We all know that we need some type of energy to run our buildings. In a perfect world, it would be great if we could generate all of the energy we needed right from onsite, with renewable sources. The wind and sun are free and consistently there every morning when we wake up…well, except when Mother Nature decides otherwise. It is not so easy, though, to actually harvest and to use that free energy. Wind turbines and solar panels are not cost effective, in most cases. Plus, the low cost of fossil fuels right now make it even more inconvenient to invest in renewable energy.
Over the last 10 years, the term “zero-energy building” has become widely used. Recently, the Department of Energy and the National Renewable Energy Laboratory developed a definition for the industry to use: “An energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or equal to the onsite renewable exported energy.” What this really means, is that the amount of energy used from off-site sources is less than the amount of renewable energy generated onsite.
The word “zero” may be misleading in the context of sustainability and stewardship. What about the total amount of energy used to operate a building or campus over the course of a year? The above definition does not really address the issue of energy consumption itself. The actual amount of energy that a building consumes can be so enormous that this concept really does nothing for the environment. In the hands of the wrong marketers, this idea is just another form of green-washing.