Energy Efficient Appliances
Alternative energy power systems can be designed to fulfill a great number of functions, from interior and exterior lighting or dedicated water pumping to whole-house power systems. However, there are some household power needs that are simply not well suited to alternative energy power. The largest electric power loads in most households are the hot water heater, refrigerators and freezers, electric clothing dryers and ovens, and air conditioning. In general, anything that heats or freezes using electric power is not an efficient addition to an alternative energy system.
- Cooling Without Air Conditioning
- Alternatives to Electric Water Heating
- Energy Efficient Refrigerators/Freezers
- Gas Heated Clothing Dryers
- Advantages of Gas Ovens
- Related Product Information
These appliances consume such huge amounts of electricity, building a large enough renewable energy system to support them would not be cost effective. For homes using both grid power and alternative energy, the simplest solution is to leave existing heating/cooling appliances on a dedicated grid power circuit. However for locations without access to grid power, or for long term reduction in electric bills, replacing these appliances with energy efficient alternatives will prove very cost effective in the long run.
While air conditioning isn’t as common in Alaska as it is in many southern climates, some homes and many RVs use traditional air conditioning systems. One energy efficient alternative to traditional air conditioning is an evaporative cooling system, often called a "swamp cooler." Evaporative coolers are an excellent option for interior cooling in dry climates.
A swamp cooler works by drawing air in through a vented surface of the cooler box, where it flows through a water saturated pad and is blown into the household or RV ventilation system. The heat in the air is used to evaporate water in the cooling pad, leaving the air much cooler and slightly more humid than when it entered the cooler. Swamp coolers are so much more efficient than traditional air conditioning because the only electrical draw in the cooling system is the circulating fan and a small circulating pump. They also avoid the environmental hazards of freon.
Swamp coolers are available not only in household sizes, but also in portable 12 volt DC models ideal for cooling an RV cab while driving, or a sleeping area at night. However, a swamp cooler will be completely ineffective in a humid climate. If the incoming air is already saturated with humidity, no evaporation will occur, and warm wet air will be blown into the living area. Also, if the moisture in the cooling pads cannot evaporate, the pads themselves will begin to develop an unpleasant odor, which will also be blown into the living area.
Of course the simplest way to cool without using an air conditioning system is to use window fans during hot summer months. When combined with exterior window shades, simply maintaining good air circulation through the house or RV can make a major difference in comfort level.
An electric tank water heater is a seriously inefficient appliance. In order for hot water to be available when needed, a large volume of water must be kept heated at all times. Electric heating elements are one of the least energy efficient items in any electrical system. Also, the water is not heated very quickly, so the available hot water supply will run out if the heated "reserve" water is used in large volumes.
One alternative to a traditional electric water heater is to use a propane-fired tank heater. This eliminates the electric draw of the heating elements, and is fairly well suited for an alternative energy system. However, any tank water heater will run out of hot water during a long shower, and enough propane must be consumed to keep a relatively large volume of water heated at all times.
The most efficient method of hot water heating for household use is a propane tankless heater. These water heaters consist of a coiled copper pipe, with a propane burner at the bottom of the unit. They are usually wall mounted, and no larger than a suitcase, making them very space efficient as well. Water is heated on demand, so propane is only used when hot water is actually in use. There is no need to keep a tank full of water heated 24 hours a day. Also, since the burner is only heating the small volume of water present in the copper pipe, the water is heated very quickly. One of the most appealing advantages to tankless heaters is that the hot water supply never runs out, unless the propane runs out or the water supply dries up.
Wood-fired water heaters are also available for high demand water heating like a hot tub. Rather than using electric heat to run the hot tub like an open-air tank heater, a wood-fired heater uses no electricity whatsoever. An electrically heated hot tub would be out of the question for most alternative energy systems, but using wood heat is perfectly feasible for even the most remote locations.
Even the most energy efficient major brand refrigerator or freezer is a huge power draw in any electrical system. The cooling system in a traditional refrigerator is mounted on the back of the unit. This causes a large area of the refrigerator surface to absorb heat produced by the compressor and condenser. Obviously, the cooling system must run longer to compensate for the cooling loss caused by it’s own functioning. It’s a vicious cycle when it comes to the energy consumption of the unit.
One option in energy efficient refrigeration is to purchase a refrigerator with the condenser and compressor mounted on the top of the unit. Not only is the surface area between the cooling system and the refrigerator reduced, leading to less heat absorption by the refrigeration area, but it is far easier to insulate the top freezer compartment from the heat than it would be to effectively insulate the entire back of the unit. One company produces a line of top-mount compressor refrigerators which use half as much electricity as the nearest competitor, and less than 1/4 of the energy used by the average domestic refrigerator.
Another option in reducing electric use by a refrigerator/freezer is to purchase a propane powered model. Propane refrigerators are available either as propane-only models, or with electric blower motors in addition to the propane system. Obviously, a propane-only model would completely eliminate any electric draw, but the cost of the propane consumption should be factored in to the purchasing decision.
While electric clothing dryers may only be used occasionally, the amount of power they consume during use is tremendous. There is currently no way to completely eliminate electric use by a dryer because the drum motors are electric powered, but electricity consumption can be greatly reduced by switching to a gas heated model.
Since the electric heating elements are the least efficient part of the dryer, using gas heat eliminates the majority of the power draw. Buying a high-efficiency washer with an effective extraction spin cycle can also greatly decrease the power use (whether electric or propane) of a clothing dryer. The more moisture that is wrung out of the clothes before drying, the less moisture there is to be heated out of them in the dryer.
An electric range/oven is perhaps the least efficient household appliance ever invented. The only reason it does not top the list of household power draws is because the burners on an electric range are not left on 24 hours a day, unlike an electric tank hot water heater. However, the electrical draw is still tremendous, particularly in a household with multiple occupants where a good deal of time is spent cooking.
Gas ranges have long been considered the best option for high quality cooking, and are used almost exclusively in top restaurants worldwide. In an alternative energy system, a gas range/oven has the added appeal of not requiring any electrical power at all. Many gas ovens feature electric burner igniters rather than gas flame pilot lights, but the power draw required to produce a small, occasional ignition spark is negligible.
For anyone in the process of building a home, making the effort to purchase efficient appliances as the home is completed is an excellent idea, whether the home will be grid powered or off-grid. For an established on-grid home, the initial expense of replacing existing major appliances may be daunting, but the energy savings will prove worthwhile in the long run. Appliances may be replaced one at a time, with the used electric models being sold to help recoup some of the cost of their replacements. The increased efficiency of the new appliances will shortly make up for any additional expense.
Outfitting a home with energy efficient appliances has many important benefits. For on-grid homes, immediate savings will be seen in monthly utility bills, and increased use of energy efficient appliances helps worldwide reduction in harmful side-effects from many methods of mass energy production. For off-grid homes, propane powered appliances may be the only way to fit a full-size refrigerator, dryer, hot water heater or oven into an alternative energy system with limited electrical output capacity.