Off-Grid Appliances

Ultra-Efficiency Required
Beginner
Solar Clothes Dryer
Solar Clothes Dryer
Gas Engine Geneator
It may look easy, but operating and maintaining an engine generator is a dirty, loud, and expensive way to make energy.
Sun Frost DC Refrigerator/Freezer
Sun Frost’s DC refrigerators and freezers are highly efficient units that don’t require an inverter. High-efficiency AC models are also available.
Compact Fluorescent Bulb
High-efficiency compact fluorescent bulbs are a cheap and easy way to reduce energy loads on- or off-grid.
SunDanzer Chest-Style Fridge
The ultra-efficient SunDanzer chest-style fridges and freezers run on DC.
Bosch Dishwasher
This Bosch dishwasher saves energy by using (and thus heating) only 1.6 gallons of water per load—159% better than the DOE’s energy-efficiency standards.
Staber Horizontal-Axis Washing Machine
Staber offers efficient horizontal-axis washing machines that are top-loading.
Efficient Laptop Computer
Laptops offer all the computing power of desktop computers, while using a fraction of the energy.
Solar Hot Water Collector
PV- and engine-generated electricity are too expensive to use for heating water. Instead, use a solar collector to make hot water directly from sunshine.
Electric Chain Saw
When the batteries are full and the sun is still shining, the author uses the surplus energy for “opportunity” loads, like laundry or cutting firewood with an electric chain saw.
Solar Clothes Dryer
Gas Engine Geneator
Sun Frost DC Refrigerator/Freezer
Compact Fluorescent Bulb
SunDanzer Chest-Style Fridge
Bosch Dishwasher
Staber Horizontal-Axis Washing Machine
Efficient Laptop Computer
Solar Hot Water Collector
Electric Chain Saw

If you’re on-grid, energy efficiency is important. It saves you dollars and reduces your environmental footprint. But it’s even more important if you’re off-grid—or planning to move off-grid.

Renewable energy (RE) systems generally produce electricity that is more expensive than heavily subsidized grid electricity, with all its socialized costs and impacts. The utility grid also provides you with essentially unlimited electricity 24/7/365, without a need for storage. This makes renewable electricity seem expensive by comparison (though it really isn’t if you look at the big picture).

Why Ultra?

Off-grid RE systems must provide for all the electrical energy you want, day or night and no matter the weather. There can be several consecutive days with little sun or wind—and even when it is sunny or windy, you need a buffer between your energy sources and your energy loads. This means a battery bank, which is costly and also limited in capacity. Your backup for when energy production and the battery is low is not the utility grid, but usually a noisy, polluting, and expensive fuel-fired generator.

All of this is why, in 1984, at a time when I was not accustomed to spending thousands of dollars on anything, I bought a $2,500 refrigerator. This was shocking to my on-grid neighbors, who couldn’t imagine why I would spend so much on an appliance, when nothing else on my property had cost that much.

The explanation was clear: If I had purchased the lowest-cost fridge from the local appliance store, I would have had to spend many more thousands of dollars on additional RE gear to power the initially cheap—but lower efficiency—fridge. Energy efficiency is often the best investment you can make, if you take the long-term view.

How About DC?

My fridge is direct current (DC), a choice I might or might not make today (and would be much less likely to make for a client). Going with DC avoids the losses inherent in an inverter, which converts PV and battery DC to conventional alternating current (AC)—the electricity type most people are used to. This makes a simpler system in some ways, since the batteries are tapped directly.

When I started with RE, efficient inverters were non-existent. So my home still uses a lot of DC. The drawbacks to this strategy are that DC is not conventional, so it’s not always easy to find appliances, and some appliances—made for the RV and marine industry—are not as efficient or robust as their AC counterparts.

The other drawback is that you’ll typically end up with dual household wiring systems, because very few people can live with only DC. Most often, AC appliances are also desired, which means having two sets of wiring (DC and AC), a more expensive option. Usually the wisest choice for a modern, whole-house system is to choose all AC, buy an efficient inverter, use ultra-efficient appliances, and add a bit more energy capacity to the system to cover the inverter losses.

