• Orientation: Ideally, a south-facing roof in the northern hemisphere is optimal for solar panels. This orientation captures the maximum sunlight, leading to higher electricity production and faster system payback. However, panels can still be mounted on east or west-facing roofs, albeit with slightly reduced energy generation (about 75% compared to south-facing roofs). Flat roofs offer flexibility as panels can be angled to face due south regardless of roof orientation.
• Shading: After ensuring the right roof orientation, it's crucial to minimize shading on the solar installation area. Shade from trees, chimneys, dormers, and vents can significantly decrease electricity output. Installers often use tools like the "solar pathfinder" to assess potential shading from objects throughout the day.
• Surface: Solar arrays perform best when installed on a large, unobstructed surface. Features like dormer windows, chimneys, vents, skylights, and HVAC units can pose challenges to array installation.
• Durability: Consider the age of your roof; if it's over 15 years old, replacing it before installing solar panels might be wise. Solar vendors typically recommend durable roofing materials that match the system's lifespan (at least 25 years) to ensure long-term performance and protection.

Solar panels consist of photovoltaic (PV) cells crafted from silicon, which convert sunlight into electricity upon exposure to sunlight. These cells are interconnected to form a solar panel, typically sized at three feet by five feet and coated with tempered glass for durability against harsh weather conditions.

While a single solar panel cannot power an entire home or business, multiple panels are combined into a solar system, also known as an "array." This array, whether installed on rooftops or ground-level, comprises interconnected panels generating direct current (DC) electricity. However, most electrical devices operate on alternating current (AC), necessitating the use of inverters to convert DC to AC.

Two common types of inverters are central inverters and microinverters. Central inverters handle the entire system's electrical output, converting DC to AC at a central location. They are cost-effective but may be affected by variations in panel performance, such as shading reducing overall output. In contrast, microinverters and DC optimizers attach to individual panels, ensuring each operates independently. This individualized approach minimizes the impact of shading and allows for easier expansion of the solar array in the future.

Once converted to AC, the electricity flows through the electric meter into the building, where it is used immediately. Any surplus electricity can be fed back into the grid through the electric meter, contributing to local energy resources.

Consider your solar array as a long-term investment spanning 25 years or more. Solar panels are designed to reliably produce electricity for at least 25 years, with warranties covering their performance over this period. Although panels can continue generating electricity beyond 25 years, their output may gradually decline over time. Microinverters typically remain functional for the entire lifespan of the PV system, but central inverters may require replacement after approximately 15 years to maintain optimal performance.

Determining the optimal size for your solar array involves several factors. First, it's essential to understand how solar systems are sized and measured. Solar panel capacity is measured in watts (W), typically ranging from 250 to 300 W per panel. To calculate your system's total power, add up the wattages of all installed panels. For instance, if you have ten 300 W panels, your system's total wattage would be 3,000 W or 3 kW, as 1,000 W equals 1 kilowatt (kW). The average solar array size is around 5 kW.

Your installer will assess factors like your roof's size, sun exposure, and shading to determine the ideal array size. Limited roof space can be compensated for with high-efficiency panels (300-350 W), maximizing electricity production per panel. Geospatial data helps optimize system size based on roof orientation and local climate, ensuring efficient electricity generation. Additionally, installers tailor the system size to your budget, maximizing solar coverage within your financial constraints.

During sizing, installers evaluate how much solar output will offset your electricity needs, measured in watt-hours (Wh) or kilowatt-hours (kWh). Utilities bill based on kWh consumption monthly. Solar production varies by location, with installers accurately forecasting annual kWh output. Tools like PV Watts help estimate solar production and its impact on offsetting utility consumption. Divide the annual kWh production estimate by your annual utility kWh consumption to gauge solar's offsetting effect on electricity needs.

Solar panels are adaptable to various roof materials and structures, including flat or pitched roofs. They are affixed to your roof using a racking system tailored to your roof's structure and the type of roofing material. Your installer will assess these factors and recommend the most suitable racking system for optimal performance and compatibility with your property.

The process of designing and installing your solar array usually spans one to two months. This timeframe includes obtaining initial permits from your local government and securing interconnection agreements with your electric utility. The duration may vary depending on your specific permitting office and utility interconnection team, ranging from a few weeks to a couple of months.

Once permits and agreements are secured, the physical installation of your array—comprising panels, inverter, racking system, and wiring—typically takes one to two days. Subsequently, the installer seeks final approval from the municipal permitting office and secures the utility's final interconnection approval. This final approval stage can extend from one to three months, depending on the jurisdiction's processes and timelines.