An Architecture Firm's Push to Build Net-Zero Apartments—on a Budget

Inspired by the Dutch concept of “Energiesprong,” or “energy jump,” a developer in France retrofitted a group of townhouses for social housing to be more environmentally friendly. They installed polyurethane facades to avoid heat loss and solar panels on the roof. Upgrading the units to be more green cost more than a conventional retrofit, but over time, energy bills were cut in half. These green retrofits are being implemented in towns around the world and could be a model for developers that want to reduce their carbon footprints.

A collaborative partnership among local and national organizations made it possible to install solar panels on 10 Greensboro homes for free. Because of this effort, many low-income families have seen a significant decrease in their energy bills and an increase in value of their homes. Although convincing people to install the panels was a challenge, organizers are now figuring out how to scale the initiative and make it sustainable in the longterm.

More and more commercial real estate projects are popping up around the United States that are focused on “deep green” building. This movement suggests that it’s not enough to just make a building out of renewable materials, but they can also be self-sustaining. For example, the Watershed, an office building in Seattle, has a slanted roof that collects rainwater that is then used in toilets. These types of projects can be more complicated and expensive to build, but developers can save money in the long run with the improvements.

An apartment complex in Utah includes a solar battery in every apartment allowing the resident, power utility, and building developer to save costs for generating electricity. Through a unique partnership, the power systems can provide 12.6 megawatts of power for the building, which translates into residents saving up to 40 percent on the energy bills. This setup might not be easy to scale, but the developer plans to expand the model in other states.

A growing population has led to a growing mountain of trash for Africa. One city is taking control of the issue by turning that trash into energy which not only reduces the amount of physical rubbish by 80 percent, but also powers 30 percent of the city's household energy needs.

An economic shift to renewable energy could take decades, but thanks to rapidly evolving disruptive technologies, dropping prices of solar and wind power sources, and increasing market demand for green business, the new age of renewable energy could encompass the world economy much more quickly.

In Stockholm, old Christmas trees are being converted into biochar. When integrated into the city's highly-efficient power grid, the project has been wildly successful--not only in improving soil, but also in retaining groundwater, greening the city, and lowering carbon emissions. For this reason, officials as far away as California have been eying the plan with interest.

Rahr Malting, a brewery in Shakopee, MN, has found a creative way to sustainably address their energy needs. The company partners with the Mdewakanton Sioux Community to use waste barley hulls from the malting factory to generate electricity for their facilities, selling excess power to the public grid while the waste heat sprouts the malt to make beer.

An architect in Chennai, India, is retrofitting private residences and public buildings to be more sustainable. They make changes like installing energy-efficient upgrades, solar panels, improved ventilation, and low-flow plumbing fixtures to reduce water and energy consumption.

A team of Finnish engineers havevinstalled the first commercial battery made of sand, which can store green energy in it for months. Solar panels or wind turbines generate electricity, which is then stored as heat in the sand battery. When needed, the battery can discharge hot air to heat up water which is then used to heat homes, offices, and a swimming pool. This solution may be difficult to scale, but it’s a low-cost storage idea that could be useful when it’s cold and energy is more expensive.