Dive Brief:

• Wisconsin's largest rooftop solar array is nearing completion on a building at the American Family Insurance headquarters campus, in Madison, according to the Wisconsin State Journal. It is expected to be operational by early November.

• The system comprises 4,488 solar panels that will produce up to 1.03 megawatts of power, cutting the entire campus’s annual grid-power consumption by up to 9%, or $191,000.

• Other solar arrays currently under construction in the state are expected to eclipse this project. Those include a 3.4MW array in Flambeau, WI, and a 1.4MW system elsewhere in Madison.

Dive Insight:

The roofs of big boxy buildings like corporate offices and manufacturing and storage facilities are prime real estate for solar power generation — and not only because they provide unshaded terrain for PVs. The addition of rooftop solar usually also allows the building owner to reduce its energy consumption and, as a result, its monthly power bill.

Tesla is following the trend at its $5 billion gigafactory, in Nevada, to help fulfill its net-zero energy goals. The electric carmaker expects that the 70MW solar farm will generate enough energy to power its operations there.

In addition to private companies, municipalities are investing more in solar with Maine and Missouri recently breaking ground on the largest such arrays in their respective states. Meanwhile, a handful of cities in California and Florida now require most new residential construction and significant remodels to include rooftop solar.

Yet intermittent energy sources like PVs aren't fail-proof. A blip in output from solar utilities during last week's solar eclipse went largely unnoticed, Utility Dive explained, not because it wasn't significant but because the country's use of solar power is still limited. For perspective, renewable wind and solar contributed around 10% of the country's electricity in 2016 while fossil fuels accounted for roughly 80%, according to the U.S. Energy Information Administration.

GE Power's Chief Digital Officer Ganesh Bell told Utility Dive that the solar power sector had enough notice of the eclipse to shore up its supplies. That might not be the case with more critical events such as unexpected outages and major storms.

After all, the eclipse was short by comparison and only in a relatively thin band of the U.S. was the sun ever fully blocked out. Even utilities in the path of totality reported that advanced planning allowed them to account for the down time, Bloomberg reported.