Living off-grid with Solar Power
As of this past June 2016, my wife and I have been living off-grid in our tiny house using solar power as our only source of energy along with limited amounts of propane for cooking and hot water heating. Through our entire process of planning for and living with solar power, we have learned about many aspects of solar power including:the basics of how it works, how it’s sized, and ways to live with your solar power most efficiently and still enjoy the experience. As I describe the following tips and info in this or any other blog I write, bear in mind, like many people living off-grid or homesteading, I am not a professional and have no previous experience with solar power, electrical installations or construction, but with a lot of research and with a focused mindset, any person can take information they read and apply it without having any previous knowledge of that subject. That said, take the info I’m giving with a grain of salt as these are all things we have learned along the way and continue to learn on our journey to a self sustaining homestead.
No matter the structure you decide to build or live in, you will either be connected to the grid or totally off-grid. (I will also write future blogs on different sustainable housing options but for now let’s keep on the solar topic.) When living with solar power but connected to the city power or “the grid” you have solar panels that supply power to your house during the day and at night when the sun is no longer supplying free energy, any power consumed is taken from the city source. If you are connected to grid power you still have the potential to produce more solar power than you consume during the month and by the end you could technically get a check or credit back from your power company. This is one of a few ways to draw people to installing solar. Solar power also offers tax credits for installing “green” or renewable systems in your house. Check your local cities tax credits for green initiatives if you plan on installing solar power, as rebates differ on your location. On the other hand, if you live off-grid, all of your electrical needs are supplied by the panels and the batteries that store it. If that is not enough you will need a back-up source in times of prolonged spans of bad weather. When you are planning on living with solar power you will need to size your system based on your personal power consumption. You can get an idea of what you use by looking at your monthly electric bill and being mindful of what appliances you use every day.
When sizing your system, you will need to think about all the appliances you will want to use on a daily basis. This includes things you may not think of like kitchen or bathroom fans, lights, and water pumps and fridges to name a few. Also, include any other random appliances you may use on occasion i.e. Power tools, cordless tool batteries, kitchen appliances like blenders, juicers, or whatever else you can think of. When planning your appliances you will use, make sure to take energy efficiency into account and remember to unplug appliances when not in use. For us, every product we wanted to have, we considered if it was 1) absolutely important to being able to function on a daily basis and 2) that it was the most efficient product we could find. Tip: any products that are used to produce heat of some sort i.e. (hair dryer, toaster, microwaves, electric heaters etc.) are normally avoided in an off-grid solar system. They consume large amounts of energy that if used for long periods of time can zap your systems battery storage.
Once you have made a solid list you will be able to figure out more of a ballpark of how many watts of power you would be consuming on a daily basis and size your system accordingly. You will need to look up specs of the products you want to use and and multiply that by how many hours a day you would use them. If you can’t find watts, you can use the formula: Watts=Amps x volts. If you use a computer or gaming console and it uses 200 watts, if you use if for 3 hours a day that’s 6oo watts of power consumed. If you want more specifics on how to size your system, you can Google solar calculators or contact a solar installer and they should be able to answer all your sizing needs. After much debate, we decided to go with the latter option having a licensed solar company size and install our systems which was definitely a little more expensive, but takes the planning and stress off your hands. Besides your appliances, you need to consider the most important factor of your system, your panels and your batteries. Your batteries are important because in off-grid living, it is your sole source of electricity that will power your house when your panels are not drawing anything in. There are lots of different types of batteries to choose from with different sizes,capacities, and different costs so do research and make a decision of what works best for you. Based on your daily electric consumption, you want a battery storage capacity that can supply enough energy for your house for 3-4 days of possible inclimate weather, where you wouldn’t have solar gain and batteries would continue to deplete during the day. Also, for the health and longevity of your batteries, your system should never really be using more than 30% of your systems battery storage. For example, our system is a 1800 watt or 1.8 kw system with (6) 300 watt panels and 8 deep cycle batteries. If we use 1000 watts of power a day and we need 3 days of backup, that’s 4 days and 4,000 watts and that should only be about 30% of your system. Your talking about around 14,000 watts or a 14 kw system. That’s a lot of power storage and that’s why off grid solar systems can get expensive very quickly.For us, I am not experienced or confident in installing solar systems, and although it can be installed by a competent person with some experience, for the size and complexity of our set-up, we chose to have a solar company size and install our system. It was a substantial cost factor in our homestead, costing around $15,000, but it was worth it to not have to worry about installing things improperly and potentially leading to a hazardous electrical fire down the road. We did have some small issues with our system in the beginning, but the company was very helpful with fixing the issues that came up, and that was a great benefit of hiring a professional and an insured solar installer that backs their work.
