Green Home Profiles: O’Rourke House
Solar panel on roof
Solar panel on roof

Net-Zero Energy Home
Steve and Maria O’Rourke, Homeowners
Steve works as V.P. operational efficiency for Microgrid Energy, St. Louis

General Description:
Single-family ranch-style suburban home, built in 1962 as part of a large subdivision in unincorporated St. Louis County. Investment in a super-efficient energy system overhaul facilitated powering by solar photovoltaics. Their electric vehicle “runs on sunshine.”

Project Background:
This home’s energy footprint was cut in half in a period of four years by investing in energy-efficient lighting and HVAC systems, as well as additional insulation and reducing leaks in the exterior walls. When a solar array was installed in 2012, it provided over 2/3 of the electricity used. When the family acquired an electric vehicle, which added to their home’s electrical load, they continued to work on everyday operational efficiencies, toward their goal of net-zero energy consumption.

“This is a conventional home in a typical suburban development, Robinwood West,” Steve O’Rourke relates, “a community of 478 homes built in the early 1960s. We have some pieces of the original marketing literature. Some of the homes are award-winning designs. Siting the development close to McDonnell–Douglas and Lambert St. Louis International Airport was a generator of middle-class workforce housing at that time.

“About 90% of the homes in this development have no basement. They have slab concrete floors with radiant heat. Our home has a partial basement, with concrete walls and concrete ceilings supported by concrete girders—like a bunker! The finished half of the basement is naturally cool, and our storage section is a windowless shelter.”

What’s Green about this project?
“We replaced our original air conditioner in 1999, after it died on the hottest day of the summer,” says Steve, “so we didn’t have time to shop or make a smart decision about the best equipment to buy. We ended up installing the most ‘affordable’ unit.” That’s a mistake Steve urges others not to repeat. “Shop in the off-season and buy the most efficient unit you can,” he advises. “It will save you money and stress in the long run.”

Tankless boiler
In 2010, they upgraded from that 8-SEER unit to a 16-SEER air conditioner with a heat pump. They also upgraded the home’s original boiler, which was only 60% efficient, to a new 90% efficiency unit that doubles as a tankless water heater. The combined footprint of the water heater and boiler was reduced to a wall-mounted unit that left room in the small mechanical closet for storage. In addition, the old metal flue pipes exiting the roof were replaced with PVC through the wall. Savings were significant. “Because we’re not keeping 40 gallons of water hot 24/7, our gas bill has been reduced by over 50% in the summer and 40% annually,” Steve reports.

The gas boiler is the primary source of radiant heat through the three months of a St. Louis winter. The electric heat pump generates warm air to keep the house comfortable in the transitional months, October–November and March–April. “The heat pump is actually more efficient than a gas boiler,” Steve says. “It works like a refrigerator, extracting the heat from the cool outside air, and blowing that warm air into the house.”

The O’Rourke’s upgrades combined energy and financial strategies. “We made use of two big energy efficiency incentive programs,” Steve says. “We used the St. Louis County SAVES low-interest loan program to finance the project, along with rebates from the Missouri Department of Natural Resources Energize Missouri Homes program. We got a $7,500 rebate on about $12,000 worth of work, including the required energy audit, HVAC upgrades and 16″ of attic insulation (to R-49). We used the rebate money to help finance the solar PV system.”

License plate
Their Chevy Volt added about 50% to the home’s energy load, increasing it from about 7,000 to 10,000 kWh a year. The Volt runs entirely on electric energy, but has a gasoline powered generator to keep the batteries charged enough to run the car for long distances. The car can run on the battery pack for 30–50 miles, and then gets about 38 MPG when running on the generator. 

“I have to drive to Columbia or Jefferson City (about 250 miles, round-trip) several times a year, so I’m not limited by the range of a solely electric vehicle,” says Steve. “Over 80% of my miles are electric. In 3 ½ years of owning the Volt, we’ve only used about 250 gallons of gas to drive over 40,000 miles! Our solar PV system produces 50% more electricity than we need to charge the car. We love driving on clean, renewable energy.

“I also love working in the yard,” Steve adds. “When we first bought our home, I did what most homeowners do: used chemical fertilizers and herbicides. A neighbor invited me to consider the environmental consequences, and encouraged me to work with natural methods. We haven’t used yard chemicals over the past 15–20 years, and we’re slowly converting our flower beds to a more natural landscape with native perennial plants.” They also installed rain barrels to reduce storm water runoff and water the garden beds with stored rainwater. “That’s a bit more of a challenge than I anticipated,” laughs Steve. “You have to be very mindful about when to open and close the valve!”

