Many homeowners might have given up and bought a different home when faced with the utility hassle that landowner Derrick Zearley experienced. Instead, he looked to solar + storage to avoid interconnection altogether.
Derrick Zearley’s family resides in an off-grid home in South Carolina that’s powered by solar with backup battery storage. Firefly Solar
Zearley purchased land located on a boundary of two utility territories in Anderson County, South Carolina — Duke Energy and its energy cooperative Blue Ridge Electric. That led to a back-and-forth between Duke and Blue Ridge to determine whose territory it actually was. When Duke Energy laid claim to the plot, the next step in the process was getting signed petitions from Zearley’s neighbors to give right of way on their properties to run electricity to the site.
But after distributing the petitions, no neighbors signed. With half a year lost to the utilities and unwilling neighbors, Zearley reached out to Palmetto State Solar (now Firefly Solar), an installer based in Greenville, and pitched the idea of an off-grid solar system to be built for, and alongside, a 5,500-sq.-ft building in an unelectrified remote location in South Carolina.
“I’m somewhat of a cowboy, so I was interested in the challenge and kind of being able to give the utilities the middle finger after they gave us the run-around,” Zearley said.
Residing in a remote location like this usually comes with additional energy conservation requirements, such as limiting household electricity usage to when solar panels are receiving the most sunlight. But Zearley didn’t want an off-grid home with energy limitations. He wanted to build a full home with an attached workshop that electrically functioned on his own terms, with power after sunset — not a cabin or a trailer that relied on a few measly kilowatts of solar power.
Raising a solar-powered barn
Firefly Solar didn’t have much experience with off-grid projects prior to this one.
“We get calls from time to time from people who want to go off grid, but for the most part it’s not feasible, primarily from a financial perspective,” said Aaron Davis, owner and president of Firefly Solar. “So, when Derrick called, I went out and visited him and I sort of threw out some rough numbers of what he might expect, and he was willing to get into that, especially because of the difficulties he had with the utility companies.”
Zearley’s home resides on a 27-acre property, with about six acres being open yard. The building he wanted was a pre-engineered steel structure with a single slope roof in a color that takes inspiration from red barns found in farming communities. Zearley likened it to “barndominiums,” which are similarly wrought structures known for ease of construction through prefabrication and energy efficiency.
Firefly was willing to do the project and Zearley was willing to put down the money, and the plan was for solar + storage technologies to primarily power the site.
Firefly Solar installed a 19.5-kW solar system atop the home, slightly oversizing it to compensate for the roof angle. Firefly Solar
“I think it piqued my interest once I learned that he thought the technology was available, but no one’s really done it yet in our area, and so there wasn’t anything really to mimic, to design after,” Zearley said. “It was kind of an interesting challenge, I think, for the both of us to figure out how to do this. Then once we started going down this road, I told the energy companies that we didn’t need them anymore.”
To take the site off the grid, Firefly Solar installed a 19.5-kW solar + storage system made of 60 Panasonic 325-W modules, 60 Enphase IQ 7X microinverters, IronRidge XR100 racking with S-5! ProteaBracket metal roof attachments and four Tesla Powerwall 2 batteries. And just in case solar doesn’t cover it, a 20-kW Kohler gas-powered backup generator was installed too.
Firefly lucked out, because when Davis reached out to Tesla about the project, the company was just starting an off-grid program. Previously, the warranty language on Tesla storage hardware didn’t cover off-grid applications. Just as the Powerwalls were being installed, Tesla was rewriting operating code to make the hardware work in this application.
“Derrick approached this with kind of a ‘no compromises’ attitude and what he wanted was basically a home that was off-grid but didn’t seem like it was off-grid,” said Ryan Wagler of Firefly Solar, who was the design project manager on this project. “Typically, with off-grid you’re talking about, ‘All right, we need to limit your usage and we need to install LEDs everywhere.’ With this, we really just went for it and we installed the capacity to handle the everyday usage of a home of this size, and that was new for me.”
The building’s roof is angled flatter than typical pitched rooftops, but the surface area made it possible to fully conceal the 60 modules from observers at ground level. The panels are mounted flush to the roof and the system is slightly oversized to compensate for the angling, using Panasonic 96-cell modules, hardware that Firefly has used extensively.
