If you yearn for spaces far away from the hustle and bustle, where the day begins with the first light of the sunrise and the stars are so clear at night that they shimmer like diamonds – solar power might make it possible for you to call this place home.
Solar power for a home is not just awesome for the environment; it’s also a great way to get power in situations where there are not power lines for miles.
Solar allows you to live in places so remote, your nearest neighbor is a moose that visits each morning at sunrise.
In this article, we we will go over what you need to know to implement solar for your home, including how much power you’ll need, the different parts you’ll need for your solar system, and other important things to consider when using solar.
How many solar panels are necessary?
This is a question that is most often asked and it can be confusing at first. One thing that I learned a very long time ago is that if you break your problem down into small pieces, it is easier to find your solutions.
In order to know how many panels you are going to want to solar power your home, ask yourself these questions first:
1. What do you intend to power?
This is critical. Do you need to run a refrigerator? Will there be a toaster? Make a list on a piece of paper. Write down every item that you will be using in your off-grid home.
As you might imagine, the fewer things you are powering, the fewer panels you will need. For now, make your list and try to be reasonable.
List the things you cannot live without first. The second half of your list should be the things you can possibly live without, but would be nice to have.
2. Now that you have your list, how much power do these use?
In a column next to each item, you’ll write down the energy use requirements of each item on your list. This will take a little time, but the information is valuable.
Not only will you be able to plan your solar needs effectively, but you’ll also gain more respect for how much electricity we tend to waste each day.
Let me give you an example. The average 32-inch LED television has a label on it, as will all of your appliances. A 32- inch LED television has a power rating of 18 watts.
If you increase the size of the television, you increase the power usage as well. A 40-inch LED television uses 31 watts.
These numbers tell you that your 32-inch LED television is going to use 18 watts of power for each hour that it is on. It will also draw a phantom charge when turned off.
In other words …
That red light on the front that tells you the tv is off is using power, even though you aren’t actively watching television.
That’s called a phantom charge.
Microwaves, toasters, computers and virtually all appliances steal power via phantom charges. Go through your list and find the power rating in watts for all of your listed items.
If you can’t find tags, you can look most things up online and get a good idea.
3. Now, figure out how many watts you need per day.
Take the hourly rates and multiply them by how many hours you realistically will be using these appliances each day.
If you plan to watch television for 4 hours per day, then 4 x 18 watts = 72. This means you need to generate 72 watts of power each day to power your television.
There are solar power calculator tools available to use, usually on the websites of panel distributors. This makes your work a bit easier, but you can do it on paper exactly the same way.
Adding a refrigerator can get costly as far as watts needed. The average 14.5 cubic foot refrigerator uses 600+ watts per hour.
This refrigerator compressor kicks on and physically runs approximately 8 hours of each day. That means that your refrigerator is going to potentially use as much as 4,800 watts per 24 hour period.
In other words, you need a lot of solar power for home refrigerator use.
If you are trying to stick to a budget and your refrigerator is going to use far more panels than you expected, you have two choices …
- Time to spend more on panels
- Time to decrease the power usage by downsizing the fridge and appliance list
The choice is yours, which is one of the beautiful things about using solar power for home applications.
How Many Watts is a Solar Panel Capable of Producing?
Now that you’ve got an idea of the power you are going to need, you can figure out how many panels you will need.
Panels come in several sizes. You can purchase 100-watt panels, 200-watt panels, 300-watt panels and higher.
The higher the wattage of the panel, the more expensive they become, but they may be more cost-effective in the long run. It really depends on how many watts you need to produce and the deals you can find.
For simplicity, I’ll use 100-watt panels for the math. A 100-watt solar panel is capable of generating 100 watts of power per hour that it is in direct sunlight.
If the day is cloudy, it may not work at 100% and you should plan on this. A cloudy day will still generate power because there are still UVB rays from the sun.
Your panels may only draw 40% of what they typically could on a sunny day.
That means that each panel might only harvest 40 watts of energy per hour. One panel will run your television with a bit left over each hour. Solar panels will also produce power only when it is daylight.
Charts are available that will show you how many hours of sunlight your area of the country receives each day. This will help you to decide if solar will work well for your needs.
I’ll use where I live as an example – in Tennessee, you can expect 4.5 hours of direct sunlight each day. That doesn’t seem like much, but it takes averages into account.
These numbers are available from US Solar Isolation Maps. The numbers will begin to show you that the solar panels aren’t ever able to draw 100% of their capability. This is due to environmental changes, rainy days, cloudy days, etc.
The best thing for you to do here is to add up your hourly watt needs, then pad that number by increasing it by 40 to 50% and you will have a good idea of how many watts, in panels, you need.
At that point, it is simply a matter of determining the best prices you can get for panels.
I personally was able to find 100-watt panels for $75 each with free shipping on Amazon that have worked great. You can find those here.
Personally, my power needs are minimal. I only use a dorm-sized refrigerator in the summer and utilize a. cold box outdoors for food in the winter.
