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Off-Grid Homes

Updated: Feb 3

Choosing off-grid solar for your new home can be an favorable alternative to grid power, particularly in remote areas where connecting to the grid can be prohibitively expensive. However, the journey to design, plan, and budget for a completely off-grid system is significantly more complex than integrating backup power to a conventional grid-tied setup.


This comprehensive guide will provide you with important insights into the off-grid lifestyle, equipping you with the necessary knowledge to make a well-informed decision about whether this path aligns with your home construction goals and personal values.


Adopting an off-grid lifestyle transcends cost savings; it embodies a commitment to self-reliance, from understanding how your energy system works to proactive energy management and maintenance. It's a choice that not only demands a shift in how you interact with energy but also offers the rewarding challenge of living independently.


Our approach to off-grid projects is meticulous, advancing only when we're assured of achieving a fulfilling result. If you're drawn to the concepts of energy autonomy, self-reliance, and leading an energy-efficient life, exploring off-grid living could be right for you.


Note: Homes that are already grid-connected can also achieve energy autonomy through the implementation of back-up systems.


As your solar power installer, we are committed to helping you achieve the best outcome for your off-grid project. That's why we only install proven systems that are designed to offer the functionality and reliability you will need. We will help you achieve the best outcome, but your satisfaction with an off-grid lifestyle depends on you.


Key Considerations


Please become aware of these important considerations before planning an off-grid home:


  • Consult with us before finalizing the home design or starting construction. We offer consultation services for preliminary design and planning.

  • The home construction methods and electrical system design should have energy efficiency in mind. Energy inefficient homes, tiny homes, and trailer homes are not favorable in terms of cost or reliability compared to moderately sized homes that are build to high efficiency specifications.

  • There must be no shading of the solar panels by nearby trees or structures. In most cases, ground-mounted solar arrays are necessary for snow removal. It is best that the location of the ground-mounted solar array be within 400ft of the home and possible to trench a conduit to. Roof-mounted arrays can be a suitable alternative but have specific requirements for the roof design.

  • The battery system must be installed in a room such as a mechanical/utility room where the temperature is maintained between 50 and 80 degrees (for the best performance). At least six feet of wall clearance is required for the solar inverter and battery.

  • For backup power, you must have a large propane tank and a standby whole-home generator installed (by others) that is approved by the manufacturer for off-grid applications (typically 14kW to 24kW).

  • We only service equipment that we install. We do not sell or service generators at this time.

  • Homeowners must regularly monitor the system and be familiar with the system's daily performance and battery state of charge. This is most important during the winter, or whenever sunshine is limited and energy consumption is increasing. As the system installer, we can remotely view system characteristics for evaluation and troubleshooting, but we do not regularly monitor the system and cannot notify you of a power outage.

  • Power outages are not guaranteed. Your home battery is like a tank of fuel that you are using continuously every day. When solar energy is low for an extended period and the battery runs low (typically in the winter), power may turn off briefly while a backup generator starts. In other cases such as system faults (sometimes caused by the building's branch circuits or appliances), power outages may occur until the fault is cleared and the system is manually reset by someone on-site. While these situations are rare, additional uninterruptible power supplies should be utilized for critical devices including internet connectivity.

  • It is the homeowner's responsibility to be present and/or using the included monitoring system to be aware of the system's status and be able to identify a low battery or power outage. In the case of an unmonitored off-grid system in an unoccupied building, we cannot assume responsibility for any incidental damages due to power outages, such as loss of refrigeration, temperature control/freezing, internet connectivity, or security systems.

  • If the primary standby generator fails to start, a 240V portable generator may be used as a secondary backup. We recommend that you purchase a portable generator to have available for emergencies.

  • There must be internet access on-site for remote monitoring and troubleshooting. Starlink is recommended.

  • Having multiple heat sources is highly recommended, including air-to-air heat pumps and an energy recovery ventilator. Multiple energy sources for heat such as propane or wood are necessary. Electric (resistive) space heating such as baseboard or cove is not recommended in most cases, as it will rapidly deplete or overload the battery.

  • Water lines must not be dependent on power (i.e. heat tape) for freeze prevention.

  • During construction, contractors must use their own generators. Battery power systems will not be installed until construction is complete and internet access is available.

