Video: Introduction to Solar Electricity

Georgeann Moss:
Thank you, Timothy. Paul, you want to pull up your presentation now? There it goes, Thank you. Good afternoon, everyone. We're going to start in about two minutes. It's 11:58 right now.

(Pause, setup, background noises)

Okay. It's straight up noon. We'll go ahead and get started. Good afternoon again. My name is Georgeann Moss and I am the Executive Administrator of Sustainability Outreach and initiatives for Dallas College. On behalf of the sustainability outreach and initiative team, our wonderful sponsor and partner Earth X and Dallas college, we welcome you today to this Sustainable U event. For those of you who have never participated in one of these before, we have two ways you can communicate with us. The first is chat. Use that if you just have comments, if you want to make kinda rolling comments. But if you actually have a question that you want to have answered, we will relay that to the speaker, but just type it in the Q&A box that you'll see at the bottom of your screen. And the reason that we ask you to do that is with the questions, we can actually respond directly to you. Whereas with the chat, people keep adding their comments in and we can't ever reply exactly to your question. So, and again, you can use the navigation bar at the bottom your screen to do all these. At the end of the webinar, we're going to ask you to fill out an evaluation. And we really appreciate it if you do that because that helps us continually improve. And I do have to say that we were delighted last week, we got a comment from one of the attendees who had been to many of our webinars and said that last week was the smoothest one he'd ever been to. So, we are happy we’re getting better and we trust that today all the technology is going to work. Everything's gonna be great again this week. So, the webinar is going to be recorded and it will be available on the Dallas College website in about two weeks after we get it transcripted and make sure that everything is ADA accessible. Also, Paul's, our speaker’s, PowerPoint is going to be available on his website, which we will give you the address of that website at the end of the… at the end of the webinar.

So, I've already mentioned that our guest speaker today is Paul Westbrook. He… I'm going to read this excellent bio about him that came from our Earth X website. Paul designed his own solar home in North Texas in 1996, which won the energy value Housing Award for innovative design. It still ranks as one of the most efficient homes in Texas. Paul worked at Texas Instruments for 33 years. He is a mechanical engineer by trade, but his last 12 years with them were spent as TI’s Sustainable Development Manager. A tour of Paul's house inspired the green features of a Texas Instruments factory, which was the first LEED gold certified semiconductor factory in the world, not just in Texas, in the world. So, he led the effort to improve the energy and water to water efficiency of TI’s 20 million square feet of global facilities. There were… they were able to double the company's energy and water efficiency in less than ten years. So that is really, really impressive. In 2012, Paul was named Senior Fellow for the U.S. Department of State's Energy and Climate Partnership of the Americas (ECPA) program. He visited Honduras, Bolivia, Columbia, and Peru, where he worked with governments, universities and industry on energy efficiency and renewable energy. In 2019, Paul published a book, The Joy of Efficiency, and so one thing you might also want to know is Paul has a band, an 18-piece band, that he works with and I'm sure that information will be available to you on his website as well. So, without further ado, I'm turning it over to you, Paul. Thank you so much for joining us today.

Paul Westbrook:
Alright, Thanks for that introduction and it reminds me of the days when we used to be able to travel… remember those days. Okay. Well, thanks for having me today. I was asked if I could give you kind of a basic introduction to solar electricity. And, so, for some of you, some of this will be really basic. I'm going to throw in a few technical nuggets for those who are a little more advanced in the subject and again, as we go, feel free to ask questions, we'll try to keep up with them real-time so we don't get too far down and if you ask about something that's coming up, I'll just say it's coming up shortly. With that, I will get us rolling here. I plan to talk just a little bit about, What is solar photovoltaic? That's the official name and everybody uses “PV”, as you can see, because it's much easier to say. I'm going to break down and talk about the system components, and then we'll talk about how do you size one, how do you decide how big a system you need, and then a few things about how to optimize the system. And then the piece everybody is always interested in is the financial pieces. And then I put solar on my own home. We have a passive solar house, but I put active PV panels on the House in 2012. So I'll just give a little case study that will hopefully tie all the stuff we've talked about together so you can see how it works in a real application.

So very basically a solar PV panel produces electricity from sunlight and the simplest explanation is photons from the sun, which is sunlight knock electrons out of an atom and they have to end up traveling through a circuit to get back and restore that electrical balance. That's, in its simplest form, you are using a photon of light to displace an electron which flows through a circuit and that's what electricity is, is electrons flowing through wires. So on its most basic level, that's how they work. It's pretty interesting. People think of it as fairly new, but the first effect of light producing energy was noted in France in 1839. And there were observations during the 1800s in France. And there was some work with Selenium based solar cells back in the 1800s. And some… Einstein got… Some guy named Einstein, who had his hand in a lot of stuff, published a paper on photo electricity in 1905. But it really didn't, I guess catch attention until the 50s when the silicon-based solar cell was invented at Bell Laboratories. Then it became popular in space satellites. Initially there were very high cost, but they also, you know, when you're in space, you're gonna aim at the sun all the time. So it was the best source of energy for satellites. When the US had oil embargos in the 70s, interest began and the Department of Energy was formed. They started putting some money into research and development and that began to drive the cost down. And then probably sometime around 2012, which is when I decided to put some up, production volume got high enough that the price became palatable for most people. And now today it's cheaper than almost every fossil fuel-based energy source. So lot of history, but, but it's interesting to see how long it's taken to get to the point that we are.

