The first CED post in this series explored non-traditional uses of renewable energy that went beyond traditional on-roof and on-ground arrays. Those included solar canopies, roofs, and shingles, whose value-add is the possibility of producing a space that can be used for more than power generation. But not all options are about creating additional space. In some cases, the best option is to add solar generation capabilities to existing spaces in the least intrusive way. How do you generate clean energy at a park without unsightly modifications? Where do you install solar panels on a modern skyscraper? What if you want to modernize an existing structure? For each of this questions, the answer lies in new solar technology capable of adding solar generation capabilities to a wide array of spaces.
Solar Tiles, and its bigger cousin, Solar Roadways, are solar panels that have been built with reinforced materials that allow them to carry heavy loads while serving as road pavers. While Solar Tiles are used for smaller jobs, such as office campus or park walkways, Solar Roadways, as the name implies, are replacements to the traditional pavement roadway. Currently, Europe leads the charge for solar roadways, with ambitious plans taking shape in countries like the Netherlands, France, and Germany. Although this technology is promising, it continues at the proof of concept stage. Issues such as loss in energy production from debris and muck, shadows from surrounding greenery or structures, and solar tile lifespan can potentially limit the feasibility of the technology. Nevertheless, if the technology is proven to be feasible, the implications are astounding. With over 40 Million miles paved around the world, converting the road network into a power source would help meet sustainability goals.
Structures such as modern glass skyscrapers tend to be some of the biggest energy guzzlers, as air conditioning systems need to work harder in an attempt to compensate for the heat gained through its glass facades. Solar Windows, new technology in solar generation, have helped offset this issue through a combined two-pronged approach. Not only do Solar Windows produce energy that will help compensate for the higher-than-average energy consumption, but by adding solar cells to windows, solar radiation and heat gain through them is limited. The amount of power generated and light transmission through the windows can be designed to project specifications, allowing for greater control of the overall look and feel of the building environment. One of the biggest drawbacks to this technology is the need for an expensive and complicated installation. High upfront costs tend to draw investors away from this long-term solution.
Solar Double-Skin Façade
Sometimes, old buildings can be repurposed for modern uses. When lacking historical significance and when structural integrity is not an issue, an option often considered is adding a Double-Skin Façade. This solution implies adding a new façade over the existing one that will modernize or enhance the existing facade without extreme modifications to the overall structure. By using specialized solar panels, a Solar Façade allows for energy generation, while also reducing heat gains and adding a modern look to a building. By adding an air barrier between the second skin and the original façade, heat gains for the building drop dramatically, helping reduce energy consumption through air conditioning. Different than Solar Windows, Solar Double-Skin façades do not imply higher installation costs. Nevertheless, upfront costs are still higher than other Double-Skin alternatives in the market, and as such, adoption is low.
As solar technology continues to advance and solar systems become more price competitive, we will continue to see an increase in non-traditional solar solutions. These solutions will allow users to maximize energy produced by projects new and old, permitting us to reach carbon neutrality and meet sustainability goals. As the push towards sustainability continues and the electric grid moves from carbon sources into cleaner alternatives, new sources of solar energy production will be needed. Retrofitting existing structures is an option that should be considered because of the low amount of additional environmental impact it implies.
Diego Garza is a first-year MBA student at Duke University, The Fuqua School of Business and a Community Revitalization Fellow at the Development Finance Initiative.