Net-Zero, Primary Residence Homes, Part 3

One way to build a truly Net-Zero house is to design the house in such a way that all heating and cooling and lighting devices are electric.  Everything in the house gets its power from the grid. If this is the case, then it’s very easy to measure our consumption of electricity because the electric meter does it for us. This would be our tool to let us know how much electricity we need to contribute back to the grid using Renewable Energy.  In my mind, this is the most reliable way to claim “Net-Zero” performance and to prove it with measurable data.

A Net-Zero home can also incorporate the use of other forms of carbon based fuels such as oil, coal and gas. But this is where it gets a little complicated.  In its purest form, in order for any home to achieve a Net-Zero performance, it must generate enough additional electricity to offset not only the Kilowatts that it consumes in electricity but the Btu’s consumed by its carbon based fuels. There’s an easy formula we can use to convert Btu’s into Kilowatts. That’s the simple part.  The complicated part is a financial one and it has to do with a relationship you have with your Electric Utility Company. As a rule, Utility Companies only trade kilowatts generated for kilowatts consumed. This is referred to as Net-Metering and it’s all accomplished through the electric meter.  If you are making more electricity than you use, the meter “runs backward”.  That’s fun to watch if you still have one that spins.  When you are using more electricity than you are generating, then the meter “runs forward”.  The goal is to balance out forward and backward motions so that it lands perfectly on zero.  Easier said than done, for sure.  But this is the best Yankee Trade ever because the Government keeps their hands off your value-for-value trade.  There’s no tax or accounting done with a “like-kind” exchange. But there’s also a catch.  Utility companies won’t compensate you if you generate more electricity than what you use. They won’t even send flowers or a “Thank You” card. They just take your excess power and sell it to someone else on the grid.  So this means that you have a choice to make.  For some, it’s a moral choice and they choose to make the sacrifice; sincerely desiring to achieve a Net-Zero lifestyle. For others, they’re not so enthused about spending additional money to build a Solar PV system that will be large enough to offset the Btu’s consumed by their Carbon Based fuels; knowing full well that they are getting nothing for it in return.

• There are some people out there who still choose to donate the additional electricity to the grid, anyway, and that way, their conscience is clear.  They need to know that their donation of kilowatts is equal to the amount of Btu’s consumed and by so doing, they enjoy knowing that they are truly living a “Net-Zero” lifestyle.  

• Other people are content to claim that only their consumption of electricity is 100% offset by Renewable Energy.  They don’t split hairs over the fact that they have a back-up gas generator that might use a few gallons of propane in a year. Purists would aggressively debate against this point, insisting that a truly Net-Zero home must have a Net-Zero Carbon footprint. What do you think? Since a backup generator is becoming more and more essential with empty nesters, retired and elderly, should it be considered as a factor in the normal day to day consumption of energy or can we lighten up a little and acknowledge that our focus is not so much on the consumption of energy during emergencies but on the other 364 days of the calendar year throughout our life here on earth? 

There are many variables that come into play when we try to calculate how much energy we think a certain home will consume in a year. The task would be so much easier if nobody ever lived in it and we could just leave the thermostat at 50. The truth is that there is no set formula that works.  All we can do is guess because of Planet Earth’s greatest variable; the human. Technically, a home could qualify as Net-Zero by by an occupant who lives a very frugal lifestyle.  But he could sell that same home with the claim that it was Net-Zero to another family and they could move in with six children, dogs, cats, chickens and horses, thinking they can use all the energy they want and never see a bill.  In their mind, if it started out as Net-Zero, then it should always be Net-Zero.  Some other human variables are as follows:

1. Occupancy count, and dynamics of human behavior
2. Newlyweds – frolicking socializers – party hardy type – every light is on …
3. Millenialist –  shared spaces – nomadic community – no predictable habit
4. Career Couple, no children- hardly ever home – just eat & sleep there
5. Family of four or five –  Now the meter starts to really spin
6. Then cometh the “Teenager” –  little or no regard for energy conservation
7. Windows open
8. Heat’s  on downstairs
9. A/C is on upstairs because the heat’s on downstairs
10. All lights on…everywhere
11. Shower running for 20 minutes
12. Computer, chargers, hair dryers, curling irons, etc.
13. Empty nesters – live in a couple rooms – big empty spaces hardly used
14. Retired – Universal design – Home all the time – Feel Cold & Hot at same time, take lots of baths, likes to garden, has hot tub – uh-oh

• Who determines the average amount of energy consumed by one person/year?
• Energy Efficiency of the design and construction of the home – this is easy part and that’s the main reason why we are here  today.