This is an interesting case study:
A Lake Wales, FL home is touted as one of the most efficient in North America.
According to Residential Energy Services (RESNET) Maurice Ramirez and Allison Sakara’s home has a HERS rating of -63. The average score for a home in America is about 100.
Check out the interview and story here: Lake Wales home touted as one of North America's most efficient
But how efficient is the house?
It has a HERS rating of -63
I understand. But it sounds like, with a HERS rating of 80 before the addition of renewables, that the energy efficiency features of the actual house are unremarkable.
I agree, Ed.
The house itself scores an 80 but, add $100,000.00 in renewables and you get a -63. So, in my book, that does not make an efficient home ... just one that is HEAVILY offset with renewables.
Don't get me wrong, I'm still happy when people offset their energy burden with renewable energy. However, I wonder what the "need" would have been if 'deep conservation' measures had been the initial focus ... and then offset the small remainder with solar and wind.
Love & light.
Lets do some quick math... If this home's energy bills before all the updates were $500/mo or $6K/yr., their energy bills now are $30/mo. or $360/yr, and their wind turbine cost was $100K, They are saving now $5640/yr, which is 17.7 years NOT 12. Now, lets add 81 PV panels generating 20kWh... how much was did the PV cost? Whats the ROI on the PV? Producing enough energy for 3 houses? Really??? That is not efficiency!
As Ed questioned, what is the HERS rating after building envelope updates (assuming) but BEFORE any renewables were added. That tells us if the house was remodel to energy efficient standards. Anyone can add enough bling (turbines, PV, etc.) to make the HERS come out negative. And if its -63, why are they paying $30/mo. Not buying!
News like this makes it harder for the rest of us to to teach clients about ZEH's and ZERH as a cost effective way to build new or remodel houses.
In addition, $6K per year for a an energy bill is astoundingly high, unless the house is very big. In my mid-Atlantic region, a house with a HERS of 80 uses less than $1 per square foot per year, so in Florida with no heat and more A/C it should be about the same or less. Is there any 6000 ft2 house that could be called truly efficient??
Great comments. Thanks for a deeper discussion of the issues around the energy efficiency of this home. I changed the title of this discussion to: Home touted as one of the most efficient in America. Is it?