Underground is the way to go. If you are going to spend the money to bury an underground tank, you might as well save a small fortune and go the 1000 gallon route. The cost for a 1000 gallon underground tank is not twice as expensive as a 500 gallon - it was only 50% more expensive back when we had them installed. The cost to bury a 1000 gallon tank is the same cost as burying the 500 gallon tank. Excavating the larger hole only takes a few more minutes to do. Also, the 1000 gallon tank makes it immediately possible to save 40-50 cents per gallon when you are purchasing more than 500 gallons. Different suppliers have different rules. Speaking of different rules I recommend staying away from any business that falls under Suburban Propane. They have a really ridiculous "contract" that they require, and if you agree to all of their "rules" they have all sorts of rights to trespass on your property unannounced - to perform "safety inspections" - not something I'm willing to tolerate.
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Solar Power
- Thread starter Ret60sp
- Start date
Been at it for almost 5 years now. You got some catching up to do.
You first
What's wrong with a Ferrari? The enclosure in front of the power pole houses a 7kw diesel generator. note the manual transfer switch mounted to the side of the meter box. The only tool in my shop that I cannot run is a large shaper........too much starting current. Common sense required of course, maybe too much to ask these days.
"hope" is not a very good strategy. solar power is great for electronic loads like a trickle charger on an automotive battery or any small DC devices. Without heavy government (taxpayer) support, solar power for large inductive AC loads will never be affordable as the purchasing power of the fiat-USD is being stolen every second of every day....part of the WEF/Biden regime plan for the controlled demolition of our once great nation since 1971.
Yep: knowing what you are doing is key to many endeavors.
Thats the thing about "Dead End" roads....come down them with evil in your heart and it might end exactly as stated..
Ha!!you'd prolly LOL for saying that ^^^ if you knew the dead-end road that I live on !!
My definition of using less is to design the SHTF power system around what will we need when the SHTF. In the mean time I use as much as I can afford - mainly in an effort to build what we need should the grid start failing with the trending push to make everyone plug in a car, or two, or three. Thats the thing. Its not ONE EV car that they want us to plug in, its ALL the cars at your house! So while it might seem that one EV sucking power from a home solar system build might be sustainable, imagine your car, your wife's car, your children's car(s) and you'll probably need an external plug for a friend or family member that travels from afar to visit - they'll need power to recharge their car..... so that's not using less. Thats using more. The only thing the liberals want us using less of is gasoline, diesel, beef, pork and chicken. They want us using MORE electricity. Obviously electricity is something they are clueless about, yet they want us using "smart" appliances, "smart" phones, "smart" meters and all of this "smart" stuff. Whats so smart about it? The "smart" features give third parties access and control over all of these "smart" devices and they don't have to set foot on your property to "monitor" everything we are doing. Is this using less?
The liberals want you dead or under totalitarian control.
Names withheld -
Ok, so you have started down the path of having reliable backup power during a power outage. If you didn’t already know (and you should already know), you need to know that your backup power source is “emergency” power. It has limitations. Let me explain:
Your home was originally wired to 150 amps (36,000 watts) wherass most homes are wired to 200 amps (48,000 watts) or dual 200 amp panels but de-rated to 360 amp service (86,400 watts) service. That load distribution can be and is actually divided at the main breaker panel(s).
If you added another load panel, you could split your utility loads into two pathways – one going to the Sol-Ark, and the second going to a non-critical loads panel. The 12K Sol-Ark is designed to handle about 40 amps of the loads (60 amps from the grid, or 40 amps from a generator, or 37.5 amps from the batteries), any load beyond that must be powered by the grid or a very powerful generator, or a second inverter with another battery bank.
I think your current portable generator is a 10Kw? I know the new one **** has on wheels at ****’s shop is a 20Kw. Lets say you are going to use the 10Kw for now. A 10Kw generator is (at maximum) a very temporary 40 amp power provider (9600 watts). With it alone, you will not be able to live life and use all of your appliances at the same time. You might think you did before, but I know for a fact that the wiring of your generator was so haphazardly done that it would have tripped off or caught fire in the wiring under your house if you actually got close to using it near the 10,000 watts that it is rated for. I say this because the wiring your previous installer used for your generator connection was too small to handle a 40 amp load (10 AWG), and it would have caused the wires to catch fire if they were subjected to more than 30 amps @ 240 volts (7200 watts) for any length of time. I believe ****** found scorch marks where it was installed and he had to re-wire it to make it safe?
The” new” generator. It is a 20Kw propane powered 4 cylinder (LPG gas) engine. It is capable of producing 83 amps @ 240 volts, or 20KW. It will probably function flawlessly at a 60 amp load (75% capacity) all day long, but you don’t have that much of a power demand to keep it loaded at 75%. So it is still a GREAT addition to replace that 10Kw gasoline generator. Why? Because the Solark is capable of recharging the batteries at 9600 watts, which would suck the entire capacity out of your (10,000 watt) 10Kw generator and cause it to fail in short order. Why? Because that little portable 10Kw is NOT DESIGNED to provide 10Kw for more than a few seconds or minutes at most. It is air cooled. It might be rated for 10Kw, but it will function best if you load it to about 6,000 watts maximum. The “new” generator is much more capable. It is liquid cooled. The engine driving it is powerful enough to run it all day at 90% of its rated capacity. But you won’t need to run it that long since you have batteries attached to the Solark.
The batteries: Each of your batteries are capable of delivering 5120 watts of power. You have six of them. That’s 30,720 watts of stored power (30Kw) of power combined. It cannot be used all at once, but it can be used through the inverter at a rate not to exceed 37.5 amps (9000 watts). That means you divide that 30,000 watts by 9,000 watts (maximum) and that’s your maximum sustained run time = (3.3 hours @ 100% useful load). Use less power and it lasts longer. Very few homes actually draw 37.5 amps for any length of time, with exception of the dumbasses with EV’s.
Its safe to say that if the grid goes down your backup power is your battery bank, and your battery bank can handle about 27 amps (6500 watts) of power continuous without issue. That leaves enough overhead to start and stop duty cycle loads like refrigerator and freezer compressors, air conditioning and your well pump. If you use less power it lasts longer. Just know that your battery array further limits your power and you cannot function as if life is normal. Your batteries will need to be recharged.
You might have thought that your 10Kw generator was better than your new inverter and battery backup – you would be mistaken. Your portable 10Kw generator cannot run more than 9,000 watts for a few seconds or minutes before it will overload, overheat, or cause an undervoltage, under frequency or imperfect sine wave (dirty power) which will harm the electronics in your home. Contrastingly, your Solark Inverter/charger produces a perfect sine wave and can handle a 9000 watt balanced load without harm to anything. More on load balancing later.
