NZ: Why and How?

Why Net Zero?

The collected best wisdom from the climate science community says we must limit climate change to 2°C (3.6°F) or we are in trouble.  They say that limiting climate change to 2°C will take an 80% reduction in our CO2/GHG (Green House Gas) emissions — we call that Net Zero 80% or NZ-80. 

How can we do NZ-80? 

To achieve 80% GHG reduction will require essentially eliminating ALL fossil fuel use from buildings (except cooking maybe), nearly all fossil fuel use from cars and industry.  It is a substantial change.  We do have most of the technologies now to make NZ-80 possible — Net Zero Buildings (PV/GHP/EE/etc), Electric Vehicles (EV), and high temp solar thermal and geothermal. 

In the graphics below, we will show how NZ-55 is achievable, a goal that only needs off-the-shelf technologies.  First we show in pieces how we can immediately get to NZ-37 – almost 40% GHG reduction – by converting just our buildings to NZ.  Then we show how 55% GHG reduction is readily in our hands by applying currently available NZ Technologies to Industry and Transportation.  The only question for NZ-55 is when will we have the necessary personal, business, societal, and political will to achieve it and build wealth doing it.  Going past NZ-55 will take some effort, but we are confident that ingenuity and engineering will take us all the way to NZ-80 once we have the societal will.

NZ-37 with Proven Off-The-Shelf Net Zero Technologies — Residential/Commercial

All the below graphics are all based on the U.S. Department of Energy’s (DOE) Energy Information Agency (EIA) annual reporting (see Notes at the bottom).  In the first two, we present a simplified picture of the Residential and Commercial Sectors, with the full detail graphics shown further down the page.  In all the below graphics, on the left are the several sources of energy we use, with the non-fossil energy sources at the top left followed by the fossil-fuel sources.  On the right are the energy consuming “Sectors”.

Current situation for the Residential and Commercial Sectors

 If we just apply Net Zero for all buildings, the Total Energy picture will become as shown in the below graphic.  Much of the energy used in homes and offices is from electricity, and electricity generation from fossil fuel is a very wasteful process.  You can see that eliminating all energy from Residential and Commercial alone will reduce GHG emissions by 37%.  That savings is achieved in two large parts – store heat from the summer and reuse it in the winter with GHP, and generate the remaining electricity needed with PV/Wind/etc.  We “can” actually eliminate 39% of GHG from Residential and Commercial, but we conclude that the 2% coming from cooking with gas will not change.

Net Zero for all buildings is affordable and can be accomplished within 25 years with strong national leadership.  And, with the strategic need for 80% GHG reduction, it is clear we must transform all of our buildings to Net Zero for 37% reduction — the easiest piece of the GHG challenge.

Industrial and Transportation

A simple analysis of the Industrial and Transportation Sectors shows moderate additional increases that can be made with existing NZ Technologies.  A very large savings is available with electric vehicles (EV’s) charged from PV/Wind — already happening in some places.  However, it is not yet shown what percentage of all fuels used for Transportation can be readily eliminated.  Assuming we can displace a moderate 32% (half of the petroleum after maximum use of Nat. Gas), that will result in an additional 10% — thus Res/Comm 37% + Trans 10% = NZ-47%.  The 3rd graphic below shows this approximate NZ-47 status. 

Finally, we can definitely make significant improvements in Industry.  As you can see in the “Age of Free Energy” slide show and NZ Technologies, Solar Thermal Concentrating Collectors producing over 700°F are now being deployed — most energy consumption in industry is for thermal energy.  Further, additional PV/Wind/Batteries can displace nearly all of the electricity used in industry just as they do for the Residential and Commercial Sectors.  This can readily produce 31% Industrial energy saving where GHG producing fuels are currently used.  That takes us to NZ-55 — a good interim goal with over 50% GHG reduction.  See the 4th graphic below to see the full Res/Comm plus partial Transportation/Industry Net Zero GHG producing energy reduction potential.


We have the NZ Technologies available to achieve NZ-55.  This is enough of an interim goal to avoid catastrophic climate issues.  We will need to continue this work even further to reach NZ-80, and it will take real Leadership.

Detail U.S. Energy Use — Current to NZ-55: (click large graphic to zoom)

 Note 1: Sources for these graphics and conclusions are:

  • Inventory of U.S. Greenhouse Gas Emissions and Sinks:1990–2013, EPA 430-R-15-004, April 15, 2015
  • Natural Gas Consumption (Btu) and Energy Intensities by End Use for All Buildings, 2003, EIA, September, 2008 (shows cooking gas use)
  • Consumptive Water Use for U.S. Power Production, December 2003, NREL/TP-550-33905, P. Torcellini, N. Long, and R. Judkoff