Aloha from a Solar Newbie in Hawaii

[WH6FQE]

How many towers do you have ? Another route is 48VDC computer PSUs.

https://www.powerstream.com/DC-PC-48V.htm

But only 70% efficient

48 Volts?

With a 48 volt system I would have wasted all the money on everything I already have and would have to start over again from scratch because everything will handle either 12 volt or 24 volt, but not 48 volt.

I have an HP Z400 Workstation connected to two 23" widescreen HD LED monitors and a MacPro connected to three 27" HD LED widescreen monitors.

In an emergency, I could transfer the load over to the HP from the Mac, but I would have to add an additional monitor to that computer to do that. That would get me down to one tower computer during an outage.

[SunEagle]

How many towers do you have ? Another route is 48VDC computer PSUs.

https://www.powerstream.com/DC-PC-48V.htm

But only 70% efficient

The OP still needs to match up all of the voltage and amp load connections between that power supply and what the Tower uses. That might not be easy.

Unfortunately a Tower is a lot more complicated concerning it's internal loads then a laptop. But there are some high end laptops that are as fast and powerful as a Tower PC. You just have to pay the price.

[Mike90250]

How many towers do you have ? Another route is 48VDC computer PSUs.

https://www.powerstream.com/DC-PC-48V.htm

But only 70% efficient

[WH6FQE]

So every time I think I finally found a way of making this system work, I find out I am still at the same dead end. It's not going to work with these tower computers, and I can't get everything switched over to the laptops to lessen the energy requirement.

[inetdog]

I never ordinarily suggest this, but this might mean PWM charge controllers may be better for you overall. You will have to be a lot more careful with panel sizes/voltages/connections tho.

Note that it was jflorey, not bcroe, that suggested PWM. I also disagree with this recommendation.

[inetdog]

I wonder how feasable this would actually be. Do you think it would this be possible for me to run the PC tower, and Mac Pro tower, all the monitors and radios directly on the battery bank? Im thinking that the cables to the computers would have to be huge to handle the current at just 12-volt.

The standard computer power supply produces not just +5 and +12. It also typically produces -5, -12 and, depending on the CPU, somewhere between 3V and 5V to optimally power the logic for least heat. So if all you have available is +12V you will still need a substantial amount of power conversion. It may be more efficient than conversion from 120V AC, but not necessarily as much as you might expect. And as for cost, AC input computer power supplies are a commodity good with lots of price competition and economies of scale in production. A 12V DC input supply that provides all the other regulated voltages may be a lot more expensive.

[WH6FQE]

A PC tower usually has multiple loads at all types of DC voltages. While the AC power supply can be inefficient at least it is designed to power all of the equipment at the correct DC voltage including any video boards, cooling fans or other add on modules.

I appears that everything is either 12 volt, 5 volt, or 3.3 volt

[SunEagle]

I wonder how feasable this would actually be. Do you think it would this be possible for me to run the PC tower, and Mac Pro tower, all the monitors and radios directly on the battery bank? Im thinking that the cables to the computers would have to be huge to handle the current at just 12-volt.

A PC tower usually has multiple loads at all types of DC voltages. While the AC power supply can be inefficient at least it is designed to power all of the equipment at the correct DC voltage including any video boards, cooling fans or other add on modules.

[SunEagle]

On the plus side, not many places to drive to . . . .

Maybe time to look into an EV.

[bcroe]

I thought PWM controllers caused interference as well.

That is what I said, PWM turns your panels into interference radiating antennas.

That is something that has always puzzled me, you connect a computer to
110 volts so that it can power its internal 12 volt power supply which powers everything else.
There should be an easy way of bypassing all of that wasteful conversion.

That is what I said, find out how much power is just being wasted. Then find a way to avoid
those losses. Feeding things direct from a DC source could save a huge amount. Bruce Roe

[WH6FQE]

Computers can be retrofitted with 12V power supplies. If they are LCD monitors, they typically run on 12-19 volts DC, so you may be able to dispense with the inverter altogether.

I wonder how feasable this would actually be. Do you think it would this be possible for me to run the PC tower, and Mac Pro tower, all the monitors and radios directly on the battery bank? Im thinking that the cables to the computers would have to be huge to handle the current at just 12-volt.

[WH6FQE]

OK, good. One problem solved.

I never ordinarily suggest this, but this might mean PWM charge controllers may be better for you overall. You will have to be a lot more careful with panel sizes/voltages/connections tho.

I thought PWM controllers caused interference as well.

Computers can be retrofitted with 12V power supplies. If they are LCD monitors, they typically run on 12-19 volts DC, so you may be able to dispense with the inverter altogether.

That is something that has always puzzled me, you connect a computer to 110 volts so that it can power its internal 12 volt power supply which powers everything else. There should be an easy way of bypassing all of that wasteful conversion.

I have several old computer power supplies that I have converted to work as radio power supplies for new hams. They work great and save them an arm and a leg getting their first station setup.

I never even thought about the monitors, I was just searching online for 12-volt monitors, but not having a lot of luck besides little 10" things that are smaller than the laptop screen to begin with, lol.

In general you don't need relay type isolators for this - a simple set of diodes would work fine. The battery charger can connect directly to the batteries, and if there is any current being backfed, a diode can ensure the supply is isolated.

These I got mainly for the auto switching, so that as soon as power stopped coming from one source it automatically switched over to the second source very quickly, and then switched back when the main source was restored.

Yes, I am a ham radio operator, but I can't build a cheese sandwich without something going wrong with it, lol. I am much safer purchasing pre-made items than to try to build them myself. My hands are no longer steady enough to solder and the doctor refuses to stretch my arms out to make them longer so I can read easier, lol.

[littleharbor]

On the plus side, not many places to drive to . . . .

Since I brought my latest truck over I'm getting just a hair over 7MPG. So about a dollar a mile.
But for about a 35 mile round trip we have this to enjoy.

S6300696.jpg Buffalo over Little Harbor.jpg

[jflorey2]

Wow! The price you pay to live in paradise. I can relate, somewhat. I live on Catalina Island. My issues with restrictions and cost of living here could fill a book. How about $7.xx a gallon for gas? That picture isn't current. We've had GAS prices in the $7.25 range.

On the plus side, not many places to drive to . . . .

[jflorey2]

My antennas do not shadow my roof at all.

OK, good. One problem solved.

Yeah, thats the part that is worrying me now. I may be doing all of this for nothing if it interferes with my radios.

I never ordinarily suggest this, but this might mean PWM charge controllers may be better for you overall. You will have to be a lot more careful with panel sizes/voltages/connections tho.

The only thing that is on 120 are the computers and monitors.

Computers can be retrofitted with 12V power supplies. If they are LCD monitors, they typically run on 12-19 volts DC, so you may be able to dispense with the inverter altogether.

My radios and lighting are currently connected to a pair of 50amp power supplies and battery isolators that will be connected to the system.

In general you don't need relay type isolators for this - a simple set of diodes would work fine. The battery charger can connect directly to the batteries, and if there is any current being backfed, a diode can ensure the supply is isolated.