The Importance of the “Energy-Water Nexus”
What and Why
The energy-water nexus refers to the interconnected relationship between energy and water resources; the nexus is an important concept for the real estate industry to incorporate into design, construction, and management.
Energy is required to extract, convey, and treat water, and water is needed to produce energy, particularly in the generation of electricity. For example, in thermal power plants, water is used to cool turbines, while in hydropower plants, water is used to generate electricity. At the same time, water scarcity or poor water quality can affect energy production, while energy production can lead to water pollution and depletion.
The efforts of climate change amplify the need to manage our interdependent water and energy systems more mindfully. Policymakers, planners, and researchers are working together to identify ways to improve efficiency, reduce waste, and increase sustainability.
Government Policy
Policymakers, planners, and researchers are working together to identify ways to improve efficiency, reduce waste, and increase sustainability.
On March 2020, 2023, California Senate Bill SB 48: Energy and Water Savings Act was amended. This bill would create building performance standards for improvements in energy efficiency and reductions in the emissions of greenhouse gases in large buildings, including measures to ensure that making the necessary investments to improve these buildings will improve equity and avoid displacement or increased energy burdens, especially in disadvantaged communities.
Included in the Legislature:
(3) While changes to the California Building Standards Code (Title 24 of the California Code of Regulations) have dramatically improved the efficiency of energy and water use and lowered utility bills in our newer residential and commercial buildings, older buildings are often far less efficient and are not required to make code-compliant upgrades unless a major renovation is undertaken.
(4) Building performance standards have been enacted in 10 United States jurisdictions as of January 1, 2023, including in New York City and Washington, D.C., and statewide in Washington, Maryland, and Colorado, as a practical policy for requiring large buildings to improve efficiency, lower utility costs for tenants, and reduce emissions of greenhouse gases, with interim targets that become more stringent over time while giving building owners flexibility and time to plan for how to achieve those requirements.
(5) A focus on improving the performance of large buildings is desirable because large buildings represent a small share of total buildings, but a much larger share of total energy and water usage and emissions of greenhouse gases, and the owners of large buildings are usually more capable of making plans and obtaining capital for the needed improvements than the owners of smaller buildings.
Source: energy.gov
There are several strategies that can be used to reduce building energy and water use,
and the most effective ones will depend on the specific characteristics of the building and its occupants. However, some commonly used strategies that have been shown to be effective in reducing building energy and water use include:
Improving building envelope design (i.e., walls, roof, and foundation) to be well-insulated, airtight, and resistant to heating and cooling transfer. This can include using high-performance insulation materials, air sealing, and designing windows and doors to minimize air infiltration.
Upgrading lighting systems to more energy-efficient LEDs and using daylighting strategies.
Installing high-efficiency heating, ventilation, and air conditioning (HVAC) systems, and maintaining them regularly to ensure optimal performance.
Upgrading to high-efficiency water fixtures, such as low-flow toilets and plumbing fixtures, and installing drought-tolerant landscaping and efficient irrigation systems.
Implementing water conservation measures and circular systems, such as rainwater harvesting, greywater, and blackwater reuse.
Installing renewable energy systems, such as solar panels, to generate clean energy on-site.
Using smart building automation systems (such as sensors) to monitor and adjust energy and water use based on occupancy, weather conditions, and other factors.
Educating building occupants on energy and water conservation practices and encouraging behavior changes.
Implementing a combination of these strategies can lead to significant reductions in building energy and water use, resulting in lower utility bills and reduced environmental impacts.
