After a decade of talking and planning, we’re finally ready to take the plunge and go off-grid. Fearing that we might also plunge ourselves into darkness, we’re looking at investing in a 3,000-watt generator as a backup energy supply.
Before investing, however, I want to be sure the generator will be powerful enough to run our essential appliances.
As we also want to use the generator on camping trips, I’m keen to find out how many of my husband’s camping gadgets it would be capable of running.
I used this generator wattage calculator to figure out which appliances I could run simultaneously.
Watt’s The Difference Between Starting and Running?
Some appliances require an extra boost to get them started, which means they’ll draw more power when starting up than they do once up and running. A standard washing machine, for example, needs around 2,250 watts to get started but then drops down to 1,150 for its running requirements.
If I want to do a load of washing using my 3,000-watt generator for power, I need to restrict the rest of my usage to just 750 watts for the first two to three seconds of its cycle.
Many household devices rely on resistive and capacitive electrical loads, so they don’t fluctuate at any point.
A 75-watt lightbulb, for example, will draw precisely 75 watts of power for the entire time it’s switched on. Similarly, the average laptop charger will draw no more than 90 watts from the moment it’s plugged in.
Everything You Need To Know About Generator Loads
While you can run a generator at full load, it’s generally more efficient to run it at no more than 90%, although requirements and abilities vary from product to product.
Prime-powered diesel generators, for instance, are usually optimized to run at 50 to 80%, whereas continuos-rated diesel generators run more efficiently at 70 to 100%, as do gas generators.
Loading your generator at less than 30% or consistently at 100% can cause numerous problems, including:
- Unplanned downtime
- Increased maintenance
- Increased operating costs
For a 3,000-watt generator to run most efficiently, it needs to be supplying between 30 and 90% of its maximum power capability. In other words, you’ll want to run enough appliances to draw between 900 and 2,700 watts.
Before the day begins in earnest, I may not want my fridge, freezer, or washing machine running, but I can still stick to a 30% load by running the following:
- Coffee maker @ 800 watts = 800
- 2 standard lightbulbs @ 60 watts each = 120
- 2 phone/tablet chargers @ 12 watts each = 24
Total = 944
Once I’ve got my coffee fix, I can increase my load to 2,700 watts, allowing me to run the following:
- Refrigerator @ 200 watts (running) = 200
- Freezer @ 200 watts (running) = 200
- Washing machine @ 1,150 watts (running) = 1150
- Coffee maker @ 800 watts = 800
- 3 standard lightbulbs @ 60 watts each = 180
- 2 phone/tablet chargers @ 12 watts each = 24
- 2 laptop chargers @ 90 watts each = 180
Total = 2734
I would need to start each larger appliance separately to ensure I don’t exceed my generator’s capacity with the starting wattage.
Related: Running a refrigerator on a generator.
How Many Appliances Can I Use At The Same Time?
How many devices you can use simultaneously will depend on the amount of power they need to run. If you’re starting your washing machine, you’ll need to turn off almost everything else to free up the 2,250 watts it needs to power up.
Once it’s running, however, you can plug in as many appliances as you like, as long as they don’t consume more than 2,500 watts.
With small appliances, you’ve got more room for maneuver, which is good news when camping.
With 3,000 watts to play around with, I figure I can power all my husband’s off grid gadgets, including the 350-watt camping refrigerator, outdoor lights, portable camping heater, USB charger, and portable fish finder!
Is There Anything A 3000-watt Generator Can’t Run?
While it looks as though a 3,000-watt generator will be capable of running most of my essential household appliances, it won’t be able to run everything simultaneously.
Some devices draw too much energy to be viable. An electric water heater, for instance, runs on 4,000 watts, so I’m glad we switched to solar hot water before making our off-grid bid.
Clothes dryers are also out, as they need a whopping 6,750 watts to start and draw well over 5,000 when running.
How Long Will A 3000 Watt Generator Last?
If all goes according to plan, we’ll only run our generator periodically, providing backup electricity when the weather fails to provide solar.
The best indoor backup generators have a life expectancy of around 3,000 hours, whereas portable diesel generators can last for up to 20,000. In other words, if you run a diesel generator for four hours a day, it should last you approximately 14 years before requiring a major overhaul.
Conclusion
According to my calculations, a 3,000-watt generator should be enough to see us through those dark times when solar power isn’t an option. I may not be able to get the karaoke machine and strobe light going, but it should keep the lights on and the coffee hot.
