Commercial and residential buildings use nearly 70% of the electricity in the United States (National Renewable Energy Laboratory). Improving the energy efficiency of our homes and offices is therefore a vital part of putting money back into people’s pockets and increasing the competitiveness of our industries and businesses. It is simple economics.
What is Net Zero?
The pinnacle of building performance and energy efficiency is creating net-zero buildings (NZB). The Department of Energy defines NZB as a building that produces “enough renewable energy to meet its own annual energy consumption requirements, thereby reducing the use of non-renewable energy in the building sector” (Department of Energy).
NZB is not about being green or protecting the environment — though those can be welcomed by-products. It is about lowering costs and improving efficiency. Structures rubber-stamped as NZB will operate with no energy costs. It is even conceivable that as the cost of renewable energy sources continues to decline, NZBs will turn a profit. Imagine profiting from your office building’s production as opposed to paying for its consumption.
How to Achieve Net Zero
There are many available sources for learning more about NZB, but here are the fundamentals:
What do NZB structures actually look like?
We identified some of the most innovative and interesting NZBs to contextualize them and put in perspective the kinds of changes that helped organizations and individuals achieve net zero. These are cutting edge structures, and it is very likely that adoption of these types of building techniques will become the mainstay in coming years. A few outstanding examples are right in our backyard.
North Carolina Parking Garage
This is 1,250 space net-zero parking garage with a solar farm. The use of photovoltaic panels on the parking garage made a huge impact on the building performance, generating 1,28+ Million kilowatt-hours of power per year; enough to power nearly 165 homes annually (Solar Energy Industry Association).
Kentucky Elementary School
This normal 550-student school (77,466 square feet) was built using insulated concrete blocks that prevent air leaks and control temperatures. Heating and cooling system, lights, and other electronic systems utilize sensors to modulate the environment: adjusting the light in a room, or warming a room as necessary. The building also has what’s called a “active daylighting strategies.” Classes face the sun and solar tubes located in the ceilings of classrooms redirect sunlight into the classes, avoiding the need for artificial light. The school’s roof and parking structure have solar panels, which should produce more clean energy than the school consumes.
Illinois Grocery Store
Walgreens’ Evanston store is the company’s first NZB (13,995 sq ft). It has about 850 solar panels, two wind turbines, and a geothermal system deep beneath the store. To generate power and improve efficiency, the building uses:
- 35-foot-tall wind turbines powered by Lake Michigan’s steady breezes;
- energy efficient structural building materials;
- LED lighting and daylight harvesting;
- CO2 refrigerant for heating, cooling, and refrigeration;
- and stable temperatures from a 550-foot-deep geothermal tap to help warm and cool the store.
U.S.-built Energy Skyscraper
A U.S. architectural firm built this 1740-foot-tall, 99-story net-zero skyscraper. It features:
- simultaneous light entry and shading to illuminate without overheating the building;
- a wind funnel that cools higher floors;
- solar panels around the perimeter and rooftop;
- and a geothermal tap that keeps the temperatures stable.
Video courtesy of SOM
Asheville Net-Zero Homes
These homes used a combination of renewable energy sources and energy saving strategies — from smart meters and efficient heat pumps to daylight harvesting, thermal mass floors, and other innovative methods similar to those used in large-scale commercial buildings.
North Carolina Mountain Home
This NC home was built with cost savings in mind:
- The builders used over $50,000 in financial incentives to help fund the build
- Their energy bill is around $0 every month
- It costed $156 per square foot to build (national average is $150 per square foot)
Finally, here is an excellent case study on a net-zero home to show how it works from conception to completion.
By envisioning a future in which 100 percent NZB is the ultimate goal, and taking tangible, incremental steps toward that goal, we will continue to make our state and nation more efficient and competitive. Whether you aspire to implement a few features of a net-zero building or just want to incrementally improve your energy efficiency, there are cost effective and rapid ways to get there. There are organizations and financing options available to educate and guide North Carolinians through the process of improving commercial and residential efficiency.