How much Solar Power we would need for 5 Dell Servers to run 24x7 ?

[soamz]

Hi, my server room has around 5 Dell Rack servers and 5 switches, routers.

How much solar power do I need to run them for 24 hours a day ?
Means, completely off grid and all the power being used from the solar power generated energy only ?

Dell Servers Power Rating are 750w, 2 power plugs for redundancy.

[Yaryman]

Not the expert many here are, but one BIG problem with running the servers with solar only is that it's not sunny every day and solar is pretty
useless at night. So to implement your plan you would need a very reliable, VERY expensive battery system.

Better to be grid tied with solar and let the fine folks at your regulated power monopoly provide energy when you can't.

[Sunking]

You are not going to like the answers. but who cares right? It will never happen

OK just based on what little information you have provided:

• Panel Wattage = 34,000 watts. Roughly $50,000 USD, higher outside USA
• 8 x 80 amp MPPT Controllers. Unit Cost $700 each x 8 units = $5600 USD higher outside USA
• Batteries = 675 Kwh capacity. 48 volts @ 14,000 AH. That is a battery that weighs 40,000 pounds/ 18150 Kg and cost you $140,000 every few years. You will need a dedicated large room with enforced floor to hold the weight with air conditioning year round. The room and mechanical systems wil cost more than the batteries. Who cares right?
• 50 Kw Diesel Generator, 500 gallon Diesel tank, 48 volt 800 amp Rectifier, concrete pad another $40,000 out of your pocket.
• Misc hardware Inverters, wiring, shipping, and all the other crap to make it work another $40,000 USD

When said and done just under $300,000 in equipment cost alone. Does not include permits, engineering, and labor. So I can do this Turn-Key for you for $500,000 if you are in the USA. Otherwise you are on your own. Just give me you Fax Number and I will send you a Contract. Sigh and return it with $50,000 check and I can get started. Be sure to have your lawyers look over the contract. I can also build your battery room for an additional $200,000 but there is a catch as it will require commercial AC power for the air conditioning.

So are you ready to get into dirt cheap free power? Just sign the contract. When said and done by going solar you have elected to pay 5 to 10 times more for electricity for the rest of you rlife vs buying it from the POCO. Really a great strategy for any business looking to throw money away and go bankrupt. You will be out of biz before you know it.

[soamz]

Now Im more confused with the confusing replies

[JFinch57]

Now Im more confused with the confusing replies

You didn't really give clear inputs to the equation. Is it 750W X 2 inputs (1500W) or 750W between the 2? What is the power of the other equipment? Also, didn't state that the servers are required to run 24/7 with high availability, thus the need for a generator when the batteries run out, or can you afford down time since you have an alternate site that can assume the data flow. The bottom line is that off grid with batteries is very expensive to build and maintain.

[soamz]

You didn't really give clear inputs to the equation. Is it 750W X 2 inputs (1500W) or 750W between the 2? What is the power of the other equipment? Also, didn't state that the servers are required to run 24/7 with high availability, thus the need for a generator when the batteries run out, or can you afford down time since you have an alternate site that can assume the data flow. The bottom line is that off grid with batteries is very expensive to build and maintain.

Its 750 in between. Normally it wont use even 350W.
yes, servers will run 24x7.
And it will be connected to grid as well in case solar gets short.

[JFinch57]

Its 750 in between. Normally it wont use even 350W.
yes, servers will run 24x7.
And it will be connected to grid as well in case solar gets short.

So it will be grid tied and the power requirement is probably 1/4 of what was calculated above. Your switches and routers should be minimal, so the continuous rating would be about 2KW, right? That changes everything!

[lkruper]

So it will be grid tied and the power requirement is probably 1/4 of what was calculated above. Your switches and routers should be minimal, so the continuous rating would be about 2KW, right? That changes everything!

Yes, instead of 1/2 million with labor it will only be $125,000 to implement. Then the OP can spend 10X the utility price for electricity forever. Why is this good?

[SunEagle]

Its 750 in between. Normally it wont use even 350W.
yes, servers will run 24x7.
And it will be connected to grid as well in case solar gets short.

If the servers are connected to the grid then you just need to size a UPS system big enough to allow a generator to start up and then supply the power to the servers.

Forget about going with a solar / battery system if you are worried about the cost or reliability.

When it comes to large continuous loads running off batteries, you are going to need lots of money.

[Sunking]

Its 750 in between. Normally it wont use even 350W.
yes, servers will run 24x7.
And it will be connected to grid as well in case solar gets short.

You would be a fool to go solar. I build Data centers and telephone switching offices for a living for the last 35 years. No company would ever think of going solar. By doing so you just opened yourself to unnecessary outages, and paying 5 to 10 more for electricity. No manager would ever think of doing something so stupid.

