Hello from Miami - residential condo association

[PetroDrlgEngineer]

Researching solar systems to reduce our $5600/month residential condo association electric bill. Roof is a FiberTite XL 50 ml membrane, over a concrete deck with post-tension cables.

Gary

[J.P.M.]

Researching solar systems to reduce our $5600/month residential condo association electric bill. Roof is a FiberTite XL 50 ml membrane, over a concrete deck with post-tension cables.

Gary

How much do you want to reduce that $5,600/mo.?

[PetroDrlgEngineer]

Hi J.P.M. - Ideally as close to zero as FPL (utility provider) allows but know they have some charges we can't eliminate.

Researching multiple objectives of:
* Reduce electricity bill as much as economically practical.
* Have battery storage for nights - periods when electricity is out as backup emergency natural gas fired generator.
* Supplement backup power for pending new requirements due to changing Fire Department requirements such as fan to pressurize enclosed stairwell so we reduce risk of having to upgrade generator.
* Potentially supply two EV Charging stations - one inside garage for owners-guests to charge for free with 2 ports; another set outside to generate revenue / offset costs
* IF FPL becomes as progressive as Texas, copy Tesla example and Sell power back to grid at higher rates during high demand periods with phone application

Best Regards;
Gary

[J.P.M.]

What preliminary research have you done for the project ?

[Calsun]

I would start by installing a heat pump to heat and cool the building as this should be done regardless. You do not want to add solar panels over a roof that has less than 20 years of useful life so a new roof is often part of the cost of adding solar.

Adding UV tint to windows results in no loss of visibility but reduces the thermal load inside. This and other strategies have no doubt been used by other townhouses in Florida and it would be worthwhile to call them and learn about what they have done that was effective.

There are companies that focus on residential solar installations and you want one that specializes in commercial installations as they have access to higher output panels and are familiar with multi MPPT charge controllers. A lot of companies now recommend using microinverters where one is installed on each panel. I do not think that these can withstand a lightning surge very well as there cannot be a surge suppressor installed inline as with a single inverter.

On ground level panel installations it is much easier to reach a failed micro inverter and replace it than if the panels are mounted on a roof. Often for commercial sites a carport roof is used for solar panels.

Solar on Parking.JPG

[PetroDrlgEngineer]

What preliminary research have you done for the project ?

J.P.M. -- Likely isn't not productive for me to attempt to document - prove my research on here but do have a Bachelor Degree in engineering but not a solar expert. Just trying to vet the technology such as Adhered BIPV - try to find some successful cases that address concerned found in my research that most thin-film / flexible panel manufacturers have gone bankrupt, and these panels have issues with heat buildup as no space or air movement below the panels. Therefore would much appreciate if anyone has installed panels directly on top of a membrane roof so we are NOT the first to attempt this as a successful case.

Am interested in these due to our membrane FiberTite XL 50 ml roof, flat roof and lots of space. Preliminary research is that the racking system + labor can be roughly 1/3 of the cost of the total system. Is this a good estimate? Hence to optimize the economic payout, one works to reduce the system cost, therefore eliminating racking is good IF it doesn't reduce the panel life so below when it achieves economic payout. Do others agree?

Has anyone installed a solar panel system on a flat roof over membrane for a residential condo association? Trying to find successful cases for lessons learned, thanks in advance.

[PetroDrlgEngineer]

[QUOTE=Calsun;n436989]I would start by installing a heat pump to heat and cool the building as this should be done regardless. You do not want to add solar panels over a roof that has less than 20 years of useful life so a new roof is often part of the cost of adding solar."

Several of us did expensive research on roofing materials in Florida and decided on the FiberTite member roof for various reasons. One of these was similar roofs still in place with documented roofs installed in 1984 at Longboat Key, FL 06-05-1984, and in 2018 this was 34 years after install. Our roof was installed in 2018, so max of 4 years into expected +30 year life. Why - we have a warranty. We have and are keeping with the Roof Maintenance program. We have a 6 foot parapet wall around the perimeter which we wrapped the FiberTite up and over the wall to try to keep wind from getting under it during hurricanes, etc. etc. Therefore we want to evaluate solar NOW, and not wait another +20 years and 'do it with the roof'. Didn't share these details previously as want to try to keep this on topic as this is a Solar Forum.