So here are… there are variations in size, but this is the vast majority of solar panels. If you look at the two on the left, those are panels and they’re roughly 39 inches wide by 65 inches long. There's two different types. One on the left is a polycrystalline, the one on the right is a monocrystalline. It really just has to do with the way the silicon is processed. And polycrystalline on the left is, has generally been lower cost, but it's been lower efficiency. It's about 29% of the market share right now and it's falling. Because the one in the middle, a monocrystalline has more efficiency and that's been improving quite rapidly, has the longest life. It's higher cost initially, but that's often offset by the, by the efficiency. You might need fewer panels. And because each one is going to produce more energy and it's at 65% of the market share and actually growing. The third type, which is a small percent of the market right now. But there's an awful lot of activity in various materials science classes going on. For thin film type panels, you can see they can be made flexible. They’re kind of almost like printed, mass printed.

So those are three different types and you'll see them rated at the top. You see I have a 180 watts, 240 watts, 300 watts. That will be the DC power rating of a panel. So DC, I just mentioned, that's direct current. If you have a AA battery that produces direct current, it has a positive terminal and a negative terminal. So photovoltaic panels, PV panels, make energy in direct current. Batteries also use direct current. But in your house, almost every appliance you have plugs into the wall and that is alternating current. And that's the transmission, all the transmission lines, all of our electrical distribution systems in alternating current. So how do you get from direct current to alternating, there's a device called an inverter. And that will both turn DC into AC and then also synchronize with the electrical grid. You can't put a wave form onto the grid that's not in sync with it. So it has, it has these inverters have a few different functions. So there are three different types of inverters. And one is on the left is the string inverter. And it's called a string because you basically string all your panels together in DC, bring that into the inverter, and then it does the AC conversion and synchronization to your house. I'll flip over to the one on the right. And that's a micro inverter. And it's a small inverter that attaches to the back of every solar panel. There's a hybrid in the middle where you use a string inverter and then attached to every solar panel is a DC optimizer.

Paul Westbrook continues:
And now I'll talk about the differences, pluses and minuses between the different systems. There's not one that's right or wrong. They're really just kinda depending on your application, it would be the one you want to use. The advantage of the string is there's no electronics on the roof. It's usually done in a garage or maybe inside of the house if you’re running all of the electricity in DC already. So it's easier to connect batteries up if you want to use batteries. And it generally has had the lower cost per watt of energy. Its big downside is it doesn't optimize each panel. It runs wires in DC, which fewer electricians are familiar with DC wiring than AC wiring. And it's a single point of failure. If your inverter goes down, all of your panels are offline. The microinverter, flip it the other side. That one optimizes each panel's output, it runs the wiring and AC, which all electricians are very familiar with the codes. And it gives you a panel level monitoring on your system. You can look and see how every panel is operating. It's harder to integrate batteries and it's a little more expensive for them. Why?

Now, why would you want to optimize each panel? Well, if you have a string inverter and you have say, 20 panels on your roof and one of them is kinda near a tree and it gets shaded in the late afternoon. When you have them all together, they can only operate at the lowest common denominator. So if one of your panels has a manufacturing defect, then it's a little bit weaker than the others or it's got shading, it will drag the whole system down. Whereas the micro inverter, it optimizes every single one. So the shaded panel, it's, yes, it's output is down, but every other panel is still producing at full power. And that's what happens when you use the DC optimizers, is it will do that optimization in DC and keep every panel operating at its peak.

So, I see a question coming and I'll try to take them real time. What solar inverters do you recommend for a small condo? Condo, that'll, that'll be interesting, because you have all your association to deal with, but if you can get the approval to do panels, either one is probably fine. If you have a fully sunny space where there's not really any shading characteristics, a string inverter would be fine. A string inverter with DC optimizers might not buy you much if the panels are all well-matched. I personally use the micro inverters and I'm happy with those. I think when you're, when you're looking for a system, you'll get bids and suppliers will kinda have their favorites and why. And really kinda just comes down to, as you'll see when I talk about costs, it just comes down to who's giving you the best value in dollars per watt.

Now, a couple of technical terms. So there's power and energy and these get interchanged way too often. Panels and inverters will be rated by their power. It'll be in watts or kilowatts, and kilowatts is just 1000 watts. How much energy something uses is stated in kilowatt hours. And that's what you get billed for when you get your electric bill. If you open it up, you may say you use 700 kilowatt hours this month and that is 1000 watts running per hour is eight kilowatt hours. So an example, if your TV was a big TV drawing 150 watts and you watched it for ten hours, one day, you would have used 1.5 kilowatt hours. Your electric rate was $0.10 a kilowatt hour. Even spent too much money to watch the TV for the day, but over the course of a month it can add up. Now, how did you mount these? Well, there are several approaches. Roof mounted will often use some screws into the shingles, some waterproofing, and the rails are put on top and the panels are mounted on the rails. Ground mounted systems will have poles in the ground with these rails mounted on those. If you have maybe a flat commercial roof, there's ballast mounted and that way they can be easily removed if you ever need to reroof. So they'll use like a cinder block or concrete block for weight to keep the wind from picking them up. And then a little framing system. And then most recently we started seeing Tesla bidding the most famous, the solar roof, where they actually make the shingles, in, out of solar panels. And so instead of buying a roof and a solar system, you just buy one and it has both.