“Amidst all the uncertainty, we felt we needed some products we could trust,” Wagler said.
Outside of the challenges presented by installing solar with new construction on an off-grid site, Firefly was also working alongside several other trades. Davis said, at one point, there were seven different contractors onsite. Since there was no electricity on the property yet, everyone was running off of gas-powered generators. That is, until the solar was installed, then all the trades could run their equipment without generators.
Zearley, Firefly Solar and a number of trades managed to build a home from the ground up that operates entirely off the power grid. Firefly Solar
Retrofitting a home to be off-grid usually comes with the added challenge of compensating for switching out existing electrical appliances and equipment that are high energy. Heating and cooling systems, well pumps and other necessary home loads require a lot of power at startup.
In Zearley’s case, with new construction, it was possible to make sure every major electrical load used a soft starter for less initial voltage, since every building trade was present at the same time.
“Now, trying to get the electrician, the HVAC guy, these different components of construction together because they had absolutely never dealt with anything like this before. It was a bit of a challenge,” Zearley said.
Still, Firefly contractors were able to ensure everything from the well pump to garage door openers were on soft starters as they were being put in.
“The opportunities outweigh the challenges in this case, because we were able to build in exactly what we needed to the system,” Wagler said. “If you can have some input into how those things are chosen, you can actually make a big difference in how the system works and functions down the road.”
An off-grid home and workshop without energy compromise
Zearley ended up with the home he and his wife hoped for. Seven-foot storefront glass windows look out into the wooded property and meet a concrete slab floor that matches the countertops of the kitchen.
The Zearley family stands in the garage of their off-grid home, next to the four Tesla PowerWalls keeping the lights on after the sun sets. Firefly Solar
The roofline extends past the structure, creating a covered porch. The windows open garage door-style to bring the outside in when the weather’s fair. The shop, or as Zearley described it, his “man cave,” is open air, and a section of the home protrudes into the building, creating a mezzanine where they can look down into the space.
And solar is powering it all, with energy storage keeping it running after sunset.
“It’s just a neat feeling to be in the house and know that you’re responsible for generating your own energy,” Zearely said.
Projects like this demonstrate that solar + storage technologies can be a viable, consistent energy source even in larger applications.
“I think there’s going to be the microgrids and small communities with distributed energy resources all sort of coming together,” Davis said. “There will be a lot more control as this evolves, and a lot more people breaking away from monopoly utility companies. I think a lot of this depends on the research and development that goes into storage in the coming years.”
I have enjoyed reading and trying to self educate myself about how to hook up solar. I’m in a 2000 sq ft home on 9 acres and hand made well. I would like to and am ready to get set up solar. I lived very simply for years 6 miles off grid raising my babies in the mountains living extremely simplified with 2 panels that ran a slow pump to pump water and minimal lights inside the house. I’m not willing to live that substantially at this point but want to be energy independent. In Washington state we are required to pay a basic fee to PUD even if we are generating all of our own energy through solar. I want independence and have done many things on my own as a single parent living in the mountains such as electrical wiring, creating gravity water systems, sheet-rocking, tiling, etc… I think I can save lots of money by doing or hiring a diy person to help me do it myself. I enjoy the challenge and want actually understand the system I have instead of being dependent financially on others to keep it going for me.
Amen to all the folks pointing out the costs involved here. It must be quite nice to be rich and young. This dude’s car costs more than my house! I’m just jealous of course, and sick and tired of all the stereotypical American over-engineering. Who needs a 5500 sq ft house? Why use the most expensive panel on the market? I’m sure he would’ve paid about the same dealing with Electric Companies here. I’m in NC and costs per pole = $12K for new construction. I’m designing and plan on DIY’ing my own much more humble system (9.6KW solar, 30KWH storage, 12KW Sol-Ark inverter), for about a 3rd of what this dude paid. I’ve been saving for years.
Try something like Solarwholesale dot com or bluepacificsolar dot com for DIY kits and BOS components. I like the bluepacificsolar site best, they give a lot of information to consider for on grid, off grid and grid interactive systems.
