New construction offers an opportunity to plan for the integration of a solar and/or battery power system, which can save on installation costs and offer a better result compared to a typical retrofit.
By sharing your building plans with us we can provide valuable guidance. A detailed building plan including the roof dimensions enables us to accurately determine a system size that fits the home, suitable equipment locations, and an accurate estimate.
Moreover, we can even undertake some electrical work during the rough-in phase. This phase occurs after the framing is complete and before the rough-in inspection. This includes planning the configuration of the utility power connection, and installing conduits or circuits for the solar and battery system components,
Here are some important tips for your planning:
Electrical. During the rough-in phase, conduits for the solar circuits can be installed. For backup power systems, the main utility service connection to the home and the main breaker panel can be planned for ease of installation, reducing retrofit costs. A typical installation provides backup for the whole home by intercepting power at, or right after the utility meter. In other cases, the home may be partially backed up by installing a secondary breaker panel and separating backup circuits from non-backup circuits (such as electric heat). In the case of partial backup, the backup and non-backup circuits should be wired separately during the rough-in phase.
Roof. A simple roof design with minimal hips and valleys is strongly preferred. If you have flexibility in the orientation of the building, the best orientation for roof-mounted solar panels is any south-facing or even directly east or west can be good in some cases (north will not be used). Avoid positioning pipes, flues, and vents on the south-facing side of the roof to maximize usable solar panel space. A minimum pitch of 4:12 (18 degrees) is recommended, but 5:12 to 9:12 (22 to 37 degrees) is preferred for better performance. On average, a home will need around 300 square feet of solar panels to cover half of 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 rooftop post.
Ground mount. When the roof option is unfavorable a ground-based solar option may be an alternative option if there is a suitable location. Ground mounts may add a considerable amount of additional material and labor, but also improve accessibility to the panels for snow removal. A trench between the solar array and the building may be needed early on when foundations are prepared. Ground mounts also have to be fenced-in or elevated on tall poles to pass the electrical inspection. Learn more about ground mounting in our ground mount post.
Battery location. Batteries must be installed in a space like a garage, a mechanical room, or other conditioned space indoors where the temperature is between 50 to 85 degrees Fahrenheit for most of the year (32 degrees minimum). The ideal installation setting is located near the primary electrical service and breaker panel. In most cases, the battery cannot readily be installed in a detached garage, unless the detached garage is where the primary electrical service is located or a spare conduit is installed between the buildings.
Standby/Backup Generator. If a backup generator is desired, 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 the battery is empty; in some cases, the generator can be used to charge the battery. For installations that do not include a battery, solar power will only be generated when there is grid power; the generator will power everything when the grid is out.
Utility. Though you will not be able to choose your utility provider, you may have some discretion over the type of service you will be assigned. Each provider has a unique set of options. In most cases, a regular residential or total electric service is preferred. In installations with batteries, a demand charge or time-of-use rate may also be suitable. For utilities that offer a special (submetered) electric heat rate or EV charging rate, these options may not be compatible or allowed when a solar power system is installed. Learn more about utility rates in our post about the local electric utility providers.
Energy efficiency. When building a new home we highly recommend taking steps to improve energy efficiency. Steps like air sealing and insulation must be done during the construction phase and can save a lot in energy costs over time. Neglecting energy efficiency measures will lead to higher energy consumption for heating and cooling and reduce the potential level of energy independence.
Envelope/Insulation. Heating and cooling is the largest energy requirement for most buildings, so insulation and air-tightness are the most critical aspect 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 of the heating needs throughout the year. There are different types of heat pump systems to choose from based on your building's needs. Some heat pumps also come with additional electric resistive heating elements for extra power when the heat pump is less efficient in extremely cold temperatures. If you are instead installing regular resistive heat such as cove or baseboard, and plan to have a battery backup system, these heating circuits will not be backed up (in most cases) and need to be wired to a separate breaker panel than the remaining electrical circuits.
Ventilation. To maintain air quality in an airtight building, it's important to have a mechanical air exchange, air filtration, and humidity control system in place. An Energy Recovery Ventilation (ERV) system can perform all these tasks in one unit. This provides better air quality than a conventional, leaky home. Whole-house ventilation fans are also an effective option.
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're looking to minimize your energy usage and take advantage of the latest technology, check out our Off-Grid post where this is discussed in detail under the appliances section.
We hope these tips have been useful to help you through your planning stages. We try to present everything you need to know here on our website, but when you need further assistance feel free to contact us.