Does Solar Really Pay Off

[Cheap 4-life]

I agree with your points, but I still think its silly not to be able to use your solar installation when the grid goes down though. Even if there is no storage, the system should always be able to use an automatic transfer switch so you can still use your system, just like a Generac generator system.

Agree that would be silly to have all that pv power just sitting there and couldn’t use it during a power outage or if SHTF. That’s why (as I said above) a small critical panel with just the essentials moved to it could be done. Simply using a small cheapo offgrid inverter that will rarely ever get used.. and keep a spare.. and yeah a generator with a lock out breaker or transfer switch is another option

 

[wattmatters]

I agree with your points, but I still think its silly not to be able to use your solar installation when the grid goes down though.

But it can, provided you design it accordingly.

The reason most grid tied PV systems switch off when the grid goes down is because that's the cheapest and easiest way to conform to the (very necessary and important) grid isolation requirements for small scale generators connected to the grid.

But switching off is not the only option for confirming to those requirements - you just need to specify the solar PV set up to have the capability to operate in isolation from the grid when the grid goes down. It's just more expensive to have equipment capable of doing that, and for the vast majority of homes with grid tied PV it's just not a priority or worth the extra such capability costs.

Already the latest Fronius Gen 24 grid tied inverters have a feature to provide a battery-less backup circuit capable of supplying up to 3 kW of power, provided the PV array has enough sunshine to supply the power. But naturally that's not of much help at night, but it most certainly could be used to charge up a portable power station in the daytime.

If you want grid outage protection with a grid tied PV system, obviously a system with a battery and automated isolation equipment is the better option as it makes management of the balance between supply and demand easier. Again it's all completely doable now. There are about 100,000 grid tied systems with this capability in Australia now.

 

[Cheap 4-life]

But it can, provided you design it accordingly.

The reason most grid tied PV systems switch off when the grid goes down is because that's the cheapest and easiest way to conform to the (very necessary and important) grid isolation requirements for small scale generators connected to the grid.

But switching off is not the only option for confirming to those requirements - you just need to specify the solar PV set up to have the capability to operate in isolation from the grid when the grid goes down. It's just more expensive to have equipment capable of doing that, and for the vast majority of homes with grid tied PV it's just not a priority or worth the extra such capability costs.

Already the latest Fronius Gen 24 grid tied inverters have a feature to provide a battery-less backup circuit capable of supplying up to 3 kW of power, provided the PV array has enough sunshine to supply the power. But naturally that's not of much help at night, but it most certainly could be used to charge up a portable power station in the daytime.

If you want grid outage protection with a grid tied PV system, obviously a system with a battery and automated isolation equipment is the better option as it makes management of the balance between supply and demand easier. Again it's all completely doable now. There are about 100,000 grid tied systems with this capability in Australia now.

Technology is constantly improving. Many more options than there was a few years ago.. Many grid tie inverters nowadays can utilize batteries when there clouds and at night.. backfeeding into the grid is becoming less desirable for several reasons. Then it’s just a matter of getting some small offgrid inverters that utilize the sane battery voltage or getting a hybrid inverter (grid tie and offgrid) to start with

 

[Ampster]

The reason most grid tied PV systems switch off when the grid goes down is because that's the cheapest and easiest way to conform to the (very necessary and important) grid isolation requirements for small scale generators connected to the grid.

To say it differently, the least expensive design and the one that will have the greatest volume for manufacturers, is one that does not have to produce a 60 Hz signal. GT inverters rely on the grid signal and when it is gone they do not produce any power, so as you said no additional isolation elements are needed.

 

[12VoltInstalls]

anarchist's cookbook'

I wish I knew where my copy was. I’m afraid to go find one online and buy it because nowadays they’d probably be monitoring and put me on a watch list or something. I’m curious, like learning things, but I’m about as far removed from ‘terrorist’ as one could get

 

[Vigo]

To say it differently, the least expensive design and the one that will have the greatest volume for manufacturers, is one that does not have to produce a 60 Hz signal.

Since i messed with car audio amplifiers long before i started messing with 'power inverters' (a rose by any other name, would smell as sweet) I have wondered about taking a big audio amplifier and playing a 60hz track through it and trying some AC appliances on it.

Maybe the people with those inverters should find a way to use YouTube as an input.. ?

 

[G20]

I bought the Masons when they first came out, and were selling at a huge discount. That said, you can still get 280AH cells for about $100 each on Alibaba, and a JK 200amp BMS for about $175. Add in cables and a DIY box, and your at about $1900 for 14KW. Signature Solar EG4's 5KW are about $1500 each, so you would need 3 of them (15KW @ $4500) to match one DIY battery.

Why are most of the server rack batteries 100Ah ?

Is there any reason why they are not 280Ah ?

TIA

 

[32 volt boater]

Since i messed with car audio amplifiers long before i started messing with 'power inverters' (a rose by any other name, would smell as sweet) I have wondered about taking a big audio amplifier and playing a 60hz track through it and trying some AC appliances on it.

Maybe the people with those inverters should find a way to use YouTube as an input.. ?

Online Tone Generator - generate pure tones of any frequency​

Its especially fun when telemarketers call.

 

[Sanwizard]

Why are most of the server rack batteries 100Ah ?

Is there any reason why they are not 280Ah ?

TIA

Yup. Weight. The 200ah batteries need a few good men to lift. I built mine on a garage workbench, but needed to go to harbor freight to buy a lift to move it from the workbench to the floor. Even then, it was a pain to move it anywhere. I finally bought the expensive DeWalt shelving system that Will uses in his youtube videos to mount them. That being said, one of those 14KW beasts is almost 3x as dense as the usual 100ah batteries, so much less space for much more power.
You just need to have some buddies around if you need to move them.

 

[timselectric]

Why are most of the server rack batteries 100Ah ?

Is there any reason why they are not 280Ah ?

TIA

Weight

 

[32 volt boater]

And listen to the difference square wave vs sine.

 

[G20]

Yup. Weight. The 200ah batteries need a few good men to lift. I built mine on a garage workbench, but needed to go to harbor freight to buy a lift to move it from the workbench to the floor. Even then, it was a pain to move it anywhere. I finally bought the expensive DeWalt shelving system that Will uses in his youtube videos to mount them. That being said, one of those 14KW beasts is almost 3x as dense as the usual 100ah batteries, so much less space for much more power.
You just need to have some buddies around if you need to move them.

Thanks much.

I just saw a 48VDC 2P16S 32-cell build (28.6KWH) on YT where the DIYer welded up a vertical 2 row angle iron rack similar to a 2-row dumb bell weight rack. The upper and lower rack each held 16 cells in a single row. They probably won't be moving it any time soon.

Finally bought a chain hoist this year. Should have bought one years ago.

 

[Vigo]

Finally bought a chain hoist this year. Should have bought one years ago.

About 2 years ago I decided i needed a better way to move engines and other heavy pieces across dirt. I was gonna buy a truck bed crane and figured man a truck is kinda hard to get into a lot of places around here, so i figured i'd put it on a riding mower and if it didn't work i'd just put it on the truck.?

So i built it..

Eventually I made it nicer so the crane would swing around and you could put the hood back on it.

It has lifted over 500lbs and driven it around. Took a little doing to get it to that point, though.

And then what did i do? Bought tractors with front end loaders. Which is cool and all but now this thing i built hasn't moved in like a year..