So I'm going to put a couple of schematics here just to kind of show you. This would be a string inverter, a central string inverter. All your PV panels would be there and would be running DC wiring. You could optimally, you could optionally have optimizers, that's a tongue twister, on each panel. This would be if you wanted to use batteries for storage, you could use a charge controller and the PV panels could go directly to the batteries, and the batteries could feed the inverter. And then here's your load, your house energy. And you've got a meter on the side of your house and that's connected to the grid. What I have is the micro inverters. So every panel has a small inverter on it. This is AC wiring goes to the house and the load. And again we have the meter and the grid. It's a distributed point of failure, which is nice if one of my micro inverters goes offline, the rest of the system continues operating.

Now, net metering is a key term you'll, you'll hear. And I just put a, you know, some sort of generic system and here's all your loads in your house and you might have an electric vehicle and there's your electric panel. You've got a smart meter on your house. And this meter can spin in either direction. So during a sunny day, in fact, at my house here today, it's cool so we're not running the air conditioning. I can go outside and my meter is spinning backwards. I'm actually feeding my solar power electric electrons, back into the grid and they're going into my neighbor's home, and so I am getting credit for that. The meter isrolling backwards. And that's a key piece and we'll talk a little bit more about that in the financial section.

So here's, I mentioned the cost dropped, you know, in the seventies. Panels. You'll see people talking about dollars per watt. So if you have a 300 watt panel and it costs $300, that's $1 per watt. It cost a $150, that's $0.50 per watt. So back in the seventies, when there were just going on satellites, they were $76.67 per watt. And lot R and D went in and the price came down, down, down, down, down. And then it kind of meandered along for a while. And then suddenly volume production started kicking in with some government incentives and you can see this around 2009, 2010, and then the momentum just kept building. Now 20 years ago, if you wanted to put in a whole solar system with all the components, the panels were half, at least half, of the cost. There's inverters and the racking, the wire, and the labor and profit and all these other things. But this was the main, main piece. Well today, the systems are cheaper, 75% of the cost is gone, because everything's gotten cheaper. But you can see the cost is very distributed now the PV panels are no longer the driver of the system, it’s all of what they called balance of system. All of the rack and the wire and your permitting and the inverters and marketing and sales from the company so it's been interesting to see the shift. Here is, here's what a 20-20 costs look like. Panels, profit, it's all very well distributed and there are many people working on every slice of that to keep driving the cost down if they can.

So how do you size a system? Well I always wanna, I'm a big efficiency proponent, and you know, I want to say efficiency first. Make sure your home or business has addressed energy efficiency. Because that way you'll need a smaller solar system to cover your needs. You, you don't want to waste energy in any form. Also, many efficiency projects have a faster payback than solar PV does, even with the current price drops, their efficiency projects that can often pay you back in a year or two. One strategy is to go ahead and add a small solar system and continue to work on efficiency so that initially maybe your solar system is covering 30% of your needs so it's still reducing your bill. But as you continue to improve efficiency, that climbs to 40% or 50% or 60%. So that's an alternate way to approach it as in parallel.

Georgeann Moss:
Hello?

Paul Westbrook:
Yes

Georgeann Moss: We have a question and I had to step away for just one minute. So if you've already answered this, my apologies, but the question is what solar inverters do you recommend for a small condo and since you are talking about small houses there, I thought this was a good time to insert that question.

Paul Westbrook:
I saw that one pop in while you were away and we and we already got it covered. And I'll cover a little bit more of it here in a, in a, in a bit. But I really, any of them work. It's depends on your installer’s comfort level. They're all good paths, they’re just different.

So how do you size a system? Well, the best thing is if you've got utility history, you can review your past utility bills and you understand the usage. And I went and did some research and found, kind of a typical North Texas energy use, is January through December, and the left axis is kilowatt hours per month. And as you can see, certainly if it's an all electric home, you're going to have hotter use in, in January, it'll start declining in February, March, and April, pleasant months in the summer climb commences. August is usually the worst bill, July and August. And you get a little breather again in the fall and then it starts climbing. But if you understand your bill and your usage, that's a, that's a very good first step.

Then the key is all of the utilities have different policies. I'm in a co-op. I’m in Grayson electric co-op. They have their own completely different policy from any other, either co-op or large commercial utility. So you really need to understand what their policy is. And the question is, what is their net metering policy and how did they handle it if you make more energy than you use, that's a really key point. It can really determine the financial payback differences of the system.

