I Can't Afford So-Called "Tier 1" Equipment. What's Good at Tier 2?

[1201]

Not

Is there correlation to inverter size and idle usage?
It often seems explained as cheap = high idle and Vice versa. However, now that it is becoming more common to see larger inverters, even “expensive” ones seem to have a fairly high idle (often similar for 2x small vs 1x large it would appear)

In the situation that someone does not have grid fallback, in your opinion, is it then preferable to take those loads you mentioned (range, laundry) and run gas? That is my intent, but I believe theres also concern with the long term cost/availability.

Not exactly. Some inverters use a lot more than others of the same nominal size.But if you are using multiples then the idle usage stacks up.

I would sun dry my clothes and rig up a solar thermal system for the hot water . Or move somewhere with grid access ?

 

[Crowz]

Is there correlation to inverter size and idle usage?
It often seems explained as cheap = high idle and Vice versa. However, now that it is becoming more common to see larger inverters, even “expensive” ones seem to have a fairly high idle (often similar for 2x small vs 1x large it would appear)

In the situation that someone does not have grid fallback, in your opinion, is it then preferable to take those loads you mentioned (range, laundry) and run gas? That is my intent, but I believe theres also concern with the long term cost/availability.

Well you have to feed the transformer on LF inverters like mine or keep those capacitors charged on HF ones. The more or bigger of either of those need more power. So as you climb in capacity in either type your going to climb in idle consumption. No way around it.

 

[fafrd]

Well you have to feed the transformer on LF inverters like mine or keep those capacitors charged on HF ones. The more or bigger of either of those need more power. So as you climb in capacity in either type you’re going to climb in idle consumption. No way around it.

Are there any areas where a 5+5kW HF split-phase inverter is noticeably deficient versus a 10kW LF split-phase inverter? Is it just for ability to deliver surge power of 10-15kW on one leg?

I have no problem starting my fridges and freezers with a 120VAC 3kW PSW inverter and my average load is only 300W, so I’m thinking a 5+5 HF will probably be more than sufficient and am looking for arguments I may be overlooking.

 

[Crowz]

I have found it is way cheaper in the long run to purchase what you need from the start and build your system to handle your needs.

What are you running at 15Kw? 20 hp electric motor?

My Official Loads Test Technician (the wife) can't even load down the system that hard. Maybe 10Kw total at any given time, usually 6Kw on one leg and 4Kw on the other.

I don't think 3 LV6048's are going to work for you as well as you think. You will need to have a very good balance on both legs.

The only problem with buying what you need at the start is if your going to wait awhile about ever starting.

I had solar at the old house and knew a bit about it all from then but todays equipment can do things that was only a dream then. Hybrid for one thing. Back then it was all or nothing solar wise. Now with the hybrid stuff its a dream come true for me compared to what I went thru back then.

Just the fact of not having to install a multi circuit transfer switch like I had to do on the old house to go between grid and solar depending on the weather and time of day is a true game changer.

While I loved this little toy when I bought it I now see it was like being a slave to it and then later a few of them:



Anyways the point is you can't know what to buy when you start out. It takes time. So its either go modular and get into it and learn what you can do and whats out there to do it with or buy all at once and kick yourself for being locked into a system that probably isn't what you wanted or needed.

I like the modular over time method myself since I don't have the patience to wait and learn before getting started doing something

If someone ever figures out how to do that "If I knew then what I know now" stuff then all at once would always be the way to go.

With the tp6048 I installed it with a sub panel running off of it. Then I just moved circuits from the main panels to the sub panel as I get more panel power.

Sure I could move it all at once (up to what the tp6048 can handle) but by doing it this way I was able to figure out what I actually wanted to put on solar right now. Unlike most people have I 60 circuits or more in multiple breaker boxes and I honestly have no clue what they all go to.

The previous owners were using my home for a daycare at one point (not the little daycare stuff but the 50 kids or more government type deal). I have 14 sinks for instance and some bathrooms have two toilets side by side
It's been interesting restoring the house.

I will end up with multiple tp6048's or other stuff. But since I bought the single unit I'm not locked into anything. I could for HF for the next ones or more LF ones. The main thing is with the hybrid stuff I started saving on my power bill and allowing me to be "wasteful" running ac's whenever and at whatever setting we found comfortable just by installing the one unit and having enough panels.

I'm more limited by panels this way than anything else since I just buy out of pocket and not sinking savings into it or doing a loan.