  • We do not sell or service wind turbines or other power sources.

  • We strongly recommend that the homeowner be willing to learn about how the system operates, and being willing to contact the system manufacturer for support in some cases.


Building Efficient, Sustainable Homes


Opting for quality construction over cheaper alternatives can save you money in the long run, especially in off-grid living where energy efficiency is crucial. A well-insulated and tightly sealed home significantly reduces the need for heating and cooling. This is particularly important in colder climates where heating dominates energy consumption.


Key elements for an energy-efficient home include:


  • High insulation levels (R-40 for walls, R-60 for ceilings, plus under-slab and footing insulation),

  • A tightly sealed building envelope, verified by blower-door tests,

  • Energy-recovery ventilation (ERV) systems to maintain fresh air and manage humidity.


Such homes can consume as little as one-third the energy of an average home, depending on use and occupancy. Investing in energy-efficient construction and appliances not only enhances reliability and comfort but also reduces maintenance costs over the home's lifetime.


Heating an Off-Grid Home


When planning an off-grid home, it is important to consider the energy needs for heating during the winter season, which is typically when the highest energy consumption period aligns with the least amount of solar energy. We recommend installing two or more sources of heat other than electric resistive heat (i.e. baseboard or cove heaters).


Air-to-air heat pumps are also an excellent choice for mild winter weather. When the weather is coldest, a propane furnace or wood stove is recommended.


Consult with an expert HVAC contractor to choose the best heating options for your building design, as it will vary depending on factors such as the building size and layout, exposure to sun and wind, ducting and ventilation options, among other factors.


How the power system works


An off-grid solar power system works by using photovoltaic (PV) solar panels to convert sunlight into electricity, which is then converted to usable electricity and stored in a battery. The solar panels provide power directly to the home while also recharging the battery throughout the day. The stored energy in the battery is then available for use at any time.


When there is above-average power use and below-average sunshine (mainly in the winter time), a standby generator provides a backup and recharges the battery before it gets too low. An automatic transfer switch is recommend so that it is also possible to power the home directly from the generator.


For advanced functionality, usage monitoring, and individual circuit controls from a mobile device, a smart breaker panel may also be utilized.


System Sizing


Sizing an off-grid solar system for a new home requires a few assumptions. The size of the home is an indicator, but also the number of occupants, build quality, major appliances, and personal habits. Energy needs in December-January are the baseline. Preferably, solar power will cover at least 90% of energy needs during the winter, minimizing backup generator runtime.


Energy needs are usually highest during the winter months. On average, a South Dakota home's energy consumption is about 12,000 kWh per year or an average of 30-40 kWh per day. However, every building and its occupants are unique.


The power capacity of the inverter must be sufficient for the peak electrical load. An average home needs at least 8 kW of peak power capacity, but for off-grid homes we typically recommend 12 or 15 kW of inverter power to reliably handle the high-power appliances and well pump.


The energy storage capacity of the battery must be sufficient to supply the maximum power of the inverter, and large enough to continuously power the home even when the weather is overcast clouds for several days. This battery capacity will usually be between 30 to 40 kWh for a typical home.


The capacity of the solar array will typically be between 12 kW and 18 kW, or 20 to 40 solar panels, and be sufficient to fully recharge the battery for most days of the year.


Appliances


It's important to consider the energy usage of major appliances, as they are typically the biggest consumers of electricity. Larger appliances that are used frequently, such as the refrigerator and washing machine, have a greater impact on energy consumption than smaller appliances and electronics. Some appliances use so much power that it may be preferable to use propane instead of electric (such as clothes dryer and oven).


Here are some important appliance and utility-related tips to consider:


Ventilation:

  • A blower-door test is recommended to test the air-tightness of the building and address leaks.

  • Mechanical ventilation is essential for high-efficiency homes with a tight building envelope. This includes heat-recovery ventilators (HRVs) and energy-recovery ventilators (ERVs) that exchange indoor air with filtered outdoor air with minimal heat gain/loss.

  • Whole-house fans (large exhaust fans) can be a good alternative to an active mechanical ventilation system, but the air is not filtered and temperature/humidity will not be recovered or controlled.


Heating, Ventilation and Air-Conditioning (HVAC):

  • Air-conditioning works well with solar power since cooling is needed most when there is the most sunshine.