So most systems are sized to produce, not a 100% of your load, but some portion, or in some cases match the lowest monthly load. So for instance, when I installed my system, Grayson-Collin would not credit me or pay me if I sent excess. So if I put in too many panels, I would be spending capital, my capital costs, and giving them free energy during the fall and the spring, uncompensated. So that doesn't make good financial sense for me. So I looked at my bills and as you'll see when I do my case study, I sized it to meet the, the lowest uses and then it just trimmed my bill on the other months. Your size might be limited by how much sunny roof area you have. But there's a great free tool that, that probably every company uses in any individual can use called PV Watts. And National Renewable Energy Labs developed this and this would be an output. So I went to the PV watts tool and you can go there. It's, it's, you can Google PV Watt or I've got the link in here in this presentation. And you can input your location. I'm going to put 5 kilowatt system just for the example, I'm going to face it due south. [inadubile]. I'm gonna angle it 33 degrees with respect to the horizon. And I'm gonna put my rate in as $0.10 kilowatt hour. These are just to run the system. So now it gives me the output. How much electrical energy after it does the DC to AC conversion. I can expect each month with a system of that size. And based on my rate, here's the savings that I would get. So you can see I'm producing 7,644 kilowatt hours. Well, look at the months. It's fairly low here in December, 532 and pretty high up here in August 731 [inadubile]. But this is a great tool and it's free. So optimizing the systolic pause here and make sure there's no other questions coming in. So let's talk about how do you optimize. You may have noticed this or not paid much attention to it. But it's pretty interesting if you pay attention to the Sun's path across the sky, it’s extremely variable during the year. Just a couple of weeks ago we had the equinox and if you happen to go outside near sunrise or sunset, the sun was rising due east and setting due west. And going [inadubile] fairly high up in the sky. If you go back out in December 21st at the solstice, the sun is going to actually rise fairly far south of due east, stay low across the sky, only get up here to 33 degrees above the horizon and set fairly far south of the west. The summer it actually rises north of east. There was very high in the sky almost directly overhead and then sets a little bit north of due west. Now that… if you know the path, then it's pretty obvious that you want a south facing roof surface and maybe tilt it up about at your latitude to really optimize your energy use. And if you, if you're roughly optimized, then every kilowatt of panel you have produces about 1,400 kilowatt hours every year in the Dallas, Fort Worth area.

So now let's get to the part everybody loves; the, the money. So for an example of that 5 kilowatt system, that could be roughly 16 to 20 panels, depending on the wattage of each one. I've been, I’ve been seeing prices down below $3 a watt in our area. Not all the time, but if you have a good location, you know, easy access to the electrical panel, I've seen prices down even lower than this in a couple of cases, but let's just say $2.70 a watt is what your provider quotes. That would be 13,500. There are some utilities that have incentives. If you're in the Oncor distribution area, they usually have an incentive every year. The money runs out, so you have to apply quickly. And I didn't have any incentive in Grayson-Collin so I just left that blank. The federal tax credit and I'll show you how this is actually declining, this year for 2020, is 26%. So if you put in that system at the end of the year, you actually get a credit. It's not a deduction, it's a full credit. If you're paying, if you're at least paying enough taxes to get that credit, then you're gonna save $3,500 on your taxes. So that ends up making the final net cost to that system just under $10 thousand or right at $2 a watt. Now if you assume that the system is going to last 25 years, you can calculate that you basically just bought your electric, electricity output for 25 years at about 5.7 cents per kilowatt hour, probably less than your utility is charging you. If you're looking, I got some links on here. Again, I'll have this presentation available, it’s on PDF, it's on my website already. You can go look and see for your area “Are their utility incentives for my area”, there's a link for that. And there's also a nice link down here for the deregulated areas, which are areas that aren't in a municipality or co-op, which is most of the state. Some of their net metering and plans are already listed in there to save you a little bit of searching.

Now, the federal solar tax credit, I mentioned, for a number of years and back when I installed mine, it was 30% and it stayed there for a long time. This year it started ratcheting down. It’s 26%. You wait till 2021, it's 22%. And then for residential, it will disappear after next year unless they renew it. There's a 10% one commercial systems, but residential will go away. So if you've been thinking about solar, you might want to think a little faster. Because there's no telling what will happen with this. Absolutely no telling.

Paul Westbrook continues:
Now comes… the big question is, and this is a very personal issue, but I wanted to show you the options. And for each person, your best answer will probably be different. So say you've got a quote that you like and you think this is going to save us some money. We wanna go solar. Easiest is flat-out purchase. If you have money in the bank and it's earning points, .5% interest right now. The basically return on investment for solar is about 8%. So to me it may, and this is how I use, I did my system, I paid cash because over the 25-years that's basically given me a really nice guaranteed return. You can find a favorable loan term that might be a way. Many of the solar panel providers have leasing options or financing options. And there's also even more complexes of power purchase agreement where you basically agree to by the energy the system produces over times. So the lower one is there's no money out of pocket. But you're not reaping all the benefits. You're sharing some of those benefits with the company, but still it might be the right choice for you if you don't have the cash to invest. But really if you're talking to a company, there's, I put them in red because there's really three things that you wanna make sure you know. How much electricity do you use on an annual or monthly basis? So remember my… my monthly chart. You really need to know that for your average use for your house, then you get a bid. What's the net dollars per watt for the solar installed? So after the federal tax credit and after you rebates, here's my net dollars per watt. And my example, I had $2 as the net one. And then up that system, I'm putting in how many kilowatt hours am I going to get? So you can see how much of your energy it's gonna offset. And then that purchase, borrow lease. That's a personal decision. But I actually stole this from Larry Harold who gives solar basic presentations alot, you and remember financing leasing companies are like any other one, they're offering those so that they can make money, too. In some cases it's a win-win. But just be cautious and read the fine print. That's I, I will, I will tell him.

So let's talk about payback. Here's a little quiz. This is a pop quiz. You're not going to do it as a poll, but what's the payback of any of the following: crown molding with the British spelling, the fancy molding, you might put it at top of the wall and ceiling joint, a fancy $12,000 coat, solar PV, a giant SUV which, you know, $85,000 and is very low rated on Consumer Reports, stainless steel, high-end appliances, or buying fancy coffee at a coffee shop. What's the payback of any of those? Well, nobody ever asks about any of those. They only ask about solar PV when in fact, of all of these things, it's the only one that actually has a payback. And if you do an internal rate of return, an IRR calculation on a 25-year PV system, it's returning around 8%. It may have a simple payback of ten years, which may sound like, well, you know, I'm not gonna do that, butaAfter that, there's 15 years of making profit for you. So it's got a long-term guaranteed return. The stock market may return 8% 1 year, but it may take that back the next year. The solar is going to be consistently paying you back.

