Solar: whats your story?

Id like to hear from others of their experiences with solar. I have a pretty large yard (~5 acres) that i have been looking into solar options for. How did you go about it? What size array? Backup batteries? Grid tied? Do’s/don’ts? Any suggestions?

My main question is what’s your geography? I think that will be the biggest determining factor, even more than roof direction, angle, etc.

For me in northern Illinois, I have a 7.92 kW system across 22 panels, with all but 2 facing due south. I got about 1/3 rebates from the utility in exchange for selling them my electricity for 10 years. As such, no battery. They’re also still quite expensive. I got in at the federal 26% rebate. Total system cost was $27,406.50 - 8,863.00 from the utility - 7125.69 from the Feds = 11,417.81 total out of pocket. Since August 2021, our system has always overproduced our usage, even in the snowy and dark winter. As such our electricity has only cost $14 a month because that’s the base grid connection fee.

In Feb 2021, my bill was $70.19, and in Feb 2022 it was $13.83. If we saved just $56 a month, payback would be 16 years. However, the 12 months ending With my last non-sole bill in August 2021 totaled $1,393.25, so if my bill stays at $13.83, the payback period now falls to just over 9 years. If electricity prices go up, our payback period goes down even more. We’ve also started transitioning off natural gas to electricity, so our dryer is now a heat pump and a natural gas space heater has been replaced with an electric one.

I hope this helps some.

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I installed solar in 2018 on my roof in central Iowa using a local installer I found after some internet research. It is a grid-tie system, and, because of that, system sizing had to fit within the requirements of the utility in order to qualify for net metering. 4.55kW of panels and 3.8kW inverter (yes, there’s clipping on sunny days; yes, I think it’s still worth it). Note: if you’re going to hire a company to do the installation, know that (like with most things) labor is a significant percentage of the installation cost. Increasing the array size by 25% will increase the total bill by a much smaller percentage (and the increase may be only slightly more than the cost of additional materials).

Should you go grid-tie or not? You should look at what your utility’s net metering rules are. As part of the planning process, the installer asked for the last 12 months of bills. The reason is that the utility calculates the maximum size of the system allowed for net metering based on the average usage of the last year. I could install a larger system, but my net metering “deposit” would be reduced by the percentage of overcapacity. In my example, the installed system was about 1% higher than whatever the calculation came out to be. Each month, the utility takes the kWh I send to the grid, subtract the kWh I receive from the grid, take 1% of that and credit me wholesale price, and put the rest in my net metering balance. If my consumption is higher than my production, the 1% doesn’t matter.

Battery storage? This also depends on what your utility allows. If you have net metering, batteries to store extra solar probably won’t ever pay for themselves just from that alone. However, if you frequently see power outages, losing a freezer full of food once or twice a year plus a hotel stay for a few days (if the weather is such that you can’t really even stay home during an outage) makes the case for storage that can cover at least some part of your house for the duration of the outage. For some people, there’s also some psychological benefit to knowing that nighttime electricity use is still clean energy, so that may figure into your decision as well.

Grid sizing? Depends on what you see your electricity usage being in the next 5-10 years (also assuming you’ll be in the home that long). When my system was installed, we had a fossil gas furnace and water heater (and electric resistance clothes dryer and stove). Since then, the furnace has been replaced with a GSHP, and the water heater will be replaced with a HPWH in the next few years. The next vehicle replacement will likely be to an electric vehicle. All of those upgrades led to/will lead to increased electricity use. If I were to do it over again, I would have pushed my installer to oversize the array and inverter initially so that my current usage would be better covered by my production.

Another consideration for you, given your land area, is whether to do a roof-mounted system or a ground-mounted system. I don’t really have any pointers for you on this. If you go ground-mount, I have heard that it is frequently worthwhile to either have tracking on your mount or to not just point everything south (have some panels facing east for early sun and some facing west for afternoon sun to smooth out your production).

One more thing: if you hire someone to do the installation for you, see if you can find someone in the area who has a system installed by the same company and ask if there’s a referral bonus. The company that did mine would give me (and my referral) $500. Now, whether they just increase the cost of the system by the referral bonus, I don’t know. Even if the company wouldn’t give you anything, the person who “referred” you may be willing to split the referral bonus.

What dryer did you get? I looked at heat pump dryers a while ago, but, if I remember correctly, they either weren’t available (or affordable) in the Midwest. I’m in central Iowa, so there’s a decent chance we’re in the same market region.

I am a similar geographical location as you, @brian5 , NE Ohio. I am a little weary on the route to go as the following

1.) My utility company will not allow me to generate more than I use.
2.) They offer no rebates for going solar. Their argument is they don’t offer rebates that don’t benefit all of their customers.
3.) This I am unsure of, but I have heard they’re very restrictive on who is allowed to do the install of panels if it is grid tied.

