[00:00:00] Speaker A: Are you curious about what it's really like to have solar? That's what we're going to cover today.
[00:00:07] Speaker B: Welcome to the your Energy Footprint podcast, where we cover easy ways to lower your energy bill and other ways to make your home more sustainable, with a few energy industry highlights sprinkled in. Hi, I'm Robin Seidoff, and I've been in the energy industry for the past 20 years in both utilities and power generation, and I'll explain everything you need to know for some quick wins in your home to become more sustainable and save some money. Now, let's dig in.
[00:00:32] Speaker A: Today is the last episode in the four week series in honor of Earth Day, and I apologize for being a little late. We were visiting family in Central Asia last week and it definitely did a number on my schedule. Also, just to note that I will be taking the next two weeks off. I will be doing some potty training at our house and so giving myself a little bit of a break until we get through that. Okay, so in case you haven't listened to the other episodes in this series, the first covered how electrification of everything is the solution for climate change that we already have access to based on all of that technology that's already available in the next two episodes, I covered heat pumps and EV's as part of the path to electrifying everything. So in this episode, I'm going to talk through my experience with getting solar on my own house that was installed in early January. So I have a few months of data.
I definitely postponed this till the very last minute, maybe a little bit beyond the last minute, just to make sure that I had all the data I could get.
Okay, so first I'm going to talk about production.
What is the general shape of solar production? You will always get less in the winter and more in the summer. The reason for this is the angle of the sun and the hours of daylight. These are the basic concept. You know, there are calculators where you can get really in depth and maybe they could tell you, the salesperson, how much you would expect to get in the winter versus the summer. But I figured it's really not that important. The numbers don't usually show up on the proposals. So what I did is the annual estimate for my own house was 16,500 kilowatt hours per year. So I divided that by 365, and I should be getting around 45 kilowatt hours per day in order to meet my annual target. And when I can meet the annual target, then I know that the assumptions that I made in my calculator which you can find in the second course on my website. Then I know that my solar installation is economic for me and it's going to cost me about seventeen cents per kilowatt hour, which is great because I pay twenty five cents, the utility even outsourcing my generation.
So one of the things that came up in an episode I was doing a few weeks ago on the states that are best for solar. I redid some analysis on the Tesla website and I do have Tesla solar on my own house and it said that I could generate 20,000 kilowatt hours per year with a few less solar panels than I actually had installed.
So this kind of raised a flag for me because that would be fantastic.
Last year we used 18,000 kilowatt hours per year at my house. So we didn't install a large enough system to assume that we are going to cover our full usage. But if we were able to get that extra generation, then maybe we can.
I do plan to get heat pumps at some point. So then that would mean that we'd be taking that from the grid, obviously. So I called Tesla and talked to the sales team, not really expecting to get much information back, but I wanted to ask why there would be the difference between, between what I got from Tesla last year and this year. And they don't know much on the sales team. I think no solar salesperson actually knows very much at all about solar.
I did confirm that the technology that they're installing today and basing their estimates on today is the same as what I have installed at my house. So that's good news. So I would assume that whatever they're basing their assumption on, I probably will be getting a higher production than was originally estimated. Fingers crossed.
One of the things that I noticed is every time I got a quote from my house, you know, for the past year, there's always a car parked in the driveway. I assume it's the Google satellite view for the day that they took the picture. And it is a car that I don't own. So I think that maybe this picture was taken prior to me buying the house two years ago.
We have taken down some trees and on the southern side of my house that may have been there in the estimate that was originally done. Maybe the image was updated and maybe that was the driver of the increase. So fingers crossed.
So how has my system been performing, you may be wondering. January was horrible. We produce an average of ten kilowatt hours per day. I think. I was thinking to myself, what did I do this seems ridiculous.
We had a lot of snow. It's hard to remember exactly when, but, like, I feel like January, February, we had some big snowfall events.
It does melt off the panels and fall off after, I would say probably two days. But that does give you significant of time with no production. We did have a lot of rain in February, it was averaging 22 kilowatt hours per day. So not close to the 45 kilowatt hours. But in March, the average per day was actually 39 kilowatt hours. And then in April, it has been 45 kilowatt hours per day. Then also the peak production per day, I think driven by angle of sun and hours of sunlight, was almost 20 in January on the highest day. And February was 40 kilowatt hours. March was 65 kilowatt hours, and April was 78 kilowatt hours. I think that in the past few months, we've had a lot of days of precipitation with clouds. Those days are not hitting the peak production, but I see a steady climb in the sunny days and how much we're able to generate.
And we are actually able to be off grid a good bit of the time.
We used almost 1500 kilowatt hours in January and produced only 260 for the month. But in April we used. So far, it's not quite the end of the month yet. We used 960 kilowatt hours, but we've produced over 1100 kilowatt hours. So we're headed definitely in the right direction. I am definitely curious to see what happens with our air conditioning in this summer for how much electricity we use. I do suspect that we will be sending electricity back to the grid this summer if we don't turn on our air conditioning too much.
