Posted on 03/10/2017 8:44:22 AM PST by Cementjungle
I'm in the process of getting quotes from local companies to install a whole-house standby generator. I'm in southern FL and last year's near-miss with a hurricane is prompting me to move on it now. I had planned to do this anyway since moving here, but all my other projects took first priority... this is my only remaining big project for this home.
Anyway... I know I need around 27Kw and, and Generac and Kohler both seem to have comparable products at comparable cost. Both are American made.
I had one installed several years back in WA (an 8Kw Briggs and Stratton), so I am familiar with the things involved (propane tanks, transfer switch, etc.)... but this one is bigger this time around... and a very big investment.
Since Freepers have vast experience with many things, I'm looking for any feedback on these brands and any other "gotchas" that would be helpful.
And remember.... "Make electricity great again!"
Don’t waste your money.
27KW? Wow! Forget Generac and Kohler, you should be looking at Caterpillars.
27KW. Wow that’s big.
in 2006 when we had an ice storm, the Valu Home Center 2 blocks from my home ran their entire store (light, heating, phones, cash registers, etc.) with a 7KW generator.
How big is your home that it needs 27KW of power?
27kW? What are you running? A server farm?
Yes, I can certainly get by with much less during an emergency situation. However, I'm finding that a big factor is the installation cost as both require transfer switch, wiring, propane tank, underground conduit, permits, etc.
Also... the bigger units supposedly put out less noise (water cooled vs not) and run more efficiently. So, it almost makes sense if I'm doing this that I go the full route.
We live in the country on a well. No power, no water. The standard joke out here in Missouri goes like this. I know what its like to live in a third world country, I have Ameren UE power";^)
I don't try and power the whole house so the transfer switch powers a separate box that powers the well and some kitchen, bedroom, furnace fan and garage breakers. Lets us cook. Can watch TV from the bed. Powers the garage in case I need to be working on a vehicle. The furnace fan so we will have heat in the winter.
Generally you don't size a generator for running the whole house as you rarely run everything all at once. Size it to run just what you'll need. For instance you don't need to power a stovetop, just cook with the microwave.
The other thing to watch for is surge current. For instance in Florida you may want to run an AC. Make sure that the unit can handle the startup surge without popping the generators breaker.
Being in sunny south Florida you might want to consider the Tesla Powerwall, using their battery pack with solar panel generation.
Here is the link to their quick estimate calculator.
https://www.tesla.com/powerwall
Large scale power outages last far longer than the weather event and down there it seems clear bright skies follow once it has passed. So the back up battery bank tides you over for a day or two until the solar panels start recharging them.
Zoning the house for required critical elec. services would give minimal spec requirements for 24-48 hr period with perhaps a smaller gasoline genset to charge the power wall.
That 27kw presents a high bar with operating costs. Need to run some what if scenarios on the spread sheet. Quick historic research on post weather event follow on conditions and historic outage periods.
We have three central A/C units, electric everything (fridge, hot water, etc.). We could be fine in an emergency with one A/C, fridge and just some lights... we can cook on the outside BBQ grill.
It would be nice to keep the pool pump going during a 3 week outage otherwise the water would probably need to be completely replaced afterwards, which is a cost.
27kw is serious overkill for a typical home.
10kw should do the job quite nicely, especially if you’re sensible about concurrent loads from your major appliances.
I’d get my pencil back out if I were you.
Can’t speak for Florida but some power companies and some states really frown on combining a battery bank with a grid-tied system. Makes a lot of sense to me, too, to have a charged battery bank ready and waiting along with solar but Duke Energy does not allow it here in NC.
Do you remember where you got the plans for this layout from? I'd like to go with a whole house unit at some point but right now an external setup like this sounds good. Thanks! FReepers are the best!
We have had a 20KW Generac whole house generator for the past nine years. It runs on Natural Gas so it is derated to 17KW The transfer switch is automatic. It tests itself ever week. We have a 4.5KW solar grid-tie array. The Generac provides a stable frequency source so during the daytime there is little load on the Generac. We have used it twice for real. One was a six hour outage and the other was a couple of hours. It takes about 30 seconds to come on line. You won’t notice the transfer back to the grid.
Hope that helps.
Not enough info..27 kw would run almost 3 houses at one time, including the water heaters and electric clothes dryers. Diesel fuel stores for decades with proper care, and is the most efficient. Propane also stores excellent, but the generator fuel regulator can have issues if not exersized each month. Propane useage will be high compared to gas and diesel, and is less common. You need a filling station for propane, where diesel is available everywhere. Natural gas is great, as long as the pumping stations are on line. I prefer diesel with a few 55 gallon drums. Red diesel is great up here, because of the - degree temps. I have a small 5kw gas for backup, when servicing the diesel. We use ours every year living at the very end of the grid above Moyie Springs ID.
Direct hits have to be defined. Lots of the area over many miles will be damaged and
some severely. It may take much longer to get power restored and it if you have
home damage then you may have even much longer before the home is habitable.
Good luck with your process.
Hunn...I would search for a used CAT unit. That said fuel consumption is a big deal. If you don’t have power chances are your supplier doesn’t either and if the roads are a mess then getting fuel delivered is a big problem. Storing a large amount of fuel is also a problem. Propane is the worst bang for the buck and diesel is the best.
Doesn’t have to be a grid tied system.
Wire it the same way a UPS back up system, automatic shut off of mains circuit with backup kicking in. Mains circuit stays off until manual reconnect.
Surely data centers and others have such in place, so maybe Duke has objection to the feed back into the grid part only.
I am in the IT disaster recovery business. My observation is that after you go above 25kw, the price point starts getting better with diesel. I did a search on ebay, thought I would share.
http://www.ebay.com/itm/like/132105255960?lpid=82&chn=ps&ul_noapp=true
Military surplus may be an option as well.
Be sure you have proper ventilation and heat dispersion (can be used to heat the house via water radiator heat exchange system.
Sounds like a terrible waste, spending potentially tens of thousands for a battery bank just to sit there the vast majority of the time, but I guess it’s not really any worse than doing the same thing for a whole house generator. Not sure what type of lithium batteries Tesla uses, I know Lithium Iron Phosphate will hang in there quite happily unused. Others don’t.
Agree, 10KW should be fine.
I have experience with auto-switching backup generators in commercial buildings, a whole house Generac generator and a 5kw portable set up to run on propane.
If (a very big IF) you have Nat Gas available, but that huge generator in, otherwise, go with a 10KW for your max and set up an “emergency bus” that it powers. Forget elect stove and oven, elect water heater, and total HVAC system on the emergency bus. Put several room outlets that are for window A/C units,fridge, microwave for cooking, lighting, computers and TV, and you will be fine. 10KW is plenty for that.
My 5KW will run off portable or fixed propane tanks, have some BBQ tanks and a 300 gal tank on site. This works fine for lighting, fridge, wellpump, and a window A/C.
The larger you go on capacity the more expensive it gets, cost seems to go up exponentially.
If you have experience in wiring and circuit boards, which I don't (not much anyway), then you ought to be able to fix yourself up with the help of the instructions included with the transfer switch.
Your local electrical shop will have what you need.
But it can be complicated and dangerous (the power surge that can come from the main transmission lines near your house, etc.) and a good electrician will fix you up for a few hundred bucks.
Worth it, and you can watch him and learn.
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