So I'll take another pause here and then we'll go to the case study and you can see the details on my system and that'll help kinda wrap everything up here. If there is any other questions if you want to type them in or. [background noises] I will keep an eye on it case anyone comes in.

So this is my house we built back in 1996, just turned 24 years old last month. The passive features are, kinda showing in here and you can see it's a compact floor plan two story. Most of my windows are in the south with overhang. So I did everything I could. I use structural insulated panels, insulated this slab perimeter. I used a metal roof that was reflective. I use solar water heating to heat our hot water or heat our water and it becomes hot water. Did all those things to minimize how much energy we use. Just a list of the features. So we're about 80% more energy and water efficient home than a typical North Texas home. So we have a real running start, jump start in the first place.

Alright I did just see a question come in. Good explanation for IRR. Thank you. What's the minimum number of years to be in a house that would make this profitable? So if you get, if you get a quote on solar and you're around net $2 per watt, it may end up looking like a simple eight to ten year payback. And that does sound long, but if you're gonna be in the house for awhile, it's good. Now, there is another advantage that I'm not even sure I put in the slides. All of the taxing entities, the state of Texas did a poor job of rolling this out, but every county taxing district will give you, the value of your solar is not taxable, so you can have an appraised value and they all do it differently. I wish it was more consistent. But basically the value of your house will be this and then they will take off that $10,000 of your solar system and you'll only be taxed on the lower amount. So if you're selling your home, you know, even if your gonna move and sell it, there is a value to that that you can convey to the buyers that, one, they're going to have a lower energy bills and two, actually reduce, it didn't increase their taxes to have that so it's a tax exempt asset on the house. And you'd have to go to your own county website and they often seem very confused by it. I don't know that many people claim it. I've been claiming it for many years since they since the Texas introduced it. In the first year, I worked with a guy for probably six hours trying to help him understand solar because I was the first one he was doing and had no idea what it all meant. So hopefully they're a little more sophisticated now.

So here, remember my home energy use graph earlier of a typical North Texas house. Well the, the red lines are my energy use and my company didn't offer anything. So I said, I'm going to target my monthly production. I'm going to look in the spring and the fall. And I'm gonna see if my target, the size of my system so that I'm producing about that amount. And then it will just obviously trim my summer and winter bills down. So you can see that 440 kilowatt hours was my fall and spring target, and I ended up with a 3.7 kilowatt system. I have 14 240 watt panels and 270 watt panels and the reason that I have a mix of panels is I bought these off Craigslist. They were they were B grade panels which mean they had a cosmetic defect, but they… they tested out just fine and I did mostly installation myself. And so, 2012 prices weren't as low as they were in now. And this was one of my strategies to get the cost of my system download. And it still covers about 75% of our annual energy use, even with that optimizing for spring and fall.

So… I see another question come in, I'll get that one in just a second.

So here's my actual numbers. I spent about $7,500, which was $2.03 per watt because I did most of the installation myself. The tax credit, I got a $2250 tax credit so my net was about $5,250. So $1.42 a watt. That made my effective 25-year energy costs 4.1 cents per kilowatt hour, whereas my utilities charging around 11. If you add up my savings over 7.7 years, I'm at $4300, so I haven't reached payback. If you look at simple payback, I haven't reached the $5200 yet, but again, my money is basically earning an 8% return for me since I put it into solar and will continue to do that for years and years and years.

So, let me pause here. There's a couple of questions coming in.

So, this is a question about, you know, “What if you have to install them on a different face”? Well, the beauty of the PV watts tool is you can go in there and actually run different scenarios and say, what if I put them on the west side? And you'll see the output. What if I put them on the east side? We'll see the output. On the south side. What if I need 15 degrees off of due south? North is not good. Definitely don't want North. In general, if you're roughly south plus or minus 15 degrees, it's, it's, it's really imperceptibly, small penalty. West is not bad if your utility rates charge you for peak hours and stuff because you'll be getting peak sun on the west side at your highest use time when you're likely reading your air conditioner the hardest in the summer, but the PV watts tool will allow you to do what-ifs and see how much reduction you get from various faces.

So, question about week of cloudy skies. Well, I'm not on batteries. Most solar systems are not on batteries. We’re mostly grid tied and so I think that the grid is my giant battery is basically what it is. If it's cloudy, I'm producing less energy. It's not 0, but it's less and so I'm drawing a little bit more from the grid. On a sunny day, I'm spinning my meter back backwards, sending energy to the grid. So, if, unless you were trying to operate off grid with a battery system, clouds are… are not, not really an issue you think about much over the course of the year, you're gonna produce that 1400 kilowatt hours per kilowatt installed.

Now, I made a choice of a metal roof when I built the house for long life, hail resistance, and reflectivity and that made my solar installation so easy that even I can do it. For metal roofs, there's a clamp that bites onto the seam. It doesn't penetrate the roof material. And then the rails mount to those clamps. And then my microinverters are mounted to the rails and then the panels laid right over the top. So, I have a 0 penetration, roof penetration installation. I actually ran the conduit right over the edge here down the side of the wall and my electric panel is on that… my outdoor panels on that side of the house. So, I have… I have no holes in my roof and it’s a metal roof, it was a great choice 24 years ago when I put the system on.