With the above, I have been trying to figure out the best route to go. My house usage over the last 15 months was 2265 kwh/mo, however there were two months that were quite a bit higher than normal–removing those put me at 2030 kwh/mo.

@qrnef my dryer is a basic (aged, needs replaced) electric.

I appreciate all of the input. I have been trying to figure out the best way to go about this. Most places with solar around me are bigger businesses, and I haven’t had any luck getting anyone willing to talk to me about the projects.

Sorry, my question about the dryer was for @brian5 . I should have tagged him there.

@qrnef We got the LG DLHC1455v. The electronics store we got it from was backordered for a while, but we got the dryer a week before we “needed” it. That store no longer sells the silver model we got, but Best Buy does: https://www.bestbuy.com/site/lg-4-2-cu-ft-stackable-electric-dryer-with-dual-inverter-heatpump-graphite-steel/6397863.p?skuId=6397863

Three main notes:

  1. It’s a 240v unit, so I needed to install a whole new conduit run, breaker, everything.

  2. It is smaller capacity, and height, than our washer (4.5 cu. ft. vs 4.2 cu. ft.) It’s not a big difference, but we used to more or less fill the washer and we need to be a little more restrained now.

  3. The dryer is a lot slower than our old gas unit. A full dryer load takes 180 minutes vs around 80 or 90 minutes for gas.

A nice thing about the dryer being not as hot is there is a delicates setting. If you’ve got a lady in your house with bras or sweaters that used to need to hang dry, the delicate setting is nice. It runs for 30 minutes, but I’ve needed to give it a second run both times I’ve used that to actually dry the items. On a normal setting, everything has been dry after the 3 hours.

Lastly, I was concerned with the dryer taking the heat from the room, but my very unscientific thermometer I have in the room doesn’t show ANY drop in temperature from before and after a drying load.

I’ve really liked it so far and can’t wait to see if Sense can ever detect it.

Any questions for me?

Mine didn’t either. Unlike @qrnef I don’t think I had any way of going above 100%…kinda. We were right at 99% of usage with 21 panels, but we wanted to get to 100%. We were told by our installer to run more devices and use more power that month so that the 12-month historical usage was higher. We actually ended up using less that month than the same month a year ago, but when our installer wasn’t answering our question about the 22nd panel, they just added it. As our surplus expires at the end of this billing cycle, so far we’re +400kWh. I’m hoping that with a full year and more electric devices, we’ll use up more of our surplus by this time next year.

My utility has set a renewable goal, so the rebate I get from them is so they can say they have x amount of renewable in their portfolio. I take it neither your municipality, county, nor state offer rebates?

I can’t speak to this at all. I know there’s a big DIY solar website that will even design the system for you, then mail you all the components, and it’s up to you and probably a couple friends to install everything. I knew very little about solar and maybe just a little more than a moderate electrical knowledge, and I really wanted that 25 year warranty maintained. I also have no idea how to install these on a roof, so we got an installer.

I’m surprised no one nearby is willing to talk with you. Whenever I see a large install on a roof, I google the company and usually either the company, the installer, or both, brag about their installation.

I hope some of this helps!

I was surfing Craigs List and saw a 4KW system someone was retiring after only 7 years for $2400. I drove by to look at it and they had stacked the panels and told me I could have them for $2400 OOOOR I could take the racking and the inverters and sub panels and lag bolts for $1800. “Wait, that’s LESS”

“Yip, save us throwing it out.” So I got eighteen 240 watt SunPower panels with matching Enphase micro inverters. All the Snap’nRack brackets I would need, and breakers in a sub panel.

This was February, I went home and got my RV and loaded it up with everything. I set up test connections to confirm all of it worked, I built a plan using $25 software and I got an application to add solar to my home from my Utility and a $500 permit to build it on the house. I became familiar with Platt.com and my local Home Depot and a helpful site WholesaleSolar.com. I even found another ad for another 3.4KW system using similar hardware for another $1500.

Got my first inspection in July and my final inspection in September 2019 and PTO that week. I have generated over 22MWh so I have MORE than paid the system off and now I am driving on sunshine. Even wrote an app so my Tesla ONLY charges when there is free solar.

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I have Enphase solar with battery backup. Sense has a provision for detecting solar, but it cannot differentiate between what comes from the grid and what comes from the battery backup; it thinks it’s all grid when the battery is actually contributing. There would need to be a provision for another pair of clamps besides the ones for solar to separate out the contribution from the battery. The way my system is configured, if there is good sunshine or even mostly bright clouds, the battery will charge up to 100% and then run the house during the evening for as long as it can until it gets down to it’s default minimum of 30% charge. During that time there is zero actual usage from the grid. Depending on load calculations, the battery will even send power to the grid at times. I got up one morning at 5 a.m. and the battery was still running the house according to the Enphase app. From Sense’s viewpoint, however, it thinks that power is coming from the grid so it’s assessment of my energy independence is inaccurately skewed, since the battery was charged from solar. The battery is deferred solar. Fortunately the Enphase app does separate these two items out so I can get a better picture of what’s really happening. It would be nice if Sense could develop a sort of “hub” or “bridge” where additional probes could be attached, and it could be programmed to know which is which.

