NET Zero can be looked at in a multi sectional or holistic approach of reducing Energy, Water, and Waste on a facility or home. It provides a way of reducing or completely eliminating wasted power and provide a better way to design efficiencies into buildings and homes during the design and building phase, but also provides ways to update existing structures to become more energy efficient.
ENERGY - Produce as much energy as the facility or home uses while reducing energy requirements.
The first thing to look at in a facility or a home is to analyze how much energy is being used and how to best reduce that energy consumption. The first thing that should be completed is to retrofit all appliances to an Energy Star appliance. This will make the applicance energy usage as efficient as possible.
Next, analyze your air and heating options and put in automatic controls. There are many smart thermostats on the market today, but even a simple programmable system that increases or decreases the temperatures when there is no one occupying the space and bringing it back to a comfortable level when people return will drastically reduce the energy used by our HVAC systems.
Install occupancy sensors on your lighting fixture and replace all lighting fixtures to LED or Fluorescent lamps. LED light fixtures use only a fraction of the energy standard lamps used in the past while providing better lighting overall. Use of natural light in new designs can also greatly reduce the need for artificial light in office buildings and homes.
Finally, if possible, upgrade to higher rated insulation, energy efficient windows / glass, and efficient roofing materials. This will ensure that the heat and AC produced is not escaping through and holding temperatures more precisely.
Once all of these steps have been completed, then you are ready for the final investment, a renewable energy production system. For example, adding solar photovoltaic modules to the home, a solar hot water heater, etc. If this was completed first you would only be able to generate enough energy for possibly just what you were able to reduce. The first and main goal in energy reduction to obtain NET Zero is REDUCTION.
WATER - NET Zero water installation limits the consumption of freshwater resources and returns water back to the same watershed so not to deplete the groundwater and surface water resources of that region in quantity and quality over the course of a year.
Strategies such as harvesting rainwater and recycling discharge water for reuse can reduce the need for municipal water, exported sewage or storm water. Desalination can be utilized to convert briny, brackish or salt water to fresh water so it is suitable for human consumption or irrigation. There is even a device that actually pulls water straight out of the air and makes drinking water and runs completely off solar.
To achieve a NET Zero water installation, efforts begin with conservation followed by efficiency in use and improved integrity of distribution systems. Water is re-purposed by utilizing grey water generated from sources such as showers, sinks, and laundries and by capturing precipitation and storm water runoff for on-site use. Wastewater can be treated and reclaimed for other uses or recharged into groundwater aquifers. The water can also be used by repurposing into the black water systems and used for irrigation in the surrounding landscapes.
WASTE - To reduce, recover and reuse waste streams.
The approach to creating a NET Zero waste installation is similar to creating a NET Zero energy installation. The first approach to achieve NET Zero reduces, reuses, and recovers waste streams, converting them to resource values with Zero landfill over the course of a year. The components of NET Zero solid waste start with reducing the amount of waste generated, re-purposing waste, maximizing recycling of waste stream to reclaim recyclable and compostable materials, recovery to generate energy as a by-product of waste reduction, with disposal being non-existent.
Every day, more recycling strategies are developed moving beyond metals, paper and cardboard to include mattresses, glass, plastics, batteries, computer printers and motor oil. The best strategy is to consider the waste stream when purchasing items, reduce the volume of packaging, reuse as much as possible, and recycle the rest. A true cradle-to-cradle strategy considers the end state at the time the purchase decision is made. A NET Zero waste strategy eliminates the need for landfills, protects human health, optimizes use of limited resources and keeps the environment clean.
Even commercial lighting can have a NET Zero design by providing a way to produce power that offsets the energy usage required by the lights. What other ways can you see to reduce the waste provided by our current systems to help us move towards a NET Zero solution for our future?
Editor's Note: This post was originally published in October 2012 and has been completely revamped and updated for accuracy and comprehensiveness.