The use of clean energy sources has been spreading in recent decades, but nowhere is it as popular and useful as in the construction industry, where it helps promote green architecture and sustainable design.
There are a few renewable sources of energy that almost everybody has heard of – like solar and wind – but there are other ways to harness natural processes for the purpose of generating electricity or heat.
First, though, let’s take a look at the most popular renewable energy techniques and how they can benefit sustainable construction.
-Solar panels. These distinct-looking devices can be seen on more and more roofs these days, both on private residences and on commercial buildings. They have even started appearing along city streets, where they help produce electricity to power streetlights and road signs.
Solar panels are a collection of photovoltaic cells that are capable of converting light energy of the sun into electricity. For this reason, solar panels perform best in areas that receive sufficient sunlight during the year, and they have to be properly oriented (angled towards the sun) for best results. According to some estimates, up to a quarter of a building’s electricity can be generated this way, which does not leave behind the air pollution associated with coal or oil burning.
-Wind turbines. Many people are familiar with the tall, slim, windmill-like structures that cover open plains in some areas of the U.S. They are wind turbines, which convert the motion energy of the wind into mechanical power. In turn, mechanical energy can be used to create electricity. Similarly to solar panels, turbines produce in no direct CO2 emissions, though there are some efficiency concerns. Perhaps for this reason, wind turbines are more popular on offshore farms, where they can benefit from higher and more sustained winds.
-Hydropower. This term refers to the production of electricity using the gravitational force of water. Globally, it is the oldest and most widely used form of renewable energy, amounting to some 16 percent of electricity production in the world (just over 6 percent in the U.S.). The most common form of hydroelectricity generation is through dams, which are river walls that retain water and use the pressure of its accumulated volume and the difference in water height between the two sides of the dam to extract power.
Although the process of building a dam is still associated with environmental costs, once it is in operation, it produces no direct waste, and its CO2 emissions are lower than those of fossil fuel-burning power plants.
Some of the less known, but equally valuable methods of renewable energy production include:
-Geothermal pumps. The idea behind geothermal pumps is to use the heat-storing capacity of the ground to warm or cool the interior of buildings. For this reason, they are also known as ground heat pumps. In wintertime, the pumps extract the heat from the earth and transfer it indoors, while in the summer they do the opposite, using the ground as a place to channel and dissipate heat. Consumer Energy Center stresses these devices’ efficiency due to the earth’s constant and predictable temperature. It also cites data from the U.S. Environmental Protection Agency that suggest that users of ground heat pumps save between 30 and 40 percent on their energy bills.
-Anaerobic digestion (AD). Biologically speaking, this term refers to the process in which bacteria break down organic matter (such as food or yard waste) without the use of oxygen. The process releases gases like methane and carbon dioxide, which is where sustainable energy generation comes in. Simply put, the energy of these gases can be used to power gas engines for combined heat and power, or as fuel for steam generation. Facilities that make such use of their waste benefit twofold – they generate their own renewable energy and save on the costs of waste disposal. As an added bonus, byproducts of anaerobic digestion can be used as a natural fertilizer in place of toxic chemicals.
Finally, any renewable energy discussion has to include a mention of advances that have been made in sustainable powering of motor vehicles.
-Biofuels. These are clean-burning fuels made from organic materials that come from a variety of sources, including corn, sugar, soybeans, feedstock as well as vegetable oils and animal fats.
Bioethanol and biodiesel are commonly used biofuels. Although they are typically produced on an industrial scale, it is possible for individuals to make their own biofuels from locally grown crops, which can strengthen local economies. According to Worldwatch Institute, global biofuel production rose by 17 percent in 2010, reaching 105 billion liters, up from 90 billion liters the year before.
Vehicles that use biofuels – as well as those that run on electricity or hybrids – are the fundamental elements of sustainable transport, as their use minimizes carbon dioxide and other particulate matter emissions. In the construction industry, a combination of sustainable transportation, renewable energy appliances, and the use of local building materials that require shorter hauling to the construction site can significantly minimize the industry’s impact on the environment.