Allen here overcast day and we’re, never using a heck of a lot of solar energy, but I keep getting questions about how to determine how many solar panels. I actually need my home center, my farm, how many solar panels does it take to power and air-conditioned? So I’m, going to try and address those questions and go through a few fundamental questions.
We need to go through in order to to determine what our needs actually are and therefore determine what it’s going to cost. If we do go with solar panels so hold on here we go okay. So, as I mentioned, I’m going to try and help you figure out through this presentation how to size up what your solar panel requirements are for.
Whatever your specific goals are, I cannot help you determine what the costs are going to be. That’s, a very temporal thing. You know, you know you may be viewing this three years from now and solar panel costs may have come down a great great deal.
There may not be any incentives at that time. There’s. Currently still incentives, you may have an installer install it or another person may do it themselves. Some people will have a roof mount system and they need repairs to the roof first.
In order to have that climb, other people may do a rack, a rack mount system. Some people may build another building and put it on a separate building and use that building for well. For you know, for livestock, you may choose to use micro inverters or you may use a standard inverter.
You may use a grid-tied and, like I’m using or go off-grid and require a battery backup system, so the costs involved can be absolutely tremendously variable. So I can’t go into that, but I can present some information to you in this, such in this format that may help you determine jeez.
What your needs actually are a way to calculate how many solar panels you’re, going to need, so it all starts off with what are your goals. So, specifically, one of our goals was to reduce their carbon footprint.
We wanted to de-centralized decrease our dependency on outside resources. We wanted to save money, we’re, going to be living here, the rest of our lives and and therefore we’re going to be you know, electricity is going to be free.
After so many years, some people look at Jesus. They ask me what’s, your return on investment and that’s quite variable, depending on when you’re buying the system. What type of system you’re? Putting in so that’s quite variable and I look at it quite differently as a permaculturist, because the various forms of capital, so I won -‘t, go into the heck in this presentation.
But if you’re interested leave, a comment or a question, and I’d, be happy to review that in the future. So are you powering your home? Are you powering a motor home that you’re traveling around within you’re only using certain times of the year? Are you doing other specific functions like what a separate system I built was a portable power station? So I have a solar panel to to back up the batteries in that portable power station that I use in sight.
So how many panels are you going to need? Let’s, try and figure some of that out. Well, it’s. Really dependent on your geographic location, your climate, the peak Sun hours in your area, the orientation of the structure that you’re, putting the panels on.
Is it a roof mount or a rack mount? What’s? The solar exposure? Again, the geographic location has a lot to do with it or, if you’re being shaded by trees or other buildings or skyscrapers whatever the situation where you’re on the north side of the mountain in in North America.
So how much energy does your household actually use? All of these are important variables determine just you know how many solar panels you’re, going to need. So what are your energy needs? What’s? The load on the grid that you’re that you’re currently using so you & # 39.
Ve got to look at your electrical bills. The average usage often given in and a monthly report, is the kilowatt hours and that’s, just a unit of measure. It’s like a gallon or a liter or a foot or a meter.
If a unit of measure is all that is so it’s, the power use at any point in time two times the total time that it’s actually used. For example, a thousand watt high pressure sodium grow light uses one kilowatt of energy every hour, 100 watt light bulb.
You can run that for 10 hours in order to be equal to 1 kilowatt energy powered energy 100 watt 100 watt light bulb run for 24 hours. Is going to use 2.4 kilowatt hours of energy that thousand watt grow, light run for eight hours a day will use a kilowatt hour energy per day, so determining your daily usage.
You can gather up your bills over the last month, 12 months and you get them for January through December or whatever time frame that you’re looking at and if, for some reason you were away and the the usage was less than and typical Find a different way of calculating that month, because you really want to see what your annual kilowatt consumption actually is.
Then you want to divide that by 12 to determine what your monthly averages. So you know if you’re in a cold climate, your energy electric usage month might be much higher during the winter months because you’re running electric heaters or whatever, and during the summer months, in a hot climate in the desert Environment, you may be running air conditioners all summer long and that’s when you’re using your most energy, so getting the average monthly kilowatt hour usage is most important, then take that and get your daily by dividing your monthly by 30 and that daily average kilowatt hour usage is what we’re, going to be using in all our calculations further down the road.
But first we’re, going to introduce another topic peak Sun hours, so a Peaks on our is the hour during the during which the intensity of the sunlight is a thousand watts per square meter. You know that definition, isn’t that useful and it helps us determine what the panel’s can produce in our location where we are in the country.
So if you’re in Arizona, your peak Sun hours is, is a higher number and therefore you need fewer panels. If you’re living where I live in the cold temperate glaciers cover well, your peak Sun hours is less and therefore you need more a greater number of solar panels, or at least a higher total wattage for the solar panel array.
So the typical daily solar energy in your area is what we’re going to use and that’s, our Peaks on hours. It occurs that solar noon when the Sun is the highest in the sky. It occurs during the summer months when the sun’s position.
Relative position in the sky is much higher. The solar energy increases as we get closer to the equator and decreases as we move away from the equator. So if you live in an area with a large body of water, there’s, more cloud cover more snow cover and that will decrease your peak sun hours.
So the peak Sun hours across most of the continental United States is between 3 & amp 5. So let’s. Look at some calculations, so they did remember. We’re, bringing forward now we calculated our daily kilowatt hours.
