New Construction Solar

New construction offers an opportunity to plan ahead for a solar and/or battery power system, which may save on installation costs and offer better results than a typical retrofit.

We can provide valuable guidance by reviewing your building plan. A detailed building plan, including the roof dimensions, lets us determine how much solar power will fit, advise suitable equipment locations, and provide an accurate quote.

During the rough-in phase, we can begin relevant electrical work alongside your primary electrical contractor. This is a critical time for planning the optimal configuration of the utility power connection (service panel) and installing conduits or circuits between the solar and battery system components. This must be planned ahead to avoid conflicts, retrofits, or change orders.

Here are some important planning tips:

• Electrical. During the rough-in phase, conduits for the solar circuits can be installed. The main utility service panel and breaker panels will also be planned accordingly. A typical installation will provide whole-home backup by intercepting power between the utility meter and the main load center. Sometimes, the home must be partially backed up by installing a separate breaker panel for non-backup circuits (such as electric heat). In the case of partial backup, all backup and non-backup circuits need to be wired accordingly during the rough-in phase. 400-Amp services, now typical for larger homes, require planning ahead with your primary electrical contractor.

  
  

• Battery location. Batteries must be installed in a garage, a mechanical room, or other indoor conditioned space where the temperature can be maintained above 40 degrees, preferably between 60 and 68 degrees. The ideal installation setting is near the primary electrical service and breaker panel. If the battery will be installed in an attached garage, the appropriate, dedicated conduits between buildings must be installed early on.
  

• Standby/Backup Generator. If a backup generator is installed, it can be incorporated as a backup to a battery system. In most cases, an automatic transfer switch (ATS) is incorporated with the battery system connected on the grid side of the transfer switch. The generator will take over when the grid is out and after the battery is depleted. A transfer switch must be installed for generators with Tesla installations. Systems other than Tesla, particularly those designed for permanent off-grid, can use generator power to charge the battery.

• Utility. Solar and/or battery recommendations can vary depending on which utility you are connected to. Learn more about utility rates in our post about our local utilities. If you are not planning to connect to the utility, learn more about off-grid systems.

• Roof. A simple roof design with minimal hips and valleys is strongly preferred. When possible, orient the building so the solar panels will be mostly south-facing or combine southeast and southwest roof faces. Avoid positioning pipes, flues, and vents on the south-facing side of the roof to maximize usable solar panel space. The minimum pitch must be at least 4:12 (18 degrees), but 5:12 to 9:12 (22 to 37 degrees) is preferred for better performance. Higher-pitched roofs are acceptable but not necessarily recommended. On average, a home will need about 300 square feet of solar panels to cover half its electric use. Solar panel mounting hardware can accommodate various roof types, asphalt-shingle being the most common, but standing-seam metal or Euroshield rubber slate will give you a maintenance-free roof, and these options are highly recommended. Learn more about roof mounting in our roof mount post.
  

• Ground mount. When the roof option is unfavorable, a ground-based solar option may be an alternative. Ground mounts add material and labor costs but also have benefits. To pass the electrical inspection, they must be fenced in or elevated on tall poles. Learn more about ground mounting in our ground mount post.
  

• Energy efficiency. We highly recommend designing for enhanced energy efficiency when building a new home. Steps like air sealing and insulation must be done during construction, and significant energy costs can be realized over time. Neglecting energy efficiency measures will lead to higher energy consumption and increased dependence on grid power.
  

  • Envelope/Insulation. Heating and cooling are the largest energy requirements for most buildings, so insulation and airtightness are the most critical aspects of building efficiency, especially in winter climates. This is particularly true for solar-powered homes that aim to be fully self-powered during the winter when there is the least sunshine.
    

  • Heating/Cooling. Heat pump technology is an efficient way to heat and cool a home, making it an excellent choice to cover most heating needs throughout the year. Different types of heat pump systems are available based on your building's needs. If your home's primary heating is electric, such as cove or baseboard, these heating circuits should be wired to a separate breaker panel that will not receive backup in the case of a battery backup system. This includes backup electrical resistive elements found in some heat pump systems.
    

  • Ventilation. To ensure good air quality in an airtight building, a mechanical air exchange, an air filtration system, and humidity control are essential. An Energy Recovery Ventilation (ERV) system can handle all these functions in one unit, offering better air quality than a traditional leaky home.
    

  • Appliances. Most modern appliances have high-efficiency ratings, so you don't necessarily need to invest in the most expensive or efficient options. However, if you want to minimize your energy usage and take advantage of the latest technology, check out our off-grid post, where appliances are discussed in detail.
    

We hope these tips have been useful in helping you through your planning stages. We try to present everything you need to know on our website, but when you need further assistance, feel free to contact us.