So now I'm going to get a little, this is a little complex. But I want to show you how it's pretty interesting how your utility policy can really affect the payback and value of your system. I mentioned that there were no carryover credits when I installed. No. You know, if I produced extra, I gave it away for free. My utility changed their policy and in January of this year they started allowing banking unlimited carry over hours. It didn't expire. Then they had another policy change in mid-year where instead of just one fixed rate plan of $0.11 a kilowatt hour, they offered a variety of plans, including one with free nights and weekends. Now, I'm, as you can probably tell, I’m a big data guy. I've got more data on my electric use and solar use and running them than probably anybody in the world and I knew exactly my hourly energy use. And so I ran some pivot tables, looked at this plan and I thought, oh my gosh, this, this matches beautifully with my solar production. I may never have another electric bill again. And that is turning out to be the case. So there's a lot of stuff on here. I'm going to step you through this here.

Paul Westbrook continues:
Make sure I’m good on time, I'm getting close to the end.

So here are my billing, the unbilled, at roughly the middle of the month. So, 1/14, 2/14, 3/14, that's the period that my billing period ends. Right here is my total net kilowatt hour from the utility. And then when we went to the day and night plan, I broke out a couple of columns here for the last two months. This is my electric cost and there's a base fee and then there's some taxes and stuff like that. So, let me show you in January, February, March, and April, I was using net energy from the grid. My solar was producing, but that's winter, doesn't produce as much. So I was using a little bit of energy from the grid. And you can see I had an electric cost. I had $27 dollars, $35, $14, $10. There have a little power factor cost. Here's my base fee. So for the month, my electric bill was this amount, the energy portion was that amount. Then in May, the May billing period, I started generating extra, actually banked 77 kilowatt hours. So I had 0 energy costs, just the base fee. My utility charged a $5 penalty if I didn't use at least a 100 kilowatt hours. So I paid $24.40 for that month, and then the next month, and then the next month. I used some of my bank, but I was still going. Now I switch to the new plan and I'm banking energy. I'm actually during the day in July and August, the two hottest months of the year, where the air conditioners running, I ended up with net banks of energy and I used all my energy only at night and on the weekends. So my bill, when they went to this plan, they changed the base feed of the $23, so I don't I don't have that $5, it’s basically rolled in. So my utility bills every month are probably going to be $24.40 from here on out because I'm banking enough that I'll bank more in this month. Bank more than the next month. That'll ride me through the winter. And so what's interesting is the size of my solar system is now almost perfect. My wife only charges her electric vehicle at night. So that's free. Because our daytime rate is now $0.16 a kilowatt hour. But the beauty is, that's what I'm banking my solar production at $0.16 a kilowatt hour so that, that plan, you know, like I said, the, unless you know, your energy use and you know what's going to work for you. Have a very wellinsulated house. I can air condition it at night, it will ride through about half of the day and stay comfortable. So for me it works perfectly.

Georgeann Moss:
We had a question come in. Who is your utility?

Paul Westbrook:
I'm… Grayson column co-op is my utility. They serve most of Grayson County and probably the roughly the northern half of Collin County. And maybe just a little bit. I'm not sure if they're over into Hunter, but it's an old municipal co-op from the days when from the late thirties, I guess when co-ops came about. So this is just to show you the efficiency of my house and kind of summarize this. This is kBtu per square foot per year. Btus are an energy you can convert kilowatt hours. A typical Texas houses around 41 kBtu per square foot per year. And that's other energy, water heating, heating, cooling. My house only needs seven KBtu per square foot per year. So remember that's my efficiency that I did. My renewable energy system produces 5.8 of that. So I have a lower footprint and I produce most of it with a fairly small solar panel. There are some other benefits to solar as well. So the kilowatt hour price is now less than half of my utility costs. System pays for itself in less than a decade and then it generates free electricity basically for at least another decade. Solar is the lowest carbon content electricity, and no air pollution.

Efficiency is number one, remember if you don't need any energy, that's the greenest of all choices. But then when you do need energy, solar is probably the best one out there. Uses no water, it's silent, no moving parts. Distributed solar actually reduces the peak load on the grid. I I argued with my co-op when we were first to witness the value of my system. Look in the peak, when you're trying to feed electrons to all these houses running air conditioners. I'm using, I'm generating solar, and so I'm not drawing very much, so I'm actually, I'm actually saving your grid from being peak loaded. And so all of us do that. And so there's value in that to you and I hope you recognize it. And then eventually I think they have. Local generation means less energy loss. You know, you lose about 9% of the energy content coming out of the power plant just in losses in the grid, right? I mean, there's resistance of the wires. So when I'm producing locally, I don't have those losses. And when I'm feeding a little to my neighbor, there's very little loss going right across the street.

