October 23, 2014

Sustainable Engineering: Energy Modeling

Sustainable engineering utilizes energy modeling, or the virtual simulation of a building that focuses on energy consumption, utility bills and life cycle costs of various energy related items such as air conditioning, lights and hot water. It is also used to evaluate the payback of green energy solutions like solar panels and photovoltaics, wind turbines and high efficiency appliances.

Determining a building’s energy use is not always an intuitive process for even the most seasoned sustainable engineering and industry professionals. An energy model can be a powerful tool to assist in accurately evaluating energy reduction strategies by viewing the life-cycle impacts of design changes while comparing various design schemes. It also provides valuable data to optimize building design to achieve carbon reduction and gain a better understanding of a building’s energy performance. Energy models can aid in predicting energy costs in order to implement future strategies; this quantifies the operating savings over the life of the building.

BuildingGreen, Environmental Building News stresses the importance of modeling “early” and “often” for the biggest savings in energy and costs.

With new buildings, the benefit of an energy model is its ability to help guide design decisions. They are an effective tool that can be used first to help guide critical sustainable engineering design decisions, continue to be useful tools for code compliance and energy incentives and also aid in green rating systems’ requirements. They are also needed to qualify for utility and government incentives (such as OPA’s High Performance New Construction program) and for the U.S. Green Building Council’s Leadership in Energy and Environmental Design Rating System (LEED™) certification. In the case of existing buildings, energy models can help flag operational inefficiencies and provide results to help determine most effective capital improvement options.

According to the U.S. Department of Energy, commercial buildings represent just under one-fifth of U.S. energy consumption, with office space, retail space, and educational facilities representing about half of commercial sector energy consumption.

The top three end uses in the commercial sector are space heating, lighting, and space cooling, which represent close to half of commercial site energy consumption.

Commercial floor space and primary energy consumption grew by 58% and 69%, respectively, between 1980 and 2009. The Energy Information Administration (EIA) projects that they will continue to grow at slower rates between 2009 and 2035, 28% and 22%, respectively. Average energy prices, on the other hand, have been, and are expected to remain, relatively stable.

In 2009, commercial buildings consumed 17.9 quads of primary energy, representing 46.0% of building energy consumption and 18.9% of U.S. energy consumption. In comparison, the residential sector consumed 21.0 quads of primary energy, equal to 22.3% of U.S. energy consumption.

By understanding the energy-conserving measures incorporated into building designs, KMB, a sustainable engineering firm, can employ the most appropriate software or analytical tools to quantify the impact of those measures, both environmental and economic. Optimized buildings result in lower energy costs, lower carbon emissions and greater occupant thermal and visual comfort. We understand the need to provide our clients with the lifecycle costs of various building components to ensure the most economically sound alternatives are presented.