PV Solar Advice Needed

I had a 10kw solar array in NJ for 15 years, but now I am in FL and wondering if I want to install one here. I know the technology has changed from my Sharp 185 watt panel and SunnyBoy string inverters. What should I be looking for? Are micro inverters the better way to go now or regular inverters with power optimizers. Also what brand panels and other equipment would people recommend? What should I expect to pay for an installed system in terms of dollars per watt before and credits or rebates?

Lastly, I unfortunately have the one utility in FL that no longer offers true net metering. Our power costs around 11 cents a kwh, but they only credit you at about 3 cents per kwh for power you put out on their system which kinda stinks. Some installers have suggested going with Tesla Powerwalls or Sonnen battery systems to balance things out but this adds a lot of cost to a system. Is it worth while to go with storage or would I be better off just putting in a smaller system where I would be sure I would always use 100% of output?

Any other advice always welcome.

Personally I would start with a list macro-scale stuff to work out your likely future energy needs:

  • Single-family home? How old are the kids? Gonna be there forever?
  • EV or 2? How far is work etc. When do you drive? [e.g. a Tesla [car] is a “Powerwall” as far as exploiting solar goes]
  • HVAC upgrades soon? Hybrid hot water system/integration? Geothermal?

You should definitely aim for 100% use OR collaborate with neighbors.

Anybody in my mind who buys into Sense & solar (you?) is likely to attempt to live within the energy environment they create … or at least that’s the aspiration … so creating a system you “shrink to fit” is better than one that you “grow into”.

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After running Sense for a month I realized there wasn’t really anything I was going to be able to do to seriously reduce my electric bill so I ran out and bought someone else’s old 2011 Solar System. It has eighteen 240-watt Sunpower panels and eighteen Enphase M-210 microinverters. It came with the original racking system that I have laid out on my roof and it will fit perfectly there. I paid $1440 for the system. I still have to buy the mounts for the rack and get a permit.

I like the idea of the microinverters as you don’t have to run fat DC wires to the ground and if one panel goes belly up it has no impact on the rest of the system, same for shading, only the one panels output is lost. A friend of mine recently had Tesla install panels on his roof and they used a Solar Edge string inverter, but they have something called Optimizers that have basically the same advantages, but it’s still DC that makes it to the ground.

I am paying $0.28/kWh so it will take less time to pay back my system (a year) than it would take you at only 11 cents. That’s not the cheapest I have heard people pay but that would probably have me spending less time looking for cheap charging for my car.

You must be in JEA’s territory, I’m guessing, by the net metering concern. Bummer…

Part of me says to just go whole-hog and get what you need in PV/Inverter capacity. It’ll extend your ROI, but you’ll have it all in one go, and get the tax credit before it expires. When the price of batteries comes down, you’ll already have the generation side done. Mention to your installer to plan for adding batteries later.

I’m in Orlando, and prices have stayed around the $2/watt range, but only if you shop around and negotiate a bit. The big name brands will try to use “alternative math” to justify their high price, and may eventually get competitive. But you should be able to find a local installer that usually offers better service, faster installation, and are quicker to get to a good price.

Good luck in your quest. Any way you slice it, having solar is much better than rewarding the power company that does frustrating things (like mess with net metering).

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Wow, $2/watt? Is that before or after the 30% ITC? The best I have seen is $2.85 and I just got one that was actually $3.85 :frowning: Yes, JEA sucks big time!

Price per watt comparisons should be before the tax credit. Some geographic adjustments for high-cost-of-living areas may be in order, but $2/watt is doable in most areas, from what I hear.

Have patience and be persistent. Be polite yet firm. This is a lot of money, and getting a good deal (both on good equipment and a good price) is worth the time. If they know you’re serious to buy, I have reports that some of the big guys may get competitive.

PM me if you want the name of my installer. Not sure, they may travel to Jacksonville, or refer you to someone there.

Also see if the FL Solar United Neighbors has a co-op running in your area. flsun.org. When there is a group buy active, the prices are usually right in that range.


Unless you work from home or work nights, this sounds great in theory, but in practice you’re at the office during prime solar production time. I wonder how many EV owners claim their car is “powered by the sun”, but only charge at night. Maybe they can claim “powered by the sun on weekends and holidays”



Some thoughts to extend the practice toward the theory!:

  • The challenge of recycling EV and other non-lead batteries is going to have to be met before EV use and in-home Powerwall-like systems become ubiquitous.
    See here for example: https://americanmadechallenges.org/batteryrecycling/

  • Truly global-scale solar and renewable integration inevitably juggles “small-scale” (home) vs Utility-scale solar deployment.

  • As workers aggregate at solar-powered factories and campuses (e.g. Apple headquarters) one would expect that EV charging will become part of “the deal” and will be factored in to worker benefits and the global solar equation.

  • As housing moves from single-family to multi-unit (the inevitable mutation of the “American dream”), shared/aggregated solar generation and EV charging will benefit from economies of scale.

  • Cycling back to the recycling needs above, does it not make sense that a Tesla or any other self-respecting EV should have a quickly replaceable battery? A Dyson vac may well have the same batteries as a Tesla but at least I can swap the batteries quickly on my Bosch vac & tools. As a bonus, quick battery ejection in a crashing vehicle also seems like an effective way to dissipate momentum!