No moving parts. I mentioned and I mentioned the property tax exempt in Texas. If you want to read some more about efficiency, I have, I have, I wrote this book about a year ago. It's called “The Joy of Efficiency” and it's available on Amazon and the link is on my website. You can just Google type in here. I've got details, all the details on my house efficiency, the solar system, and even the industrial efficiency that we did at Texas Instruments, commercial and industrial. So it's all in one convenient book. If you want to grab that and read some more. And then I have a bunch of links on here toward the end, I'll just briefly talk through those since we still have time. North Texas Renewable Energy Group is a great organization, non-profit group, here in north Texas that has a monthly meeting, they’re now online, in person, but they have variety of topics on solar and efficiency and just all sorts of good stuff. It's a great group of people. There's, there's really an expert in that group for almost everything. Electric vehicles, whatever you want to know about, somebody in there knows more than you and is happy to share. That's what I love about that that organization. Texas Solar Energy Society is here. We just finished last weekend, the DFW Solar Tour every October some of us open up our houses for what used to be in person tours this year we did online, but the good thing is you can go click there. We all did videos this year and had a Zoom Q&A. You can go look at the videos of the houses and sites, which are now on a YouTube perpetually, I guess. So here's the link you want. If you want to go look at my house details its EnerJazz.com/house. You could probably Google “Westbrook House” and it will come up. Right near the top, I have a PDF link of this presentation. You can download and then have all the links there. Solar United Neighbors is… There are are groups who will get together if a lot of neighbors are interested, they will use their group purchasing power to get a cheaper price. So if I'm a solar installer, instead of me having to market to every single house. If somebody calls and says, hey, there are eight of us who are interested, they come and market once, reduces their cost. If they get, if they win, they get to do all eight homes and so they passed some of that savings on to good to the neighbors and there's another site with Go Solar Texas with some, some good resources in there as well. So that's my last slide. So now we'll pop over to the question and answer.

Andrea D Ziehm:
And now there was a question that came in. Does PVP bound to have diminished performance over the years, the performance in year 15 is a fraction of performance in year one. Is there any guarantee of performance over 20 years?

Paul Westbrook:
So yes, your point is valid. On average, solar panels degrade roughly one-half percent per year. That's quite variable, but that gives you a ballpark. And I've seen that in my own, in my 12 years, I can look at my annual graph and it's sliding down just a little bit. So the beauty of it is I've actually been getting more efficient as we've replaced an appliance or as we've replaced this, I continue to improve in efficiency faster than my system is degraded before. But that's it. Now, when you get, when you get a bid, you will often see warranty or guarantee on the panel. And there will be often two different numbers. There'll be like labor and workmanship. So if the panel just flat-out fail, that helps us duration 10-15-20 years. It really, it varies dependent on the supplier. And often you'll see where they guarantee performance. It will go to some level, you know, 70% by this year or something like that. Not as common, but ask, ask for those numbers. But in general panels, certainly if you are doing the monocrystalline panels, they're well understood on their degradation. Okay, let's see.

Georgeann Moss:
Paul there was a question about insurance. What about insurance on a system? How easily can damage occur? And what if a roof needs repair replacing underneath system and then there was another question about hail damage.

Paul Westbrook:
Okay. So yeah, insurance your mileage will vary by insurance companies. So let me just throw that one out. In general, solar panels are insurable just like anything else. You could actually argue they protect the roof. And I have some photos from the tornado that came through Dallas and Richardson of a couple of roofs ripped off. And then right next to them was a roof that was half ripped off. And the piece that was still there was the part that had solar PV on it because that racking and railing provided an additional rigidity to that structure and saved it during the storm. And almost all the panels were undamaged, which was, which was pretty interesting. A couple of them had been hit by debris and broken. But they are insurable like anything else. All solar panels have to be tested. It's a one inch steel ball shot at, I think 52 miles per hour. They have to resist that. So we've had a golf ball size is about the biggest hail I've seen. Maybe just a hair under golf ball here. I've had no damage to my panels. And in general, you gotta get up closer to baseball before they'll start shattering the the polycarbonate covering on there. So they're they're fine. I think. I'm pretty sure. If you get an installer, ask them that if you need to reroof, will they come and remove the panels and then re-install them? There are various guarantees on that. It's going to be installer specific. With my metal roof… You know, it's interesting, my metal roof is class 4 hail resistant. I get a 20% discount on my homeowners insurance have for 23 years now for having a metal roof. And actually the solar panels are now protecting part of my metal roof from even getting hail themselves. So cascading is in there. Okay. I think we got that one. Let's see.

Andrea Ziehm:
There was one that came in. Can you comment on community solar versus solar PV on your home?

Paul Westbrook:
So community solar is if say you live in an apartment or a condo that doesn't allow you to put them all on or maybe you have an HOA that's more than although they're not supposed to prohibit them anymore. If you can't really install many, you're really shaded. You have the lovely wooded home site. There are community solar are when a system is installed at a sunny field somewhere, maybe a farmer, you know, leases a piece of his land and people buy into that. So you you buy into a portion of the production. I don't I haven't done it. I don't know the details on how all of that legal aspects work, but it has been done and maybe some of those links in there I just haven't dug around community solar, but it's, it can be a way for people who don't have the ability to install it on their own residence to buy into solar.

Andrea Ziehm:
Then, when the solar panels are no longer usable. How do you dispose of them? Can they be recycled?