Critical Loads: The Sol-Ark Inverter/charger will allow a little more than 60 amps (14,400 watts) of grid power (or generator power if the genset is largen enough) to cross through the inverter from the grid to your loads when the utility power is fully functional. Consider this at a dual engine situation, using a Blackhawk metaphor, where both engines are fully functional. If one engine fails (the grid power fails) the other engine (the Solark with Solar panels and/or the batteries) will pick up as much of the loads as possible. But just like the Blackawk, you can overload that one single engine. The Solark can handle a 60 amp passthrough, but if the grid power fails it steps back from 60 amps passthrough (15,120 watts) to a maximum of 37.5 amps (9000 watts) to keep you airborne. If you had solar panels attached, it would still be limited to producing 9,000 watts of AC power, but it could also draw power from the solar panels and/or the batteries to meet that load. Any excess power from the solar panels would be separately sent back into the batteries to recharge them, making it unnecessary to start your generator. If you exceed that 9000 watt limitation (up to 16,000 watts* for no more than 10 seconds or 25,000 watts* for 100 milliseconds) the system will trip, and you’ll be out of power until it resets itself (3 minutes later). Once reset, it will trip again if you don’t lighten the load to a combined load not to exceed 9000 watts.
A Non-Critical Load: An electric clothes dryer is typically given a 50 amp breaker all by itself. It normally operates on about 40 amps or 9600 watts. It doesn’t consume 9600 watts continuously though, because the heating element is not on the whole time. The element run time is dependent on the condition of the clothes and the temperature and humidity. Either way, this appliance CANNOT be operated downstream of a single Solark inverter!! It needs to be placed into a Non-Critical Loads panel and only operated when grid power is present.
No, contrary to popular belief, your 10Kw generator cannot handle your clothes dryer!
Electric Water heaters are typically placed on a 30-amp breaker. They typically draw 22.5 amps (out of 30) or 3500, 4500, or 5500 watts (depending on which element is installed) to heat your water. If this appliance (unmodified) is placed downstream of your Solark inverter (getting power from the Solark), it will use 35-70% of your available (9,000 watts) power, leaving you in peril of not being able to get water from your well pump. More on the well pump in a moment. A simple water heating element replacement to a 3500 watt element (down from the 5500 watt element) is a much better idea. Changing that element to a 3500 watt element is a simple $18 proposition at Home Depot. A smaller element will take longer for the water to heat up, but it won’t kick your inverter in the teeth while its operating.
A better solution is to heat your water with a heatpump water heater or a natural gas or propane on-demand water heater. Install a propane tank underground and have it supply a point-of-use or whole house on-demand water heater, a cooktop and a fireplace insert. An on-demand heater can be added to your existing setup and provide redundancy as well as assurances that you’ll have hot water from one source or the other depending on which power source you have available.
Now for the well pump: A Well pump typically uses 18 amps (4320 watts) to start and then has a sustained draw current of 9 amps (2160 watts) or less while its in full operation. 1.5 hp pumps are near or can exceed 2400 watts to start, and use about 2000 watts to operate. Conversely a 0.75 hp pump uses about 1850 watts to start and 1200 watts to operate. The Solark gives you that 10 second start reserve for things like this, so the math needed is in the operating current and not the start current as much. You need to reserve this capacity in your 9,000 watt allotment. Reserve 2,000 watts for well water, if you don’t know the size or lifting height of your pump, which leaves you with 7,000 watts for other loads.
Your cooktop and oven should not be considered as critical loads. Use a microwave. Although it is an unbalanced load, the microwave is much more energy efficient than you might imagine. Your cooktop and/or oven typically have a 30 amp breaker associated with them, and you should find another means for food preparation because electric ovens and electric cook tops are wholly energy inefficient and power hogs. Cook a roast on your oven for 4 hours and it will drain more than 60% your 30Kw batteries in that 4 hours. Get a gas cooktop or a wood fired grill and save your electricity for the things that are truly critical (water, lights, etc.)
So whats actually critical?
Your well pump is critical. Reserve 2000 watts for it, or nearly one fourth of your critical battery and inverter power.
Your freezer and refrigerator are critical loads and they need 2000 watts (total) if you have one of each. They both have compressors in them. Their start current could be as high as 20 amps @ 120 volts (2400 watts), but their running load is off and on (duty cycle) and they are each probably are in the 1500 start watts and 750 run watts (depending on their age), and since you have two of them you need to reserve 2,000 watts out of your 9000 watts for refrigeration just in case they happen to be in operation at the same time.
Your Lights are critical. Reserve 1,000 watts for powering your lights, outlets, chargers for your phone, TV, Internet modem, emergency radio, ceiling fans and battery chargers for your cordless tools. You’ll need those cordless tools for repairs – why else would your power be out? You might have had an ice storm, or something common happen, and it could be hours, days or weeks before power is restored. You’ll need your tools.
So where are we on consuming those 9000 watts? We have reserved 2000 watts for the well pump, 2000 watts for refrigeration, 1000 watts for lights. This leaves 4000 watts or 16.5 amps @ 240 volts for air conditioning or your modified water heater (but not both).
You can’t afford to operate the freeze dryer on the Solark because it uses too much power. It will draw (at times) as much as 1600 watts of power. So don’t try to operate your freeze dryer downstream of the Solark.
Don’t use a hair dryer, plug-in electric heater, flat iron, or beauty gadget when the grid fails. You simply cannot afford the excess power consumption.
Don’t plug in a car charger unless you have 60Kw of battery storage and 24,000 watts of solar PV on your property.
In the winter you need heat. I recommend a Buddy portable ceramic LPG space heater in the winter, or a gas fired fireplace insert in the fireplace (I recommend a vent-free system – no heat loss). In the summer you’ll need to dehumidify the air in your home to control humidity and mold growth. A Daikin or MrCool mini-split air conditioner is the best option there, and you should seriously consider having one installed professionally. They are not expensive, and it is actually something we can do together if you want. A one-ton unit with the cassette installed in your bedroom would be the absolute best option. These units cost about $2200 if you do it yourself (with my help if you want it).
I recommend you consider moving the following things out of your critical loads panel:
Pool Pump motor – you’ll get the pool pump operating when the 20Kw generator is on or grid power is restored.
Bathroom electrical outlets (this prevents anyone from foolishly turning on a hair dryer and tripping the whole house off). You’ll have this restored when the 20Kw generator is on or the grid power is restored.
Oven/Range – you’ll be able to use these when the 20Kw generator is on or the grid power is restored.
Electric Hot Water heater or Airconditioning – If you change the element in your water heater to a 3500 watt element you can heat water off of your Solark. Or – you can use a mini-split air conditioner. One or the other, but not both. Both will be restored when you are using the 20Kw generator or grid power is restored.