 

[Crowz]

Are there any areas where a 5+5kW HF split-phase inverter is noticeably deficient versus a 10kW LF split-phase inverter? Is it just for ability to deliver surge power of 10-15kW on one leg?

I have no problem starting my fridges and freezers with a 120VAC 3kW PSW inverter and my average load is only 300W, so I’m thinking a 5+5 HF will probably be more than sufficient and am looking for arguments I may be overlooking.

I have 2 LARGE refrigerators and one EXTREMELY LARGE freezer on one leg of my tp6048 and no issues so I think your ok there. Worse case they could be separated circuit wise.

But my unit is a LF so I can't really address how a HF would do. Surge is the only real weakness I have seen to the HF ones. If I was going to go with a HF one to keep idle usage down I would just over shoot what I needed watts wise to get enough buffer space to cover my needs.

 

[fafrd]

The only problem with buying what you need at the start is if your going to wait awhile about ever starting.

I had solar at the old house and knew a bit about it all from then but todays equipment can do things that was only a dream then. Hybrid for one thing. Back then it was all or nothing solar wise. Now with the hybrid stuff its a dream come true for me compared to what I went thru back then.

Just the fact of not having to install a multi circuit transfer switch like I had to do on the old house to go between grid and solar depending on the weather and time of day is a true game changer.

While I loved this little toy when I bought it I now see it was like being a slave to it and then later a few of them:

View attachment 157261

Anyways the point is you can't know what to buy when you start out. It takes time. So its either go modular and get into it and learn what you can do and whats out there to do it with or buy all at once and kick yourself for being locked into a system that probably isn't what you wanted or needed.

I like the modular over time method myself since I don't have the patience to wait and learn before getting started doing something

If someone ever figures out how to do that "If I knew then what I know now" stuff then all at once would always be the way to go.

With the tp6048 I installed it with a sub panel running off of it. Then I just moved circuits from the main panels to the sub panel as I get more panel power.

Sure I could move it all at once (up to what the tp6048 can handle) but by doing it this way I was able to figure out what I actually wanted to put on solar right now. Unlike most people have I 60 circuits or more in multiple breaker boxes and I honestly have no clue what they all go to.

The previous owners were using my home for a daycare at one point (not the little daycare stuff but the 50 kids or more government type deal). I have 14 sinks for instance and some bathrooms have two toilets side by side
It's been interesting restoring the house.

I will end up with multiple tp6048's or other stuff. But since I bought the single unit I'm not locked into anything. I could for HF for the next ones or more LF ones. The main thing is with the hybrid stuff I started saving on my power bill and allowing me to be "wasteful" running ac's whenever and at whatever setting we found comfortable just by installing the one unit and having enough panels.

I'm more limited by panels this way than anything else since I just buy out of pocket and not sinking savings into it or doing a loan.

My kind of guy .

I followed exactly this ‘Modular’s approach 3 years ago when I added a small DC-coupled bonus solar system composed of a DIY 14kWh LiFePO battery 1kW of new panels, an Epever SCC, and a pair of GTIL inverters.

The panels and battery can be reused and I spent less than $800 on the 60A SCC and the 2 1kW inverters.

Now I’m gearing up to move to an off-grid setup so an AIO powering a Subpanel like you are doing is what I’m looking for.

I’m interested in any advantages you believe a LF inverter would offer you since from everything I understand, it seems like an HF solution sized at 300% peak demand is going to serve just as well as a LF solution sized at 100% peak demand.

Powering well pumps or power tools are no-doubt a different animal, but having the juice to get fridges started seems well within the capability of these ever-increasing dual HF split-phase offerings…

 

[fafrd]

I have 2 LARGE refrigerators and one EXTREMELY LARGE freezer on one leg of my tp6048 and no issues so I think your ok there. Worse case they could be separated circuit wise.

But my unit is a LF so I can't really address how a HF would do. Surge is the only real weakness I have seen to the HF ones. If I was going to go with a HF one to keep idle usage down I would just over shoot what I needed watts wise to get enough buffer space to cover my needs.

My thoughts exactly. If the HF can comfortable deliver the startup surge, it seems like a better alternative (lighter, cheaper, less idle consumption).

 

[SilverbackMP]

My thoughts exactly. If the HF can comfortable deliver the startup surge, it seems like a better alternative (lighter, cheaper, less idle consumption).

I am fairly certain they (HF) have significantly higher idle consumption. At least compared to Tier 1 LF inverters.

