Aloha from a Solar Newbie in Hawaii

[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

[SunEagle]

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

Maybe time to look into an EV.

[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.

[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

[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.

[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.

[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.

[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

[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.

[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.

[jflorey2]

I thought PWM controllers caused interference as well.

They do. But they switch at most a few times per second, not 100,000 times a second. So the energy available to radiate is far lower. However you also lose a fair amount of power, so it's a tradeoff. If you can filter you are generally better off with MPPT.

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.

Well, it always requires conversion to get all the odd -12V +5V voltages. But yes, the less conversion the better.

I can't post links here, but google "250w DC-ATX 12v Mini Itx Power Supply" for an example.

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.

There are no monitors that are advertised as 12V monitors. But I have 2 LCD monitors that run at 12V, 1 that runs at 15V (that will probably run OK at 12V) and 3 that run at 19V. And boost converters (12V to 19V) are cheap.

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.

Well, if you need something simple built, and can accurately specify the goes-ins and goes-outs, let me know and I may be able to get it built for you. (In the name of emergency preparedness for the Big One.)

[jflorey2]

Maybe time to look into an EV.

Side note - I was recently offered a Smart Car Fortwo for $6000. New. Given that the tax break is currently $7500 it would have been free - and the tax break would have paid for a few years of registration and insurance. I was very tempted; even if I never used it for actual driving it's an 18kwhr battery for free.

But the wife pointed out that it would have to take up even more space in the driveway.

[WH6FQE]

There are no monitors that are advertised as 12V monitors. But I have 2 LCD monitors that run at 12V, 1 that runs at 15V (that will probably run OK at 12V) and 3 that run at 19V. And boost converters (12V to 19V) are cheap.

I found a bunch that are 15" and smaller, but I was able to find a couple that are closer to what I am looking for:

https://www.amazon.com/SuperSonic-Wi...gateway&sr=8-6

https://www.amazon.com/Free-Signal-T...ateway&sr=8-69

I may end up trying three of the SuperSonic 24". That is close to the same size that I am using now and works fine. The monitors I have now are 19-volt.

Mod Note: There was some delay while this post went through manual approval for viewing because of the links.

[Ampster]

Side note - I was recently offered a Smart Car Fortwo for $6000. New. Given that the tax break is currently $7500 it would have been free - and the tax break would have paid for a few years of registration and insurance. I was very tempted; even if I never used it for actual driving it's an 18kwhr battery for free.

But the wife pointed out that it would have to take up even more space in the driveway.

That was for the car only, correct? the battery lease would have been about $90 per month. Still a great deal. I have leased two of them over the years when I lived in a small beach town. Great for parking in those tight spaces at the beach.

[WH6FQE]

Ok, I think I may have finally figured out how to lose my HP tower computer and switch everything over to a laptop instead. I tried using a Dell Lattitude computer, but it was dismally small and way too slow to work for my needs. Its comical 2GB RAM and 80GB hard drive were definitely not going to be a replacement for my Z400 Workstation, so I switched over to a Dell Inspiron with 16GB of RAM and a 1TB hard drive which I am already running on a 12-volt cigarette lighter plugin. I will swap out the plugin for Anderson Power Pole adapters just like all of my radios and emergency lighting is as I get everything ready to add it to the system permanently.

I ordered 3 refurbished 19" Jensen 12 volt TV's so that I am not wasting power or creating heat converting to the correct power for the LED monitors that I used on the tower computer. I also picked up 3 Diamond USB Display Adapters that will allow me to run the three monitors from the laptop USB ports. I can even go up to a maximum of 6 monitors if I need to in the future, but I highly see that being necessary.

Since I will be able to have 3 monitors on the laptop now, I can get by with using just the laptop during power outages and not have to have the MacPro and its 3 monitors on the battery bank. That alone will save me a fortune in solar parts, lol.

I also ordered the Kill A Watt and the AC/DC Digital Clamp Meter to start adding everything up with. One of the 24v to 12v DC/DC converters arrived today, the other one was back ordered and supposed to be here around April 2nd.

Even though they are not due for delivery until Thursday, both of the generators arrived on the island today. Hopefully, UPS will go ahead and deliver them on Monday. FedEx is normally the only one that will make me wait until the scheduled delivery date before they deliver items here.

I feel like a plan is slowly starting to come together.