency backup, go generator. If you have big bills, go solar plus generator. If you have big bills plus time of use charges, go solar plus battery- after you do the math. Keep the portable to take some of the load off the battery for longer outages.

In reply to trucke :

Thanks, that's good to know! Having to run the gas line to wherever the generator will be is something I hadn't considered, given we'd likely want the generator closer to the electrical panel which is around the house from the regulator (and away from our bedroom window). We'd likely have to go with getting an additional panel for it too since our house is like 60 years old and while the electric was upgraded somewhat when it was remodeled about a decade ago there adding it in directly likely won't work.

How bad is it noise-wise when it's running? Have you had to use it much?

If you are looking for back up power for during long term outages, a generator is your best bet. I don't install solar,  but my understanding is the solar system needs to be "connected" to power to generate electricity, so when there is a utility outage it doesn't do anything. Maybe with a generator and or battery back up that isn't the case? But to be able to store enough power to last for days you would need some serious batteries.

imgon said:

If you are looking for back up power for during long term outages, a generator is your best bet. I don't install solar,  but my understanding is the solar system needs to be "connected" to power to generate electricity, so when there is a utility outage it doesn't do anything. Maybe with a generator and or battery back up that isn't the case? But to be able to store enough power to last for days you would need some serious batteries.

It is possible to run your house independently of the grid with solar, but yes, you need batteries.  Without something to buffer the load, you would get brownouts every time a cloud went in front of the sun.  You also need a transfer switch so that it isolates the house from the grid to prevent electrocuting anyone working on the "dead" power lines (generator also needs this).

The size of the battery bank depends heavily on what you're running off it.  If you've got natural gas appliances (furnace, water heater, range, dryer) then you're just looking at the fridge, the furnace blower, and assorted lights/cell phone chargers/etc -- call it 2kw average.  30-40 kwh of battery should do it, assuming you've got enough panels to fill them back up in the available sunlight for that time of year.  That's about a third-to-half of the battery capacity in a Tesla.

imgon said:

If you are looking for back up power for during long term outages, a generator is your best bet. I don't install solar,  but my understanding is the solar system needs to be "connected" to power to generate electricity, so when there is a utility outage it doesn't do anything. Maybe with a generator and or battery back up that isn't the case? But to be able to store enough power to last for days you would need some serious batteries.

That's totally incorrect.  There's many totally off grid solar installs.  I'm looking at doing one myself at some point semi soon.  The only reasons it needs to be connected to power is to sell back and to have grid power as a crutch.

how realistic is using a modern electric or hybrid vehicle to power a couple things like a refrigerator and the fan in a tankless gas water heater for a while?

F150 Lightning?

Prius and an extension cord?

.........This has been in my Amazon list for a year or more now:

510C Pro/Tran2 50-Amp 10-Circuit 2 Manual Transfer Switch with Watt Meters

Add a hammer store generator and a gas can and it's under $2k all in if I do the wiring  

.........This has been in my Amazon list for a year or more now:

510C Pro/Tran2 50-Amp 10-Circuit 2 Manual Transfer Switch with Watt Meters

Add a hammer store generator and a gas can and it's under $2k all in if I do the wiring  

I have the 6-circuit version of that and a B&S generator that I bought at Home Depot many years ago. The combination works great, I can run about 2/3 of the house on it.

In reply to Tom_Spangler (Forum Supporter) :

Did you wire it yourself? Looks pretty easy. I've been inside a de-energized panel before and connected the dots.