So, because the spring equinox was around March 20, and we're already hitting the average kilowatt hours per day expected. And, you know, our peak day at the end of April is already up to almost 80 kilowatt hours per day.
I think we're going to be in great shape, and maybe we're on our way to the 20,000 kilowatt hours per year. So I've heard that a lot of salespeople are conservative in their estimate of generation. It's not guaranteed ever, almost ever. But they want to be conservative so they have happy customers at the end of the day. So, so far, this seems to be proving true for us.
For the installation, it did take more than a year from when I submitted my request to install solar, to actually have it installed, which was a little bit crazy, but we have a larger system, so that could have been the reason. Getting through the permitting with the utility, I think, is what slowed it down. I would say the experience was very seamless overall. If I reached out and asked a question, then I generally got an answer in a timely manner. But there wasn't a whole lot of back and forth because it was just paperwork on their end, and they sent me the date when it was going to be installed, and it was installed as expected.
I still do have an outstanding question, which is probably not surprising. I don't know that any company would be that different. But basically, the power wall that I have includes the inverters that turn the DC electricity that's generated by the solar panels into ac alternating current, which is what it's used in your house.
The batteries themselves store electricity as DC. And I was initially thinking like, oh, if the solar charge the battery directly, then you don't have to convert it, and then you lose electricity every time you do the conversion.
That's not the case. Nobody's been able to tell me that explicitly. But basically there are two inverters in the Powerwall, and the spec sheet only includes the specs for one of them.
My neighbor was able to get a verbal response from someone on what the size of the other inverter is. So we'll check it out this summer and see if we have any limitations on our capacity. But it can be crazy, the information that is not available, because I think they don't expect to have customers with any technical acumen, and they don't train their salespeople to know anything about anything except for signing the contract.
So that's something that I hope to be able to help everybody with. If you have any questions, reach out. I can only provide information that I have access to, but I know what to look for, at least. Okay, so now, as far as operation, it has been really fun to see how much electricity we use in real time. My husband, who was not particularly excited about getting solar, had. He was checking into it more than I was, you know, driving home, needing to plug in the car because we were, you know, the battery was full, we were generating. It was the peak time of day. It has been fun to sort of keep tabs on electricity that we're using. I think we're a little bit more familiar with how much electricity goes to wet in our house, and so just being a little bit more conscious and aware, but in a fun way. And I think it's. It's dying down a little bit, wearing off a little bit. Now that we're a few months in. The thing that I love about the system that we have is that we do have a Tesla car. We have the Tesla charger that we just installed recently in March, and we now have the Tesla solar panels and Powerwall. So this is a fully integrated system where we can flip a switch in the app on your phone and charge the car from solar. So you plug the car in. We know that we're not pulling it from the grid. It is just going to top up the car as there is excess solar generation during the day.
This was something that drove me a little bit crazy, because if you're below 40% on the car, then it will pull from the power wall to charge the car, or it will pull from the grid. Pulling from the grid is fine. But I know as an electrical engineer, every cycle on the power wall is degrading it just a tiny bit. So really it kind of irks me. And I would prefer to charge directly from the solar panels to save the wear and tear on the powerwall.
Also, you know, it was. It was recommended that we get two powerwalls with our installation.
I think we do need that because of the inverters for the solar, because we have 20 solar on our roof, and they typically do last us overnight. But we would not be able to get further than one night with those two powerwalls of 27 kilowatt hours. And we do use, I believe, like 50 kilowatt hours per day on average. So it probably makes sense that that that's just enough for us.
I was kicking myself a little bit that I didn't get another powerwall just to reduce the amount of electricity that we might send back to the grid. This is cheaper if we generate it ourselves and keep it ourselves. But that's where the car comes in. The Tesla has about a 75 kilowatt hour battery that we have. So generally, if we drive a bit throughout the day or, you know, during the week, then we do have some capacity to put the overflow into the car. I do think that in the summer, though, we will be over generating and sending electricity back to the grid, but that is also okay because of the calculator in my course. I know that even with the financing, we're paying seventeen cents per kilowatt hour that we generate from the rooftop solar. And that is pretty similar to the amount that we're getting paid by the grid. So that's it for today. Do you have any other questions about having solar at your own house that you'd like to reach out and ask me? I'd be happy to field those questions. You can reach me
[email protected]. Or find me on instagramourenergyfootprint. I'll be taking off the next two weeks and I'll come back with the next series in mid May. Be sure to subscribe so you don't miss our next episode. If you enjoyed today's podcast, please rate and view the podcast to help more listeners find us. I really appreciate it. Our mission at your energy footprint is to educate consumers on ways you can be more energy efficient at home, as well as how to make significant investments like solar while saving money. You can find more information on our courses for homeowners interested in installing rooftop solar on our website, www.yourenergyfoodprint.com. All of our information is unbiased and based on my 20 years of experience working for utilities and as a renewable developer. We are not affiliated with any installers.