When considering panels, just like the batteries, they come in different sizes with different wattage they pull in. Do your research, call a professional if you have questions and make a decision that’s best for you. Based on your location in the world, the angle your panels face will depend on your longitude and latitude and is based on the angle of the sun in the sky on Winter solstice – Dec 21st, when the sun sits lowest in the sky. This is important because during the winter months when daylight hours are the shortest during the year, you want to be able to harness as much of that short daylight as possible. You can find your sun angles online by searching a sun angle calculator and typing in your location. Where you place your panels is also something to take into consideration. If possible, put them somewhere where they can be accessed for cleaning. If there is bad weather and your panels are covered in snow, dirt, or debris it will reduce or eliminate incoming solar power. Having the ability to wipe panels free of snow is important for panel performance. We had our panels installed on the ground mounted on a metal racking system that uses helical piles driven into the ground to reduce ground disturbance.
To complete our solar system, besides our solar panels and batteries, we have a charge controller and a power inverter. The charge controller prevents your batteries from overcharging or becoming too depleted which could damage or ruin them, while the inverter converts the incoming solar power from D/C (direct current) to A/C (alternating current) which is what standard household electricity runs on. You do lose a little power when you convert d/c to a/c but a/c appliances are far easier to come by and cheaper than d/c appliances due to standard a/c housing power. Our system is completely outside based on the limited size of our tiny house with all our batteries and wiring/controllers mounted on the exterior wall of our house in the Outback, an outdoor safe box specifically for solar system storage. Make sure when sizing your system that all your inverters, charge controllers, and wires are all sized to handle the size of the solar system, if you are not sure I would suggest hiring out some help. All of these features can be placed within your house in a utility room or closet. Due to the lack of space in our house we put everything on the north wall of our house which kept them out of sight when entering our property. Also, when you are planning your system and your budget is a factor, as with most people, you can always add a minimum system that will get you by for a short period while you can save more money and expand your system later. There are also companies that will sell full kits with all the components and wiring necessary to get someone started with solar power. Kit sizes will vary so once again, have a good idea of what appliances you will be using so you can choose accordingly.
Since living with solar power, there is definitely been a learning curve with how to live in harmony with your house, your solar system, and the elements to maximize the full potential of the system. We live in Colorado, so for us during the summer when days are long and nights are short, living off solar is petty easy without thinking much, we can use our appliances as needed without a negative effect. As the winter rolls in, at its peak, we have about 9 hours of daylight and 15 hours of dark, so living off solar gets a little more tricky. Luckily in Colorado we have many days of intense sunshine which really helps our system recharge during the winter. When we do have bad weather, it will typically move out within a day or two; quickly allowing the sun to melt the snow and recharge battery storage. For many other off grid-era, they live in places where the winters are more permanent and stick around for weeks or months at a time making it difficult or impossible to live solely off solar power leaving many needing to supplement with back up generators. We have been very fortunate to be able to live off solar power without issue for the first half of the winter without any backup power.
Besides our solar system, we have a few things we use in our tiny house to help our system go a little further at night without using our solar storage. Our Goal Zero Yeti 1250 is a solar powered generator meaning it can be charged with solar power or plugged into a a/c outlet and stored inside without fear of harmful emissions. It comes equipped with 12 volt outlet, 3-prong A/C outlets and USB outlets for super easy plug and play capability. It does weigh 100+ pounds and comes with wheels to roll it around due to its heavy weight so it’s definitely not something you want to tote around. It is a all-in-one solar powered system that we store upstairs in our office/bedroom. We charge it during the day by plugging it in to our solar powered house and at night when power is a commodity we unplug the Yeti from the main system and use the Yeti’s power storage to run our internet, charging phones and our 26″ iMac computer. It is really been an extremely useful tool for our situation and would recommend it to people looking for a small plug and play system as multiple Yeti generators can be linked in parallel to increase storage capacity providing enough power for a small off-grid house.
We also use a series of very cool Lumio lights. They look like a book but when opened, a soft light illuminates our small space very effectively and with its magnetic covers/faces we are able to hang it in our downstairs room by attaching a similar sized pieced of metal on our ceiling where we simply open it and attach to the ceiling giving us great light without using our lights in our tiny house.
