• Home  / 
  • Solar
  •  /  Off-Grid Solar System Design: The Basics

Off-Grid Solar System Design: The Basics

off-grid solar system design featured image

There are many reasons one might decide to live off the grid. Perhaps your choice of ideal living location is far from any utility hook-up and you do not want to spend time and energy hauling fuel for a generator. Tiny homes that are solar powered with a battery bank and charge controller are also becoming a very popular living arrangement since the overall philosophy of these houses is to cut down on both costs and the environmental impact of living. There are several ways to incorporate solar power into your home electricity plan, but if you intend to be completely off the grid, then these are the basics you should know before you take the plunge.

off-grid solar system home image

The sun provides both light and heat to our planet. While heat is essential to the survival of life, it is actually the light rays that humans have learned how to capture and convert into usable energy. We have developed solar panels that can take the sun’s rays and use them to create electricity. These panels are becoming easier to manufacture and more widespread every year, which means the cost is not nearly as high as it once was. It is, therefore, becoming increasingly common to find photovoltaic solar panels anywhere from industrial applications all the way to decorative garden lights.

solar battery sign image

Photovoltaic solar panels create direct current (DC) electricity. This type of power is most appropriate for low voltage situations, like charging batteries. The majority of electronic products that we use require alternating current (AC) power. Just about anything that plugs into an outlet is an AC powered device. Therefore, if you want to use solar power systems to generate electricity for your home you will need an inverter along with your panels that can change the current from DC to AC. This article goes a bit more into the difference between the two types of current and the appliances that can be used with them.

photovoltaic solar panels image

When solar power systems with a battery bank and charge controller are completely off the grid, you must create your own external backup system. The sun does not shine all day and depending on where you live it may not even shine at all for several days. Therefore, a backup option to solar energy is necessary. Some choose to use a fuel-powered generator for the times when their solar system is not providing enough electricity, but this is not always reliable or feasible. In most cases, off-grid solar systems incorporate large batteries that can store enough electricity to power the home while the direct energy from the sun is not available. These batteries can be very expensive so the cost of this type of solar energy system tends to be the prohibitive barrier that keeps people from switching over to completely off-grid power.

If you are looking to design an off-grid power system then the first thing you need to understand is exactly how much energy you need to produce. You can start to get this estimate by taking a look at your utility bill. This will have data on not only the amount of electricity (in kilowatt-hours) you used in the last billing cycle, but it frequently has a summary of the past year as well. While an average is a good place to start, in most locations the amount of power your home requires is cyclical and not constant from month to month. In a home that is completely air-conditioned and heated by electricity, the hottest summer months and coldest winter months can have double or more the amount of energy usage as the milder months in between. The last thing you want to do is plan your system based on the average usage and run out of power in the middle of a heat wave or cold snap.

utility bill image

Along with determining your own needs during the peak seasons, you should also figure out how much sunlight is available at these times. You might have no problem covering the hottest months in the middle of summer, but the coldest months in the winter do not receive the same amount of sunlight due to the opposite tilt of the earth. There is plenty of weather data available broken down by region that can help you figure out this information. There are also helpful tools like the Solar Pathfinder shade analysis tool which can give you even more specific information.

It is important to realize that a full off-grid solar system does not have to consist solely of photovoltaic panels that give you electricity. There are other ways to harness the sun’s power that can replace things you are currently using electricity for. For example, you can reduce the amount of electricity needed for heating water by using a thermal water heating system. Thermal water heating is like the low-tech sibling of photovoltaic solar power. Instead of converting light rays to electricity, a thermal solar panel simply traps the light to generate heat, which is then passed on to your water tank via a series of pipes and pumps filled with a liquid like water or oil. Given the amount of hot water that the average person uses on a daily basis, this can significantly cut into your electricity needs and reduce the size of the photovoltaic system that you might need.

Going off the grid and becoming independent is a lifestyle that can be extremely liberating, but it should not be undertaken lightly. While there are plenty of examples as to how it can save money in the long run, there is a hefty upfront cost. You are also trading long-term monetary costs for other ones such as time and creature comforts. If this is a lifestyle that you would like to learn more about, this article is a good overview of all the things to consider before you start to completely unplug. This is definitely not an unattainable dream—and the average person with a bit of handiness can make it happen for themselves—but it is important that you know what you are getting into and plan properly.