I envy those who can afford these things. I’d love to go completely off grid, but there’s no way for us “poor” folks to manage that. On top of the cost, our town has very unreasonable restrictions on installing solar panels (because the city owns the power company). Unless you’re pretty well off, you just can’t do this around my area.
I like his system,I have a 3k system DIY system myself does well for me just need more storage
We have a self built solar home system also. We have 2kw of qcell panels and 7kwh of Lifepo4 battery storage. Our heat, hot water, clothes dryer, and kitchen range are all natural gas. We have enough battery storage to make it through periods of overcast days. The 2kw of panels is enough to provide for our every day usage and keep the batteries charged on sunny days. We have a 1500watt inverter for our low load needs, and a 3000watt inverter and separate wiring for our larger loads. We also have a Chevy Volt with a 1500watt inverter as a backup should the need arrive. On long stretches of sunny days we can also charge the Volt. It’s just my wife and myself in our mid seventies so we really don’t use an a lot of electricity. So far the system has been meeting our needs, even in the winter. The whole system ran a little over $7500. I built the system mostly from off the shelf components that I found mostly on either EBay or Amazon. I bought wherever I could get the best deal. With our particular circumstances the system works great for us.
Pretty much none of the LiFePO4 batteries are cheap, but there are some companies that will sell you the basic battery pack. Simpliphi has a 3.8kWh pack and can be stacked for more capacity. Humless seems to be selling a 5kWh battery pack, LG Chem has just redesigned their battery pack and they seem to be trying to compete with TESLA in pricing.
This story makes it sound like a complete off the grid home electrical system has never been done before which is utter bullcrap. I’ve got a friend that built his own off the grid system at least 8 years ago. His system consists of solar and wind that powers a battery storage system with back up propane generator. This system runs his large home with all the modern conveniences mostly on the wind and solar and only occasionally needing the generator. While electricity was available to my friend, he want to be self reliant.
Relax Kevin, The wonderful thing is we can all experiment and adapt the different technologies to save money and/or be free from black outs and brown outs. Who went off grid first will not matter in the end. JKF
No, they just said it had not been done in his area, and the contractor hadn’t done it before.
Re-read it.
My 500 watt system provides 99% of all my needs. Cost $1,200 including the new 2,200 watt back up generator/ inverter and storage batteries. Rarely use my generator.
That is awesome! Your footprint is small. Wish more people thought like you. I have a 500 watt system with about 275 amp hour batteries back up. I’m still on grid, little at a time and I hope to be off sometime.
Your story and Bob’s story are important teaching experiences to those who balk at solar PV. We are institutionalized into the thought, I have a 200 Amp 240 Volt house panel, that’s roughly (48,000) watts and over 24 hours is 1.152MWh. Not true for most folks, not even close. You’ve proven it. On average in the U.S. the average home uses 1.5 to 2.0kWh as an average house load during the 24 hour period. Does one have current surges on high surge items like well pumps and air conditioning compressors of perhaps up to 100 Amps for milliseconds throughout the day, sure, but for most of the time you could supply the “running” load needs of the home with a 6kWp solar array and a 20kWh battery pack. This article is about an off grid house, but, what if you are tied to the grid and use it for only high surge events and high draw pumps and appliances?
Sounds wonderful, and suspect that the wealthy find it a viable option. I am 70 and generate less than $1,000 per mo. Am saddened that it’s a bit too late. Continue to keep the dream alive!
My entire social security is $664 a month with very little savings, often 0. My solar system cost me only $1,200 including the back up generator inverter bought new and very rarely needed. Solar system easily provides 99% of all my electricity, 100% off grid. I am 68 here in 2021. I also keep 2 of my vehicles license d and insured, and keep all property taxes up. I even spent most of 2020 on my income, in Hungary. If my SSI was $1,100 a month, I would feel like a millionaire , and build a 5,000 square foot off grid home with all that extra money!!!
All of the above is nice and I would have done it however in the great State of Florida it is in the building codes that you have to be connected to the grid to get an occupancy permit. So no off grid here.