  • This is a cheat argument: Consider a Tesla worker who drives a Tesla to work. One assumes they can charge the car at work … and one would hope from SolarCity solar. With the right metrics, it would seem to make sense to then use that car battery to power the worker’s home to a certain extent. At minimum it’s an easily replaceable and recyclable standby backup battery on wheels. Without too much of a stretch, the same argument holds for a solar worker … or an architect or an IP lawyer or a hospital worker and so on.

  • Bringing this back to Sense: Everything is going to benefit from fine-grained energy metrics and while I would love to own a solar-generating roof over my head and be monitoring that generation with Sense Solar, the beauty I see in Sense is that it’s a transitional product … eventually it will be anachronistic in the same way that data bandwidth limitations seem quaint because there will be some parity between our renewable energy generation and energy consumption. Either that or we’re doomed.

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@32259fl, you really have to look carefully at your time-of-day usage from Sense and do some detailed calculations of how much of your solar generation would offset your usage. The $0.03 /kWh credit is really terrible because at that rate, you won’t be able to recover the cost of your PV system. Battery storage is currently so expensive that it will also kill the ROI of the system and likely result in never breaking even.

  1. Do you have rough data yet on what percentage of your usage is from 10am-3pm vs at other times?
  2. Is your water heater gas or electric? You can often use your electric water heater for energy storage in that you can set it on a timer so it heats up water during maximum production of your solar array and then you use that hot water for the remainder of the evening and into the morning. It’s even better if you can get a higher efficiency hybrid heat pump water heater and in such usage it’s always good to get a bigger tank since you’re going to want to heat up enough water from 11am-3pm to last the whole day.
  3. Do you want a backup battery for power outages? This is really the only case where you can justify the cost of a battery storage system because you can “offset” the cost of the battery storage system with not having to install a separate backup generator. Plus as you surmise with battery storage you can effectively offset the full retail cost of power. However, in this situation you really do have to calculate your nightly usage throughout the year to properly size the system and I imagine it will still have a long ROI.

I got quotes for an 11.5 kW system in South Florida for between $2.50 and $2.95 per watt before incentives.

Whether you go with string inverters w/o optimizers, string inverters with optimizers, or microinverters depends on whether your roof gets any shade as well as how many different roof planes your install is going to use.

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Thanks. All good points. Were any of your quotes from large companies that might do work in the Jacksonville area as well? If so I would appreciate if you share some contact info with me. Is there any significant difference between string inverters with optimizers versus micro inverters. The only significant difference I can see is that you might be better off to avoid the micro inverters if you want a battery storage system as you are going from DC to AC on the roof and then back to DC to feed the batteries.

Email me at my username at gmail and I’ll send you my solar quotes and you can check whether they’ll do work up in Jacksonville. The company I picked is in Boca so maybe not them, but some of the other companies seem to have a national presence.

Practically speaking, there is no significant production difference nowadays between a string inverter with optimizers and micro-inverters. There are a bunch of small distinctions that shouldn’t sway you but that do sway people:

  1. Micro-inverters generally come with 25 year warranties.
  2. If one of your micro-inverters fails, all your other panels still produce while you’re getting warranty service.
  3. String inverters will generally only have 10 year warranties. I did find that I was able to buy an “extended” 25 year warranty for a SolarEdge string inverter. Note that this enables you to roll this into the base price for tax credit purposes.
  4. If you have 20 panels, you have 20 micro-inverters, any one of which could fail.
  5. Of course, if microinverters are 20x less likely to fail, you still win (approximately).
  6. You can do detailed electrical resistance-based loss calculations to figure out whether running DC from the panels to the inverter vs AC from the micro-inverters to the concentrator will result in greater losses. I did not do these calculations and I don’t think I’m going to ask my installer about wire gauges. :slight_smile:
  7. The above also figured in to conclusionless hand-wringing about whether it’s safer to have 240VAC on your roof vs 300-600Vdc.
  8. Different storage systems will have different requirements for their input feed. For example, the latest version of the Tesla PowerWall takes AC power input, while older iterations had both an AC version and a DC version. Bottom line here is that you just accept whatever the limitations are for the energy storage system you get. I considered Pika Energy and they have an integrated system that includes their own string inverter, optimizers, and DC coupled storage system. Similarly, SolarEdge sells their StorEdge inverter that integrates with DC-coupled LG Chem battery storage. Finally, Enphase just announced that they are coming out with their Ensemble integrated storage solution in 2020 that will be backward compatible with their IQ7 line of micro-inverters.

One big question I forgot to ask in my previous post is how old is your roof? Part of my solar decision was that we got a new roof after Irma so it was a perfect time to get solar. This is because, ideally, you don’t want to have to reroof during the 25 years your panels will be on your roof.

I claim to charge my EV from the sun. During the day I feed my excess energy to the power company. At night I use the credits to charge the car. At the end of the year when I settle I have a negative balance. To me that works.

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And with V2G and other systems you can also claim that you’re charging other people’s EVs from the sun via your car!