Earth Day 2021
By Wayne Evelo
Yes, it’s TOTALLY possible to convert an existing older home in the mountains outside of Albuquerque into a net zero energy and highly resilient home. We have been on this journey for a while now but are not quite there yet. The first thing to do is to make things as energy efficient as possible, because energy efficiency is cheaper than energy production. The easiest approach to energy efficiency is to look for Energy Star products. Our appliances and lighting are all Energy Star. The LED lights last up to 30 years, so I made sure to include them in my will. I hope the kids don’t fight over them.
Wayne’s World from the South side: The photo was taken in the late morning on the equinox. The sun barely makes it to the bottom of the windows, so there will be no direct solar gain on the south side from April to October. The one large roof panel is a solar hot water panel and the rest are solar electric. The thin windows on the side of the building allow the sun to heat the thermal walls.
Climate Change Driven Hailstorm Made It Happen
A totally BOGUS hailstorm hit while my wife and I were on our anniversary dinner and my teenage daughter was babysitting her younger brother. The golf ball sized hail totaled the asphalt shingle roof and broke through the plastic sky lights causing the kids to hide under the kitchen table. (Fortunately, they didn’t need therapy.)
The insurance company was willing to pay to have the roof and skylights replaced. This was the motivation we needed to put a MOST EXCELLENT 500 square foot passive solar addition over the garage on the south side of the house. The insurance money would help pay for a new roof prior to the addition of solar panels. The pitch of the roof was specifically angled and designed to hold solar electric panels and we added a solar hot water panel to a different section of roof. We took advantage of AWESOME state and federal tax credits and the local utility pays a premium for our solar electricity. The roof is a metal roof with low solar reflective index (i.e.,a TOTALLY COOL roof) and it is resistant to hail and fires. The sky lights are energy star and have tempered low–e glass.
We added insulation to the roof to make it R–50 (Code is R–30). The insulation in the existing walls was increased to R–25 and the southernmost wall was R–30 (code is R–19). The windows were all replaced with R–5 double pane low e glass (code is R–2), except the south facing windows which were specified as high solar heat gain to warm the house in the winter. The southern roof extends slightly farther than the other overhangs to completely shade the windows in the summer. However, in the winter the sun goes 8’ into the second story. (My TOTALLY AWESOME dog, rescued from the pound, loves to lie in the sun.) Two thermal walls were added to the second story. Behind the windows are 4” thick concrete blocks painted black. They are heated up by the sun during the day and slowly release heat into the house at night. In the summer they are shaded and keep the house cool, because all of that material doesn’t heat up as quickly as a typical house.
Transportation Solution
Our RADICAL set of wheels is super cheap, quiet, and quick to drive. My MOST EXCELLENT family uses a plug–in hybrid for most of our driving. The car goes about 40 miles on the battery, before it transitions to gas. An electric car cost about 4 cents of electricity per mile to run compared to a regular car that costs about 10cents in gasoline per mile.(Your mileage may vary.) Most of our trips are short and the car is charged with solar electricity from the roof. Over 65K miles we have averaged over 230 miles/gallon of gas using electricity and gas. We fill the car with gas once every 3 months and change the oil once every 2 years, whether it needs it or not. The car can turn the electric motor into a generator and use it to slow the car while charging the battery. This means the brakes hardly get used, especially considering the SUPER MELLOW way I drive, so the brakes will last forever! (I hope). We sure like saving mucho dinero.
Resilience Improvements
The house has a metal roof and stucco siding,so it is more fire resistant than a typical house.The house is passive solar when the sun is out, but what about a MONSTER snowstorm…you’re probably thinking? Well, a free–standing propane fireplace was added to the second floor. Power is not required for the propane stove to heat the second story and the airtight first floor fireplace, with an outside air source, can heat the lower level. The house gets water from a well–fed storage tank up on the hill, which holds a week’s worth of water. The solar hot water system, which feeds a standard propane hot water heater, has an 80–gallon storage tank. The solar system has also been prewired for a battery storage system. We are just waiting for battery prices to drop some more and the account balance in the bank to increase unless I can figure out how to power the house with the car’s 17kWh battery…hmm?
Excellent Journey Continues
The solar system saves enough energy, and gasoline to cover all our utility costs. The house is not yet a net zero–energy home, that will require replacing the 25–year old propane furnace with a heat pump. We have been holding off in hopes of new tax credits. We have always considered the life cycle costs of the improvements we make,and all the upgrades will pay for themselves in less than 8 years. This assumes that the value of our house doesn’t increase, but it TOTALLY did increase. Resilient high efficiency solar homes cost less to run, perform better in a disaster, are better equipped to handle climate change, and sell faster and for a higher price than standard homes. PARTY ON!
(Wayne Evelo is a lifetime member of the New Mexico Solar Energy Association and a former member of NM-IPL’s board of directors. He has worked for the Department of Energy for 30 years, where he currently serves as the Green Building and Utilities Program Manager. He is a member of First Unitarian Universalist Church).
