Roofs as Economic Generators
Author: HLP
Scorecard Categories Addressed
- Employment
- Unemployment Rate
- Median Household Income
- Live and Work in the City
- Cost of Living
- Overall Cost of Living
- Transportation
- Work Commute Time
- Resources
- Local Food
Solution Description
Roofs are a missed opportunity for economic growth of the community.
Some potential economic generators for rooftops include:
- PV Solar Panels
- Green Roof
- Edible Green Roof
The PV solar panels would, somewhat obviously, generate electricity that the building owner can use to reduce their electric bill. In the extreme case, there will be a surplus of electricity that the building owner can sell back to the local utility company and actually make money instead of just saving money.
Green roofs can significantly reduce the building's heating and cooling needs. Green roofs can also reduce urban heat islands, thereby making the city more people friendly.
Extending the heating and cooling benefits of green roofs to edible green roofs would have the additional benefit of increasing local jobs as well as local food.
Stakeholder Impact
All
If enough rooftops install solar, and the region is getting close to exceeding
current electric plant capability, these rooftop electric generators could
prevent the region from having to invest in a new power plant, thus saving
everyone an electric rate increase to pay for the new plant.
Families with Kids
More job opportunties. Access to local, healthy food. Cleaner air.
Seniors
Access to local, healthy food. Cleaner air.
City
Applying these ideas to city buildings can free up money
for other projects.
Developers and Building Owners
Another source of income. Roofs no longer just an expense.
Green Roofs:
- Stormwater management, dramatically reducing and slowing the speed of water runoff plus helping to clean the water before leaving the site.
- Extend the life cycle of the roof membrane by protecting it from the harsh elements and puncture from people doing roof maintenance.
Case Study
PV Solar Panels:
The state of Colorado recently passed a law making it much easier for non-utility companies to resell electricity. For example, the building owner could set up electric vehicle charging stations on their property and make some income from reselling the electricity.
The New Jersey and California are using public-private partnerships to get solar panels installed, for example, on school rooftops.
Green Roofs:
One on-line estimator provides some estimates for the cost savings. Some example yearly cost savings:
- Arizona State Capital Building = $24,266
- The Pentagon = $1.1 million
- Walmart SuperCenter in Bentonville, Arkansas = $179,300
Ford Rouge Plant
Largest green roof in the United States totaling 450,000 s.f. Ford saved
over $10 million on installation of a stormwater runoff treatment system.
Edible Green Roofs:
Some interesting examples of large rooftop gardens are coming from New York. Quotes from the article:
"Rooftop farms are in the midst of a boom here in New York City…"
"Driving that boom – at least in part – is New York City's Zone Green. Proposed amendments to Gotham’s zoning code that continue an inexorable march through the approval process, Zone Green would permit solar panels, green roofs, storm water systems, skylights and other green features on New York City buildings, despite existing restrictions within the 1961 code. Specifically with respect to rooftop farms, Zone Green would allow a waiver of floor area and height limits for greenhouses on top of non-residential buildings."
A second rooftop garden example comes from Brooklyn. This one is a hydroponics greenhouse on top of a warehouse rooftop that is harvesting 365 days a year. Quotes from the article:
"… hydroponics allow the urban farm to produce about 10,000 heads of lettuce a week – roughly 100 tons a year. The controlled environment agriculture uses 10 times less water and 20 times less land than traditional harvesting methods."
"“We’re producing crops and delivering it within 24 hours, definitely making it the freshest product on the market – the shelf life is passed on to the consumer,” said Nelkin. “By being the freshest, it’s also the most flavorful and nutritious.”"
Another agricultural example comes from Denver. The Brown Palace hotel in downtown Denver has added 4 bee hives and 65,000 bees to their roof and "can produce upwards of 150 pounds of harvestable honey every summer". "Marcel Pitton, managing director of The Brown Palace, said the honey is like 'liquid gold' for the hotel. The honey is used in the restaurant kitchen and as the basis for a lavender honey soap and a local beer, made with the Wynkoop Brewing Company." The article states that the beekeeping program started "three years ago, after the city passed an ordinance in 2008 allowing hobbyists to own hives." Thus, emphasizing the importance of planners working with the city to make the conditions appropriate for roofs to become economic generators.