Paul Westbrook:
So that's going to become, you know, becoming a bigger problem. But as often is the case with ingenuity, as things become a problem, somebody comes up with a solution. And there are several companies I know around the world working on reclaiming the, the solar panels at the end of life. They’re silicon base. So, you know, just the raw panel is silicon in fact, this is interesting. Waste silicon from solar, from semiconductor. Semiconductors are built on silicon wafers as well. Scrapped wafers are often sold to reprocessing companies, which then sell them as feedstock to solar panel manufacturers. So there's an, there's an upcycle almost from, uh, from, from that side. Well now the reverse. You've got a silicon based panel with some metal and there are ways to separate those components and recover. I, I, you know, I think like anything we often lazy until the need is really great and about doing those things. But I have good hope that we will solve that and panels will be manufactured in more friendly ways, that they can be recycled and recovered. At the end. It is it is an issue it's nowhere near an issue that the medical plant dumping mercury into your lake and the other things associated with fossil fuels. So people will talk about the negatives without comparing the negatives of the existing system which are still far greater. I see a question, I'll just read it here and answer. Typical grid tied inverters will not operate during an outage. If you isolate from the grid and use a separate clocking inverter can any of the inverters backup and match delivery. So question… backups are grid tied and because of safety, if the grid shuts down, my solar system inverters have to shut down and they won't come back on until five minutes after the grid is back on that’s so you don't electrocute alignment who thinks he's saved out a system and your back feeding into him with your solar panel. So that's the downside of being just grid tied with no batteries is when the grid goes down. If it's funny, I can't produce. Now, there are ways around that you can use. If you have a string inverter and a battery system. And you can disconnect from the grid and do a standalone it’s called Islanding, when you're an island, islanding is a way that it can be done. Micro inverters had no way to do this, but the newest generation that's coming out can actually island and form microgrid on your house and continue to produce. And now with like Tesla power walls and other battery technologies coming on. They're starting to, it's still a little unclear and a little murky right now, but people are starting to figure out how to make that all work together. But as of right now, the downside is if the grid is down, my solar is off. Now fortunately, our greatest inferred reliable, but that's, that'sthe way it works, but it can be overcome with islanding. Let's see.

Yeah, here's, here's a question. I have a lot of mature oak trees covering most of my roof, are solar panels for me? Probably not. If you have, like a large backyard area, you know that it's more open or a field or a space, you can do a ground bounded system out on the lawn. But yeah, solar, you know, you're going to have limitations on some homes. And I'm, my, I have two acres of heavily wooded property, but I have a two-story house. And so right where the house is, if you get on the second floor, I only get shading, just in the first hour in the last hour of the day on the panels. So I'm a little bit shaded, but… but most of the peak hours of the day, I'm in full sun. How are we doing on time? We're down to the last couple minutes. If there's any other questions, I'm happy to take them.

[Inadubile]

Georgeann Moss:
Yeah, thank you so much Paul, for that fantastic introduction to solar electricity. And so if anybody has a last minute question, please type it into Q&A or to chat, and I will go ahead and tell you about our webinar next week our own Laurie dela Cruz Lewis is going to be speaking about Career opportunities for solving the climate crisis and that one is based on project drawdown. And if you guys are not familiar with proroject drawdown, I highly recommend you check out their website at drawdown.org. Paul Hawkins is the leader of this group of fantastically talented people who have figured out the top 100 things that we can do to not only stop emissions, carbon emissions, but actually draw them down from the atmosphere. And so Laura's presentation is going to be based on careers that link back to those 100 top actions that we can take as a society. Also, just want to remind you that Paul's PowerPoint is going to be there on the side, is PDF is on his EnerJazz.com/house website. And finally, just one more reminder about the Sustainability Summit on Friday, November 6th. It is, there is no charge to attend, but we do ask that you register in advance. If you go to our website www.dcccd.edu/sustainabilitysummit you can see the entire agenda and read about our fabulous keynote Dr. Charles Hopkins.

So if we have any more. Yes. Yes, there is a question. Will the recording be posted? Yes, it will. It takes about two weeks. We have to make sure it's accessible according to ADA requirements but we will get that up at our website and if you just go onto our website, which is dcccd.edu/sustainability, click on the events and click on Sustainable U events and we're going to have to make this link up closer to the top. At the current events, scroll down to the bottom of the page and it says, there's a button that says, explore past webinars and that's where you can find the webinars that we have done in the past.

So, Lori, or Andy, do we have any more questions come in at the last minute?

Andrea Ziehm:
We have a question about do you have any comments on battery storage or about the advantages for EV owners to having solar PV?

Paul Westbrook:
So battery storage, I mean, there's a couple of general batteries and then we'll talk about batteries and any general batteries, there can be an advantage if you can Island, then you can operate offline. Or if there's a big power outage, you can all your neighbors can come over to your house and use your energy. And you'd be most popular in the neighborhood. Batteries are good. And then, you know, thinking about my rate plan, look at my nights and weekends plan. I could charge the battery overnight and use the energy during the day, kinda like a solar system. So I can, I can, I don't wanna say game, but I can work the rate plan to my advantage. With a battery system. Now, an electric vehicle is a giant battery that you use to drive around and then often just sits in your garage. In Japan, they have bidirectional chargers. The US has not progressed yet as far some company countries, you could use your EV as a bidirectional pattern. So you could charge it overnight and if you're not driving anywhere during the day and it's peak hours for energy use, you could draw off your EV batteries, just, just like any other battery. Unfortunately, that's not been implemented in many places in the US yet, but it's certainly, it's doable. It's been done and it can be done. Just haven't done it.

Georgeann Moss:
But Paul, thank you so much. We come to the end of our time. We’ve come to the end of our time. Thank you. Thank you. Thank you for the great presentation and I do want to end on, with a little more positive news about solar and Madden's Rocky Mountain Institute posted on their Facebook page today that the company, New Era, that does solar and renewable energy has a larger market capitalization now then Exxon, that is great news. Solar and renewable is here to stay. And so with that, we will sign off and look forward to seeing you next week.

Bye, bye.

Paul Westbrook:
Bye, bye everybody.