 

[Zwy]

With your twin 6548's and 54kWh battery bank. and 8.5kW PV you and I have about the same sized set up, I bet you could run your shop and home together. (but keep the 'Official Load Tester' away from the Dryer and Double oven while your in the shop?) lol.

Probably could. I could take some of the array now and divert it to a shop system. Shop is air conditioned, I've thought about installing a system just to run the air conditioning and use the system in winter for running lights and infloor heat.

 

[OffGridForGood]

I am fairly certain they (HF) have significantly higher idle consumption. At least compared to Tier 1 LF inverters.

It seems all the Tier One equipement is very low idle consumption, just check out the specs on them. (Sol-Ark, Schneider, SMA)
Looking at HF vs LF from one brand:
MPP LVX 6048 LF standby is crazy high (double) compared to the similar MPP 6548/6048 HF - at about equal total output.

 

[Zwy]

Is it worth it to even put those high demand but low energy consumption loads on an inverter?

For me, yes. Battery bank is large enough to cover 4 days with no sun with minimum loads usage but otherwise energy is just sitting there waiting to be used. With an off grid system, if you don't use it, you lose it. Battery is full by noon most days so I shift loads from gas now to electric.

My dryer runs 5.7kw but uses only about 80kwh a month(going from memory here. I'll check when I get home.)

My wife runs the dryer about every 2 days. Probably 90Kwh per month. It is the only load that we watch for loads management. If we have many items running, we use the dryer at a different time or cut loads, usually the dryer is run during the day and days of good sun. The dryer will be replaced with a heat pump/condensing type so that energy can be used elsewhere (more heat pumps for home heating) when larger units become available. Most are too small.

To me it's not worth running that with solar as the power demand is high but the energy usage is low. with the dryer on I've seen peaks demand of 15.4kw but if I leave that on the grid then peak demand to contend with would be 9.7kw. I would save one whole inverter, which at 85 watts would save 60kwh a month. So, adding an inverter and 60kwh a month to move that last 80kwh a month to solar just doesn't make a lot of sense. To me. Same thing with oven and cooktop. Demand can be super high but I maybe use 20kwh a month for cooking.

It makes perfect sense for use to run anything we can off solar. System is large enough to handle it with limited loads management. Other than that, we live like we did on the grid. We actually have increased our total electrical consumption. The capacity is there so I take advantage of it. PV is not very large at 8.4Kw but with the large battery bank (had the room in the cabinet so filled it up) it carries things thru on cloudy days.

On the other hand, my minisplits are perfect for solar. I can run all 3 on one 6kw inverter and that alone accounts for 60% of my total monthly consumption

I'll be adding another next year in the kitchen, right now it uses a 12K window unit. I installed one in living room and most days that is all we run but need to run a box fan to cool the kitchen if the window unit is off. It has to be a sticky hot day to run the window unit with the oven running.

 

[Zwy]

Is there correlation to inverter size and idle usage?
It often seems explained as cheap = high idle and Vice versa. However, now that it is becoming more common to see larger inverters, even “expensive” ones seem to have a fairly high idle (often similar for 2x small vs 1x large it would appear)

Some make a big deal out of idle usage, it really isn't a problem if array has good sun with no shade and a large battery bank.

Most anxiety is similar to range anxiety in a car. With enough reserve power with the larger battery banks, there isn't much range anxiety.

In the situation that someone does not have grid fallback, in your opinion, is it then preferable to take those loads you mentioned (range, laundry) and run gas? That is my intent, but I believe theres also concern with the long term cost/availability.

Stove and hot water is gas here. I'll probably install a dump load electric water heater at some point. We might use an induction cooktop at some point but I think the gas stove will remain. It remains a backup heat source if the furnace was to fail. It gets cold here, not unusual to see -20F.

 

[Zwy]

The only problem with buying what you need at the start is if your going to wait awhile about ever starting.

I didn't. I first purchased a monitor to see what size system I needed and planned around that. The only thing that changed was originally it was 2 batteries, then 3 then 4. I had some extra cells from previous order that I was planning to use for my boat trolling motor but decided to use something else. As I needed to order another Batrium K9 to build that battery, I ordered an extra one to save on shipping costs if I ever decided to add the 4th battery. I was already building the cabinet to hold 4 batteries. As I already had most everything in place, the only extra cost was the 16 cells. I had the money and decided, heck, might as well just buy the cells and finish building the bank all at once.

I had solar at the old house and knew a bit about it all from then but todays equipment can do things that was only a dream then. Hybrid for one thing. Back then it was all or nothing solar wise. Now with the hybrid stuff its a dream come true for me compared to what I went thru back then.

