Max and Wink
Green Colorado Organic Farm farm photos
About the Farm Seasonal News Family and Friends Ag Links Articles
Wink Davis

Got Those Utility Bill Blues

by Philip "Wink" Winship Davis

Dreading your ever-increasing utility bill? Worried about freezing in the dark (or baking in the sun)? Feel like the 1970s OPEC oil embargo all over again?

For these past 30 years, while the rest of us got comfortable and complacent with cheap energy, a cadre of prescient and persistent energy visionaries has been developing realistic alternatives. Note the emphasis on the word, realistic. This is the story of one heartening example: the Zero Energy Home, coming soon to a subdivision near you.

"What?!", I hear you exclaim, "I just wrote a check for over $150 to Colorado Springs Utilities for last month's gas and electric bill… and it could be more this summer. In the Springs the average monthly utility bill is even more than that. How can anyone turn that into a ‘zero'? There must be a catch. Is this one of those houses made of tires, tin cans, and straw? What about heat and lights and cooking? All those things use energy!"

Good point -- but there's no catch. It's not that the Zero Energy Home (ZEH) uses no energy at all. But it DOES produce as much energy as it consumes, so over the course of a year the energy bill nets out to zero. And the house is, by outward appearances and construction materials, a conventional ranch-style single-family home.

How I'd love to have that $150 bucks a month back

"How do they do it…and how can I achieve the same results?" The ZEH solution is a creative blend of new and old technologies and a willingness of the occupants to adjust their behavior. Some of these elements are available for existing homes but if you want to buy a new one off the shelf you'll have to move to Loveland or Ft Collins where developer Aspen Homes of Colorado will, this summer, begin offering the ZEH as an option in its 1,400 square foot ranch and 3,600 square foot walkout. This is the fruit of a collaboration of the Colorado Renewable Energy Society (CRES); the national Million Solar Roofs project; the Sabin brothers, owners of Aspen Homes; and Built Green Colorado (see article). Joe Bourg of Millennium Energy, LLC, of Golden, coordinates the project.

How DO they do it? The Solar Electric Connection

First of all the ZEH is an all-electric home. Electricity to match the annual consumption is generated by roof-mounted solar-electric panels (technically "photovoltaic" ("PV") panels). Energy consumption is modeled using a computerized program and panels are sized to match this requirement. This is the extent of new technology: recent advances in PV design, materials, and manufacturing coupled with economies of scale are increasing efficiency and bringing down the cost of photovoltaics.

In truth, anyone with an ample bank account and place to put them could do this part and there are some very large residential PV arrays in places like Aspen. But the point of the CRES/MSR/Aspen Homes collaboration is to make this affordable and available to the average home buyer. So, combined with producing its own power, the home is designed to use as little energy as possible and to make the most efficient use of that which it does consume, thereby minimizing the size and expense of the PV.

Passive Solar Heat

The cliff dwellers of our own Southwest understood the wisdom of exposing their dwellings to the warmth of the winter sun, shading it in the summer, and making use of the earth's residual warmth. The ZEH takes full advantage of this free passive solar resource as it has been refined and field-tested in homes since the 1970s. The long axis of the house faces south to enable the sun to shine through large windows. Stained and polished concrete floors absorb and store the sun's heat, radiate it back into the room at night, and temper heat-gain during bright sunny days. In the summer, the windows are shaded by roof overhangs and the thermal mass can store the night-time coolness.

This solar heat is retained in cold months, and excluded in summer, by excellent insulation in the ceiling and walls and high-efficiency windows. High R-value insulation enables the design to utilize a smaller, more efficient furnace and may even eliminate the need for conventional air conditioning. Back-up heat is provided as needed by a high-efficiency conventional electric forced-air furnace linked to either roof-mounted solar panels or a heat pump that draws residual warmth from the earth.

Solar Hot Water and Efficient Appliances

The free energy of the sun is also captured in solar panels that deliver hot water into the plumbing system to provide hot water for all domestic needs. High-efficiency appliances further reduce the electric demand. Recent years have witnessed a multitude of advances, especially in the refrigerator, which is typically one of the largest users of electricity in a home. Remember, when it's time to upgrade our appliances, we should insist on the "Energy-Star" label, apply for a rebate from Springs Utilities, and watch our electric bill drop.

Utility Grid Symbiosis
Another innovation that makes the ZEH work is the willingness of the utility to "bank" the home's excess electrical production. When the PV panels are generating more electricity than the occupants are consuming, as during the typical work day, the electric meter actually turns backwards ­ taking kilowatt hours OFF the meter. This power goes into the electric "grid" for use by other utility customers and reducing the utility's consumption of expensive and polluting fossil fuels. In the evening, when the sun is down and the family returns home, cooks dinner, and turns on lights, the energy will come from the grid. You can think of the power grid acting as a "battery" for the home. Over the course of a year the net energy use will be zero.

The symbiosis between the grid and the ZEH goes even further: On any hot summer afternoon in conventional homes across the Front Range people's air conditioning is working hard pumping out "coolth" and producing a peak demand period for which the utility must be prepared to provide power ­ at premium rates. The PV panels on the ZEH will be simultaneously producing power at near their maximum capacity and pumping most of it into the grid. Since the utility's "peaking capacity" is provided mainly by increasingly expensive natural gas, the energy that is provided at this time by the PVs is particularly valuable from both a cost and environmental perspective.

Energy Conserving Personal Habits.

Notwithstanding all these 21st Century innovations, it is the human factor that is perhaps the most important element in the success of any energy conscious home. It is the occupants who will turn down the thermostat and put on a sweater. We can remember to turn off unused lights and install compact fluorescent bulbs. We can reduce our use of the clothes drier and take shorter showers. And we can learn about the "phantom loads" created by instant-on appliances and learn how to turn them off when not in use. …Or any combination of the above that balances our life-style requirements with our desire to save energy and money.

My bet is that once you start noticing, you'll begin comparing monthly bills, and compete against yourself to find ways to reduce them. You may not be able to turn your home into a Zero Energy Home but you'll be able to get a lot closer than you are right now ­ and have fun and save money while doing it.

Integrated Design Strategy

Aspen Homes plans to break ground on the first ZEH at about the time you're reading this article. The energy-saving technologies will add about $35,000 to the price of the house. If the ZEH saves you $150 per month in utility bills, this translates into more than $25,000 in additional mortgage borrowing capacity at today's rates. Several mortgage lenders are initiating "Green Mortgage Programs". (See side bar.)

Joe Bourg, the program coordinator, sums it up, emphasizing: "Through the whole-building or integrated design strategy used to develop the Zero Energy Home concept, it is possible to ‘do more with less'. The occupants of a ZEH can live in a more comfortable house, save money on the utility bill, reduce their impact on the environment, and eliminate their vulnerability to volatile energy prices. When a Zero Energy Home is purchased, the owner in essence purchases the energy requirements of the home for the next 20-30 years upfront and rolls these costs into the home mortgage, resulting in a fixed price of energy for the home over the mortgage period. As a result of having fixed energy costs into the foreseeable future, the higher utility energy prices rise the more profitable the investment in the Zero Energy Home becomes."

Reprinted with the permission of Springs Magazine, April 2004.