On Peak Energy Reduction Architecture

What is an OPERA House?

It's not about singing although you may feel like it when your utility bill comes in the mail each month. Actually, it's simple logic and basic physicstm applied to the use of off peak energy. Here's how it works: There is 24hrs in a day. We get up, we start to use energy, have breakfast and then really start using energy. Between 11am and 7pm power is really flowing and is called "on peak" and you are charged a premium during this time period. Some utilities charge over 16 cents per KWH during on peak times, the national average is 10 cents per KWH.

On peak times are only in effect Monday through Friday. All other times, including Saturday and Sunday, are "off peak" and the cost of power is typically around three cents per KWH. The trick is to use as much power off peak as possible without having to stay up until 3am doing laundry. If you are building using conventional building practices you will find it difficult to maximize off peak power since conventional insulation only resists the flow of heat then stores it. Our simple designs change the direction of heat then uses the mass of the walls to absorb heat during on peak times

Whether or not your local energy provider offers off peak rates, this radical home design has many benefits even if taking advantage of lower off peak rates are not available. Below are some of these benefits:

  • The A/C unit(s) only run during the night. Lower temperatures means lower head pressures and decreased energy use.
  • The solar heated air in the attic is drawn into the clothes dryer to dry clothes using the 200 watt tumbler motor as opposed to the 6,000 watt heating element to dry your clothes.
  • Our patented mass wall system using radiant barrier rejects so much heat at the exterior (in sunny climates), that all the hot water needs of the home can be met, typically without back up just by running pipes in the wall.
  • The attic is insulated with our patented RBS Chips which changes the direction of heat as opposed to resisting it like insulation does.
  • Attic venting is three times what minimum codes require.
  • The comfort of the OPERA house is unmatched by any design due to the low mean radiant temperature of the interior wall surfaces. Many people say it feels like walking into a basement.
  • Since OPERA Houses use over 90% of the power during off peak times, this helps electric utilities make more efficient use of the generating plants and helps prevent brown outs and rolling blackouts.

About Off Peak Rates

Some utilities around the country are now offering alternative Time of Use (TOU) rates that allow them to use the generation facilities more efficiently. Keep in mind these plants must supply sufficient energy to accommodate the largest load of each day across the grid...with ample to spare. Costs of this generation is high, it's an inefficient use of the generators. It also causes the greatest amount of pollution when most of us energy users are awake and driving all over town.

If this some of this "peak" usage could be diverted to the "off peak" times it would be a win win for everyone as energy would cost less...much less. How much less? APS has rates less that are less than three cents per kilowatt hour. You could be paying as much as 16 cents now.

Both electric utilities in Phoenix AZ offer such incentives and the homes you see on this link work in conjunction with them.

Arizona Public Service on peak hours are 9am to 9pm, Monday through Friday (Arizona Public Service Company) or 1pm to 8pm Monday through Friday (Salt River Project). During off peak hours, demand charges (KW) are eliminated and consumption charges (KWH) are reduced significantly. Off peak KWH charges are less than $0.03/kwh (the national average for a kwh is around $0.11/kwh). This is a win win situation for all concerned. Users are rewarded with lower monthly bills and utilities can use power generation equipment more efficiently. .

Pro's and Con's in a conventional home:
Pro's: lower electric bills for users of electricity

Con's: Altering lifestyle to meet time parameters; doing laundry at night or mornings, etc. waiting for off peak to begin

Pro's and Con's in an OPERA House:
Pro's: 60% (or more) lower electric bills, unmatched comfort all year, healthier interior environment.

Con's: The OPERA House does cost more than conventional construction. However, when added into a 20 year mortgage, the increased cost is offset by the savings every month on electric bills. These homes have been built since 1993 with proven performance. The first OPERA House has saved over $9,000 in energy costs since being built! After subtracting the savings of smaller HVAC equipment, labor and materials the cost of OPERA technology over frame is approximately $600 per 1000 square feet.

The Goal of the O.P.E.R.A. House
To design a home with the capacity of shifting most of the energy usage to less expensive, off peak times without altering the lifestyle of the occupants. One of the most difficult design considerations was interior comfort during the scorching Phoenix summer heat. With ambient temperatures exceeding 110F the air conditioning system would be under a significant load during the expensive, on peak hours. In addition to the air conditioning load, the first O.P.E.R.A. House was to be occupied by a family of ten! Using hot water for laundry and dish washing could not be expected to be postponed until off peak times.

