Net Zero (NZ) Definition

Every Site Can Be Net Zero!

The U.S. DOE National Renewable Energy Lab (NREL) published a seminal report defining the 4 classes of Net Zero Energy sites:

  • NZEB:A — A net-zero energy building within the building footprint
  • NZEB:B — A net-zero energy building within the building site
  • NZEB:C — A net-zero energy building with renewable energy imported from off site
  • NZEB:D — A net-zero energy building with renewable energy purchased from off site

See the full DOE NREL net-zero energy building report here.  This is a very important report as it provides the definitional framework for converting any building or site to Net Zero/Net Zero Ready.

NZ, NZ Cost, and NZ Carbon

Net Zero is the conceptual core of all the Renewable Energy Technologies, defining the goal of the entire movement.  But, just what is the Net Zero goal?  Is it saving money?  Or is it the elimination of Fossil Fuels?

We at Net Zero Foundation believe “Net Zero” is the cohesive movement toward both of these goals.  Before 2015, commercial building owners had shown very little concern about climate change.  Thus Net Zero has to date only been a function of the Net Cost to install, finance, and operate the Renewable Energy Systems in a building.  The Lady Bird Johnson Middle School shown on our NZ Buildings page is a good example of this Net Zero “Cost” model.  No attention at this Net “Cost” Zero school built in 2012 was specifically given toward the carbon footprint even though it is often operating beyond carbon neutral as wind energy has become so available in TX.

Since 2015, Net Zero is beginning to be associated with corporate and individual goals to be Net Zero Carbon.  Examples include IKEA and others establishing these corporate goals, with their new stores employing PV and GHP technologies.  At this point in time, every building site in many states can now become Net Zero Carbon by contracting for the balance of their electricity from Renewable Energy services like Arcadia Power.

The Big Picture

We at Net Zero Foundation intentionally refer to Net Zero as meaning either Net Zero Cost and/or Net Zero Carbon.  We do this for two reasons:

  1. Any distinction between NZ Cost and NZ Carbon is fast becoming obsolete as Net Zero Renewable Energy systems become both easily financeable, and both will ultimately lead to NZ Carbon.
  2. We believe it is very important from a societal perspective to cast the largest net possible to get building owners to join the Net Zero Movement.  If this takes using a NZ Cost incentive for them to take the first step (tax credits, rebates, etc.), then so be it.  Net Zero is a middle-to-long-term goal, and the important thing is that all building owners join the movement soon so we can eventually eliminate carbon emissions as we move forward. 

Confusion From the DOE and Others

Since the groundbreaking, thorough, and Leading report from NREL defining 4 categories of Net Zero Energy Buildings (above), there have now been a number of additional reports and DOE projects begun using different Net Zero terminology.  This is an unfortunate development for the field as it adds “market confusion”.  Net Zero Foundation does not support this fracturing of the Strength and Leadership of the NREL 2010 report and naming structure.  We invite the whole Net Zero Community to work toward a unified and “Leading” terminology, and we lay these DOE developments out here hoping others will see the fragmentation and confusion these reports and programs are causing, and will work toward a cohesive NZ future. 

EERE 2015: In 2015, the DOE Energy Efficiency and Renewable Energy (EERE) division released a new initiative defining a “Zero Energy Building” (ZEB) — a program developed for the welathy apparently only targeted to WalMart and but limiting the definition to just those buildings that achieve full Net Zero operation using Renewable Energy generated within the building site’s footprint or “portfolio” ownership.  Thus, this “new” ZEB definition is little more than a new acronym for NREL’s NZEB:A-C shown above, and it explicitly excludes using the free market to purchase NZ energy from others.  You can read this report here. The key issues as we see them are:

“The do not allow renewable electricity purchased through the use of renewable energy certificates (RECs) to be used in the ZEB energy accounting.”

“Portfolio: A collection of building sites that contains renewable energy production systems owned/leased by asingle entity.”

Anti-business — The very core of our power as a people centers on the free market — when we have a comodity need, the free market will always provide it at a price.  The ZEB designation excludes the free market from ever participating in ZEB’s.  And, it is even worse: the ZEB program actually works to  … anti-REC … … ‘we don’t want you solar power … we don’t want your wind power’.  Why did we as a country ask those good people to invest vast funds on building wind across vast swaths of our nation, and then turn around and tell the “you are excluded from participating in “Zero Energy Buildings”?  We do not believe it is appropriate for the U.S. government to be chosing winners and losers in the Zero Energy Building world, and we absolutely do not believe the free market or the excellent Renewable Energy Certificate movement should be excluded from participating in Zero Energy buildings.

So, just who is this written for?? walmart …

Anti-utility — The ZEB designation is specifically harmful to out utilities.  ZEB’s make the utility provide free “electric battery” service in many jurisdictions.  The utility must maintain massive infrastructure that the ZEB takes advantage of, but suffer financial damage for providing this service.

  1. Creates confusion in the market place by coming up with “new” acronym for the same thing as NREL’s NZEB:A + NZEB:B+ NZEB:C but not NZEB:D,
  2. There was no need for a new acronym (although we do respect the idea of “branding” without “fragmentation”),
  3. A cohesive leadership within the DOE should merge these nomenclature systems clarifying that the NREL system is the overriding one, with ZEB being a specific targeted subset, and
  4. This report further deviates from any reasonable Clean Energy goal by including buildings that use “coke, coal, … residual fuel oil [#6]”, all of which introduce climate harms that outweigh any NZ positive effect in our opinion.  We very strongly believe that no building using non-clean-burning fossil fuels should ever be included in a Net Zero Energy/Zero Energy Building definition of any sort.

Zero Energy Ready Home (ZERH): Beginning in 2014, the DOE has started another NZ project called “Zero Energy Ready Home”.  Other than the fractionalization of NZ nomenclature, this is an excellent program that will lead to much positive effort.  However, the ZERH program has one very significant flaw: it promotes use of Air Source Heat Pump (ASHP) HVAC systems in all but the absolutely northern-most climate zones.  We have not yet spoken about this (coming!), but focusing on ASHP systems for HVAC use will lead to an un-buildable electric grid system.  ASHP’s establish both the summer and winter electric generation peaks, and a conversion from all other heating methods (nat.gas, propane, oil, etc) to ASHP will require an electric generation system with a peaking capacity unlike anything anyone has ever considered.  Almost nothing is publicly “known” about ASHP electric loading at peak conditions because the product and building codes do not require publication of those facts.  However, simple reverse engineering of even very highly efficient ASHP specifications clearly shows an efficiency way less than half that of a GHP HVAC system.  Therefore, the current state of the ZERB program would ultimately require an electric generation peak capacity way more than double what it should be — a fact that will ultimately lead to either a ZERH program change or vast economic waste in the utility sector.  Obviously the ZERH program must change, and we are sure it will.