So look at your situation like this:
You started out with 150 amps of full power from the grid. If the grid fails and you have a 20Kw (75 – 83 amp) standby generator you lose ½ your power and fall down to:
75 amp generator. It can power all of your loads, but not all of them at the same time. Even with it alone you wouldn’t be able to live life as usual. In fact, feeding that gas hungry motor would cost you about 3 gallons of LPG per hour x 24 hours = 72 gallons of LPG. LPG costs $3.00/gallon x 72 gallons/day or $216/day in propane produced electrical power. That’s pretty pricey. If the power were to go out for a week or more, and you could replenish that LPG at that same price, it would cost you $216 x 7 = $1,512 a week to keep power to your home 24/7 on that generator alone.
If you don’t have that 75 amp generator and or it were to fail:
You resort to the 37.5 Amp Generator (the little gas powered 10Kw unit you have now). You have dropped from 150 amps to 75 amps, and now to 37.5 amps. It has 1/4th the capacity of the grid. It has ½ the capacity of the large generator that costs $1,500 a week to operate, or $6,000 a month to operate. This little generator is not designed to permanently power anything long term. A few hours per day maybe, but not more than a few hours at full capacity. It’ll need oil changes much more often than the larger unit, and it’s tank probably won’t let it run longer than 3 hours without needing to be stopped and refilled. It runs on gasoline, which might be difficult to acquire ort store in a large enough quantity. Gasoline goes bad fairly quickly (measured in months) so planning your disaster with a gasoline based generator in the mix is a bad idea.
Alternatively you now have the 12K Solark and 30Kw of batteries to run everything (solar panels in the near future). This means you won’t need to run the generator 24/7, saving fuel, time, money and the risk of the generator failing due to prolonged harsh use.
Solark 12K / 37.5 amp battery inverter charger. It’s the same rated power as your little generator, but with one very serious difference. The power is pure. Its EMP protected. It will not overheat and fail if you don’t over load it. It can handle transient surges. It can allow other power sources to work through it up to 60 amps. But it is still ¼ the rated power of the grid. It is ½ the power of your large generator. And it is more than the power of your little generator if you have solar connected to it.
So what are the take-away points here? Its imperative that you either turn off, disconnect, or re-wire non critical loads so they are not connected to the Solark. If you don’t do this and the grid goes down, and potentially even if the grid doesn’t go down, the SolArk will trip its main breaker and you’ll be in the dark until you disconnect, turn off or re-wire those heavy loads away from the Solark.
If EVERYTHING is connected to the SolArk its just a matter of time before you experience a total blackout. It might only last 3 minutes, but it’ll be a blackout nevertheless. You could add another Solark Inverter and double your capacity. That might be a really good option to consider. In fact, you might consider adding the new 15Kw Solark to your setup as an addendum so you can have power to your garage and shop down the road. I’m seriously considering adding a 15K to our setup because it has 200 amp passthrough and handles more than the 12K.
Why didn’t you do this to begin with? Because they didn’t have it on the market. In fact they still don’t have the EMP hardened version on the market yet, and that’s what I’m waiting for. I’m still annoyed that they have Chinese based servers monitoring their equipment, but the simple solution there is to not connect your inverter to the internet. As soon as they release the 15K and several of the reviewers get their hands on them and wring them through their paces and reveal their strengths and weaknesses, I’ll get one – probably. But it’ll probably cost $10K and another $2K to have Johnny install it.
In the interim, we as well have the same limitations that y’all have. The only difference is we have the solar panels installed, which means we can use the power from the sun during the day to charge our batteries and run most things in the house and then later in the evening we can use that battery power instead of grid power to run most things (but NOT ALL things) through the night. As we consume all of that solar generated power the system slowly reverts back to sucking from the grid. It saves about $200/mo on power overall, which might not seem like it’ll ever pay for itself. More on that in a moment.
Our oven is not connected to the Solark. Our primary HVAC system is not connected to the Solark. Our primary water heaters are not connected to the Solark. Our pool pump and exterior lights are not connected to the Solark. ½ of our electrical outlets are not connected to the Solark. I’m probably going to move the bathroom outlets away from the Solark – just to prevent someone foolishly plugging in a hair dryer and tripping us all into a three-minute blackout.
Its all about power management. Think of it like losing one engine in the Blackhawk, and the second engine picks up the load. If the aircraft is too heavy for SE Operations the second engine will take you to the scene of the crash, but it WILL CRASH if you don’t jettison your external stores and start throwing heavy baggage out the doors.
The Solark is ONE ENGINE in this analogy. It cannot carry 24,500 lbs using the Blackhawk analogy. It alone with only batteries cannot takeoff at 14,000 lbs, but it can continue flying if the aircraft weighs less than 18,000 lbs and is already in flight. Why is that? You know it takes more power to get started than it does to maintain steady flight. The single SolArk is that Single Engine scenario. If we add a new 15K Solark into the mix in the near future it’ll more than double our in-flight weight limits, but we’ll still not be able to takeoff at 24,500 lbs unless we DOUBLE the battery bank and or use battery and solar power at the same time to get off the ground.
Its all about power management. If you put the non-critical loads into a panel that is attached to the grid/generator only, it’ll solve a number of issues that will prevent you from finding yourselves in the dark and wondering what appliance took you to the scene of the crash.
Now about the Return on Investment (ROI). Most people want to compare the cost of a solar watt against the cost of a grid watt. That proposition will ALWAYS favor the grid x3+. However, if you add in the costs of losing the contents of your freezer when the grid watt fails, and the contents of your refrigerator when the grid watt fails, the costs of repairing the busted frozen pipes, the cost of mold control and remediation, the costs of underfrequency, over-frequency, undervoltage and overvoltage damage to your appliances, HVAC system and computers when those grid watts get compromised and force you to use a standby generator, the costs start getting closer to one another. It all depends on the reliability of grid power. Live in a place that has overhead power lines and is subject to ice storms? You might see my point. Too many people buying EV’s without the local utility being able to keep up with that demand for more power, and its inevitable that the under-frequency, under-voltage issue will become a real issue. Coronal Mass Ejections, EMP bursts, lightning strikes and any myriad of things can destroy ALL of the appliances and computers in your home in an instant. Wouldn’t it make sense to have a system that is EMP hardened standing between your home and the unprotected grid power? Smart meters and Net meters (the power meter on the side of your house) are designed for a minor amount of transient power irregularities, but they are NOT designed for massive hits. So they either blow-up and stop working completely, which disconnects you from the grid, or they allow that power surge to come into your home and blow-up your appliances, possibly causing a fire or fires inside the home, again leaving you in the dark but now with smoke added.
And lastly the thing that those ROI beancounters fail to consider is the cost of a solar watt to the cost of a gas watt. In this scenario the solar watt comes out way ahead due to the fact that it can cost $6,000 a month in fuel to operate a 20Kw generator 24/7.
In a protracted grid-down scenario of less than 7 months, a $60,000 solar system with batteries and all the trimmings breaks even. After 30% federal tax breaks, $2500 in local power company rebates, the end cost of a $60k system ends up costing $39,500 to the homeowner. Divide that by $6K a month and we arrive at 6.5 months to break even. Since most generators do not produce a clean sine wave, your appliances are going to suffer from operating under a dirty power environment, and that means you might find yourself needing a new appliance or two. Good luck finding those if we are in a regional protracted power outage of any kind.