Just the fact of not having to install a multi circuit transfer switch like I had to do on the old house to go between grid and solar depending on the weather and time of day is a true game changer.

While I loved this little toy when I bought it I now see it was like being a slave to it and then later a few of them:

View attachment 157261

I needed a critical loads panel so the only extra items needed was a 3 pole double throw for a transfer switch (which I wanted ) and the panel. You could have done the same in the beginning, just transfer circuits from one panel to the other if you have the panels close together if you wanted to add later.

Anyways the point is you can't know what to buy when you start out. It takes time. So its either go modular and get into it and learn what you can do and whats out there to do it with or buy all at once and kick yourself for being locked into a system that probably isn't what you wanted or needed.

I built the system large enough from the start to handle our normal usage with some buffer. It's not hard. It takes some effort on your part to determine size.

I like the modular over time method myself since I don't have the patience to wait and learn before getting started doing something

My battery box sat in the shop for year before it was finished. I take my time the first attempt to get it right because I don't have time to go back and change things. Not unusual for me to seasonally work 80 plus hours a week.

If someone ever figures out how to do that "If I knew then what I know now" stuff then all at once would always be the way to go.

Our system is large enough we have been able to increase our usage. That is key, it opens up many options.

With the tp6048 I installed it with a sub panel running off of it. Then I just moved circuits from the main panels to the sub panel as I get more panel power.

Sure I could move it all at once (up to what the tp6048 can handle) but by doing it this way I was able to figure out what I actually wanted to put on solar right now. Unlike most people have I 60 circuits or more in multiple breaker boxes and I honestly have no clue what they all go to.

The previous owners were using my home for a daycare at one point (not the little daycare stuff but the 50 kids or more government type deal). I have 14 sinks for instance and some bathrooms have two toilets side by side
It's been interesting restoring the house.

It took 5 years from the day we took possession of this place until we moved into the house. I had to remodel the whole thing in my free time. During the process, we built the new shop and that took about 1.5 years to completely finish. I'm very patient, it allows different ideas to come in the process.

I will end up with multiple tp6048's or other stuff. But since I bought the single unit I'm not locked into anything. I could for HF for the next ones or more LF ones. The main thing is with the hybrid stuff I started saving on my power bill and allowing me to be "wasteful" running ac's whenever and at whatever setting we found comfortable just by installing the one unit and having enough panels.

I'm more limited by panels this way than anything else since I just buy out of pocket and not sinking savings into it or doing a loan.

 

[1201]

For me, yes. Battery bank is large enough to cover 4 days with no sun with minimum loads usage but otherwise energy is just sitting there waiting to be used. With an off grid system, if you don't use it, you lose it. Battery is full by noon most days so I shift loads from gas now to electric.



My wife runs the dryer about every 2 days. Probably 90Kwh per month. It is the only load that we watch for loads management. If we have many items running, we use the dryer at a different time or cut loads, usually the dryer is run during the day and days of good sun. The dryer will be replaced with a heat pump/condensing type so that energy can be used elsewhere (more heat pumps for home heating) when larger units become available. Most are too small.



It makes perfect sense for use to run anything we can off solar. System is large enough to handle it with limited loads management. Other than that, we live like we did on the grid. We actually have increased our total electrical consumption. The capacity is there so I take advantage of it. PV is not very large at 8.4Kw but with the large battery bank (had the room in the cabinet so filled it up) it carries things thru on cloudy days.



I'll be adding another next year in the kitchen, right now it uses a 12K window unit. I installed one in living room and most days that is all we run but need to run a box fan to cool the kitchen if the window unit is off. It has to be a sticky hot day to run the window unit with the oven running.

If you already have the inverter capacity and pv capacity to cover and have no grid then of course run it but for someone like me who has plenty of grid available and not looking to go off grid I can set up a smaller system and save money.

Btw. I looked and over the last 4 weeks my dryer has used 67kwh and oven cooktop have used 18.8kwh

I also feel guilty running a dryer when it's 107 degrees outside so I'm going to be putting up a clothesline and sun drying the clothes.

 

[timselectric]

Idle consumption is all about efficiency.
If you use all of the most efficient parts, you will have low Idle consumption. But the more efficient parts are more expensive. So it is a trade off between low cost versus low Idle consumption.

 

[42OhmsPA]

If you only get 0-3kW on one leg and 0-3kW on the other leg of a 6kW inverter, that’s not any ‘imbalance’ at all.