All critical communications faculties use commercial power to run the equipment via UPS and battery power. When commercial power fails the batteries take over, the generators start up and take over the load and run until commercial power is restored. If designed properly, and not installed in earth quake zones or flood plains gives you 99.99% availability. No solar system can even come close to that reliability, and the solar option is a lot more expensive.

A properly designed communication system will have a battery capacity of 2 to 12 hours for short duration outages and in the event both generators fail to start. A solar battery system needs a minimum 72 hour capacity for a non critical system like a house where being out of power for a week is no problem, otherwise 240 hours or 10 days for critical systems where power outages are unacceptable.

[soamz]

I was thinking to do a 3kVa solar backup, with 4 batteries 180Amp and 1500W solar panels.

And its tied to grid too.

So, the power always comes from solar and when solar is short, it simply uses the grid electricity.

[cebury]

I was thinking to do a 3kVa solar backup, with 4 batteries 180Amp and 1500W solar panels.

And its tied to grid too.

So, the power always comes from solar and when solar is short, it simply uses the grid electricity.

I think there is a disconnect in stated requirements here. If it's critical for no downtime 24x7, what happens when the power goes out during winter on rainy or excessive cloudy days? That is a common time for outages here... Heavy winds & tree limbs or lightning strikes onto lines. Will those batteries last long enough without a generator?

If what you mean by 24x7 is Ups backup needed to last the x minutes and auto trigger the server shutdowns when power is lost, that is very different than mission critical 24x7 production uptime.

Speaking practically there are few cases with 24x7 requirements. If the servers are up, but all the PCs are down and the lights off in the building, what good is it? If a remote server farm, will all the corresponding network links, upstream from your facility, have the redundant power capacities to keep the internet connectivity up during an outage?

Maybe you considered all these factors, and many more, but just didn't convey it.

[soamz]

I think there is a disconnect in stated requirements here. If it's critical for no downtime 24x7, what happens when the power goes out during winter on rainy or excessive cloudy days? That is a common time for outages here... Heavy winds & tree limbs or lightning strikes onto lines. Will those batteries last long enough without a generator?

If what you mean by 24x7 is Ups backup needed to last the x minutes and auto trigger the server shutdowns when power is lost, that is very different than mission critical 24x7 production uptime.

Speaking practically there are few cases with 24x7 requirements. If the servers are up, but all the PCs are down and the lights off in the building, what good is it? If a remote server farm, will all the corresponding network links, upstream from your facility, have the redundant power capacities to keep the internet connectivity up during an outage?

Maybe you considered all these factors, and many more, but just didn't convey it.

Okay thats also a point.
May be keep a generator as a backup only.

[TrueMetalGeek]

Hey guys, first post here.
I thought I'd look for a forum on solar panel discussions and this seems to be a popular place.

I however have noticed that some regulars here sure seem quick to deter people from going solar.
I know that some people who have no idea and who have crazy pipe dreams of free energy with little investment and maintenance need correction and the sooner the better for their own good. That is understandable.

But how does a question like this:

"5 Dell Rack servers / Dell Servers Power Rating are 750w, 2 power plugs for redundancy."

Become this???

"Panel Wattage = 34,000 watts. Roughly $50,000 USD, higher outside USA
•8 x 80 amp MPPT Controllers. Unit Cost $700 each x 8 units = $5600 USD higher outside USA
•Batteries = 675 Kwh capacity. 48 volts @ 14,000 AH. That is a battery that weighs 40,000 pounds/ 18150 Kg and cost you $140,000 every few years. You will need a dedicated large room with enforced floor to hold the weight with air conditioning year round. The room and mechanical systems wil cost more than the batteries. Who cares right?
•50 Kw Diesel Generator, 500 gallon Diesel tank, 48 volt 800 amp Rectifier, concrete pad another $40,000 out of your pocket.
•Misc hardware Inverters, wiring, shipping, and all the other crap to make it work another $40,000 USD"


Where on earth did that 34,000 watt number come from?

I'm new to Solar but not to electronics.
5 servers would need 3,750 watts when running at full load plus a litte bit for the routers and switches (maybe a few hundred watts max).

I'm sure you design the system a little over for unforeseen things and for some upgrades but dang, being told he needed a system that is enough to power three houses was a little excessive, don't ya think?


I've seen some similar replies in some other threads and I don't want to step on a bunch of toes as I just found this site but I just think this response to the question was a bit out there.

[TrueMetalGeek]

Now another question would be, what is cooling the server room?

That could require some A/C capacity.

Here in Arizona it takes a bit to cool in the summer. But if in a cooler climate just some fresh air and some exhaust fans will do the trick.