And then there’s finding fuel. If we are in any sort of protracted regional power outage (think Hurricane Katrina), do you think you’ll be able to safely find fuel and have it delivered? Do you think you can keep it safe?
And lastly there is the noise of running a generator 24/7. Consider it a beacon of light that all of the moths will want to flock around. You’ll still need that inverter and large battery bank when your generator needs to be serviced or runs out of fuel.
Some will say that we still need the generator for those overcast weather days – and they would be correct. But instead of operating a 10Kw generator at 100% load to recharge the house batteries for 3+ hours every 12 hours (remember, that little standby generator will blow up if you try to run it at 100% load for 2+ hours), so you actually need that 20Kw generator. Most calculators might say you’ll need a 14Kw, but for the minimally added expense it makes better sense to get a 20 or a 22Kw Generac, Briggs Stratton or a Cummins all of which operate on LPG/NG. In these instances, 10Kw of the 20Kw goes to recharging the house batteries, which leaves the other 10Kw to manage the loads in the house while the sun is not shining. Even in this scenario it only takes 2.5 hours to reach 80% state of Charge (SOC) on the batteries and then the generator can be switched off. You’ll have at least 8 hours of quiet – no moths gathering to the sounds of your generator. Manage your power, keep your lights off and muffle anything that makes too much noise (which is why I like mini-splits – they are quiet outdoors, especially the BIG ones like the York HMH7).
One really important note to know: Standard flooded lead acid (FLA) or AGM batteries (car, golf cart and marine deep cycle) all have a maximum initial acceptance charge that peaks around 30 amps @ 13.6 VDC (or 408 watts only) and falls back to 4-6 amps (80 watts) within minutes. That’s why it takes 10+ hours to recharge them. They can only get recharged very slowly and they are about 40% inefficient – meaning you are wasting 40 watts of every 100 you get from the recharger. To refill a 1200 watt battery (600 usable) of this type it takes (nominally) 14 hours to recharge them. There’s not 14 hours of usable solar daylight here in the SE USA, especially during the winter, so recharging lead based batteries with sunlight is not a tenable idea. That one (and several other) factor alone is what has kept solar power from becoming viable in the past. It literally takes ten (10) of these type batteries to amount to ONE (1) 5120 EG4-LL battery from Signature Solar. Ten Deka batteries of similar combined capacity will take up 4x more space than one EG4-LL and cost 2.5x more than one EG4-LL as well as adding wiring costs to wire them together in series and parallel to arrive at 48 volts DC.
Even if you purchased the cheapest FLA battery (s) you can find, the overall costs are greater than the cost of a single EG4-LL of comparative capacity. Then factor in the inefficiencies of the FLA and the fact that its not a good idea to store them indoors (think acidic and corrosive sulfuric gasses) and being outdoors means the connector leads are longer, more expensive and subject to damage, EMP and the elements. Contrast to the EG4-LL 5120 Lithium Iron Phosphate battery, which will accept a 1C charge (over 5000 watts) meaning if you had a mean enough charger you can recharge it in just over an hour.
The Solark has a charge limit of 185 amps (9,000 watts) for a 48 volt battery bank (54 volts actual) meaning it can recharge a 30Kw battery bank in about 3.5 hours at full capacity. I’ve seen this actually happen with our 25Kw Ark Lithium battery bank. We only drain them down to 30% when the grid is available. This preserves the longevity of LIFEPO4 batteries by a pretty significant margin, and if the grid were to go down they’ll go further down to 10% before the Solark sends a start command to our 20Kw generator.
The generator kicks on and it’ll recharge the array back to about 95% before the Solark shuts the generator down and reverts back to battery only mode. All the while 9,000 watts (45% load) is going to recharge the batteries, while the remaining power potential of 11,000 watts is being used to power both house power panels at the same time.
On any typical day we store and later use at night about 18,000 watts of excess solar power (out of the 25Kw battery bank) which gets us through most of the night without needing power from the grid (or a generator) on that load center. The non-critical load center only gets power from the grid or generator, so without the grid or generator those appliances are off.
We have tankless electric water heaters that are paneled separately to grid only. So we have three panels (#1 Critical Loads – powered by grid, generator, solar and batteries) (#2 Non-Critical Loads – Powered by grid and generator only) and (#3 Grid Only Loads – powered by the grid only).
The reason for three panels is it keeps things simple. I don’t need a bunch of electronic interconnects that would likely fail in an EMP situation. Since the tankless water heaters are electric, and being that they are 100 amp and 50 amp on-demand type heaters, they would trip the breakers on any currently known single inverter setup. So they are reserved into a grid only panel since only the grid is powerful enough to power them.
Sure I could create a system to handle that, but its not worth the added expense when we simply could (and have) installed a separate system that heats water with excess solar power when the batteries are fully charged. That’s called a “smart load” on the Solark inverter.
Instead of selling power back to the utility company, we try to consume it in a water heater. This water heater is a pre-feeder to the tankless heaters, making them unnecessary and stay off if we have plenty of sun. The water flows through a hot water recovery system (GFX) to the pre-heater and if there is enough sun to have the contents of the preheater reach 140 degrees, it exits the preheater on its way to a tankless heater. When it arrives at the tankless heater the tankless heater senses the inlet water temperature and adjusts its heating elements as necessary to meet the set limit of 130 degrees. If the sun is not present we have the grid supplying power to the instant tankless water heaters (made by Hubbell) and they manage quite well because between the hot water recovery system and the pre-heater, the out of ground 65 degree water is sufficiently raised to rarely require much interaction from either tankless water heater.
If we have a protracted period of overcast and no-grid, I have a bypass switch for the water pre-heater and we can switch it over to the critical loads panel making it the primary water heater for the whole house.
In both instances, the power for this water preheater comes from the same source (the Solark inverter) but the switchology draws from either the “smart load” breaker or from the main power circuit that feeds the critical loads panel. This way we have a source of hot water no matter if the sun is shining or the grid is down.
Do we have issues? Sure we do. Is it all automatic? No. Almost everything is, but since we sell excess power back to the grid, I have to change the time of use settings and tell it to stop selling back to the grid if the grid goes down. Those are manual settings that I click on the face of the Solark panel.
Sell Back: Right now the local EMC charges us 12.3 cents per kilowatt (after taxes, junk, etc.) yet they only give us 4 cents per kilowatt when we sell our excess power production to them. Since I’m losing 8 cents in the exchange, finding better ways to save that power became a real thing. That opened the door to the “smart load”.
