Solar power and air conditioning go hand in hand. The summer is when you most need to rely on air conditioning to keep your home cool and liveable. It is also the time of year when there is the most sunlight. Turning to solar powered air conditioners is a great way to increase your home’s efficiency, self-sufficiency, and environmentalism.
Long summer days mean it heats up indoors, but it also means more hours of sunlight that can be collected and turned into energy for your home. So it only seems natural to focus some attention on how to make solar power work for our air conditioning needs. Solar powered air conditioning units are an array of devices that combine cooling with the collection of solar power via a solar panel array.
Why go with solar powered air conditioning?
Like mechanical clothes dryers, air conditioning is a fairly new invention. It wasn’t created until the 20th century, and has only become commonplace in the past one or two generations. But now, central air is a standard feature in most newer homes.
For those concerned with conservation and troubled by pollution and climate change, foregoing air conditioning altogether might seem to make sense. After all, our grandparents likely got by without it, why shouldn’t we?
Though past generations had to make do without air conditioning as it wasn’t available, most of us today both have it available and encounter different circumstances than 100 years ago that make it impractical to go without air conditioning altogether.
First, we live in a world where weather is getting more and more extreme. Global climate change means that summers are getting hotter. At more southerly latitudes the uncomfortable summers of the past are being replaced with truly deadly heat.
In fact, 2018 was the fourth hottest summer on record. Generations of the past may have survived without climate controlled homes, but they simply weren’t subjected to the same temperature extremes.
The world is not only hotter, it’s more crowded. More of us today live in the apartment buildings or close together urban and suburban houses whose orientation to the sun and wind we have no choice in. And building a home that takes advantage of all the latest advantages in passive cooling and smart design is outside the financial reach of a vast number of people who still want to do their part to help the earth.
There are ways to need less air conditioning, but there is no way to deny that many people live in situations where it is a necessity.
But, turning to solar powered air conditioning units could be a solution. By setting up your home to cool through a solar power a/c unit you can help to provide a comfortable home environment indoors, while also respecting and preserving the climate outdoors.
There are several ways you can make the transition from traditional on-grid air conditioning to solar powered AC units. They range from the professional to the do-it-yourself.
Make a DIY Solar Powered Air Conditioner
There is a wide variety of do-it-yourself options for air conditioning (just like there is for DIY solar ovens).
On the simple end of the scale, there are lots of instructions available online for solar power AC units that provide one-room or personal cooling that you can make with common items. These systems are usually based on a small fan that is powered by a solar panel. This fan is used to move air cooled by either ice or evaporation.
The very simplest method of creating a DIY solar AC unit involves taking an ordinary styrofoam ice chest and filling it with ice, and cutting two holes in the exterior. Into the first hole you should fit a desk fan or other small fan. This is attached to a solar panel as its energy source. Air comes into one of the holes you’ve cut, and is cooled by the ice. The cool air is pushed out by the fan, and voila! Homemade solar powered air conditioning.
You can also find instructions for DIY solar powered air conditioners that use evaporation rather than ice. These are slightly more complicated, but still something you can build with a fan, a solar panel, and a small assortment of things from a home improvement store.
Even more exotic designs exist for solar air conditioners, like this dessicant design by students at San Diego State University or this one that uses thermal collectors.
These types of DIY solar powered air conditioners are not meant for whole-home cooling, and they won’t replace your home’s central air. But they do provide portable cooling during camping or RV-ing. They can also serve as an alternative to a window a/c unit for a single room. This is especially helpful if you have somewhere like a shed, garage, or boat house that isn’t hooked up to your home’s HVAC system.
These types of solar powered air conditioning units can also provide backup cooling in extreme situations such as a loss of power due to a hurricane, tornado, or other catastrophic event. If you live somewhere where these events occur with some regularity, having one of these devices premade and on hand might be a lifesaver after a storm.
Again, this won’t replace your current home’s air conditioning, but it is a simple way to get started by using a little less energy in your garage or shed, or to be comfortable when camping or RVing without relying on cooling from a diesel-generator or other polluting device. You may also wish to add a solar fan to your setup, or even an attic fan powered by solar energy.
Alternatively, if you have experience with electrical work and solar panel installation, there are instructions online that guide you through the process of installing solar panels on your roof and running those panels to a window AC unit or a ductless HVAC system. This, however, is a DIY that is only suited for individuals who have extensive knowledge on the setup of solar panels, and knowledge of electrical work.
This also requires a significant investment in a solar panel array, converter and a battery backup system to store power for use overnight. So DIY solar power generation is not for everyone.