What kinds of issues do you deal with, in your Net-Zero Home?
“I certainly pay more attention the utility bills. It’s like a scorecard. We keep track of our solar PV energy production—how much energy is exported to or drawn from the grid—and maintain the numbers in a spreadsheet to track total usage,” Steve says. “Having the electric car in the mix complicates things a bit, and gives us more information to analyze. I spend much more time analyzing data than I do cleaning the solar panels.

“Our radiant floor heating is quiet, clean and healthy, but because the floors gradually heat up and cool down, the programmable thermostat provides a little less benefit than with a conventional heating system. We have the thermostat programmed to set back at night, and kick in on time to get the floors warm by the time we wake up. The best ‘warm spots’ are in front of the bathroom sink and toilet, nice spots to be barefoot.”

How marketable is this kind of home?

“I guess we’ll find out,” muses Steve. “Once we have an empty nest, we’re ready to move on to our next green homebuilding project. I’d like to think that this will be a great home for someone with values similar to ours. I’ve kept meticulous records to show energy production and usage, and we will work with a realtor who understands the value of green home features, to educate potential buyers about the economic benefits of energy efficiency and renewable energy.”

How does the experience with your home related to your work for a solar energy and energy efficiency company?

“Living with renewable energy, including driving on it, has given me invaluable (and evolving!) insight into the opportunities our company, Microgrid Energy, promotes,” says Steve. “For example, it’s tough to be Net-Zero. You have to have a lot of solar generating capacity and not keep adding energy demands into your home. My business experience, in turn, helped us strategize around our decision to buy an electric car, and solar-power our transportation as well as our home. There’s always more to learn in the energy business, and it’s important to ‘walk the talk’. My experience is definitely an asset for Microgrid.”

What’s your energy advice to other homeowners?

  • Reduce your energy consumption! 
    • Improve lighting efficiency. Lighting accounts for 30% of a home’s energy appetite. Make use of daylight—it’s healthy and it’s free. Use utility and store rebates to upgrade to LED lighting. There’s a sentimental love affair with the orange glow of an incandescent lamp, but any incandescent bulb wastes up to 90% of the energy it consumes as heat. That just adds to the cooling bill in the summer, and it’s a terribly inefficient source of winter heat. Today’s LED lamps provide a range of desirable color temperatures, including the warm glow of your old incandescents.
    • Reduce your plug load. Electric devices draw about 10% of a typical home’s energy. Buy an inexpensive meter to see how much energy your individual appliances use in a week, and project that out to estimate their annual cost. It’s surprising how little things add up!
    • Make use of power strips to eliminate Phantom Power. That’s the 3–5% of energy consumed and wasted by the constant energy draw from anything with a clock, a timer, a remote control or an AC adaptor, those cube-shaped plugs on chargers for electronic devices. Plugging these items into conveniently placed strips will allow you to turn them off when not in use. 
    • Turn things off! From lights to appliances, your energy consciousness will yield savings! Also consider lighting controls with occupancy sensors that automatically turn lights off and on.
    • Always buy ENERGY STAR items. They are the most efficient models. Also be mindful that adding electric items increases your energy demand, even if they are efficient. 
    • Wrap an insulating blanket around your water heater. Insulate exposed hot water pipes too. 20–30% of a home’s energy goes to heat water. When replacing the water heater, consider a tankless unit that heats water on demand—and check for local utility rebates to help offset this investment.
  • Seal up leaks! Property seal HVAC ducts and air-seal around all windows and doors. Eliminating leaks will minimize heat transfer, so warmed or cooled air will not be diluted.
    • Replace worn weather-stripping around doors and windows. This will make a difference in comfort and on your utility bills.
  • If your AC system is more than 25 years old, budget to replace it. Shop around, and make use of utility rebates. Invest in the most efficiency you can afford, and factor monthly bill savings into your decision.
  • Use ceiling fans to circulate air, and add a pleasant breeze into the cooling process. But turn them off when you leave a room. They circulate the conditioned air, but they don’t cool, so fans are only an efficient element in occupied space.
  • Use rebates and incentives! Bookmark, the Database of State Incentives for Renewables and Efficiency, to efficiently research details on incentives from local utilities and government agencies.