Solark Smart Loads are meant to curb how much excess power is sold back when our battery bank isn’t large enough to need more energy. This typically only happens on really sunny, long, cool days, where both of our arrays make about 80 kilowatts combined on a good day. We average about 60 Kw per day, and we use about 100 Kw a day with everything plugged in and going as normal. So this means our Non critical loads are using about 40Kw a day, which includes too numerous things to get into right now. It involves servers, security cameras, the motorhome and lots of gadgets that we don’t need if the grid goes down. Lets call them the non-essentials. Some of the security system is essential, but I’ll leave that to the imagination. It just removes one level of redundancy when the grid goes down or someone attempts to shut-off the power. Our inverter and batteries are NOT located outside the home, so turning them off from outdoors is not possible. This might annoy some folks, but others will appreciate the fact that a “government” official cannot put us in the dark and intimidate us like that.
On those sunny days we try to wash clothes, use the electric pressure washer, recharge all of the power tool batteries, run the minisplits at the same time we run the main HVAC system (York HMH7), cook in the oven if needed, bake bread, operate a crock pot, and use anything that will get us through the following days of cloudy weather. I might recharge the SCAG mower battery, recharge the cordless tool batteries, run the pool cleaner, add water to the pool (running the well pump) and get the house extra warm or cold and then sit back and curb our uses on the cloudy days.
So hopefully this is inciteful and it creates more interest. Just know that it is NOT a break even proposition. It is a “peace of mind” proposition. Its nice to come home and pass a neighbor who flags me down and tells me, or asks me “is your power out?…..ours is…” so I pull up, hit the garage door button and up the door comes….nope….the power is not out. The freezer is stull running and I don’t have to catch it.
Ok, so you have started down the path of having reliable backup power during a power outage. If you didn’t already know (and you should already know), you need to know that your backup power source is “emergency” power. It has limitations. Let me explain:
Your home was originally wired to 150 amps (36,000 watts) wherass most homes are wired to 200 amps (48,000 watts) or dual 200 amp panels but de-rated to 360 amp service (86,400 watts) service. That load distribution can be and is actually divided at the main breaker panel(s).
If you added another load panel, you could split your utility loads into two pathways – one going to the Sol-Ark, and the second going to a non-critical loads panel. The 12K Sol-Ark is designed to handle about 40 amps of the loads (60 amps from the grid, or 40 amps from a generator, or 37.5 amps from the batteries), any load beyond that must be powered by the grid or a very powerful generator, or a second inverter with another battery bank.
I think your current portable generator is a 10Kw? I know the new one **** has on wheels at ****’s shop is a 20Kw. Lets say you are going to use the 10Kw for now. A 10Kw generator is (at maximum) a very temporary 40 amp power provider (9600 watts). With it alone, you will not be able to live life and use all of your appliances at the same time. You might think you did before, but I know for a fact that the wiring of your generator was so haphazardly done that it would have tripped off or caught fire in the wiring under your house if you actually got close to using it near the 10,000 watts that it is rated for. I say this because the wiring your previous installer used for your generator connection was too small to handle a 40 amp load (10 AWG), and it would have caused the wires to catch fire if they were subjected to more than 30 amps @ 240 volts (7200 watts) for any length of time. I believe ****** found scorch marks where it was installed and he had to re-wire it to make it safe?
The” new” generator. It is a 20Kw propane powered 4 cylinder (LPG gas) engine. It is capable of producing 83 amps @ 240 volts, or 20KW. It will probably function flawlessly at a 60 amp load (75% capacity) all day long, but you don’t have that much of a power demand to keep it loaded at 75%. So it is still a GREAT addition to replace that 10Kw gasoline generator. Why? Because the Solark is capable of recharging the batteries at 9600 watts, which would suck the entire capacity out of your (10,000 watt) 10Kw generator and cause it to fail in short order. Why? Because that little portable 10Kw is NOT DESIGNED to provide 10Kw for more than a few seconds or minutes at most. It is air cooled. It might be rated for 10Kw, but it will function best if you load it to about 6,000 watts maximum. The “new” generator is much more capable. It is liquid cooled. The engine driving it is powerful enough to run it all day at 90% of its rated capacity. But you won’t need to run it that long since you have batteries attached to the Solark.
The batteries: Each of your batteries are capable of delivering 5120 watts of power. You have six of them. That’s 30,720 watts of stored power (30Kw) of power combined. It cannot be used all at once, but it can be used through the inverter at a rate not to exceed 37.5 amps (9000 watts). That means you divide that 30,000 watts by 9,000 watts (maximum) and that’s your maximum sustained run time = (3.3 hours @ 100% useful load). Use less power and it lasts longer. Very few homes actually draw 37.5 amps for any length of time, with exception of the dumbasses with EV’s.
Its safe to say that if the grid goes down your backup power is your battery bank, and your battery bank can handle about 27 amps (6500 watts) of power continuous without issue. That leaves enough overhead to start and stop duty cycle loads like refrigerator and freezer compressors, air conditioning and your well pump. If you use less power it lasts longer. Just know that your battery array further limits your power and you cannot function as if life is normal. Your batteries will need to be recharged.
You might have thought that your 10Kw generator was better than your new inverter and battery backup – you would be mistaken. Your portable 10Kw generator cannot run more than 9,000 watts for a few seconds or minutes before it will overload, overheat, or cause an undervoltage, under frequency or imperfect sine wave (dirty power) which will harm the electronics in your home. Contrastingly, your Solark Inverter/charger produces a perfect sine wave and can handle a 9000 watt balanced load without harm to anything. More on load balancing later.
Critical Loads: The Sol-Ark Inverter/charger will allow a little more than 60 amps (14,400 watts) of grid power (or generator power if the genset is largen enough) to cross through the inverter from the grid to your loads when the utility power is fully functional. Consider this at a dual engine situation, using a Blackhawk metaphor, where both engines are fully functional. If one engine fails (the grid power fails) the other engine (the Solark with Solar panels and/or the batteries) will pick up as much of the loads as possible. But just like the Blackawk, you can overload that one single engine. The Solark can handle a 60 amp passthrough, but if the grid power fails it steps back from 60 amps passthrough (15,120 watts) to a maximum of 37.5 amps (9000 watts) to keep you airborne. If you had solar panels attached, it would still be limited to producing 9,000 watts of AC power, but it could also draw power from the solar panels and/or the batteries to meet that load. Any excess power from the solar panels would be separately sent back into the batteries to recharge them, making it unnecessary to start your generator. If you exceed that 9000 watt limitation (up to 16,000 watts* for no more than 10 seconds or 25,000 watts* for 100 milliseconds) the system will trip, and you’ll be out of power until it resets itself (3 minutes later). Once reset, it will trip again if you don’t lighten the load to a combined load not to exceed 9000 watts.
A Non-Critical Load: An electric clothes dryer is typically given a 50 amp breaker all by itself. It normally operates on about 40 amps or 9600 watts. It doesn’t consume 9600 watts continuously though, because the heating element is not on the whole time. The element run time is dependent on the condition of the clothes and the temperature and humidity. Either way, this appliance CANNOT be operated downstream of a single Solark inverter!! It needs to be placed into a Non-Critical Loads panel and only operated when grid power is present.
