How Far From The House Can You Put Solar Panels?

Solar panels are devices that convert sunlight into electricity. They are typically mounted on the roof or ground near a home or business. How far solar panels can be positioned from the building depends on several factors:

Table of Contents

Aesthetic Concerns

When installing solar panels, many homeowners are concerned about how far away the panels can be placed from the house while still looking unified and cohesive. According to SolarSkin, panels should be installed with at least a six inch gap from the roof to allow proper airflow and prevent heat degradation (https://sistinesolar.com/solar-panel-style-guide/).

General guidelines recommend placing panels no farther than 1-2 roof lengths away from the house for a unified look. For example, on a one-story ranch style home with a 40 ft long roof, panels should not be placed more than 80 ft away (https://www.insideselfstorage.com/eco-friendly-storage/solar-self-storage-design-size-location-placement-and-aesthetics-of-a-solar-panel-array).

Panels can be made more aesthetically pleasing by using flush mounting, framing panels to match the roof, and placing panels in less conspicuous locations out of primary sight lines. Ultimately the distance will depend on the home’s architecture and layout.

Cable Lengths

The distance solar panels can be placed from the home is limited by cable length restrictions. Thicker cables allow for longer runs, but add expense. According to Solair World, technically panels can be located up to 500 feet from the home using very thick cables to prevent energy loss, but more realistically most installers limit cable lengths to 100-200 feet.

For a typical residential solar installation, 10 AWG cables are commonly used and allow for runs of about 100 feet from panels to inverter. To go beyond this length requires progressively thicker cables like 8 AWG, 6 AWG or 4 AWG. Each step up significantly increases cable costs. Longer cable runs also require more robust inverters that can handle the voltage drop. So distance is limited largely by budget considerations rather than technical factors.

It’s ideal to locate panels as close to the home as aesthetically possible, within 20-30 feet if viable, according to Easy Solar Guide. Longer cable lengths lead to more energy loss through resistance, so output decreases. Each site has unique layout needs, so installers determine optimal panel positioning to limit cable runs and maximize production.

Shading

Solar panels operate most efficiently when they have full sun exposure throughout the day. Even small amounts of shading can significantly reduce their energy production. According to Aurora Solar, “Partial shading of just 9% of a solar panel can reduce power output by over 50%.” Therefore, it’s important to avoid shading on your solar panels as much as possible.

When determining placement, assess potential shading from nearby trees, buildings, chimneys, etc. Consider the path of the sun throughout the day and seasons – an object may not shade the panels in the summer but could block sunlight during winter months when the sun is lower in the sky. If existing trees or structures already shade parts of your roof, optimize placement in the areas with the best sun exposure.

Maintain any vegetation to prevent growth from interfering with sunlight over time. If some shading is unavoidable, technologies like microinverters and power optimizers can help mitigate production losses, as cited on Velosolar.com. But optimal production will come from full sun exposure, so maximize open solar access when siting your panels.

Local Regulations

Local zoning laws and permits often dictate how far solar panels must be from the edge of the roof and property lines. According to the Los Angeles Fire Department (LADFD), “A 3 foot clearance around the roof is required between the solar array and the roof perimeter or ridge.” This allows firefighters space to ventilate the roof if needed.

Homeowner’s associations (HOAs) may also have rules about solar panel placement and distance from the edges of the roof. It’s important to check with your HOA before installation. Many states have laws restricting HOAs from preventing solar installation, but they may still impose reasonable restrictions.

It’s always best to check with your local zoning office and permit authority to understand the laws in your area. Regulations often vary from city to city. Be sure to pull all required permits and have licensed solar professionals handle the installation to remain in compliance.

Energy Loss

As direct current (DC) electricity travels from the solar panels to the inverter, some energy is lost. The longer the distance the electricity travels, the greater the energy loss. This is due to resistance in the cables that increases with cable length. Thicker wires have lower resistance and less voltage drop.

