Energy profile: Where have we been, and where are we headed?
Looking at energy consumption patterns of the past can help us promote responsible energy use in the future.
It’s hard to imagine a time when energy design and building operation in the United States was conducted on a “business as usual” basis. With relatively low oil, gas, and electricity prices and plentiful energy supplies prior to 1970, the design and construction of buildings had little need to take energy efficiency into consideration. Today, however, U.S. buildings are responsible for 39% of CO2 emissions, 40% of energy consumption, 13% of water consumption, and 15% of GDP per year. To understand our nation’s high consumption of energy, we must first examine what brought on a surge in energy demand, then scrutinize where we stand today, and finally look toward the future for energy-efficient solutions.
A crisis is born
Today’s pattern of energy consumption can be traced back to the energy crisis of the 1970s. An embargo on the production and distribution of oil instituted in 1973 by the Organization of Petroleum Exporting Countries (OPEC) precipitated the first global energy crisis. Long lines at gas stations, shutdown of industry and government facilities during severe weather, and electrical brownouts highlighted just how much our nation had come to take energy for granted. Seeking a solution, the National Conference of States on Building Codes and Standards (NCSBCS) requested that the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) process a 1974 National Bureau of Standards (NBS) energy conservation report as a national standard. In August 1975, after two public reviews of the proposed standard, ASHRAE published Standard 90-75, Energy Conservation in New Building Design, with technical support from the Illuminating Engineering Society (IES). The standard alerted engineers, many for the first time, to the energy consequences of their designs, and provided building designers and operators with tools to operate their buildings more efficiently.
Since its inception in 1975, Standard 90.1 (first known as Standard 90) has been widely adopted as the benchmark for energy efficiency in buildings. In 1992, the passage of the U.S. Energy Policy Act required that all states adopt energy codes for commercial and high-rise multifamily residential buildings at least as stringent as Standard 90.1. Additionally, the act required that states update their codes when Standard 90.1 was revised subsequent to a U.S. Department of Energy (DOE) determination that the new version of the standard was more stringent than the old one. Since 1975, the standard has been revised five times: in 1980, 1989, 1999, 2004, and 2007. While different building models and simulation tools were used in the estimation of energy savings from earlier work, more recent simulations show that there is 35% more energy savings between the original standard and the 2007 standard.
While the oil crisis of the 1970s served to draw attention to our nation’s carelessness with energy and the 1990s saw a push for conservation, we still have a long way to go. The population continues to grow, which has driven increased activity in the building market. Fuel prices are climbing, which grabs the public’s attention when people open their monthly heating and cooling bills. What is the result of this tension between more people and more buildings, along with the need for buildings that are safe, healthy, comfortable, and energy efficient? There is now a greater demand on natural resources as our industry, the comfort-maker of mankind, struggles to fulfill these needs.
Buildings consume more than 40% of the energy in the U.S. The vast majority primarily depend on energy produced from nonrenewable, carbon-intensive fuel sources—coal, oil, and natural gas. In addition, heating, ventilation, air conditioning, refrigeration (HVAC&R), and water heating are responsible for about 75% of residential and 64% of commercial building site energy use. Also, take into consideration that the building sector accounts for almost half of all greenhouse gas emissions in the U.S. annually. Clearly, cost-effective energy efficiency is critical for the economy, the environment, and energy security.
2010 and beyond
Which brings us to the present: Making our way into this new century, how will what we learned in the past shape how we use energy in the future? To begin, the 2010 version of Standard 90.1 achieves nearly 20% total energy cost savings improvement compared to Standard 90.1-2004. This increase in savings is achieved by a variety of measures, including an expanded scope to cover receptacles and process loads, more stringent building envelope requirements, lighting, high equipment efficiencies, and expansion of modeling requirements.
Additionally, ASHRAE, IES, and the U.S. Green Building Council (USGBC) have published the nation’s first code-intended standard for high-performance buildings. Standard 189.1-2009, Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, provides a “total building sustainability package” for those who strive to design, build, and operate green buildings. From site location to energy use to recycling, this standard sets the foundation for green buildings through its adoption into local codes. The major goals in publishing this standard were to provide simple compliance options for green buildings and to establish mandatory criteria in all topic areas: site sustainability, water use efficiency, energy efficiency, indoor environmental quality, and the building’s impact on the atmosphere, materials, and resources. Standard 189.1 is a jurisdictional compliance option of the International Code Council’s International Green Construction Code (IGCC).
This brings us to another important aspect of improving our energy use: collaboration among technical societies. For example, ASHRAE joined with key players in the building industry to find ways to reduce our industry’s impact on the environment. We are collaborating to establish carbon-neutral buildings by the year 2030. ASHRAE, the American Institute of Architects, Architecture 2030, the Illuminating Engineering Society of North America, and the USGBC, supported by representatives of the DOE, signed an agreement of understanding, establishing a common starting point and a goal of net-zero-energy buildings. This agreement allows the building design sector to move forward with designing buildings that use substantially less energy, reduce greenhouse gas emissions, and create spaces that are healthy and comfortable.
To reach that goal, the groups agreed to define the baseline starting point for their common target goals as the national average energy consumption of existing U.S. commercial buildings as reported by the 2003 Commercial Building Energy Consumption Survey (CBECS). The CBECS data is a set of whole-building energy use measurements gathered by the DOE’s Energy Information Administration, which can be used to determine a national energy use intensity using kBtu/sqft-yr as the metric.
Outside influences are also moving toward an evolution in sustainable design. The Waxman-Markey Bill, a.k.a. the American Clean Energy and Security Act (ACES), H.R. 2454, would require new energy-efficiency standards for buildings along with 30% energy reduction by 2010 and 50% reduction by 2016, when compared to the current U.S. model energy code.
Energy use in the U.S. has gone from a “business as usual” approach to a conscious and detailed process of conservation and efficiency. While we still have a long way to go, we are well on our way: “green,” “sustainable,” and “efficient” are phrases heard with increasing frequency in the building industry. Our industry has a huge impact on our natural environment. As such, we have an equally huge responsibility to promote the responsible use of energy and our natural resources in the built environment around the world.
- Jarnagin is serves as president-elect of ASHRAE as well as chair of the Society’s Building Energy Quotient Ad Hoc Committee. Jarnagin is the former chair of the Standard 90.1 committee.