We recently hired 3 Guys Solar to install a 10.4 kW grid-tie solar system on our house. They installed 36 Axitec 290 watt mono panels with DC Optimizers on Iron Ridge racking, and a 10 kW Solar Edge grid-tie inverter.   Our final price was $2.409 per installed watt (Summer 2018).     I say final price, because we had a wide range of quotes from multiple companies, and several companies lowered their initial quote upon seeing quotes from the other companies. Our home,   with a new asphalt shingle, south facing roof with plenty of room for panels was about as simple and optimal as you can get for a solar install, so if your roof is more complicated (tile, metal, gables, vents, skylights etc) you can expect to pay a bit more. Read on for the full story of how we got to this final price.

Initial Quotes
We had initial quotes from the following companies: 3 Guys Solar, Tesla (Home Energy, formerly SolarCity), 3D Solar, and Vivint Solar which ranged from a low of $2.60 to a high of $3.65 per installed watt.

Vivint Solar is based out of Utah, has a minimal presence in Florida, and does not have good reviews with the BBB or Angie’s List. They were also the highest initial quote at $3.65, and I was dealing with a sales agent in Utah over the phone instead of in-person, so I dropped them from consideration relatively quickly.

3D Solar and 3 Guys Solar are both local central Florida Companies, and were the lower price options, with initial quotes at $2.65 and $2.60 per installed watt respectively.   3D Solar offered a better warranty (25 years on Panels & Inverter, 25 years on roof penetration, 12 years on workmanship, plus a $10,000 warranty on physical damage to the panels), but they are located relatively far away from my home, while 3 Guys Solar is based much closer to my house and many of the people I was dealing with lived within a few miles.

The 3 Guys Solar warranty period while reasonable, wasn’t quite as good: 10 years on workmanship & roof penetration, 12 year (manufacturers warranty) on the inverter, and 25 years on the panels, and they do not include   physical damage coverage for the panels, which must be covered under our homeowners insurance with its associated deductible.

Tesla (Home energy division, formerly SolarCity) is a national company, but they have a strong presence in Orlando, and their sales representative also lived close to my house. Their initial price was $3.20 per watt, but as soon as I showed them my quotes from 3D Solar & 3 Guys Solar they said that they could go down to $2.75 per installed watt.     Tesla includes 20 years of system maintenance & repairs (workmanship warranty), which can be extended to 25 years if you are referred by a current Tesla customer, or if your sales representative says you are….   They also provide 10 years coverage against leaks (roof penetration).

A unique feature included in Tesla’s contract is a “system performance” Guarantee. Basically, they promise that the system will provide a specified amount of cumulative power each year.   (The promised amount generated per year goes down very gradually as the system ages to account for normal panel degradation over time. )   If the system does NOT produce the promised amount of power, they will write you a check for the cost of the “missing” power.   This performance guarantee was unique to Tesla, but in the end I decided it was not actually worth much.   The problem (as always) is in the small print. In my contract, the “agreed price” for any “missing” power was only 6.456 cents per kWh. My electricity from Duke currently costs 11 cents per kWh, and in 10-20 years I expect that to go up by quite a bit. So basically, if a solar panel failed and didn’t produce energy, instead of replacing it (as all of the other solar panel manufacturers would do), Tesla has the ability to just leave a failed panel on your roof and cut you a check for only around 1/2 of the actual lost electricity.   This “system performance” guarantee could be worthwhile if you were able to negotiate a more reasonable “agreed rate”, but I didn’t find it to be a compelling sales point.

I was really interested in the Tesla Powerwall, as spending 3 days without power after Hurricane Irma makes you think about how nice it would be to be able to run off your solar system independently even when the grid is down, something you can’t do without a battery backup unit. However, it isn’t economical to pay $7,000+ just to have power for a few days a year (A $500 generator + $6,500 worth of gas goes a long way….).

But, Tesla offers a referral program, where if you refer 5 other households who install solar you can get a Powerwall added to your system for free. This is a tempting feature, especially if you are already pro-Tesla.

Final Prices

And here is where things get interesting. 3 Guys Solar and Tesla were my top two provider choices. I was initially planning on paying the $1,000-$1,500 premium and going with the Tesla brand name, as they were only 0.10-0.15 per installed watt more than the small local companies. However, the local 3 Guys Solar rep called me and in an effort to keep my business lowered their quoted price to $2.40 per installed watt. (The actual invoice worked out to 2.409 per installed watt, or almost 2.41, which is much like how gas stations price gasoline, but I didn’t bother to quibble over the $93 difference.) This sounded good to me, so I went with them and paid my deposit.

I should also mention that the West Orange Solar Co-Op had selected Wayfair Energy as their solar provider, and their negotiated rates could be slightly lower than this. (As low as $2.20 per watt with S-Energy Panels, SunnyBoy inverter and no DC optimizers, but the comparable quote with DC optimizers was in the $2.35-$2.43 range depending on panel choice.) A Solar co-op is a nice way to get this equivalent price negotiated for you if you don’t want to do the legwork of dealing with multiple competing quotes yourself, but I was not impressed with the online reviews of Wayfair energy, and we would have had to wait multiple months for them to get around to us if we went with the Co-Op, so I decided to pass on them. However, seeing the solar Co-Op prices makes me think that the $2.40 price I paid is very close to the “best” prices for my area this year.

How Tesla lost my business

When I told the Tesla sales representative that I was going with 3 Guys Solar because they had a significantly lower price, he came back and said that they could lower their price again and offered $2.48 per installed watt. (This would mean that Tesla was only a $900 premium over the local company, and make the decision much more difficult.)   Unfortunately for Tesla, I had already paid my deposit with 3 Guys Solar, so I was effectively out of the market.   I don’t regret this choice and have been quite happy with the 3 Guys Solar install, but if Tesla had led with a better price, or indicated that I should call them for price matching opportunities if another company lowered their rate I may have made a different decision. I get the impression that Tesla will never exactly match prices with small local companies, but that they can afford to offer prices at only a small ( 0.08-0.10 per installed watt) premium. So if you are set on the Tesla brand, make sure you present them with any counteroffers to see what they are willing to do before making your decision. [But you will probably end up paying a small premium for the brand.]

Updates:

•  Results after five months of production.
• Results after 1 year of production
• Results after 2 years of production

Duke Energy being a money loving greedy bastard update. This regulatory change allowing a $30 minimum bill will increase my payments to Duke Energy by 53%.   It will probably extend my solar systems payoff time by one year.

Reliability Update: We have had our Solar Edge inverter fail twice. The first time was a few months after installation, and 3GuysSolar replaced it under warranty within two weeks (they had to wait for SolarEdge shipping). The second time was in 2021, and 3GuysSolar replaced it again under the SolarEdge warranty (this time with an updated but equivalent power production model). In both cases 3 Guys Solar detected the failed inverter and initiated the repair procedure with no effort on our end.   We also had one Solar Edge optimizer (the box behind each solar panel on the roof) fail in the first year, which 3GuysSolar replaced under warranty.   I have since found this review about the reliability of Solar Edge inverters online, and our experience makes it very believable. Overall I’ve been very happy with the service provided by 3 guys solar and the warranty coverage provided by SolarEdge (in each case we only lost about $50 worth of solar electricity production). However, if I were in the market for a new system, I might consider the SMA Sunny Boy (I especially like the “power outage plug” backup power option on that unit.)