  • Air-sourced heat pumps are efficient for cooling and can be installed as part of a central-air ducted system/furnace or wall mount.

  • Mini-split heat pumps are good for cooling individual rooms. Multiple units may be used to serve certain areas of the home only as needed.

  • High-efficiency central air conditioners are acceptable, but avoid oversizing as it is typically more efficient to run at lower power for more time.

  • Ground-sourced heat pumps can be effective, but have a high cost and don't work well in all situations. They should be used only when carefully planned, with expert guidance, and in the right locations.

  • Electric (resistive) heat is limited to use in milder temperatures in smaller spaces and highly-efficient homes. Alternate heat sources are strongly recommended when off-grid at (or above) our latitude. Larger homes may prefer to have more than two heating sources and/or multiple zoned systems.


Water:

  • For water heating, a large hot water tank with electric elements (or a hybrid electric/propane tank) is preferred. With a timer or controller, extra solar power can be used to heat the tank during the day and not require energy at night.

  • An on-demand propane water heater can also be a good choice.

  • Do not install an on-demand electric water heater (as the power requirement is too high in most cases).

  • A combination of a small electric tank that preheats water going into a small on-demand propane water heater can offer the advantages of both options.

  • Many well pumps require a high-power start and therefore need to be fitted with a soft-start capacitor (for smaller pumps) or VFD controller (for larger pumps) to run efficiently and not overload the battery system.

  • For even greater resiliency, the well pump can fill a cistern for water storage at the surface during the day, and a small pressure pump (or gravity) can provide water pressure on demand with minimal power at any time.


Kitchen:

  • Induction cooktops are the most energy-efficient option for cooking, but a standard electric range is also acceptable. If using gas, ensure proper ventilation.

  • Most modern refrigerators and freezers are energy efficient and do not require special consideration. However, ice-makers use a significant amount of energy.

  • Dishwashers are relatively efficient and represent a small share of energy use. They can even be more energy-efficient than hand washing, especially when using efficiency settings.


Laundry:

  • Newer clothes washing machines are very energy efficient. A high-extraction (fast-spinning) washer is recommended to reduce energy use for drying.

  • Propane/Gas vented dryers are a good choice that requires little electricity. They are affordable, readily available, and easy to maintain.

  • Electric, vented (hot-air, resistive electric heating element) clothes dryers are extremely energy-intensive, inefficient, and potentially damaging to fabrics. However, they are the most affordable and widely used. A lower-powered option (under 5 kW) is preferable. Smaller dryers are not more energy-efficient, but they demand less power at one time in exchange for a longer drying cycle, which is generally more suitable with battery power. A high-powered dryer can be fine when running while there is sunshine or while the generator is running; at night it may trigger the generator to turn on in order to support the high load or recharge the batteries.

  • A condenser dryer (typically called "ventless" or unvented) is like a vented dryer except the extracted moisture is collected in a tank that must be emptied. These use slightly more power than a vented dryer, but dry clothes faster. Their efficiency is not significantly different from a vented dryer.

  • Heat pump dryers are considered to be more energy efficient than other types of electric dryers. This is because they use a heat pump system to recycle heat from the air inside the dryer, rather than generating new heat via an electric heating element. This allows them to use less energy overall and can result in significant energy savings over time. Additionally, heat pump dryers tend to run at lower temperatures, which can be gentler on clothes and may help to preserve their color and shape. However, heat pump dryers tend to be more expensive than other types of electric dryers, and they may take longer to dry clothes.


Electronics:

  • Power usage should be considered, as some electronics use power even when not in use. To reduce this, use power strips or smart switches to turn off power to home entertainment systems and gaming consoles when not in use.

  • Internet connectivity is essential for monitoring and updating solar and battery power systems, but it is important to choose a newer, more efficient modem and router as they need to operate continuously. Avoid rentals provided by internet service providers, as they may be outdated and inefficient. Satellite-based internet modems tend to use much more power than regular modems/routers, but Starlink is a low-energy satellite system.

When it comes to appliances, investing in high-efficiency options can lead to cost savings in the long run. These appliances may have a higher initial cost, but they will use less energy and have better overall quality. The benefits of these appliances include a smaller solar power system size, increased reliability, and improved performance.


Thank you for reading this guide!

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