No, contrary to popular belief, your 10Kw generator cannot handle your clothes dryer!
Electric Water heaters are typically placed on a 30-amp breaker. They typically draw 22.5 amps (out of 30) or 3500, 4500, or 5500 watts (depending on which element is installed) to heat your water. If this appliance (unmodified) is placed downstream of your Solark inverter (getting power from the Solark), it will use 35-70% of your available (9,000 watts) power, leaving you in peril of not being able to get water from your well pump. More on the well pump in a moment. A simple water heating element replacement to a 3500 watt element (down from the 5500 watt element) is a much better idea. Changing that element to a 3500 watt element is a simple $18 proposition at Home Depot. A smaller element will take longer for the water to heat up, but it won’t kick your inverter in the teeth while its operating.
A better solution is to heat your water with a heatpump water heater or a natural gas or propane on-demand water heater. Install a propane tank underground and have it supply a point-of-use or whole house on-demand water heater, a cooktop and a fireplace insert. An on-demand heater can be added to your existing setup and provide redundancy as well as assurances that you’ll have hot water from one source or the other depending on which power source you have available.
Now for the well pump: A Well pump typically uses 18 amps (4320 watts) to start and then has a sustained draw current of 9 amps (2160 watts) or less while its in full operation. 1.5 hp pumps are near or can exceed 2400 watts to start, and use about 2000 watts to operate. Conversely a 0.75 hp pump uses about 1850 watts to start and 1200 watts to operate. The Solark gives you that 10 second start reserve for things like this, so the math needed is in the operating current and not the start current as much. You need to reserve this capacity in your 9,000 watt allotment. Reserve 2,000 watts for well water, if you don’t know the size or lifting height of your pump, which leaves you with 7,000 watts for other loads.
Your cooktop and oven should not be considered as critical loads. Use a microwave. Although it is an unbalanced load, the microwave is much more energy efficient than you might imagine. Your cooktop and/or oven typically have a 30 amp breaker associated with them, and you should find another means for food preparation because electric ovens and electric cook tops are wholly energy inefficient and power hogs. Cook a roast on your oven for 4 hours and it will drain more than 60% your 30Kw batteries in that 4 hours. Get a gas cooktop or a wood fired grill and save your electricity for the things that are truly critical (water, lights, etc.)
So whats actually critical?
Your well pump is critical. Reserve 2000 watts for it, or nearly one fourth of your critical battery and inverter power.
Your freezer and refrigerator are critical loads and they need 2000 watts (total) if you have one of each. They both have compressors in them. Their start current could be as high as 20 amps @ 120 volts (2400 watts), but their running load is off and on (duty cycle) and they are each probably are in the 1500 start watts and 750 run watts (depending on their age), and since you have two of them you need to reserve 2,000 watts out of your 9000 watts for refrigeration just in case they happen to be in operation at the same time.
Your Lights are critical. Reserve 1,000 watts for powering your lights, outlets, chargers for your phone, TV, Internet modem, emergency radio, ceiling fans and battery chargers for your cordless tools. You’ll need those cordless tools for repairs – why else would your power be out? You might have had an ice storm, or something common happen, and it could be hours, days or weeks before power is restored. You’ll need your tools.
So where are we on consuming those 9000 watts? We have reserved 2000 watts for the well pump, 2000 watts for refrigeration, 1000 watts for lights. This leaves 4000 watts or 16.5 amps @ 240 volts for air conditioning or your modified water heater (but not both).
You can’t afford to operate the freeze dryer on the Solark because it uses too much power. It will draw (at times) as much as 1600 watts of power. So don’t try to operate your freeze dryer downstream of the Solark.
Don’t use a hair dryer, plug-in electric heater, flat iron, or beauty gadget when the grid fails. You simply cannot afford the excess power consumption.
Don’t plug in a car charger unless you have 60Kw of battery storage and 24,000 watts of solar PV on your property.
In the winter you need heat. I recommend a Buddy portable ceramic LPG space heater in the winter, or a gas fired fireplace insert in the fireplace (I recommend a vent-free system – no heat loss). In the summer you’ll need to dehumidify the air in your home to control humidity and mold growth. A Daikin or MrCool mini-split air conditioner is the best option there, and you should seriously consider having one installed professionally. They are not expensive, and it is actually something we can do together if you want. A one-ton unit with the cassette installed in your bedroom would be the absolute best option. These units cost about $2200 if you do it yourself (with my help if you want it).
I recommend you consider moving the following things out of your critical loads panel:
Pool Pump motor – you’ll get the pool pump operating when the 20Kw generator is on or grid power is restored.
Bathroom electrical outlets (this prevents anyone from foolishly turning on a hair dryer and tripping the whole house off). You’ll have this restored when the 20Kw generator is on or the grid power is restored.
Oven/Range – you’ll be able to use these when the 20Kw generator is on or the grid power is restored.
Electric Hot Water heater or Airconditioning – If you change the element in your water heater to a 3500 watt element you can heat water off of your Solark. Or – you can use a mini-split air conditioner. One or the other, but not both. Both will be restored when you are using the 20Kw generator or grid power is restored.
So look at your situation like this:
You started out with 150 amps of full power from the grid. If the grid fails and you have a 20Kw (75 – 83 amp) standby generator you lose ½ your power and fall down to:
75 amp generator. It can power all of your loads, but not all of them at the same time. Even with it alone you wouldn’t be able to live life as usual. In fact, feeding that gas hungry motor would cost you about 3 gallons of LPG per hour x 24 hours = 72 gallons of LPG. LPG costs $3.00/gallon x 72 gallons/day or $216/day in propane produced electrical power. That’s pretty pricey. If the power were to go out for a week or more, and you could replenish that LPG at that same price, it would cost you $216 x 7 = $1,512 a week to keep power to your home 24/7 on that generator alone.
If you don’t have that 75 amp generator and or it were to fail:
You resort to the 37.5 Amp Generator (the little gas powered 10Kw unit you have now). You have dropped from 150 amps to 75 amps, and now to 37.5 amps. It has 1/4th the capacity of the grid. It has ½ the capacity of the large generator that costs $1,500 a week to operate, or $6,000 a month to operate. This little generator is not designed to permanently power anything long term. A few hours per day maybe, but not more than a few hours at full capacity. It’ll need oil changes much more often than the larger unit, and it’s tank probably won’t let it run longer than 3 hours without needing to be stopped and refilled. It runs on gasoline, which might be difficult to acquire ort store in a large enough quantity. Gasoline goes bad fairly quickly (measured in months) so planning your disaster with a gasoline based generator in the mix is a bad idea.
Alternatively you now have the 12K Solark and 30Kw of batteries to run everything (solar panels in the near future). This means you won’t need to run the generator 24/7, saving fuel, time, money and the risk of the generator failing due to prolonged harsh use.
