Energy Efficiency and Conservation

ILLUSTRATION CREDIT: LESLIE CARLSON / SUNPLUGGERS.COM
Switching from regular incandescent bulbs, above, to compact fluorescents,
below, can give you a first-year return on your investment of more than 200
percent.

Any solar-electric system is an investment, and the idea is to pay back the initial cost quickly by cutting utility bills, then start generating income. But most homeowners waste a disturbingly large percentage of the energy they purchase from the utility. Before considering solar electricity, it’s essential to look at how much energy you use, how much it costs you, and how investing in conservation can affect the bottom line.

Take a close look at your utility bill. Somewhere on there, you’ll see how many kilowatt-hours of electrical energy you used the previous month and for each month of the past year, along with how much it cost you. According to the U.S. Energy Information Administration, the average American homeowner uses 11,040 kwh per year at an average cost of about 11 cents per kwh, and pays a yearly electric bill of about $1,214. European electric rates are often more than twice that, so it’s no surprise that the average homeowner there uses about half the electricity each year compared to an American. In developing countries, electric rates can be even higher.

The easiest solution for lowering your electric bill would simply be to install a big enough PV array to cover all your average yearly electricity needs. But there is another, highly recommended investment you can make first that pays back much faster — energy conservation. Every dollar spent on conservation can save you $3 to $5 on the cost of a PV system that can bring your electric bill to zero.

Conservation

“Change the lightbulbs on your ceiling before you put the solar panels on your roof.”

This conservation mantra has been preached by solar energy professionals since the industry was in its infancy. And despite the rapidly falling cost of PV and generous federal, state and local tax credits and incentives, it still holds true. It makes no sense to invest in PV equipment to generate energy that you will simply waste, and for many households the waste can be half or more of energy used.

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Investments in efficiency and conservation pay back faster than investments in PV, and similar federal, state and local tax credits are available for improvements, ranging from caulking and storm windows to replacing inefficient appliances.

ILLUSTRATION CREDIT: LESLIE CARLSON / SUNPLUGGERS.COM Turn
off lights and appliances when you’re not using them.

The less abundant your solar resource, the more critical conservation becomes. A typical home in Minneapolis gets about one-quarter less solar energy every year than a home in Denver, so the Minnesotans must invest that much more in a PV system that will cover the same 11,040 kwh of yearly energy use. If they cut their energy use in half by eliminating waste, solar becomes far more affordable.

The “Half Plan”

Renewable-energy advocate and author Gary Reysa has been putting conservation to the test in his Bozeman, Mont., home since 2006 with his “Half Plan,” featured in both The Mother Earth News and Home Power Magazine. He and his family decided that they were going to cut their energy consumption in half over the course of a year, and do all the work themselves. It worked, and you might find it very surprising how simple conservation can be. To get started:

Change Your Energy-Use Habits

• Turn off lights and appliances when you are finished using them. This sounds trivial, but Mr. Reysa calculated a savings of 438 kwh and $44 a year, at a cost of zero.
• Tame your computers. A couple of personal computers and the assorted printers, routers, scanners and such that go with them can easily add up to a 300-watt load. Don’t leave them on all the time, as that’s 2,628 kwh per year at a cost of $289 in electricity. Using “sleep” mode can help, but turning all the equipment completely off when not in use is better.
• Eliminate phantom loads with power strips. Computer equipment, televisions, entertainment centers and indeed anything that you can turn on with a remote control or a button (instead of a switch) or that plugs in via a “wall wart” uses energy even when turned off. Such so-called “phantom loads” are small, but they add up. Power strips are incredibly useful for eliminating phantom loads, giving you total control. For example, in my off-grid home the entertainment center uses three power strips — I can turn on one to just listen to the radio, flip the second one to watch television and then fire up the third one to get full surround sound for watching movies. The Reysas calculate that they save 1,779 kwh and $178 per year by using power strips, at a cost of only $10 per strip.