Kind of counter intuitive. Florida is one of those places where storms can be brutal and power can be out for days. What one can do is set up a grid interactive micro-grid and use solar PV with smart energy storage (most of the time) and use the grid for arbitrage of your own ESS and if the power does go out, be able to switch over to off grid to a critical circuits circuit breaker panel that allows things like some receptacles, lights, ceiling fans and the refrigerator/freezer and perhaps the microwave to run independently on solar PV and battery power for days, weeks, months. Grid agnostic is a little better in that when the grid is up you can “buy” their off peak or super off peak power to store in your battery for the next day when the sun is just coming up and the solar PV is not making good power yet.
Yeah, but you could still do the same, and even though you’re technically “on grid”, you won’t be buying their power, and could possibly be selling TO them.
I am on the Grid in Indiana where it is a little bit colder in January and February and my system is 25% bigger, 80 325 kw panels but it would take an enormous battery pack to make it through the cold months. Luckily for me we are on a one to one exchange with our grid partner. Also our panels angle with the season from 18 degrees in the summer to 45 degrees in the winter. Plus I to have a 24 kw propane generator since my inverters shut off if the grid shuts off for safety reasons for the grid owners employees. If I were to build from scratch I would definitely start with a large ground water heat pump. I hope and pray that the Lefts New Green New Deal sides with home owners on the Equal Exchange so I do not have to install batteries or at least Grandfather we solar owners the deal we started with. Our Grid Cost is $16.05 a month.
Since most homes use more electricity to cool in summer and more gas to heat in winter, your whole argument here doesn’t make a lot of sense.
Here in Sunny California, even with solar panels and batteries, the criminal mobs ( ops, missprint – I meant to say PG&E, SDG&E, Edison) are still required to charge “grid fees” as per state law. It supports those massive kickbacks ( ops, I meant to say it shares expenses of the campaign contributions and vacations for Congress-persons and California Public Utilities Commission “expenses” in guarding the public from high rates).
There was a recent white paper written by an affiliate of the CPUC that predicts both SCE and PG&E will have average electricity rates of $0.30kWh to $0.35/kWh for PG&E and SCE by 2025 to 2030. SDG&E is predicted to be at ($0.47/kWh) in this time frame. A move towards grid agnostic solar PV systems is a wise decision in mandate madness California.
Would you please provide a link to the white paper?
I couldn’t find the original paper, but the CPUC does have this one: https://www.cpuc.ca.gov/uploadedFiles/CPUC_Public_Website/Content/Utilities_and_Industries/Energy_-_Electricity_and_Natural_Gas/Rates%20En%20Banc_white%20paper_v.2.0.pdf
offgrid with 19.5kw???
you must not have kids and use very little power
I have a 24kw system and it generates about half my daily usage.
kudos to you!
Wow. I living was mostly off grid with a 1kw system. I could even run my ac unit when the sun was shining (only had 2kwh of storage so had to stop overnight or run the 3.5kw generator).
Even in my place now 3kw would be way more than enough for my usage except for in the height of summer
Guess you missed the photo of the guy with his wife and three kiddos.
Fascinating! Owner should by another EV: Tesla’s don’t have vehicle-to-grid possibilities. Then he can also store power via his car and use it if needed, or bring extra power to his home.
I don’t think I would be on speaking terms with my neighbors. What kind of Aholes say no to someone needing to run electricity to their house?
I think after I got some stuff paid off I would buy some more batteries and solar panels it looks like he has plenty of room. How about 5 windmills about 10 ft in diameter would help for when the sun isn’t shining. I think I could make something like that.
If they had to clear a wide swath of trees to run the lines, you might say no too.
PG&E won’t hardly clear trees in California. Different crews to mark and cut live and dead tree hazards. Very inefficient. I keep asking them to cut more on my place but tbey won’t. So more fires.
Nice setup, but with no shading issues, firefly is could have built this much much cheaper, simpler and just as reliable, by not using the microinverters and going with off the boat from China batteries. Could buy a full blown car with twice the capacity, with bidirectional charger, for the cost of 4 powerwalls.
Even with tax credits it had a cost 30 to $40,000, I would really like however for some genius to figure out how to generate electricity from the temperature differential was a closed water loop system that they currently use for air conditioning by digging a tube 6 or 10 ft below soil level
That’s probably similar to the cost he was facing to run new lines and poles. Then he’d be on the hook for life, paying a monthly bill to the power co. Now he’s free and clear.