Imbalance is when a LF 6kW split-phase inverter can deliver 4kW on one leg and 2kW on the other leg (for example) because of the integrated Autotransformer…

Thanks for pointing that out.

I know I've seen over 3kw on one leg, but I've never really intentionally pushed it. I will next time I'm bored and have an abundance of photons.

 

[Crowz]

Thanks for pointing that out.

I know I've seen over 3kw on one leg, but I've never really intentionally pushed it. I will next time I'm bored and have an abundance of photons.

Have you tested idle consumption on your tp6048?

Solar Assistant shows 45watts being used by the unit itself but I have no clue if that is accurate or true idle consumption.

 

[Zwy]

Idle consumption is all about efficiency.
If you use all of the most efficient parts, you will have low Idle consumption. But the more efficient parts are more expensive. So it is a trade off between low cost versus low Idle consumption.

I never even worry about idle consumption. If the inverter is running to power loads, it just part of the loads.

My house has a baseload draw of about 300W 24/7. That load is powered constantly by the inverters. Inverters take about 150W to 200W for the pair. That's 6000W for 12 hours overnight. It's 10% of my battery bank, which is true every day when I look at capacity used overnight monitored by the Batrium shunt.

If idle consumption is a problem, you need more battery.

 

[42OhmsPA]

Have you tested idle consumption on your tp6048?

Solar Assistant shows 45watts being used by the unit itself but I have no clue if that is accurate or true idle consumption.

Yes. When I first connected it to the DC side before adding AC loads it was north of 115w but don't remember the exact number.

 

[Crowz]

I never even worry about idle consumption. If the inverter is running to power loads, it just part of the loads.

My house has a baseload draw of about 300W 24/7. That load is powered constantly by the inverters. Inverters take about 150W to 200W for the pair. That's 6000W for 12 hours overnight. It's 10% of my battery bank, which is true every day when I look at capacity used overnight monitored by the Batrium shunt.

If idle consumption is a problem, you need more battery.

I wish I could get down to 300 watts. Mines 1600 watts minimum.

 

[Zwy]

I wish I could get down to 300 watts. Mines 1600 watts minimum.

I'd be looking into that. I never shut any of the computers off or printer, the one paired with the Batrium never sleeps and the screen is on 24/7. 2 big screen TV's plugged in plus DVD player, alarm clocks and router plus wireless link between house and shop.

Biggest user might be outdoor motion lights, the cats like tripping the lights all night long. Those aren't baseload though. 2 freezers and fridge run whenever.

 

[EastTexCowboy]

I wish I could get down to 300 watts. Mines 1600 watts minimum.

Mine is probably close to that. It rarely drops below 1kw anymore. Part of that may be there seems to always be at least one AC running somewhere, but there's some always on stuff that just stacks up such as the air compressor for the septic system.

 

[Zwy]

Mine is probably close to that. It rarely drops below 1kw anymore. Part of that may be there seems to always be at least one AC running somewhere, but there's some always on stuff that just stacks up such as the air compressor for the septic system.

AC is not baseload.

Baseload are those things that always draw power, such as computers, TV's (draw when off), routers.

 

[EastTexCowboy]

I'd be looking into that. I never shut any of the computers off or printer, the one paired with the Batrium never sleeps and the screen is on 24/7. 2 big screen TV's plugged in plus DVD player, alarm clocks and router plus wireless link between house and shop.

Biggest user might be outdoor motion lights, the cats like tripping the lights all night long. Those aren't baseload though. 2 freezers and fridge run whenever.

As of last week we now have 5 freezers and 2 fridges so the odds are one of them is running at any given time. I'm not complaining. It's doing exactly what it's supposed to do - power all those loads. A couple computers but they don't pull much and go to sleep when not in use. But all the little stuff adds up. I did notice a bump when I added that last big freezer in the garage. But the other factor right now is the heat. We're looking at another 116F head index today and probably at least 10 days of the same to look forward to. Last week when the temps dropped into the mid to high nineties my consumption dropped by 10-15kwh per day. I'm hitting that point where it takes a lot of power to overcome those few extra degrees in temperature. Here's today vs a week ago when the temps were just a few degrees lower. The lows didn't change much but the high usage was for more extended periods. That's all AC/heat pump. Still not bad on peak loads considering all it's doing.

 

[timselectric]

I never even worry about idle consumption. If the inverter is running to power loads, it just part of the loads.

Same here.
Idle consumption is just the cost of doing business.
My system is never idle. So, it's just efficiency losses.