Natural Gas Generators

[IReallyLikePizza2]

I'm looking at the Generac PWRCell on their website now, but I can't find anything on how it would run with a generator. I don't want the generator to kick on when the power goes out if I have a small load and stored power in the battery

 

[NoloC]

This is a pretty good forum for generator advice. Power Equipment Forum

 

[CCTVCam]

I'd love a system that can link everything together and figure out the best (and most cost effective way) to get power

If there was a fancy box I could link Solar, PowerWall, Generator and the Grid into.

Then you could also set it to do things like charge the PowerWalls from the Generator if needed to have power at night, and have the generator turn off. Don't think anything like this exists though

I can't see in theory why that wouldn't be possible and why any specialist central control would be necessary. I watch a lot of Tesla Powerwall stuff and the controls look for a failure of the incoming supply and then switch seemlessy over to battery and then back when power is restored. By the same token, it's possible I believe, the guy with the Powerwalls above will know, to control and charge the batteries using grid if required.

BTW, not all power wall installations that are grid connected can provide back up power if the grid goes down. It's a feature on newer units as prior to this, the Powerwall had to swicth off to keep the grid lines safe for mainenance engineers - the danger was they switch the grid off, and all the powerwalls feed the grid and make it live again potentially electrocuting the engineers. For this reason I believe many grid connected powerwalls from ealier installtions cannot supply the house with power if the grid fails despite having stored energy. I believe Tesla made changes to the control units in later grid connected models to ensure if the unit switches to battery backup it isolates itself from the grid making use as a power fail backup possible.

Anyway, going back to the topic, if the power wall controller just sees power coming in, it's not going to know where it's coming from, so I see no reason why you could not have a generator upstream of it mounted as the 1st device on the supply that kicks in if the grid fails as I don't see how the powerwall would know it was the generator and not the grid supplying the back up power. It would potentially just switch power to powerwall supply between the grid going down and the generator kicking in, then back to "grid" when the generator came in. I do wonder though if the generatoe might be better downstream of the powerwall so the power wall supplied power first and the generator second, just simply because you presreve the fuel that way. I defer to electrians on the actual possibilities.

One last point, be safe with propane heaters guys. Carbon monoxide is a real and present danger indoors. I suggest getting an alarm in every room where one is used.

 

[ptzman]

I'm looking at the Generac PWRCell on their website now, but I can't find anything on how it would run with a generator. I don't want the generator to kick on when the power goes out if I have a small load and stored power in the battery

Just thinking, if the output of the powerwall is fed into an automatic transfer switch as the primary and the generator is fed as the secondary before it goes into your main power panel , the generator should only come on when the powerwall fails to produce.

 

[tigerwillow1]

The Powerwall and PWRCell products look like the modern day equivalents of the battery backed grid tie solar system I've been running for about 10 years. The big difference is in the packaging. Instead of one box I've got a separate inverter, charge controller, and cabinet full of AGM golf cart batteries. My original main goal was solar power but have since learned that its biggest value might well be that it's a "almost" whole house UPS. Most of our power outages last between a few seconds and an hour, and we often don't know it happened unless a neighbor calls to see if out power is out. The switchover to battery power is fast enough that there's at most a faint flicker of the lights.

With a long-term outage it's for survival, not for comfort. It will run the fridge and freezer, blower on the propane heater, lights, TV, and of course, the IP camera system. If there's a multi-day outage with not enough sun I have to fire up a portable generator that will run on gasoline or propane. The generator can recharge the batteries so it can be shut down overnight. The cooktop running on propane is an advantage. A system like this isn't a replacement for the big generator, but it is a different approach alternative.

 

[samplenhold]

So those of you with solar panels, I take I they are on your roof?

What happens when you need to change your roof? Pull the panels I guess? These 30 year roofs in Houston last about 15-18 years. Mine is now 10 years old. I guess if I was to get panels, I should first get a new roof?

 

[IReallyLikePizza2]

I've been thinking that I'll get a high quality metal roof before getting solar panels

 

[tech101]

So those of you with solar panels, I take I they are on your roof?

What happens when you need to change your roof? Pull the panels I guess? These 30 year roofs in Houston last about 15-18 years. Mine is now 10 years old. I guess if I was to get panels, I should first get a new roof?

Or if you need both roof and solar panel. Look into Tesla Solar Roof.

 

[samplenhold]

Or if you need both roof and solar panel.

Really don't NEED either at the moment. Just kicking around ideas, just in case I finally get bored with IP cams and need another hobby/obsession.