I have 3000sqft home, my own well, vineyards, 2 heat pumps, all electric appliances, and an EV. 17kW of solar, 4 Tesla powerwall 2s, and I no longer have utility bills at all. We stay connected simply because Southern California Edison pays us a measly $0.02 per kWh. I commute with the car and still only use about half of what we generate.
I have installed a similar system and chuckled about the Contractors using generators to run their tools as that’s exactly what happened for the first few months until the metal roof was installed. Now they’re running off the solar and batteries. They’re in rural Kansas where the utility was going to charge a fortune. The customer has $35k in a 12kw system with 30kwh of lithium rack batteries. They are running propane for heat for now but I think ground source heat pump is in their future.
I really appreciate the robustness of a PV & battery system where each panel has its own inverter and so can be regarded as an independent supplier of energy.
With 4(+) PowerWall batteries, can they also be regarded as an array of independent units?
I like the idea of a “smart ESS” to be able to ration the power around the 24 hour day.
Could a smarter ESS have an annual prediction to ration the power around the year?
I would like to be independent of the fossil fueled backup generator.
Could it be compressed air started, bio-diesel fueled?
There was no mention of the heating/cooling system details.
With all that land I assume that a ground source, heat pump system would offer the best year round efficiency, and be electricity powered.
A mini split heating/cooling unit was installed. It was sufficient through the summer, but in the winter the generator would come on more than desired. He installed a wood burner to heat the home, and that sufficed for the rest of the winter. The generator is never needed now. (Or extremely rarely.)
Nice to see the guy who installed the system commenting. Nice project.
“I like the idea of a “smart ESS” to be able to ration the power around the 24 hour day.
Could a smarter ESS have an annual prediction to ration the power around the year?”
Sonnen ecolinx 30.0 has some smart home ability and can be set up with a communications link that can talk to smart appliances. One can control loads in the house from a smart phone APP or the Sonnen HMI itself can be programmed to schedule loads. An example might be an on demand or all electric hot water heater. If there’s no one home during the work week, one could program the water heater be off during the day and on in the late afternoon and early evening. There are actual “microgrid” systems with modular energy storage being introduced to the public, one actually has choices from mild to wild. Simpliphi, Sonnen, GENERAC PWRcell, Humless Universal, ELM Fieldsight. If one goes towards the larger commercial and industrial microgrids that are three phase based, there’s a whole ‘other’ group of medium to large scale microgrids available.
Going Solar + Storage is great. Keep it up.
Here in Northern California, PG&E territory it’s not only the cost of the interconnect to the “public” (I keep asking where the public is in the California Public Utility Commission) grid and/or the delays involved have driven homeowners to look for alternatives. We have one customer building a big home who was told it would be $300,000 and almost 2 years to get power to his property which isn’t in a remote or even rural area. We designed and installed one of our Interactive Energy Grid™ systems using solar, batteries and and a propane fueled micro-cogeneration system (along with a high-efficiency boiler) to provide and distribute both the electrical and thermal energy needs of the home. The smart control system acts as the home’s energy broker always utilizing the most efficient energy source(s) to power the residence regardless of the circumstances. While the overall cost was more than the interconnect fee the home is energy independent. The system will not only pay for itself in 12 years based on utility bills alone and the infrastructure added immediate value to the property. Another advantage is the system is future proof; it can use energy from almost any source (electrical or thermal) that may become available in the future. The ability to manage multiple DER’s to satisfy thermal and electrical needs in the most efficient and economical manner possible is the future of micro-grids. We treat on and off-grid installations very similarly because PG&E’s “Public Safety Power Shutdowns” (a euphemism for; we are turning off your power because we didn’t maintain our distribution system and its huge liability) can last for many days, with the difference being how we manage the loads, shedding the large mechanical loads when the grid is unavailable to maximize the amount of time the DER’s can support the “essential loads.
Off grid systems are way more common than people think. There is a whole community online. Start with YouTube. This system would be considered high end and somewhat experimental. My off grid ranch, has 10kw of solar panels, 10k low frequency inverter, and 684AH of battery storage, 14k backup generator. So far spent $17k. Never will ever need the power company.