Solark 12K / 37.5 amp battery inverter charger. It’s the same rated power as your little generator, but with one very serious difference. The power is pure. Its EMP protected. It will not overheat and fail if you don’t over load it. It can handle transient surges. It can allow other power sources to work through it up to 60 amps. But it is still ¼ the rated power of the grid. It is ½ the power of your large generator. And it is more than the power of your little generator if you have solar connected to it.
So what are the take-away points here? Its imperative that you either turn off, disconnect, or re-wire non critical loads so they are not connected to the Solark. If you don’t do this and the grid goes down, and potentially even if the grid doesn’t go down, the SolArk will trip its main breaker and you’ll be in the dark until you disconnect, turn off or re-wire those heavy loads away from the Solark.
If EVERYTHING is connected to the SolArk its just a matter of time before you experience a total blackout. It might only last 3 minutes, but it’ll be a blackout nevertheless. You could add another Solark Inverter and double your capacity. That might be a really good option to consider. In fact, you might consider adding the new 15Kw Solark to your setup as an addendum so you can have power to your garage and shop down the road. I’m seriously considering adding a 15K to our setup because it has 200 amp passthrough and handles more than the 12K.
Why didn’t you do this to begin with? Because they didn’t have it on the market. In fact they still don’t have the EMP hardened version on the market yet, and that’s what I’m waiting for. I’m still annoyed that they have Chinese based servers monitoring their equipment, but the simple solution there is to not connect your inverter to the internet. As soon as they release the 15K and several of the reviewers get their hands on them and wring them through their paces and reveal their strengths and weaknesses, I’ll get one – probably. But it’ll probably cost $10K and another $2K to have Johnny install it.
In the interim, we as well have the same limitations that y’all have. The only difference is we have the solar panels installed, which means we can use the power from the sun during the day to charge our batteries and run most things in the house and then later in the evening we can use that battery power instead of grid power to run most things (but NOT ALL things) through the night. As we consume all of that solar generated power the system slowly reverts back to sucking from the grid. It saves about $200/mo on power overall, which might not seem like it’ll ever pay for itself. More on that in a moment.
Our oven is not connected to the Solark. Our primary HVAC system is not connected to the Solark. Our primary water heaters are not connected to the Solark. Our pool pump and exterior lights are not connected to the Solark. ½ of our electrical outlets are not connected to the Solark. I’m probably going to move the bathroom outlets away from the Solark – just to prevent someone foolishly plugging in a hair dryer and tripping us all into a three-minute blackout.
Its all about power management. Think of it like losing one engine in the Blackhawk, and the second engine picks up the load. If the aircraft is too heavy for SE Operations the second engine will take you to the scene of the crash, but it WILL CRASH if you don’t jettison your external stores and start throwing heavy baggage out the doors.
The Solark is ONE ENGINE in this analogy. It cannot carry 24,500 lbs using the Blackhawk analogy. It alone with only batteries cannot takeoff at 14,000 lbs, but it can continue flying if the aircraft weighs less than 18,000 lbs and is already in flight. Why is that? You know it takes more power to get started than it does to maintain steady flight. The single SolArk is that Single Engine scenario. If we add a new 15K Solark into the mix in the near future it’ll more than double our in-flight weight limits, but we’ll still not be able to takeoff at 24,500 lbs unless we DOUBLE the battery bank and or use battery and solar power at the same time to get off the ground.
Its all about power management. If you put the non-critical loads into a panel that is attached to the grid/generator only, it’ll solve a number of issues that will prevent you from finding yourselves in the dark and wondering what appliance took you to the scene of the crash.
Now about the Return on Investment (ROI). Most people want to compare the cost of a solar watt against the cost of a grid watt. That proposition will ALWAYS favor the grid x3+. However, if you add in the costs of losing the contents of your freezer when the grid watt fails, and the contents of your refrigerator when the grid watt fails, the costs of repairing the busted frozen pipes, the cost of mold control and remediation, the costs of underfrequency, over-frequency, undervoltage and overvoltage damage to your appliances, HVAC system and computers when those grid watts get compromised and force you to use a standby generator, the costs start getting closer to one another. It all depends on the reliability of grid power. Live in a place that has overhead power lines and is subject to ice storms? You might see my point. Too many people buying EV’s without the local utility being able to keep up with that demand for more power, and its inevitable that the under-frequency, under-voltage issue will become a real issue. Coronal Mass Ejections, EMP bursts, lightning strikes and any myriad of things can destroy ALL of the appliances and computers in your home in an instant. Wouldn’t it make sense to have a system that is EMP hardened standing between your home and the unprotected grid power? Smart meters and Net meters (the power meter on the side of your house) are designed for a minor amount of transient power irregularities, but they are NOT designed for massive hits. So they either blow-up and stop working completely, which disconnects you from the grid, or they allow that power surge to come into your home and blow-up your appliances, possibly causing a fire or fires inside the home, again leaving you in the dark but now with smoke added.
And lastly the thing that those ROI beancounters fail to consider is the cost of a solar watt to the cost of a gas watt. In this scenario the solar watt comes out way ahead due to the fact that it can cost $6,000 a month in fuel to operate a 20Kw generator 24/7.
In a protracted grid-down scenario of less than 7 months, a $60,000 solar system with batteries and all the trimmings breaks even. After 30% federal tax breaks, $2500 in local power company rebates, the end cost of a $60k system ends up costing $39,500 to the homeowner. Divide that by $6K a month and we arrive at 6.5 months to break even. Since most generators do not produce a clean sine wave, your appliances are going to suffer from operating under a dirty power environment, and that means you might find yourself needing a new appliance or two. Good luck finding those if we are in a regional protracted power outage of any kind.
And then there’s finding fuel. If we are in any sort of protracted regional power outage (think Hurricane Katrina), do you think you’ll be able to safely find fuel and have it delivered? Do you think you can keep it safe?
And lastly there is the noise of running a generator 24/7. Consider it a beacon of light that all of the moths will want to flock around. You’ll still need that inverter and large battery bank when your generator needs to be serviced or runs out of fuel.
Some will say that we still need the generator for those overcast weather days – and they would be correct. But instead of operating a 10Kw generator at 100% load to recharge the house batteries for 3+ hours every 12 hours (remember, that little standby generator will blow up if you try to run it at 100% load for 2+ hours), so you actually need that 20Kw generator. Most calculators might say you’ll need a 14Kw, but for the minimally added expense it makes better sense to get a 20 or a 22Kw Generac, Briggs Stratton or a Cummins all of which operate on LPG/NG. In these instances, 10Kw of the 20Kw goes to recharging the house batteries, which leaves the other 10Kw to manage the loads in the house while the sun is not shining. Even in this scenario it only takes 2.5 hours to reach 80% state of Charge (SOC) on the batteries and then the generator can be switched off. You’ll have at least 8 hours of quiet – no moths gathering to the sounds of your generator. Manage your power, keep your lights off and muffle anything that makes too much noise (which is why I like mini-splits – they are quiet outdoors, especially the BIG ones like the York HMH7).