 

[tech101]

Really don't NEED either at the moment. Just kicking around ideas, just in case I finally get bored with IP cams and need another hobby/obsession.

I guess soon I be back @ cams once Andy can get us the new catalog for this year. I am planning to buy something with Laser if something has a good sensor size and all..

 

[tigerwillow1]

What happens when you need to change your roof? Pull the panels I guess?

You guessed correctly. I have 2 independent solar systems and one of them uses ground mounted panels. I like that a lot over the roof mounted panels because I can clear the snow off of them without risking my life. Not much of a concern in Houston I presume. It's really frustrating to have a cloudless day where the solar production is zero-point-zero. With most homes in the city, roof mounted is unfortunately the only alternative.

 

[IReallyLikePizza2]

Not much of a concern in Houston I presume.

3 weeks ago I would agree with you, now not so much

 

[IReallyLikePizza2]

Some interesting stats here, I am super glad I went with the 27kw Liquid cooled unit, this is comparing to my neighbors 22kw air cooled unit (Also Generac)

For these stats keep in mind the 27kw unit does 25kw on NG, and the 22kw unit does 19.5KW on NG.

At full load mine uses 14.36 ft³/hour per KW of Natural gas, but his uses 15.69 ft³/hour per KW. So the liquid cooled unit is more efficient but uses more gas overall

When you look at 50% load, it looks a little more interesting though

When the 27kw Liquid cooled unit is run on NG and is at 50% load, it provides 12.5kw and uses 197ft³/hour of gas.

When the 22kw air cooled unit is run on NG and is at 50% load, it provides just 9.75kw and uses 203t³/hour of gas!!! Thats more gas, and less power.

 

[biggen]

Any reason they quoted you for a 27kW? That seems huge for a house unless you live in a very large home with multiple A/C/heating units you want to run at once. My father-in-law in Alabama had a 16kW Generac installed about 4 years ago in his ~2100sqft home. It was approx $12k installed. It's easily big enough to run his central A/C and everything else in the house. My brother-in-law (also in Bama) had a 12kW installed and it's too small to turn the A/C over. He wished he had gone with the 16kW unit instead.

I've not gone through all the thread but do you also have an electric oven/range and hotwater heater? None of those are gas?

 

[bigredfish]

I’m a big fan of overkill

 

[biggen]

I’m a big fan of overkill

Normally I am as well. I'm just curious what the installer quoted as the power draw from his home and what the largest appliance users were.

 

[bigredfish]

Yeah, I looked into the whole house unit briefly after the 2017 storm and having bought the 8000/10,000 portable. (Which served us well) and was told 16-20KW was plenty for our modest 2000 sqft

 

[IReallyLikePizza2]

There is a few reasons I went with the 27kw Liquid Cooled

1. I 100% wanted a liquid cooled unit, the air cooled units in my opinion are not as good
2. The smallest liquid cooled they do is 22kw, and its almost the exact same price as the 27kw. The install would cost the same, and you save less than $500. So for $500 you get 5kw extra, no brainer there
3. The company I am getting it from doesn't even stock the 22kw, it would have to be special order. They don't stock it, because it doesn't make sense financially and they keep the units down to a minimum to make installation and support easier
4. I have gas everything, but my range is electric (But soon to be gas), with it being the 27kw unit, it means that I don't need any load shedding which makes the install slightly simpler
5. Once I get the gas range I'll have a ton of extra power to play with. So in a few years when one (Or both?) Of my vehicles are electric, I could still charge it at home if there was a large outage and I still wanted to drive around

That last point might be the best point actually, because finding gas even around here when the winter storm hit was an issue. If I had an electric car or a hybrid (Like the new F150), I could easily drive wherever I wanted every day with no worry about finding a gas station, pretty cool.

Bonus point number 6: My neighbor got an air cooled 22kw, so I had to one-up him

 

[IReallyLikePizza2]

Getting real annoyed that the link between solar, batteries and generators is not better yet.

Last year I looked at Solar + Power Wall, and they told me there is essentially zero link between a generator. So they can't work together at all really, according to them

When the Generac PWRCell came out, I figure it would be perfect, as they lead the home generator market. But no, everyone I have called about it states it doesn't have any integration with generators

I want solar + PWRCell + generator. If the power goes out in winter when I don't need my 4 ton AC, I should be able to run on battery until they get low, and then if I turn the AC on, the generator should kick on

 

[biggen]

Why do you want batteries with a Gen? Just run the Gen until power comes back on. If you are concerned NG runs out during a storm, then go with an LP Gen and bury a tank.

Batteries suck. They are huge, heavy, expensive, and require tons of maintenance. They also have limited life spans.