I put together a do it yourself system much smaller capacity with surplus batteries for my summer cabin. Batteries are powered with solar, wind and a back up DC charging system that powers a 5K/10K inverter. Sometimes we run the gen for 20 minutes before bedtime to top off the batteries for the night. Heat and refer are propane. Simple and cheap. All done for under $5K.
Don’t let anyone tell you that you can’t do it.
You are still using propane and a generator. That is not a sustainable solution. Using solar and batteries is not requiring any fuel source for years.
Its like something I heard a while back. A world full of Prius’s is world still addicted to oil.
Yeah they will have problems in a power outage. The power available will not suffice with Telsa’s batteries
The home is off-grid, it is in a constant “power outage”
That’s was a good one. What was he thinking?
He has installed four PowerWalls that have a combined storage capacity of 54 kWh. That is about 150% of my daily energy requirements and I have a very average home of 2100 square feet. He also has enough solar to generate about 75 kWh per day, based on NREL projections. Therefore he can fully charge his batteries and still have around 20 kWh of energy left over to run the house in the daytime. I have installed two similar systems in Tennessee where we have about the same solar irradiance as this system and this will definitely work. In case we get into monsoon season and have 9 days of clouds and rain in a row, there is always the generator there for backup. All he lacks is electric vehicles and he should be able to forget gas as well.
He has a Tesla. Look at the picture
“In Zearley’s case, with new construction, it was possible to make sure every major electrical load used a soft starter for less initial voltage, since every building trade was present at the same time.”
An overall good point, either specific energy star motors, pumps and appliances or “soft start” feed the motor to be used. This set up, this guy has the room on his roof and overhangs to install 5 times the solar PV array capacity he has now. Something like $85k installed for this set up. Some installations by the utility are charging around $10k per pole to the property (IF) you can get a right of way. Just 20 years ago, this would have been a $200 to $250k system installed. Keep going, get the “packages” of solar PV + energy storage that can be fully off grid (or) for less one could have a grid agnostic system, if you happen to have a grid connection great, it will be backup, if not use a smart ESS to determine and control loads in the home to run off of solar PV and battery over a 24 hour period. Solar PV inverters are becoming more robust and there are some that have 25 year in use warranties. Careful applications of these technologies are making longer lasting systems, making the utility less useful for one’s daily energy needs.
How much is the final cost ? Without that information one cannot even consider such as this. Without the final cost where will the funds come from. I am a general contractor and I am interested in this information.
Your question is relevant and this article lays out a specific case. This guy wasted a lot of time trying to get a right of way to put in an electric feed to his property. Each property will be different. Some rural examples of a developer buying a few acres in a remote area, breaking the properties into smaller acre or so lots then developing them have run into utility proposals like $1million dollars or more to extend a utility feed into the development area. Laying in utilities like buried electric to each lot can cost from $100k to $500k a mile. Search for one such project: Silvies Valley Ranch, Burns Oregon. This development used Humless Universal Microgrids for each home built.
I live in Gainesville Florida there’s a lien on my property I can’t get financing to put solar on my house and I’m being strapped to light bills between 250 and 325 a month and it’s very expensive and I was hoping there’d be a better way I could possibly do it please give me info thanks
Well if you’re fortunate enough that your time is so valuable that cost is no option than your reply makes sense. Otherwise I agree with John. This sounds and looks cool but so does a $500K Ferrari.
The VAST majority of people couldn’t afford anything near this and won’t for decades, if ever. “Green” energy is great but everything is for the 1%
Things have changed in just the last 5 years. solar PV is cheaper now to adopt than it was 15 years ago, 10 years ago and I’ve been using the simple solar PV roof array that is grid tied for 16 years now and can say payoff in less than 15 years is ‘probable’ across the U.S.. Those folks that bought a larger array and got a home charge station and a use EV like the Leaf, are able to pay off a relatively large solar PV system in about 5 years with monthly energy savings of not having to buy electricity and gasoline for the EV. I can assure you, I’m no where near the 1%, maybe not even in the bottom of the ‘top’ 40%.