The point is …
When you start calculating and accounting for every watt of power that you use, you start finding ways to conserve that power and save it.
Which brings me to the next issue. How do you store power for using later?
Solar Power Banking
Each solar system is meant to pull more power than you need on perfect weather days.
If you can keep your home needs to a few hundred watts under what your panels can collect each day, then you can put that power into a savings account for using later or after dark.
This is called a ‘battery bank’ and it is made of 12 or 24-volt batteries.
As your panels absorb sunlight, they get very hot and the molecules inside each photovoltaic cell begin to move rapidly. This chemical process produces energy.
Solar Power Regulators
That energy is captured and fed via wires to a solar power regulator. This is a device that is wired between your solar panels and the battery bank.
This simple device has a big job. It prevents your batteries from overcharging, which would cause them to get hot and be destroyed.
The regulator also will prevent your batteries from being discharged too low, which can ruin cells and cause the battery to no longer function at peak capacity. It will need to be replaced, eventually.
As you’ll find out, these batteries are anywhere from $65 to $250 each, depending on the size of the batteries you choose.
You want to preserve your batteries as long as you can and the solar power regulator helps you to do that.
The power that is being drawn by your solar panels is DC (direct current) power. You should make sure that your panels and batteries are the same voltage rating. For example, 12-volt panels should be hooked to 12-volt batteries.
I’ve found that 24-volt applications are only necessary for large-scale projects. If you are doing a tiny home project, you will most likely be just fine with 12-volt and it is simpler.n
Your solar regulator will have an output where you can run wires directly to 12-volt light fixtures.
You can even shop for RV camping accessories and install 12-volt outlets for charging cell phones and tablets directly from DC power.
12-volt appliances can be found too. If you are interested in a 12-volt coffee maker, they are manufactured for camping and for truck drivers.
The more batteries you have, the more power you can save for those rainy days. The amp-hour rating is important, so make sure to choose batteries with the highest amp hour rating you can afford because they store the most power.
You also need to use deep-cycle batteries; those which are made for marine and RV applications work well.
Some people use golf-cart batteries, but those won’t store much power; they are, however, cheaper to invest in to start. You are free to decide which size of batteries best suit your need for solar power in your home.
So now that you’ve got the power into the batteries … how do you get it back out? In order to operate things like the television or refrigerator, you’ve got to turn that DC power into AC (alternating current).
The power that typically comes from the electrical grid that are designed to function on is AC.
No worries! There is a solution called a power inverter.
A power inverter is hooked directly to the batteries and it converts that stored power into usable AC power.
The inverter will have outlets for you to plug 2 or 3 things into. This is a fantastic do-it-yourself way to bring power to a tiny home.
If you want to wire your cabin like a regular home, it is possible to wire your inverter directly to a fuse box to a 20 or 30 amp fuse; this depends on the size of the inverter that you purchased.
This is something that you can do if you are comfortable with wiring it yourself. However, if you are not comfortable with doing electrical wiring and you plan on wiring into an electrical junction box, have an electrician take a look.
When you choose your inverter, you’ll want to pick one that can handle the maximum draw that can happen all at once.
What I mean is that even though your refrigerator is rated at 600 watts, it might actually draw twice that much when it kicks on, just for a second. You will need an inverter that can handle a ‘maximum load’ of at least 1200 watts in that case.
For my own application, I’ve got a 1500-watt inverter that can handle a maximum load of 3000-watts. I’ve had no issues. I run a dorm refrigerator, a 32-inch television, a modem for my internet access (which is also how I watch television), and random appliances that I am careful to unplug when not using.
I save power by using 12-volt recessed lighting, and I cook and heat with propane.
Wood stoves are the best way to heat cheaply, but the older you get, the harder cutting firewood is and, in my case, having asthma doesn’t make breathing easy when burning wood indoors.
These might be considerations for you too. (For everything you need to know about wood stoves for tiny homes, click here.)
I’m a morning coffee person, and if I’m being honest, it is absolutely essential to my life. For this, I opted to go with a stovetop percolating coffee pot to save power.
The coffee pot that you are using in your home can draw as much as 1200 watts of power when it brews the coffee! That was an unacceptable use of power in my home solar plan.
Like I said earlier … you start to pay attention and respect power usage a lot more when you begin planning your solar system.
Those are the basics…
These are things that are most essential for you to know. You should read as much as you can find and plan thoroughly on paper before you invest in your components and panels. Know your needs and plan accordingly.
Taking the time to write down all of the appliance you use now, and determining how many watts they all use will help you pare down to your absolute needs.
You’ll begin to realize that certain things, like electric coffee makers, really can be replaced with a percolating coffee pot or a French press.
Neither of these will use any power and let me tell you….
They produce a mighty fine cup of coffee.
The more detailed your list is, the more closely you will hit the mark with how many panels will give you the solar power for your home to live the life you want to liv,