Install a Heat Pump on a building built in the mid-1970's with 81 separately owned condos, each that already has a Heat Pump at their unit? We have a huge expensive Cooling Tower and related equipment - boiler - computer controls on the roof which cool - heat water that's circulated through the building. Not a heat pump expert, but can one really economically redesign the building, remove the cooling Tower - etc and install ONE heat pump on the roof to manage 81 different units? Sorry but this is also outside the scope and don't understand how it's economic or practical for the Board to spend time considering.

Happy New Year!

[PetroDrlgEngineer]

Application - building is 13 stories tall next to the bay just north of Miami, Florida. Roof is 230' x' 75' = 17,350 ft2.
Roof is LIKE NEW, with +25 years of warranty plus hopefully life after the warranty, hence we do not want to wait for solar until next roof replacement.
Still doing research - confirming that the new Federal IRA (Inflation Reduction Act) has a 30% tax credit - cost offset and that we can structure the solar purchase to qualify as our residential condo association is a Not For Profit Company, meaning we neither make or lose money and pay no state or federal tax.

Can't get photos to upload at present, there is a 6 foot parapet walls around the outside parameter, therefore shade is a concern next to the walls.

[Mike 134]

Gary,

As you're quickly discovering most if not all on this forum have only residential and perhaps some small-scale commercial solar experience. I can appreciate your board wanting real life experiences, but I think your best direction to go would be to hire an EE firm with larger solar projects under their belts to give you a couple of options and budget numbers.

Just out of curiosity your cooling tower a Baltimore Aircoil or an Evapco? Those are the 2 favorites of the mechanical engineers in my neck of the woods.

Good luck, Happy New year.

[J.P.M.]

Application - building is 13 stories tall next to the bay just north of Miami, Florida. Roof is 230' x' 75' = 17,350 ft2.
Roof is LIKE NEW, with +25 years of warranty plus hopefully life after the warranty, hence we do not want to wait for solar until next roof replacement.
Still doing research - confirming that the new Federal IRA (Inflation Reduction Act) has a 30% tax credit - cost offset and that we can structure the solar purchase to qualify as our residential condo association is a Not For Profit Company, meaning we neither make or lose money and pay no state or federal tax.

Can't get photos to upload at present, there is a 6 foot parapet walls around the outside parameter, therefore shade is a concern next to the walls.

If it was my project, I'd start my preliminary research by finding out what the building electrical load is and how much of that is available to be offset by PV.
Then, I'd use FPL tariff information to estimate how much could be saved on an annual basis by offsetting that annual electric load in, say, 10% increments.
Then, I'd do a preliminary life cycle cost analysis and see what each of those savings increments might be worth in terms of present value.
Then, and depending on the electrical load and so the size of the project, I'd contact an engineering outfit that does commercial solar installations and maybe invest a bit to have them determine the project feasibility.

As you probably know, there is a lot to any large project and from what you write and how you write it, seems to me that since, and by your own admission, you're out of your area of engineering proficiency, it might be a good idea to get some help from a suitable engineering outfit. If you have experience in project engineering or project management, you know what I'm writing about.
For your information and as a start, I'd download a copy of "Solar Power Your Home for Dummies". It's a bit dated and not geared for what sounds like a somewhat large project, but there is information on the basics that you might find informative.
I'd also check out a site called "pveducation.org", particularly the references.
I'd also check out something called PVWatts from NREL. And/Or, depending on your engineering knowledge and how you want to use it, chap. 23 of "Solar engineering of Thermal Processes", by Duffie and Beckman. The book is online and while it's primarily a solar thermal engineering text, that chap. is what I'd consider the most concise treatment of PV basics I've seen.
If/When you do talk to solar pros, you'll find the information you glean from the above sources and others helpful if for no other reason than to help the conversations with design/engineering firms stay as productive as possible.

Good Luck.
Happy New Year.