Experts recommend keeping voltage loss under 3% for optimal solar system performance. For a 48 volt system, this equals about 1.5 volts of loss. To achieve under 3% loss at 48 volts, the cable length between panels and inverter should be 100 feet or less. Exceeding 100 feet can result in significant energy degradation of 5% or more [1].

For longer distances, thicker wires are required. 10 AWG wire can transmit 48 volts up to 120 feet with under 3% loss. 8 AWG wire allows runs up to 150 feet. Going beyond these distances will cut into solar power production.

Higher system voltages like 240 volts can tolerate longer runs, but voltage drop should still be minimized. Locating panels as close as possible to the inverter is the best practice for efficiency.

Installer Guidance

Solar installers typically recommend placing panels within 100 feet of the electrical interconnection point on a home in order to minimize voltage drop and power loss (Green Job Hazards – Solar Energy: Falls). For grid-tied systems, panels are often mounted on the roof or garage to limit cable distances. For off-grid systems, panels may be ground-mounted but still kept reasonably close to the batteries/inverters they supply.

According to Canadian Solar’s installation manual, the maximum distance between a standard solar panel and the inverter should be less than 33 feet for 12 AWG cables to limit voltage drop (Installation Manual, p. 41). Thicker cables allow for longer distances but add to material costs.

Installers recommend keeping panels close enough to easily access for maintenance and repairs. Ground-mounted arrays are typically limited to distances where inspecting connections and cleaning panels can be done with extension poles (Zhonghui Solar). Rooftop systems should not be placed beyond safe working limits.

Maintenance Access

Easy access to solar panels is crucial for regular maintenance and repairs (RenewGenius). Solar panels need to be kept clean and free of debris, so installers and homeowners need access to safely reach the panels for cleaning. Many solar panel manufacturers recommend cleaning panels at least twice a year, so the panels should not be placed in areas that are difficult to access or require special equipment. For example, solar panels should not be placed high up on a steep, pitched roof without safety rails or tie-off points if frequent access is required. Fall protection and procedures would be needed in those cases.

It’s also important to consider access for repairs or replacement of defective panels or electrical components. Placing panels too far from the roof access point or in tight spaces can make repairs more challenging, dangerous, and costly. A good rule of thumb is to ensure panels can be reached by standard ladders or roof access walkways. Consult local building codes for any requirements regarding placement for maintenance access. Leave enough space around panels and between panel rows for workers to safely maneuver and perform cleaning and upkeep. Proper maintenance access will maximize system performance and lifetime.

Safety Issues

One concern when placing solar panels far from a home is the potential fire hazard they can pose. Solar panels that are not properly maintained or that malfunction can overheat, causing a fire risk. This is especially concerning when the panels are a long distance from the home, as a fire could grow out of control before being detected. Proper maintenance and upkeep is critical for remote solar installations.

According to the Occupational Health and Safety Administration (OSHA), solar panels can pose electric shock hazards, especially when damaged (SMECO). If panels located far from the home incur damage from weather, animals, or other causes, exposed wiring could present a serious safety issue. OSHA recommends staying at least 10 feet away from any solar installation.

Safety precautions like proper grounding, guarding, and insulation are especially important for more distant solar arrays to mitigate electrical and fire risks. Any damage or issues that arise could go unnoticed until they become serious if regular monitoring does not occur.

Conclusion

When determining how far solar panels can be placed from your house, there are several key factors to consider. Aesthetic concerns, like wanting the panels out of view, may lead some homeowners to place them farther away. However, this must be balanced with technical limitations like cable lengths and energy loss over distance. Local regulations also play a role in stipulating required setbacks from property lines. While each home’s circumstances are unique, most solar installers recommend keeping panels within 150-300 feet from the inverter to minimize efficiency losses. This allows sufficient cable length for most installations while maintaining a reasonable distance for maintenance access. With proper planning and installer guidance, solar panels can be placed at an optimal distance to maximize sunlight exposure while addressing homeowner preferences.