In our tiny house, in order to keep track of our power consumption we have a small digital reader that can control our solar system and shows the current state of charge of our batteries. We use this feature daily as it helps us to keep track of our power status and usage, so appliances are used accordingly. We also like to do certain things like make our protein shakes in the morning with a blender and create delicious homemade juices with our juicer. Both of these products do have high electrical consumption but we use these products for very short periods of time and normally during the day when the sun is out, so we are still able to have these luxuries without depleting battery storage. We have also had some eye opening learning experiences living with our off-grid solar system. When we moved in to our house It had been siting vacant over the winter without electricity or water in the systems. When we moved in early spring, we plugged in our submersible water pump that’s located within our 1,700 gallon buried cistern. It supplies water to our house, but I will talk more about water storage tanks and off grid water @ a later time. We had running water which was a delight and another catastrophe I can talk about later, but after a couple weeks, we started experiencing issues when our house didn’t have any power once the sun would go down. We had just paid a large amount of money for this system, and we were essentially camping in a tiny house. Needless to say, we were pretty upset and worried that we were getting in over our heads. After lots of trial and error over the phone and a couple trips by the solar installer out to our property, we found out the issue we had been experiencing. According to the pumps spec sheet, it uses 900 watts during use. For some reason we have still not figured out, our pump was pulling power from our system just from being plugged in, not just when we opened the tap. Over the first few weeks we lived there, the pump was essentially running 24/7 draining our batteries to the point that our house was working properly during the day when the sun was out, but when the sun went down we had no solar power and no stored battery power. When we figured this out, it was the last thing we wanted to hear as each battery costs around $230 and, at the time,there were 4 in the system. Lucky for us, after testing each battery we realized only one of them was bad which meant fixing the system would cost $230, not $1000. Once the new battery was installed our system functioned flawlessly and now to avoid this issue again, when we want to use the water, we simply turn on a switch on a power outlet that the pump is plugged into. Since then we have also added another 4 batteries to the system making 8 batteries total. Our system was producing plenty of power, but not storing enough for our night time use even though we were living as modestly as we could running only our mini fridge and charging our phones. The addition of the other 4 batteries has been the sweet spot for our system storing enough power for our nighttime needs while keeping our systems batteries at a high state of charge by the morning, around 85-90%.
Our most recent tweak we have made to our solar system is our new more energy efficient under counter mini fridge. This came about from noticing a decrease of power storage over night and narrowing it down to our mini fridge. Your fridge will probably be your biggest electrical draw since it has to be on 24/7, but the one we had was drawing more than expected. Do research as there are many fridges with different costs, insulation and ability to hold in cold, and efficiency. Because these fridges are half as small, if not more, than a standard household fridge, people would assume that they use much less power. As you would find out with some research, this is not the case. If anything, many mini fridges are actually less efficient and use as much if not more power than a full-size fridge. The original mini fridge in our tiny house was the only appliance that was chosen by the builders without regards to its efficiency. After some research, I found a cheap fridge at Home Depot that was way more efficient and slightly larger than the one we already had so that was a double plus. When comparing the two mini fridges energy star rating, which most products display in their product description, the new mini fridge we purchased ended up using around 85,000 watts less annually than the other mini fridge. This is an insane power difference when relying on solar power, so again the importance of choosing the appliances you use will help your solar system work better, longer, and make the experience living with it more enjoyable. TIP: When looking at appliances energy star rating for choosing the appliances you want to use, the monetary difference it costs to run two different products for the year may not be much different but the actual wattage they consume can vary greatly, as was the case with out fridge. This is due to the fact that a majority of the country lives on grid power and paying for electricity is relatively cheap commodity. On the other hand increasing the size of your solar system in order to operate a large appliance that isn’t necessary to function on a daily basis will far outweigh the products benefits and end up costing you a lot of money.
Despite the few difficulties we have experienced learning to live with solar, we have loved living in our tiny house with solar power. It has taught us what is really important in life, like spending more time outside in nature, and even though we still have wireless internet and use our iPhones and computers, it makes us realize that all these things are good but in moderation, and that these tools of technology we have should be used to our advantage to educate and expand our knowledge, to help lead us to find our purpose in life. All we can do is be thankful for each day we are given do the most you can with it. I hope that the info I talk about helps people to live or at least be aware to living a more sustainable life whether that is in your off-grid grid, tiny house living, homesteading, living in an urban environment or a combination of them. If you have questions regarding this blog, please feel free and ask!