If your skillset is something less than expert-level, there are still options for solar powered air conditioning units for your home. The next option is less of a solar powered air conditioning unit and more of a solar offset setup.
Have Solar Panels Installed in Your Home to Offset Air Conditioning Usage
Another way to use solar energy to power your air conditioning is to use conventional solar panel installation to provide equivalent energy to the power grid to offset your air conditioning use.
To do this, you would first want to know how much energy you typically use to power your home’s air conditioning during summer months. This information is often available online from your energy provider.
Many energy suppliers have ways to track your energy use over time. Some electric companies even have ways to break down power usage by the area of the home, so you can compare energy drawn from, say, the kitchen, to energy drawn into your HVAC system.
If, for some reason, your energy company doesn’t provide this historical information online, you can review your paper bills during the summer. You can also estimate your use by checking the wattage on your HVAC unit and breaking that down into the approximate kWh (kilowatts per hour) that the air conditioning runs per day.
Regardless of how you obtain that information, once you have an estimate of how much energy your air conditioning pulls from the grid, you can determine the solar panel array that would be needed to create that amount of energy.
Do keep in mind that solar power generation rates differ based on your geographical area. The amount of energy a solar panel generates in Arizona is more than the same panel would generate in Seattle.
If you have already installed, or had someone install, solar panels on your roof or property to connect to your home’s electrical system, you may already be offsetting your air conditioner usage.
If not, adding solar panels to your roof (or in some cases elsewhere on your property) can turn a conventional air conditioning unit into a solar powered AC unit.
Having solar panels on your roof can actually lower your overall need for air conditioning by a bit as well. Since the photons from the light are collected by the solar panels, those photons don’t hit your roof and turn into heat.
This contributes to smart design of your home. Remember, solar powered air conditioning units are one factor in creating a greener and more sustainable home, but smart design and passive cooling strategies can lower your need for power overall, which can make even more of a difference.
Purchase A Solar AC Unit
Of course, the simplest method of entering the solar powered air conditioner world is to purchase an air conditioning unit specifically designed to run on solar power.
Window units with solar panel attachments are probably the quickest to install form of a solar AC units. There’s no need to route your solar panels back into your home’s power grid, or set up a separate converter or battery backup.
The great advantage here, is that most of these solar powered air conditioning units are not reliant on anything in your home’s electrical or duct system being converted, and so this is an option available for those who cannot do extensive electrical work.
However, an air conditioner is a power hungry appliance. That means that you should only look at solar powered AC units that have an appropriately large array of solar panels, and you should take care to place it where it will get the right amount of sun to charge your air conditioning.
Failure to properly place a solar panel array could result in an air conditioner that does not cool, or that runs out of power when you need it most. Solar AC units rely on strong, plentiful sunlight. They won’t do well if they are less than optimally placed.
Keep in mind, also that solar power AC units are much more expensive than typical window units. You should be ready to make an investment. However, do look out for opportunities for government rebates or tax breaks based on the installation of solar panels or solar appliances (of course, check with your local government agency for details specific to your area).
Is Solar Powered Air Conditioning For Me?
Solar powered air conditioners are a great idea for creating a more sustainable future. However, there is no perfect solar air conditioning setup. Each type of solar AC unit that we’ve discussed has pros and cons.
DIY solar powered air conditioners are easy to make if you are a bit handy, but most of the kinds that you could easily create are meant for camping, emergency, or survivalist type situations. They’re not your everyday air conditioning unit. And they won’t dehumidify or clean your air the way an efficient HVAC system will.
Creating a solar panel array that feeds into the power grid offsets the use of power for an AC unit. This makes the most sense for many homes, and is common enough that you can find a skilled technician to help you with setup and installation.
But in some senses, this doesn’t create truly solar powered air conditioning units, but more of a trade of power from conventional method to solar. It also represents a significant initial investment. Though the money saved, and rebates and tax breaks can make this a very worthwhile investment.
And finally, a standalone solar powered air conditioner can be purchased easily from specialty retailers or online stores. But these solar AC units are expensive, especially compared to standard air conditioning. The attached solar panels must be carefully placed, and there are still significant limitations on what a single window unit can do, especially if you have a large home.
The key is to choose the system that works with what you have available at this time. Every bit of power that you offset with solar is progress. Additionally, when you are thinking about how much energy your air conditioning uses, then you are much more likely to use it thoughtfully and only when needed and not unthinkingly keep it on for 6+ months of the year.
Solar power is a great way forward towards clean, cost effective energy. It can even stand in for traditional electrical appliances (see solar refrigerators, for example.)But that must be combined with thoughtful design, and mindful energy use. The more we dedicate ourselves to using solar energy in a positive and progressive way, the brighter our future looks.