Solar Builder

JAN-FEB 2019

Solar Builder focuses on the installation/construction of solar PV systems. We cover the latest PV technology (modules, mounting, inverters, storage, BOS) and equip installers/contractors with tips and tools to make informed purchasing decisions.

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SOLARBUILDERMAG.COM | 9 ⁄ E nter the Twilight Zone with me. Tomorrow, we wake up in a reality where solar energy is a standard component of all new homes built across the United States. Between that day and 2026, more solar energy capacity would be installed on just new homes than the entire U.S. cur- rently has installed to this point. By 2045, solar installations on new homes alone would total 203 GW. Imagine the ripple effects. OK, now wake up. That's not the world we live in, but the day feels much closer. Starting in 2020, that will be California's reality thanks to the California Energy Commission's (CEC) 2019 Building Energy Efficiency Standards. Here's how the California Solar and Storage Association (CALSSA) breaks down the opportunity for us: "Each year there are roughly 120,000 residential solar installs (105,000 retrofit on existing homes and 15,000 on new homes). California averages 75,000 to 80,000 new homes built per year. So, this new rule will see an increase from 15,000 to 80,000 new solar homes (65,000) each year. If retrofit stays the same (roughly 105,000/year), that increases overall installations to 185,000 per year, or a 54 percent increase over the cur- rent 120,000 installs per year. "If the average system size for a new solar home is 3.5 kW [a rough guess based on minimum system size of 2.5 kW ], the additional 65,000 installations will result in an additional 225 MW. Compared to the total current market of customer-sited solar in California of approximately 1,100 MW, this is an increase of 20 percent." My guess is after the results of California's experiment, like skateboarding and West Coast IPAs, this cool new trend will work its way across the country and get us closer to that Twilight Zone scenario. At last count 100 cities across the country have announced timelines to source 100 percent of their energy needs from renewable sources (Cincinnati being No. 100), with several already mulling their own version of California's blueprint (places as off the solar radar as Milwaukee). This is why we're spending all of 2019 considering the impact of California's new building standards in this year-long news series, Countdown to 2020. To kick things off, let's do a deep dive into everything notable about the Building Energy Efficiency Standards as they are written. Efficiency equation The addition of the solar mandate grabbed the headlines, but systems won't just be plopped onto homes that don't make sense. The CEC's 2019 Building Energy Efficiency Standards include PV as just one piece of an integrated, forward-thinking step toward a zero net metering world. Some key elements: Flexibility. The mandate allows for homebuilders to offset some or all of the required solar PV capacity by providing access to community solar systems. Homes in this bucket are those with less than 80 contiguous sq ft of unshaded roof area due to shading from permanent structures. Sensible sizing. A home's solar system must be "appropriately sized" to generate the amount of electricity used by the home over the course of a year, based on the square footage of the home, the num- ber of dwelling units and the climate zone. Tailoring system size in this way, and not overbuilding, is important for keeping system costs reasonable and cur- tailing the excess generation sent back to the grid. With solar panels being standard, home- builders can then design homes and devel- opments to maximize the energy a system can produce with roof angles or panels placed on multiple planes and directions to capture exposure during different times of the day. Closer partnerships between solar companies and homebuilders would help lessen design costs, for example, by encour- aging the creation of standardized models of home energy systems. Solar installers could also take advantage of the opportuni- ty to install panels on multiple homes at the same time to reduce labor, permitting and even supply chain costs. We will be diving into this area much more in future articles in this series. Efficiency focus. Increasing energy effi- ciency is just as critical in this new world as the solar mandate. Consider that the aver- age single-family home in the U.S. would need over 9 kW of solar panels to match its electricity usage when the average size of a By Chris Crowell Installment 1: New Builds, New You

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