ILLUSTRATION CREDIT:
LESLIE CARLSON /
SUNPLUGGERS.COM
Don’t leave computers on all
the time, and eliminate phantom
loads with power strips.

Invest in Efficient Lights and Appliances

• Replace all incandescent lights with efficient substitutes. Fluorescent, compact fluorescent (CFL) and LED lights are more expensive, but pay back the investment quickly and last longer. LEDs are not yet as efficient as CFLs, but are still very useful for task lighting (such as under-counter or reading lamps) thanks to their highly directional beam. Mr. Reysa calculates that for their investment of $65 in CFL lighting (reduced to $50 by a local utility rebate), they saved 1,168 kwh and $117 in one year — a first-year return on investment of more than 200 percent. Many local utilities have CFL rebate programs.
• Buy an energy monitor to sniff out inefficient appliances. For under $30 you can buy a “Kill-o-Watt” meter to track the energy use of any given appliance. Move the meter around the house as your curiosity dictates. A new furnace, air conditioner, TV, fridge or washer can be a big investment — but after doing the math about energy use and cost using the Energy Star rating of the new appliance, the payback time and ROI results might surprise you.

Invest in Thermal Efficiency

Heating and cooling (of both air and water) are likely your single biggest energy costs, estimated at an average of over 35 percent by the EIA. So don’t waste energy heating the great outdoors in winter, or trying to cool it in summer ― leaky houses with large air conditioners are not a viable solution to global warming, they make it worse! The efficiency of any old furnace or air conditioner can be greatly increased simply by not wasting energy. In the following examples, we’ve converted the cost for propane or natural-gas heat to the equivalent electric cost in kwh.

• Consider a thermal evaluation. It’s not expensive to have a home energy auditor visit your home with a thermal imaging camera. This will pinpoint the areas where you can get the maximum return for minimal investment in sealing and insulation.
• Seal up air leaks. The Federal “Cash for Caulkers” program now has tax credits available for thermal efficiency improvements, and there are numerous state and local incentives nationwide. The Reysas saved 1,980 kwh and $156 the first year, at a cost of $50 for an eight-hour, do-it-yourself project. Doors, windows, ducts, plumbing and electrical openings, and attics are all likely spots where energy (and dollars) could be leaking from your home.
• Upgrade insulation. Additional attic and floor insulation is inexpensive, and makes for another fairly easy task if you want to do it yourself. About $400 in insulation and some itchy hours spent installing it can save $200 a year or more, for a 50 percent first-year return on investment.
• Install insulated window shades. Windows don’t have much insulation R-value compared to walls, floors and ceilings. Pulling down insulated shades on cold winter nights can result in large seasonal energy savings, and can be used to block sunlight and reduce air-conditioning loads in summer.
• Don’t forget water-heating efficiency. You don’t keep a kettle of water boiling on the stove 24/7 in case you want to make tea — that would be wasteful. So why would you keep a tank of water hot 24/7 for when you want to take a shower or wash your hands? If your water heater is old, consider replacing it with an on-demand (tankless) version, whether electric or gas. With a traditional tank water heater, be sure to insulate the tank and pipes with thermal blankets.

ILLUSTRATION CREDIT:
LESLIE CARLSON /
SUNPLUGGERS.COM
Consider switching
to a tankless
water heater.

If You Can Start From Scratch…

If you are designing a new home from the ground up, energy efficiency can be built in at very little additional cost compared to retrofitting an existing dwelling. Contact a LEED-certified green building consultant or architect before breaking ground! If your new home is sited and designed to take advantage of natural heating and cooling, is well-insulated and sealed, and includes only modern, efficient appliances, the energy you use each month can be drastically reduced as soon as you move in.

And Once You’ve Conserved All You Can…

Then it’s time to do your math on solar energy, starting with evaluating your resource. That’s coming up in Chapter III of the Solar Power Primer.