Phantoms Loom Larger

For large residential RE systems, small phantom loads (appliances that use energy when “off,” or for no useful purpose) are not necessarily a big deal. It’s important from an environmental point of view to reduce or eliminate them, but they are not deal-breakers when the grid or large renewable generating capacity is available.

Comments (9)

bongo's picture

the test for suitability of the 'solution' I had found useful was to plug in an incandescent bulb on the circuit close to the mis-behaving appliance. If it stabilizes the wave-form sufficiently for digital elements the more permanent solution would then be the capacitor. a new washer and dryer can be a pleasure, so OK, but did you try the incandescent bulb test first?

Peter Clark's picture

I've got a Xantrex SW4048 inverter that handles power from my solar powered battery bank and Kohler propane fired generator. I am off the grid. I have not had success with clothes washing machines - have owned a Staber and now a Frigidaire (manufactured by Electrolux). The computer control boards on both (plus on my propane fired dryer) have often needed replacement. I want to buy a new washer and dryer (propane fired) that will work and last. I'd love to hear from people who use the same inverter (Xantrex SW4048) and have had success with their washer and/or dryer.

bongo's picture

try capacitor on output, see next comments on your thread

Peter Clark's picture

hi Bongo,

Are you suggesting a capacitor between the 120VAC output of the Xantrex and the Frigidaire appliance? I have always thought of a capacitor as a DC device, but there are a lot of things I don't know. What specifications would the capacitor need?

thanks,
Peter

bongo's picture

yes, capacitor on output of Xantrex. One leg each side of output. It solved the problem. The Grainger stock # I have is 5X433. regards technical specs, etc, I'm, not an electrical engineer, but this was what was figured out by Xantrex engineers years ago in response to many fried circuit boards. I went deep in their system; why they do not pass this info along to ALL users eludes me, but here you go.

label on capacitor reads GE, paperwork reads Mallory. Highlighted section of paper reads 50microfarad 370vac catalog #24FD3750. Go down that path and see if it makes sense to your electrical advisor.

Solved my sensitive electronics frying issues, hope it helps you and onward.

Peter Clark's picture

Thank you so much bongo! I've forwarded this information to my adviser, and hope that this will do the trick. I am not an electrical engineer either - this may therefore be an ignorant question. The capacitor has two posts. Do you connect the live wire (output from Xantrex) to one and the ground to the other? Then continue the live wire onto the circuit box, and the ground wire as well? One capacitor can handle the whole output of the Xantrex, or is it better to make these connections just for certain circuits? One capacitor for each 15 amp circuit? Thank you again so much!
Peter

bongo's picture

Yes, one capacitor for entire system. One side of capacitor wired into each active leg of output of Xantrex at circuit box, not ground.

The metaphor by which I understand it's action is that it's similar in function to an expansion talk in a closed plumbing system or a shock absorber, ie, it absorbs roughness/irregularities in the output waveforms of the electricity.

Betcha it'll make sense to an engineer. Would love to have one of them chime in and give proper explanation, I just know it works, not fully why. Again, the test/experiment is to put an incandescent light bulb into the same circuit as the sensitive electronics are on. I did and watched the scrambled display instantly respond and stabilize, I think my words were something like 'halleluja'. Had fried a few boards, spendy and annoying.

Good luck, let me know if it solves.

Peter Clark's picture

Unfortunately, the capacitor did not work. The voltage varied wildly. I removed the capacitor - ended up biting the bullet and buying a new washer and dryer. I went with a stackable full size LG set (WM3570HWA / DLGX3571W) - the dryer is propane heated. They have both been working perfectly for several months now.

roger pangburn's picture

We've been off-grid since 1978 in San Diego area. Also paid about $2500 for a Sunfrost ( my son is still using it today with only a thermostat replaced ). Always set ac loads up with a switch to avoid phantoms. Now use a very efficient Whirlpool refrigerator. As we got more panels, started to leave the inverter on 27/7. The fly in the ointment is batteries for off-grid. I hope one or more of the new technologies will beat this problem. Payback with solar happens from the first day you get it. Forget all the calculations!

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