Solar Power in USVI...
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Solar Power in USVI - can costs be financially justified?

Posts: 60
Trusted Member
Topic starter

I'm still perplexed how solar is cost effective solution in USVI even with the crazy WAPA rates.  Granted we are part timers, but our WAPA bills average about $6K-$7K per year and solar install with batteries runs at least $75K. 

Best case that's a 10-year payback ignoring time value of money, plus degradation of the solar panel and battery efficiencies over that time period and inevitable once a decade hurricane that is likely to take the solar panels off the roof.  

Coupled with the "ugly factor" of roof mounted solar panels, how are people today financially justifying this the upfront capital cost versus sticking with status quo WAPA with a back-up generator for the power outages?  Lucrative "net metering" plans are gone, so how does this work now?

Posted : March 23, 2023 12:36 am
Posts: 1049
Noble Member

I just looked at one of our more recent quotes for one of our houses to see what the numbers looked like.  The house is about 4500 square feet and that quote came in at 53k.   And there is a federal tax credit shown in the calculation for 26% (2020-2021 installations).    2022-2023 installations get a 30% federal tax credit.  Without that tax credit it’s hard to justify without a doubt.  I’m not sure how big your place is but if you are spending 6-7k a year in wapa 75k quote for a solar system seems high.  

Posted : March 23, 2023 2:29 am
Posts: 2929
Famed Member

I'm one of those grandfathered into the original 1:1 net metering program for 25 years. We have a 7.5 KW system and it paid for itself in just less than 4 years. We get a credit every month for about $150 even with AC running all night.

When we had our system installed 8 years ago, batteries were unaffordable and still are IMO. Instead of batteries, we bought a military surplus MEP-802 diesel generator (only 47 hours, like new) for $6500 which easily runs the whole 3500 sf house. With the aux. fuel tank, it can run for about two weeks 24/7 and is super quiet.

For the few times a year we might need them, I'm glad we didn't spend the extra $50K+ for the batteries because clearly we don't need them. For most homes, batteries really aren't necessary and without them, your payback will be considerably shorter and make more sense (or cents).

Posted : March 23, 2023 8:27 am
Posts: 525
Honorable Member

We had a 10kW system with 37.5kWh of battery backup and a 12K inverter installed a couple of years ago on St. Croix.  Total cost was roughly $50K before any tax incentives.  I actually initially had a single battery but my usage showed the 2nd battery was needed.  I don’t have any net metering (something I need to investigate) but on a typical day both batteries are full by around noon when we’re only minimally using the A/C.  When we’re off island during the summer months and leave the A/C running 24/7 the batteries are typically at 100% SOC by about 3:00pm.  When we’re not here we set the A/C at 82 degrees, mainly to keep the humidity away.  But basically we use more power when we’re gone than when we’re here, as odd as that sounds.  I would estimate we save between $500 and $600 a month on average because of the system we installed.  We did also install a rather expensive (but impressive) 30 kW Kohler diesel generator with automatic transfer switching as additional backup in the event of a major storm.  The generator also backs up our two cottages and garage, which are on separate meters so not connected to our solar.  My thinking has always been equally split between wanting sustainable power and energy independence as much as the raw economics.  Assuming the price of electricity stays the same (which is optimistic IMHO) the payback on the solar will be roughly 7 years (with tax incentives), not counting the generator, which I see as a completely separate precaution, from an investment perspective this is acceptable to me.  The peace of mind it buys (lack of inconvenience) is just an added benefit.  There are also the intangibles, will a solar system with batteries extend the life of my appliances as the power interruptions are measured in a few milliseconds, not sure but it can’t hurt. 

Posted : March 23, 2023 12:57 pm
vicanuck reacted
Posts: 203
Estimable Member

I guess my situation is very different, being much smaller in scale. My house is just over 1,600 square feet, although we do have a 1,000 square foot apartment. We don't have or need full time a/c, having good breezes aalmost constantly. Our system is 3 1/2 kw, with 21 kwh of storage (almost 4 days) for storms. We also use a 7kw Honda inverter generator for backup.

Like vicanuk, we were grandfathered in on the old 1:1 net metering plan and like stjohnjulie, our batteries are normally full by lunch. We sell back our excess power to offset the demand for when company comes. We did add about 1kw to our capacity last year (because some of our company doesn't understand how light and fan switches work), but the couple thousand we spent (including the licensed electrician) will  be paid back next year.

I look at our solar investment more as an investment in self sufficiency - it doesn't bother me when WAPA goes out. After Maria, the previos owner of the house had the panels back up in less tthan 2 days and didn't need to run the generator for all of the months that WAPA was out.

Posted : March 25, 2023 7:46 pm
jaldeborgh reacted
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