The topic of why something should be in place (batteries) comes up all the time in Enterprise. Having worked in such industries and spaces from a birds eye view it came down to a combination of risk vs reward. If the company was a tight twat it didn't matter what you said or did in terms of offering historic facts. One would think historic data to make a
Business Case is the very information a person needs to make an informed decision?!?
Again, in most IT departments they are usually left with the lowest budgets which doesn't even rank with the person in charge of the stationary!
If we just assume its not even a budget issue or having the finances to implement a sound back up / fail over infrastructure it came down to
What are the chances and the bulk of them just rolled the dice in hopes of seeing a hard 8.
Regardless, the whole premise of On Line UPS is to insure constant filtered AC power. This eliminates the possibility of dirty power, transfer time, and isolates end devices. Having a On Line UPS allows the generator to spool up and than provide the long term power within the facility. Those interested in doing the same on a consumer level need to understand the vast amount of consumer equipment rarely if ever offer the same I/O and options to run primary, secondary, tertiary, power.
This is made worse when such options are present these same (systems) have limited abilities as to how they will be called to operate in different situations.
One thing many people fail to understand is unless the system is well defined to operate off grid almost all of them will by default operate in
Island Mode. Meaning once the system detects a loss of grid power that solar PV system will stop the flow of power to the home. When a person adds a battery to a PV system the transfer switch is supposed to relay all consumer loads to the battery / inverter. Again, some older systems that were grid tied would automatically go into Island Mode and thus would cut off PV generation.
The net effect was the batteries would be consumed but had no way to be recharged while the grid was down and ultimately became depleted. Newer systems have taken that into account and allow the PV to recharge the battery pack while inverting. Which leads to another problem that not everyone is aware of is that not all solar PV systems will allow you to receive power from the PV array vs battery pack.
When a system allows both the battery and solar PV array to supply consumer demand this offers greater power while off setting the need to dip into the battery reserve!
Again, anyone who intends to walk this path needs to ask these basic questions as to how the system will operate when its grid tied. As every maker has slight differences as to how and when such power will be made available - assuming it allows it.
In a home a person should size the battery pack / inverter to the realistic load needed to be powered and for how long. If its for a few hundred watts for one hour a smaller battery pack will save you a lot. The reverse is also true having a larger battery pack which will allow you to save money on fuel costs as (IF) the battery pack is large enough to provide longer run times working in concert with a solar PV that fuel costs to power the generator is reduced ten fold.
With the advances in LiFePO battery technology generally speaking the DOD, and Cycle life has increased dramatically vs other battery chemistries like SLA, AGM, Gel, Lithium etc.
In the ideal situation a home would be powered by the solar PV and any excess is sent back into the grid to reduce the monthly / yearly costs to the consumer. If and when there is a grid down event the system will simply trip the transfer switch and the home will continue to be powered by the solar PV during the day and any extra power requirements are made up by the battery packs. Once the sun goes down the home will continue to operate on batteries until a well defined DOD is seen / met to insure the longest service life. Once that DOD is seen the generator will kick on to do one of two things based on need vs wants.
Ideally, the generator would simply recharge the battery pack to 100% and rinse and repeat. Going this route reduces fuel costs, wear on the generator which equals less maintenance, and obvious noise, and a target on your back as your the only one making noise!
Well, besides the fact you're rocking stadium lights and blasting out 1000000000000 dBs . . .
It really comes down to a persons budget, how serious they are, and what measure of so called bullet proof of a system they want to have.
Lastly, one of the major benefits to the Generac system is it allows a person to scale up. While also replacing the large cells vs the Tesla incorporates all of the electronics (transfer switch) and there is zero ability to replace a battery pack / cell. As the entire thing is just a massive (individual) battery pack tied together.
