Whether it’s a residential, commercial or utility solar project, contractors strive to install systems that generate the most energy at the lowest lifecycle cost. Solar panels operate at their peak output when the sun is perpendicular to the panel. So for maximum energy collection, tilting the solar panels at the local latitude (37 degrees here in San Jose) facing south is generally best.
Because of existing building structures, compromises are necessary when installing solar panels. Residential systems are generally installed flush to the roof because tilting the panels is unsightly, and the efficiency benefit of tilting the panels is not worth the additional mounting system costs. Commercial systems on flat roofs are generally installed on racking at a relatively low tilt so that more panels can be installed — but almost never horizontal since flat surfaces collect dirt and debris.
But large-scale solar installations do not need to compromise when it comes to tilt angle and orientation. Systems can be more easily oriented due south and tilted at the angle of the local latitude. Taking things one step further, since the sun moves throughout the day, an additional 10-25% efficiency can be achieved if the panels track the sun.
Single axis solar tracker systems generally towards the east in the morning and west in the afternoon. More complicated dual axis solar tracker systems tilt east-west daily and adjust north-south seasonally. Because of the increase in efficiency, trackers have become a standard feature on large solar farms. Essentially, the added complexity of moving parts is worth the big increase in energy output.
NEXTracker was recently ranked the number one tracker company globally. They provide tracking systems and engineering for large utility scale projects all over the world. My guest on this week’s Energy Show is Alex Au, CTO and co-founder of NEXTracker. Alex was one of the pioneers in the solar industry as a key member of the team that developed the first integrated racking AC solar module, and then developed NEXTracker’s core tracking technology.
Please listen up to this week’s Energy Show as Alex shares his insights on NEXTracker, their technology and their recent work in incorporating flow battery technology to help eliminate the imbalance between peak demand and renewable energy production for utility scale applications.
Every time I fly into a city I’m amazed at the number of naked, white, empty flat commercial rooftops that should be producing megawatts of power. Even in solar friendly cities such as San Jose there are only a few blue rooftops that one can see from the air. On this week’s Energy Show we’ll be talking about the tremendous opportunity for installing solar on flat roof commercial buildings.
There are three reasons why commercial solar hasn’t grown as quickly as residential and utility solar. The first is customer economics: most commercial buildings are occupied by tenants who pay the electric bills, so the building owner does not have a compelling financial motivation to invest in solar to reduce the tenant’s operating costs. The second reason is that many building owners do not have the up-front capital for installing solar, nor do they have the long-term credit viability for a PPA or lease. The third reason is that, even with the ITC and low solar panel prices, the payback is still three to five years — too long for businesses making shorter term investments.
Fortunately, technology for installing solar on flat roof commercial buildings has continued to improve, reducing the mounting system and labor costs substantially. These new mounting systems are able to maintain the roof’s structural integrity, while at the same time addressing seismic and water intrusion issues.
My special guest on this week’s Energy Show is Costa Nicalaou, CEO of PanelClaw. They have completed nearly 10,000 flat roof projects in 30 countries and over 2,000 permit offices. Please listen up as Costa explains PanelClaw’s newest products, and how they provide supporting engineering and permitting services to their network of commercial rooftop installers.
When I first got into solar, Florida seemed to be a natural market. After all, it’s the sunshine state. In spite of the sun, there is one big problem that was holding back the market: the state of Florida prohibits residents from purchasing electricity from a source other than a utility. Unlike all other sunny states in the U.S., third party solar companies such as SolarCity, SunRun and Vivint are prohibited from providing solar leases and PPAs to homeowners. This utility-biased state policy has made it difficult for homeowners to finance their rooftop solar systems.
Fortunately, affordable solar loans are now available in Florida. These low interest and easy qualification loans help homeowners get to positive cash flow (electricity savings > financing costs). As a result, the rooftop solar industry in Florida is finally growing, in spite of the utilities’ anti-competitive policies.
My guest this week is Justin Hoysradt, CEO of Vinyasun, one of the leading residential solar installers in Florida. Please join me on this week’s Energy Show as Justin talks about the opportunities for rooftop solar in Florida, as well as some of their unique requirements — such as mounting systems and panels that can resist hurricane-force winds.