Designs for the Future

First, we designed a thermal flywheel into the home using mass construction. All exterior walls and one 8' x 20' interior mass wall were constructed of cinder block and filled with mortar and left uninsulated on the inside to absorb interior heat loads (light, people, appliances, etc.). This mass system is cooled during inexpensive, off peak times and effectively stores 12 tons of cooling with a temperature differential of only 4 degrees during off peak times. A home of this size and occupancy would normally require 5 to 6 tons of cooling. The OPERA House is being heated and cooled by one 3 ton, 11 SEER heat pump.

The exterior walls are wrapped with two layers of our Radiant Wrap product which effectively retards heat gains and losses. This was covered by Dow expanded polystyrene foam board and then a stucco finish. The total R value of the exterior walls in OPERA II is R-2. The home is pre cooled at night during the less expensive off peak rates, and runs minimally during the day to maintain temperature and comfort.

The capacity of the hot water tank was upsized from a standard 60 gallon to an 80 gallon tank and wrapped with two layers of Radiant Wrap. We then increased the temperature to 160F and installed a mixing valve which tempered the 160F water with incoming cold water. This would insure a delivery temperature of 130F effectively making the 80 gallon tank larger. The tank is controlled by a timer which was added to insure the tank would not be consuming electricity during the more costly on peak rate charges. Since 1993, the family of ten has never run out of hot water or heated water during expensive on peak hours even with guests staying over.

Infrared thermography testing over the years has shown us that conventional insulation not only slows heat but very effectively stores heat. In an effort to minimize this we installed Radiant Barrier Chips over a bed of blown cellulose with an R factor of 19. This design effectively retards heat gain/loss and keeps the home from consuming large amounts of expensive on peak electricity. An added benefit in all of our RBS Chip installations is the increased comfort of the home throughout all seasons.

The chart clearly illustrates the performance curve of the O.P.E.R.A. House throughout the year. A family of ten, living in a 2300 square foot, all electric south facing home spent $56.00 on air conditioning in August! Local utilities recommend a 66/33 (66% off peak, 33% on peak) split for savings on time of use rates. The more you shift to off peak times, the more you save. O.P.E.R.A. house I averages a 87/13 shift throughout the year occupied by a family of ten. O.P.E.R.A. House II consistently uses 92% off peak regardless of the outside temperature.

These values would be impossible using conventional insulation products in a desert environment.

O.P.E.R.A. I House Specifications
  • Orientation: South
  • Livable square footage: 2300 square feet
  • Occupancy: family of ten
  • Construction: block
  • Wall insulation: R-10 polystyrene foam with two layers of Radiant Wrap
  • Ceiling insulation: R-19 blown cellulose covered with Radiant Barrier Chips
  • Windows: dual pane aluminum sliders
  • HVAC: Rheem 3 ton, 11 SEER split system heat pump
  • Electric Bills: Less than $240 per year for heating and cooling.

O.P.E.R.A. II House Specifications
  • Orientation: Southwest
  • Livable square footage: 2150 square feet
  • Occupancy: family of four
  • Construction: block
  • Wall insulation: R-2 polystyrene foam with two layers of Radiant Wrap
  • Ceiling insulation: R-19 batt fiberglass with two layers of Radiant Wrap stapled to the flat roof deck.
  • Windows: dual pane aluminum sliders
  • HVAC: Rheem 4 ton, 12 SEER split system heat pump
  • Electric Bills: Uses less than 10% on peak power
  • Highest summer electric bill for cooling: $45
  • Heating costs in the winter average $2 - $3 per month
  • Tracking the usage of this home shows 92% of the power is consumed during off peak hours

How to make your new home an O.P.E.R.A. House
Send your blueprint including floor plan and elevations to our office for review. There is no need to alter the design of your home, only how it is built and where insulation is placed. You will be supplied with a detailed plan and instructions for implementing our designs.

Our consulting design charges are on a per home basis depending on size and complexity of your plan. The plan will be reviewed and returned with O.P.E.R.A House specifications, designs and upgrades.

There is no "extra cost" to build an O.P.E.R.A. House. The few thousand extra dollars once rolled into the mortgage will be far offset per month with energy savings. Not to mention the increased comfort of your home.

If your new home is in the planning stage, we can offer suggestions to build energy efficiency into your new home. If your home is the framing stage, you still have time to install the most efficient product in the walls and attic. Contact Us!