The screenshots are from a while back from the Enphase app when I reported this to Sense Support.


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That second screenshot! “Energy Independence” - I love it. That’s what Sense should have called the “Powered by Solar” section of the app that always confused people.

I have the very same basic design you have though with Sunpower panels and Tesla batteries and also see ‘faux’ solar production at night that is actually coming off my batteries. About half the year we are able to run off the batteries all night and still have power when I get up also. From mid April till sometime in October we don’t have enough due to the A/C. It means Sense’s totals for solar production are off, but I have the Tesla and Sunpower apps for this. None of them match the other due to how they round anyhow.

I am coming up on 2 years with my system installed now. The only incentive I got was the federal tax credit. I think that now has stepped down to 22%. As you can see from the posts one person I believe had a utility rebate. I got a 13.4kW system with 41 Sunpower panels and 2 Powerwalls. Our usage warranted a 16kW system and 3 Powerwalls, and I intentionally undercut us intending to figure out why we were using so much more power in this new to us smaller house compared to our prior larger home. Sense was supposed to be part of that equation. We got the federal tax credit on the Powerwalls also which is what made it work. In order to have a third Powerwall we definitely would have needed the 16kW I feel in order to put power into it. In the end we will reach ROI in a little over 6 years on my system, so ~4 more. I intentionally planned it this way so once we are at ROI we can take advantage of economies of scale and always add more once prices have decreased further. I am SOOO happy that we went solar. We pay a $9.79 base customer charge to stay connected to the grid. That is almost always a requirement and really isn’t a big deal.

How did you go about it? What size array? You didn’t mention where you are and that does play into this. I would consider looking to see if your area is covered by the non-profit solar co-op at https://www.solarunitedneighbors.org/. They help you learn about solar, financing options, batteries, etc. The array is sized based on what your average usage is within the limits (if there are any) that your utility allows. The installers all know how to help you calculate this but you can also do it yourself by going to https://pvwatts.nrel.gov/ or https://sunroof.withgoogle.com/ which help you with basics on sizing and the number of sunhours you have available. Most utilities won’t let you install too much more than your average. My utility allows you to go to 125% only, but there is not a huge advantage to oversize because my net metering payout is 1.5 to 2 cents at the end of the year so it costs too much to oversize beyond what you will use. I buy any power for a little over 13 cents now. It’s better to owe a couple of dollars rather than get 50cents back, imo when I paid a lot for the panels on the roof. Tesla also will give you completely online quotes so you can compare pricing. I used an installer that did installations for a co-op that was in another county nearby my location and had more experience with tile roofs than the one that did my county. I knew someone who was installed with that co-op and knew other people who had used the company outside of the co-op. With the land you have you probably want to do ground mount, that is always more expensive than roof mount but is worth it due to your space.

Backup batteries? Lithium backup batteries are pretty pricey at this point, but depending on your location they can make sense. I am in Florida on the river just over the bridge inland from the ocean in the Cocoa Beach area. We have regular, relatively short outages all the time and then if there are hurricanes even if they don’t directly hit us, everything shuts down over the bridge on either side of us and we often will lose power for extended periods of time. Thus in my area there area lot of automatic standby generators, and we have a portable model that we used at another home when we didn’t have power for almost a month post-hurricane. For most people the expense may not be worth it. For us, it was and we have two Tesla Powerwalls, but we did need three and I didn’t want to spend the money on it yet. Still have the generator if needed. Lead acid batteries can be used but you have to collect a lot of them and it’s pretty much an all DIY thing.

Grid tied? In almost all area you have to be grid tied, unless you can prove inaccessible to the grid and even then the local utility will not give up easily. The advantage is in many areas you have to ability to sell extra power you are not using at that exact moment back to someone via net metering, SRECs, microgrids or other various arrangements. You want this, even with my Powerwalls I still send a lot of power back to the grid for ‘storage’ essentially. Incentive power buyback arrangements all depend on your area and your utility and they vary all over the place. Incentives to installing solar are the same, they completely vary.

Other thoughts. My utility got the state to pass a minimum customer charge that they are going to start in June that will be $25 though that includes the base customer charge so in the end what I did with not having too much solar makes sense and I can just use a little more A/C in the summer if we get nailed with this. My spouse will be thrilled to have more A/C. I have another non-solar property with another local utility that already started charging for this in January. The normal bill was only $11/ month but they are charging a $30 minimum. This is why it is good to be aware of what is happening in your area. The Solar United Neighbors group is good for learning all these details too.

Good luck. Hope this helps.

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