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Precise solar system sizing is crucial for maximizing energy production, return on investment, and customer satisfaction. This blog dives deeper into the technical aspects of energy system sizing and installation, leveraging energy bills and advanced software tools.

Understanding Energy Consumption

Detailed historical analysis: Analyze 2-3 years of electric bills to identify usage patterns, peak demand periods, and the potential for load shifting with battery storage. For example, in a residential setting, a thorough analysis might reveal that peak energy demand occurs in the early evening when solar production is declining, and an EV is plugged in to charge, highlighting the importance of battery storage for shifting energy usage. Don’t forget to discuss projected future energy increases, such as adding a heat pump.

Rate structure breakdown: Account for fixed charges, time-of-use rates[e], tariffs such as NEM 3.0, and demand charges to optimize system design for cost savings. For instance, a commercial client on a demand charge rate structure might benefit from a system with peak shaving capabilities to reduce high demand charges during peak usage periods.

Client Objectives and Constraints

Beyond minimizing grid use: Explore goals like reducing recurring energy costs, being prepared for inclement weather, consumption offset, bill offset, or powering electric vehicle charging. For a sustainability-minded client, designing a system that meets their energy needs and enables them to achieve net-zero status can be a compelling selling point.

Balancing budget and roof space: Use software simulations to model different system sizes and configurations within the budget and available roof area. For a client with limited roof space but a desire to maximize solar energy production, exploring high-efficiency panel options or considering a ground-mounted system could be viable solutions.

Technical Considerations for System Design

Panel Selection: Compare efficiency ratings, temperature coefficients, and warranty terms of different panel options. For example, in a region with high temperatures, selecting panels with lower temperature coefficients can help maintain performance during hot summer months.

Shading Analysis: Use software tools like Solargraf to identify potential shading from trees, chimneys, or nearby structures. Design layouts to minimize shading impact and consider microinverters for shaded areas. In a scenario where shading is unavoidable, incorporating microinverters can mitigate the effects of shading on overall system performance.

Temperature Impact: Factor in local climate data and ventilation strategies to mitigate performance losses due to high temperatures. For instance, installing panels with wider spacing or incorporating passive ventilation techniques in a hot climate can help dissipate heat and improve overall system efficiency.

Consider environmental impacts

Derating for Efficiency: Account for real-world system losses (soiling, inverter efficiency) typically around 10-15%. For instance, when sizing a system, accounting for efficiency losses due to dust accumulation or inverter inefficiencies ensures that the system can still meet the client’s energy needs under less-than-ideal conditions.

Solar Irradiance: Use local solar irradiance data from NREL (National Renewable Energy Lab) or PVWatts to estimate annual energy production. For example, even a modestly sized system can generate significant energy output in a region with high solar irradiance, making solar a compelling investment for clients in such areas.

Benefits of Solar Design Software

Comprehensive data sets: Access detailed information on shading, roof pitch, azimuth, and local weather patterns for accurate system modeling. For example, by inputting specific site parameters into the solar design software , installers can generate accurate performance predictions tailored to each client’s unique location.

Streamlined workflows: Automate repetitive tasks, reduce design errors, and generate professional proposals for clients. For instance, using software to create detailed proposals with 3D visualizations can enhance client presentations and streamline sales.

Comparison tools: To optimize performance and cost-effectiveness, compare panel options, inverter configurations, battery storage options, and system layouts. Software tools that compare performance and cost can help installers recommend the most suitable choice for their clients.

Advanced Considerations

Complex Roof Layouts: Utilize software tools with 3D modeling capabilities to design systems for non-traditional roof configurations. For instance, 3D modeling software can help visualize how a solar array will fit on a complex roof layout, ensuring optimal placement for maximum energy production.

Battery Backup Integration: Factor in battery capacity and discharge rates to meet backup power requirements and self-consumption goals. For example, sizing a battery backup system to provide uninterrupted power during grid outages can enhance resilience for clients in areas prone to power disruptions.

Inverter Sizing: Choose the proper inverter size based on total system DC (Direct Current) wattage and ensure compatibility with the chosen battery storage solution (if applicable). For example, selecting an inverter with sufficient capacity to handle the solar array and battery storage system ensures optimal performance and reliability.

By considering these technical details and leveraging advanced software tools, professional installers can design high-performing solar systems tailored to each client’s needs. This consideration will improve customer satisfaction, increase project profitability, and positively impact the environment.

Solargraf simplifies solar and storage system design and proposals. Schedule a demo if you would like to learn more.

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