Water: A Crucial and Sustainable Resource

Water is one of modern society’s most precious resources. Our demand for water is immense, and in many areas, it is becoming an increasingly scarce and vulnerable commodity. In order to maintain the well­-being of our environment, it is critical to address the issue of water consumption from a pragmatic viewpoint and incorporate technologies that serve to preserve this limited supply of our vital resource.

The production of greywater and blackwater by buildings such as hotels or senior care homes provides another key opportunity to implement innovative solutions and address the water shortage. According to sustainablewater.com, an estimated 365 billion gallons of drinking water is used for non­-potable purposes each day.

Greywater and blackwater recycling systems allow for the collection and neutralization of water which would typically be wasted, thereby providing a means to reuse this water for non­-potable applications such as surface irrigation and toilet flushing. Recycling these types of water is extremely beneficial to the environment because it results in a net reduction of water consumption by up to 90%, which is highly pertinent considering current water shortages. Greywater and blackwater recycling systems can also provide more LEED points for a building and give properties an additional source of landscaping irrigation ­ a category of water consumption which may be highly restricted depending on location.

A fundamental aspect of a commercial building’s daily operation is the need for both hot and cold water. The traditional model for providing hot water involves the use of a stand alone on-site boiler or water heater, which heats up water with electricity or gas and transfers the hot water to other areas on-­site where it will be used for space heating, pool heating, or other domestic hot water applications. The problem with a stand alone water heater, however, is that when viewed from a broader scale, these systems are wasting unnecessary amounts of gas and electricity due to inefficient scales of operation. Such waste poses a problem for sustainability efforts, and hurts the bottom line of property owners and investors. 

When a building draws power from the electrical grid to be used for water heating, the plant which produced that power gives off a large amount of energy as wasted heat, which is unable to be used for any practical purpose. More than half of the energy inputs that are used in the large­-scale production of electricity by large utility companies is wasted in this form of “thermal pollution”.

Cogeneration systems allow for the most efficient production of energy by combining the production of electricity and hot water, and doing so at a scale that is perfectly tailored to the needs of a specific building. These systems generate plentiful hot water through the capture of nearly all of their waste heat and deliver it to the building directly on-­site. This process reduces consumption of electricity and gas by sidestepping the thermal losses incurred by large scale electrical utilities. By implementing a cogeneration system in a building which demands consistent electricity and hot / cold water, proprietors cut costs by minimizing their expenditures on separate energy and energy needs.

Overall, it is clear that sustainability issues related to water and urban properties are widespread. What is also evident, however, is the extensive availability of technologies and options to address these issues in a cost-effective and advantageous manner. From a sustainability standpoint, cogeneration offers a pragmatic solution to reducing waste heat as well as emission of various pollutants and greenhouse gases, in addition to offering the highest “bang for your buck” in terms of GHG reductions per dollar of capital investment, when compared to other sources of energy. Furthermore, on-­site blackwater and greywater treatment systems allow for drastic water savings and offer significant improvements towards achieving sustainable solutions in light of current and future droughts.