We divide that by our peak Sun hours that gives us the kilowatt hour energy that our whole solar panel array, all the solar panels, hook together in total, need to meet. So we take our daily kilowatt hour, average divided by our peak Sun hours, and you can get that off the internet and that will give us a kilowatt hour, energy that our whole solar panel already needs to.
So we know what our full footprint is going to kind of requires to our total number of solar panels. The total bondage is going to have to be. We multiply the kilowatts needed by our total solar panel array by a thousand to get the total watts needed by our solar panel array because we buy our solar panels in watts.
So excuse me, so we multiply again. We multiply the kilowatt hours needed by our total solar panel array by a thousand to get the total watts needed from our solar panel array. So now we & # 39. Ve got got the divided to the wattage that we just calculated by the size of the solar panels that we select.
So if you’re using a 250 watt versus a 300 watt, you need fewer 300 watt panels than you do 250 watt panels, because they’re more powerful and they have higher wattage and therefore the total wattage from our solar solar Panel array will be met by the number of panels as being necessary by the the total wattage of each individual panel.
Now, if you needed to go by the square footage of your of your roof, and you had good solar exposure there and if n cheese I’ve got a really small roof. You could calculate the number and I think they’re.
Three by five, approximately the solar panels, you could calculate how many of those you could fit on it and divide the number of solar panels into the total wattage of the solar panel array and determine what wattage you need to get the minimum wattage.
You need to get for your solar panels. Okay. In 2015, the average annual electricity consumed by residents in the United States was ten thousand eight hundred and twelve kilowatts annually, so almost 11 thousand kilowatt hours annually.
So let’s. Do a calculation we’re, going to use a number even bigger than that we’re going to say our our monthly kilowatt hours used is 1,100 kilowatt, which is more than that. The average – and this is just use, the more than the average daily, obviously annual consumption in the u.
s.. So we’re going to use this number. Is it’s, a nice easy even number to work with, and you and you can plug in any numbers in this formula, so we have our our wattage per month. We need eleven hundred kilowatts per month.
We divide that by 30. That gives us thirty six point: six six. I rounded up to thirty seven kilowatt hours per day. So now we know what our daily kilowatt hours is. Now we take our daily kilowatt hours and we divide that by our peak Sun hours, so our peak Sun hours, so it we’re, going to take the average between three and five.
We’ll use for we divide the 37 by four. That gives us nine point two five kilowatt hours for our four for your location. Let’s say you’re in Tennessee and it’s. Four. I don’t know that it isn’t, but in a Swingle it’s.
Three, so excuse me, so you divide your daily kilowatt hour by the peak Sun hours and all, and that gives you the total of nine point two five kilowatt hours for for this specific location. Excuse me now: we need to multiply that times, a thousand in order to get nine thousand two hundred and fifty watts in PAMP in total panels to meet a hundred percent of our needs when we multiply our kilowatts by a thousand in order to determine what our Total wattage is so we now.
In this example, we need nine thousand two hundred and fifty watts and all of our panels put together to meet 100 % of our needs. Now you may decide, I only want to meet 60 percent of my needs, or I want to meet 120 percent.
I want some buffers on you determine what percentage you actually want to meet so in this. In this example, we got nine thousand two hundred fifty watts and total panels. Now we can go ahead and divide that by 250 watt panels and come up with 37 panels.
We need now again. This is a very large system system, larger than the average u.s. resident. So that tells you need 37 250 watt panels to meet your your your requirements to meet a hundred percent of your needs annually.
Now, during the winter months you won’t meet debt completely, but during the summer months you’ll produce more than what you need. I hope that makes sense so the 37 times a 250 watt gives you 1,100 kilowatt hours per month.
So you can get 150 watt systems 350 watt systems, and these I’m, not sure how far they’ve gone up now, but they’re, probably even much higher. So what are things to consider? Certainly think about communicating with a certified solar panel installer.
They’re, going to help you with tax incentives to understand that some people want a lease a lease option, as opposed to purchasing this system and and some of the lease options actually pretty good. You know they, you’re, paying a fixed rate for so many years and it may be 10 15 years and then you have a buyout option.
You know, for you, know a hundred dollars or whatever, and I don’t know the details of that. I’m just making it up right now, so you can look at various lease options. It’s, really dependent on the type of inverters that are being used.
I’ve got micro inverters because at the time they seem like the very best system to install, because I didn’t have to worry about my total production being decreased when there’s. Trees, testing shade on to some of the solar panels so and they’ll, recommend various specific panels in your area as well, so that’s.
The end of this presentation, I hope it helped answer some. The questions I’ve received and and if there are any further questions, I’m very happy to go further into these. I know that in the past, people had wanted me to go ahead and demonstrate how I built my battery backup power station that I made that I bring around the property and use with the chainsaw.
So I hope this was helpful. Please like and share this with your friends and leave, leave a comment. Ask questions interact with me. So I know. Is this the sort of thing you want more of in the future I’m heavy into the permaculture.
I haven’t started doing some of my nutrition ones yet, and there are many how to do farming things that I’m, going to be doing around here and more construction as well. So let me know what you think about this presentation as well, thanks so much and have a great day folks, bye, bye, now
