Looking for suggestions for a 3-5kw solution for a wireless ISP

My company is a small wireless ISP launching in North America.

We're building new sites that will have 3-5kw of equipment running 24x7.

I'm trying to figure out what the best solutions might be to keep these sites running in the event of a grid outage.

One scenario would be a battery system (happy to explore DIY vs commercial solutions) to keep the site running long enough for the tower generator to kick on and power the site. Most sites we're installing have a generator at the property already.

The other scenario is a site that doesnt have a generator. Do we install a battery system that lasts for +/- 1 hour until we can drive a generator there? Or do we install a generator on site and just enough battery capacity to last until the generator kicks on? What generator is affordable, has such capabilities and is in the 10kw range?

Power outages in our area are not common, but I wanted to see what options are available and to do a cost/benefit analysis.

Our network design has a lot of relisancy in it, so if a local site goes down we're likely still operational for the rest of the network.

I'm not an electrical expert, but we have a good small team of people (including a mechanical and electrical engineer) and have local electricians who can help.

Thank you for your advice!

You need a UPS that will last for at least 2 hours. That will give you time to react. Then after that is your backup power. Depends on your budget and your uptime needed. You can go with a simple diesel or natural gas generator. Both are stable fuels that can sit for a while. Diesel fuel might need to be reconditioned after a while but gives the longest run time. If you have multiple sites and not enough budget for a generator backup per site, then get a towable generator that can be transported on-site and beef up your UPS to 4 hours uptime so you can reach it. Keep in mind that UPS bateries needs to be swapped every 4-5 years. So you need to budget for battery replacements.

UPS
https://www.eaton.com/us/en-us/cata...urge-it-power-distribution/eaton-9px-ups.html

Generators
https://www.electricgeneratorsdirect.com/power/diesel-generators.html

First of all how Long should they last???

I recommend a standard Ups to. Dont do DIY battery packs for a commercial system like this. You dont save money.
IF you want to go solar system Them you consider hybrid or offgrid system.

"I'm not an electrical expert, but we have a good small team of people (including a mechanical and electrical engineer) and have local electricians who can help."

From your questions I think you should talk to your own experts first because your questions show you don't know the sites already have a UPS (in the instance they have a generator).