One really important note to know: Standard flooded lead acid (FLA) or AGM batteries (car, golf cart and marine deep cycle) all have a maximum initial acceptance charge that peaks around 30 amps @ 13.6 VDC (or 408 watts only) and falls back to 4-6 amps (80 watts) within minutes. That’s why it takes 10+ hours to recharge them. They can only get recharged very slowly and they are about 40% inefficient – meaning you are wasting 40 watts of every 100 you get from the recharger. To refill a 1200 watt battery (600 usable) of this type it takes (nominally) 14 hours to recharge them. There’s not 14 hours of usable solar daylight here in the SE USA, especially during the winter, so recharging lead based batteries with sunlight is not a tenable idea. That one (and several other) factor alone is what has kept solar power from becoming viable in the past. It literally takes ten (10) of these type batteries to amount to ONE (1) 5120 EG4-LL battery from Signature Solar. Ten Deka batteries of similar combined capacity will take up 4x more space than one EG4-LL and cost 2.5x more than one EG4-LL as well as adding wiring costs to wire them together in series and parallel to arrive at 48 volts DC.
Even if you purchased the cheapest FLA battery (s) you can find, the overall costs are greater than the cost of a single EG4-LL of comparative capacity. Then factor in the inefficiencies of the FLA and the fact that its not a good idea to store them indoors (think acidic and corrosive sulfuric gasses) and being outdoors means the connector leads are longer, more expensive and subject to damage, EMP and the elements. Contrast to the EG4-LL 5120 Lithium Iron Phosphate battery, which will accept a 1C charge (over 5000 watts) meaning if you had a mean enough charger you can recharge it in just over an hour.
The Solark has a charge limit of 185 amps (9,000 watts) for a 48 volt battery bank (54 volts actual) meaning it can recharge a 30Kw battery bank in about 3.5 hours at full capacity. I’ve seen this actually happen with our 25Kw Ark Lithium battery bank. We only drain them down to 30% when the grid is available. This preserves the longevity of LIFEPO4 batteries by a pretty significant margin, and if the grid were to go down they’ll go further down to 10% before the Solark sends a start command to our 20Kw generator.
The generator kicks on and it’ll recharge the array back to about 95% before the Solark shuts the generator down and reverts back to battery only mode. All the while 9,000 watts (45% load) is going to recharge the batteries, while the remaining power potential of 11,000 watts is being used to power both house power panels at the same time.
On any typical day we store and later use at night about 18,000 watts of excess solar power (out of the 25Kw battery bank) which gets us through most of the night without needing power from the grid (or a generator) on that load center. The non-critical load center only gets power from the grid or generator, so without the grid or generator those appliances are off.
We have tankless electric water heaters that are paneled separately to grid only. So we have three panels (#1 Critical Loads – powered by grid, generator, solar and batteries) (#2 Non-Critical Loads – Powered by grid and generator only) and (#3 Grid Only Loads – powered by the grid only).
The reason for three panels is it keeps things simple. I don’t need a bunch of electronic interconnects that would likely fail in an EMP situation. Since the tankless water heaters are electric, and being that they are 100 amp and 50 amp on-demand type heaters, they would trip the breakers on any currently known single inverter setup. So they are reserved into a grid only panel since only the grid is powerful enough to power them.
Sure I could create a system to handle that, but its not worth the added expense when we simply could (and have) installed a separate system that heats water with excess solar power when the batteries are fully charged. That’s called a “smart load” on the Solark inverter.
Instead of selling power back to the utility company, we try to consume it in a water heater. This water heater is a pre-feeder to the tankless heaters, making them unnecessary and stay off if we have plenty of sun. The water flows through a hot water recovery system (GFX) to the pre-heater and if there is enough sun to have the contents of the preheater reach 140 degrees, it exits the preheater on its way to a tankless heater. When it arrives at the tankless heater the tankless heater senses the inlet water temperature and adjusts its heating elements as necessary to meet the set limit of 130 degrees. If the sun is not present we have the grid supplying power to the instant tankless water heaters (made by Hubbell) and they manage quite well because between the hot water recovery system and the pre-heater, the out of ground 65 degree water is sufficiently raised to rarely require much interaction from either tankless water heater.
If we have a protracted period of overcast and no-grid, I have a bypass switch for the water pre-heater and we can switch it over to the critical loads panel making it the primary water heater for the whole house.
In both instances, the power for this water preheater comes from the same source (the Solark inverter) but the switchology draws from either the “smart load” breaker or from the main power circuit that feeds the critical loads panel. This way we have a source of hot water no matter if the sun is shining or the grid is down.
Do we have issues? Sure we do. Is it all automatic? No. Almost everything is, but since we sell excess power back to the grid, I have to change the time of use settings and tell it to stop selling back to the grid if the grid goes down. Those are manual settings that I click on the face of the Solark panel.
Sell Back: Right now the local EMC charges us 12.3 cents per kilowatt (after taxes, junk, etc.) yet they only give us 4 cents per kilowatt when we sell our excess power production to them. Since I’m losing 8 cents in the exchange, finding better ways to save that power became a real thing. That opened the door to the “smart load”.
Solark Smart Loads are meant to curb how much excess power is sold back when our battery bank isn’t large enough to need more energy. This typically only happens on really sunny, long, cool days, where both of our arrays make about 80 kilowatts combined on a good day. We average about 60 Kw per day, and we use about 100 Kw a day with everything plugged in and going as normal. So this means our Non critical loads are using about 40Kw a day, which includes too numerous things to get into right now. It involves servers, security cameras, the motorhome and lots of gadgets that we don’t need if the grid goes down. Lets call them the non-essentials. Some of the security system is essential, but I’ll leave that to the imagination. It just removes one level of redundancy when the grid goes down or someone attempts to shut-off the power. Our inverter and batteries are NOT located outside the home, so turning them off from outdoors is not possible. This might annoy some folks, but others will appreciate the fact that a “government” official cannot put us in the dark and intimidate us like that.
On those sunny days we try to wash clothes, use the electric pressure washer, recharge all of the power tool batteries, run the minisplits at the same time we run the main HVAC system (York HMH7), cook in the oven if needed, bake bread, operate a crock pot, and use anything that will get us through the following days of cloudy weather. I might recharge the SCAG mower battery, recharge the cordless tool batteries, run the pool cleaner, add water to the pool (running the well pump) and get the house extra warm or cold and then sit back and curb our uses on the cloudy days.
So hopefully this is inciteful and it creates more interest. Just know that it is NOT a break even proposition. It is a “peace of mind” proposition. Its nice to come home and pass a neighbor who flags me down and tells me, or asks me “is your power out?…..ours is…” so I pull up, hit the garage door button and up the door comes….nope….the power is not out. The freezer is stull running and I don’t have to catch it.
Hey Magnum! How’s Higgins doing these days?
