Renewable energy makes use of naturally occurring and inexhaustible resources, as opposed to fossil fuels which take millions of years to form in our earth.
By Linn Smith
February 11, 2015—Most conventional buildings use fossil fuels for heating and electricity, emitting carbon dioxide and other greenhouses gases into the atmosphere, which perpetuate climate change. A zero-energy building or zero net energy-ZNE, is a building that consumes about as much renewable energy as is created on its site. These residential or commercial buildings can get energy from the grid and return an equal amount to the grid, therefore, even though using some fossil fuels when renewables aren’t available, they make up for their use by placing the excess renewable energy back into the grid for others to use, thus classifying it as a ZNE building. As yet, there is no economical means to store excess energy on site, but this will be coming in the not so distant future, as the manifestation of ZNE buildings has moved from the concept stage of several years ago to current mainstream reality. Buildings are currently being constructed that minimize energy requirements and have renewable energy systems on site that meet these minimal energy requirements.
Zero Net Energy by 2030
According to an article by the National Institute of Building Sciences, Executive Order 13514, “requires all new Federal buildings that are entering the planning process in 2020 or thereafter be designed to a achieve zero-net-energy by 2030 and require that 15% of the existing buildings over 5,000 sq. ft. meet the High Performance and Sustainable requirements by 2015, with annual progress towards 100% conformance.”
Using Renewables vs. Fossil Fuels
Building with renewable energy may consist of solar, solar water heaters, biofuels or wind turbines, whatever is most cost effective for the area. Renewable energy makes use of naturally occurring and inexhaustible resources, as opposed to fossil fuels which take millions of years to form in our earth. Today, these fossil fuels are being using faster than they can form, therefore, they are called exhaustible. Most Net Zero buildings are still connected to the electrical grid, which allows for traditional sources of energy, i.e. coal and natural gas, to be used when renewable energy can’t meet the heating and electrical needs of a building.
Why are builders and architects moving in the direction of Zero Net Energy? According to NREL (National Renewable Energy Laboratory) It is estimated that traditional buildings, commercial and residential, consume up to 40% of the energy used in the U.S. for heating, and approximately 70% of the energy in the U.S. for electricity, a significant contribution to greenhouse gases building up around our planet! With approximately 80 billion sq.ft. of commercial space in the U.S. requiring heat, electricity and/or air conditioning, it is necessary to start breaking our dependence on fossil fuels and look to a future dependent on renewables.
To lesson future environmental impact, the embodied energy of the building material must be considered before construction. Embodied energy is the, “sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or embodied in the product itself.” This means comparing the amount of energy it takes to produce the product with the amount of energy the product will save over time. To obtain the embodied energy of a material, long-term calculation of energy use must be considered in extraction, transporting the materials, manufacturing, assembling, installing and in, our modern world, destroying the building when it is no longer of use, and disposing of the materials. It must be asked: What is the life cycle and environmental impact of the materials used in construction? Will they contribute to or reduce global warming?
Building with Reclaimed Materials
Another consideration in building may be the use of reclaimed materials. Buying reclaimed, or used materials, such as doors, windows, ect. can not only save up to 40-60% of the building cost, but can also be a greener way of building or remodeling. Instead of Home Depot, look at other options, such as Habitat for Humanity Restore, Craigslist or supplies from buildings being demolished near you. A website called, planetreuse.com will make connections for you by networking in your area for what you need, finding materials that will meet your project’s certification standards. Also, the website, http://www.zerohomes.org, will inform you about courses in building zero net homes and communities.
Here’s a comment on an article I recently read, ” Don’t forget that some people have to have the ‘latest up to datest’ in everything, like those who buy new cars every year. It doesn’t mean something was wrong with the old!”,— or that Home Depot is the answer to all your building needs!