Can solar and historic buildings work together? The answer is a resounding “Yes!”

Here are two examples.

Modus Engineering, Des Moines, Iowa

Modus Engineering of Des Moines has built its reputation on designing energy-efficient buildings, many of which qualify for LEED (Leadership in Energy & Environmental Design) status for its clients. When it came time to create a new headquarters for itself, it selected an old brick factory which it has converted to LEED Platinum status to showcase its talents.

The building seems like an unlikely candidate for LEED status. Built in 1888, it is a four-story brick warehouse that once served as a steam tractor factory. It was used as a military supply depot during both World Wars. Soot still covers some of the bricks from when it caught fire around 1914, according to The Des Moines Register.

“Sustainability doesn’t mean freakishly expensive,” said Justin Doyle, a principal with Modus Engineering. “It doesn’t mean these wild systems. It can be economically justifiable. It just takes the right design.”

In addition to new, energy-efficient windows and LED lighting throughout, that design includes a highly efficient ground-based geothermal system for heating and cooling the structure. It also includes two solar panel arrays, one on the roof of the parking area and one on the roof of the building itself. Together they combine to produce more than one megwatt-hour of electricity on sunny days.

Renamed Market One, the old factory is now a “net zero” facility — the first in Iowa. “Net zero” means the building will produce more electricity than it uses over the course of a year. The solar panels can produce more than twice the building’s energy consumption in the sunny summer months, which will offset shorter winter days.

Being “net zero” is easier said than done, according to Scott Bowman, an engineer and chairman of the Iowa Chapter of the US Green Building Council. “I’ve heard of lots and lots of people claiming net zero but when you look at the details, (achieving) net zero is hard even for platinum buildings,” he says.

Modus expects its energy improvements will be recaptured in 10 years or less.

Laclede Lofts, St. Louis, Missouri

Laclede Lofts is a joint venture of Universatile Development and Rothschild Development. The 50-unit apartment building is a former pharmaceutical factory located near St. Louis University. Like Market One in Des Moines, it was retrofitted with solar panels to create 25 kilowatts of electricity.

“We estimated, for the course of a year, the total electrical usage for everything in the common areas: parking lot lights, lobby and hallway air-conditioning, elevator, gate opener, and security system. Even by the more conservative production projection, the array is producing 62% of our usage needs,” says Jeff Winzerling, president of Universatile Development.

The solar power system consists of 98 solar panels with microinverters connected to the building’s common-area meter. It was designed and engineered by Microgrid Solar, a leading solar energy company headquartered in St. Louis. “This is a unique project, utilizing solar on a historic renovation project and an apartment building – you just don’t see this sort of thing very often, due to the challenges involved. We are thrilled to have been a part of the project,” says Microgrid CEO, Rick Hunter.

A link has been added to the building’s website that allows building residents and others to monitor the production of the system’s 96 solar panels over time. It helps them to see the electrical output converted into reduced carbon dioxide emissions either in trees planted or miles not driven. In all, almost two-thirds of the electricity used for the building’s common areas comes from the sun.