Backup wind power

Does anyone use wind energy as their backup power? I am on grid but would like to incorporate some type of backup. My backup does not need to run a whole home, more like fans, lights, and possibly a fridge.

Original I had thought about getting a few solar panels, but this requires batteries to be a backup solution. Wind can be harnessed day and night.

I've researched a few generators but the reviews all claim they don't produce the wattage they claim. Does anyone have a good resource or website that reviews or sells quality generators? Is anyone using wind as a backup?

Wind and solar both function intermittently. Batteries can help even out the availability of electricity. However, if you feel content about using electricity only when the wind blows, or the sun shines, then you do not need batteries.

Mike Bettis wrote:Does anyone use wind energy as their backup power? I am on grid but would like to incorporate some type of backup. My backup does not need to run a whole home, more like fans, lights, and possibly a fridge.

Original I had thought about getting a few solar panels, but this requires batteries to be a backup solution. Wind can be harnessed day and night.

I've researched a few generators but the reviews all claim they don't produce the wattage they claim. Does anyone have a good resource or website that reviews or sells quality generators? Is anyone using wind as a backup?

Every small scale wind turbine i have seen either feeds the grid directly or requires batteries. The way the units work is they need something to push against that is consistent or else you can get a high reving turbine. Offgrid we accomplish this with batteries and a dump load controller. If you need batteries anyways solar is a more reliable option for most smaller projects. Wind is fun but small wind unless you have the perfect site is usually not worth it. Of course situations vary and ultimately the choice is yours.
Cheers,  David

Thanks for the replies. I guess no one is using it as backup as I'm understanding? My hope was in times of outages I can run a small turbine to run a few electrical devices. My plan would be to put a switch at my main lines from the transformer. So this would not be grid tied. But as you said they need resistance? Hmm I haven't heard of that but I've also never had any experience with wind generators.

I guess it depends on what you expect it to do, and how reliable your wind supply is. I would suggest more research before you spend money.

Do you have commercial wind generation in your area (i.e., the monster big windmills)? This is potentially an excellent source of information. They feed into the grid, and their output is logged over time. In my area that is public information.

Is there a time of year when you are more likely to need wind generation as backup power? Up here, that usually means the dead of winter when a giant slug of arctic air, a high pressure system, sits over us at -40C. And there is no wind at all -- commercial windmills produce zero power.

Mike Bettis wrote:Thanks for the replies. I guess no one is using it as backup as I'm understanding? My hope was in times of outages I can run a small turbine to run a few electrical devices. My plan would be to put a switch at my main lines from the transformer. So this would not be grid tied. But as you said they need resistance? Hmm I haven't heard of that but I've also never had any experience with wind generators.

No, you just don't understand.  A wind generator is not a device you just plug things into and expect to have them to run.  First, there needs to be substantial wind.  Not a light breeze ruffling the leaves, but wind that pulls your hat off your head.  Because the windmill is a variable speed generator, based on the speed of the wind, that means the power produced is going to vary in voltage.  It might be running at 12V, or 30V, but it will not, and can not make continous 120VAC that everything in your house consumes.  For that you MUST have a battery bank and an inverter.  And a charge controller that can take the varying voltage output from the windmill generator, and convert it into charging current for your batteries.  No way around that.

But, as others have indicated, you can right now today, put together a solar system that can accomplish what you want it to do.  The very first thing you need to do is to itemize your loads and calculate just how much power you need to make.  You made a partial list, being lights, fans, and a frig.  The very first thing you need to understand is that the power required varies with orders of magnitude.  That is, a light might need 7-25W to light, a fan, maybe 100-150W to run, and a frig maybe 1.0 to 1.5 kWh to stay on 24/7.  You may express this in watthours (Wh), or kilowatt hours (kWh).  So, one 25W compact flourescent light bulb might consume 100Wh if you left it on for four hours, or 0.1kWh, depending on what units you want to use.  The fan that runs on 100 Watts will consume 500Wh if left on for five hours (0.5kWh).  My 18cuft refrigerator/freezer consumes ~1.2kWh per 24 hours.

Just to speed this along, let's itemize a few things for you.  You can update the numbers yourself to customize for your own lifestyle.

Two CFL bulbs on for 4 hours: 25W X 2 bulbs X 4 hours = 200Wh (0.2kWh)
One 100W window fan on for 5 hours: 100W X 1 fan X 5 hours = 500Wh (0.5kWh)
One 50W TV/Computer on for two hours: 50W X 2hours = 100Wh (0.1kWh)
One standard AC refrigerator running on and off = 1.2kWh per day
AC inverter left on, consuming 30W per hour: 30W X 24 hours = 720Wh (0.72kWh)

This all adds up to 2.0kWh per day.  This reflects closely to what I've seen with my own off-grid system.  Lowest I've ever seen in winter with the frig cycling very little and zero lights or TV was 1.5kWh.  Today, with Starlink internet, and all the little electrical loads like the stove clock, weather station, and whatnot, I'm at about 4.0kWh.

So, how will you make at least 2.0kWh of power?  Solar will do that, assuming you have sunny days.  In Illinois in December, I'd suspect you get about 3 sunhours worth of power, and maybe 6 sunhours in June.  So, to make at least 2.0kWh of power in the winter, you'd need 2000Wh/3 sunhours = 666Watts of solar panels.  250W, 30V rooftop residential panels are dirt-cheap right now, so you could make a functional system with three of those.  Four or six panels would be even better, but three will make it work.

You'll need batteries to store the power you make.  Remember, even a windmill only system will need batteries.  I'd go with at least a 24V battery bank.  You can get 210Ah, 6V golf-cart batteries at CostCo right now for ~110$ each.  Wire four of them in series to get a 24V battery bank.

Next you need a charge controller to convert the raw solar DC into battery charging current.  You should get a MPPT charge controller.  An MPPT controller acts like a transformer, taking raw high-voltage DC current from the panels, and transforming down to battery-charging voltage.  The extra volts gets transformed into extra charging amps.  You would wire all three panels in series to make ~8.3A at 90V, so select a controller that can handle 150V.  Don't ask why you can't use a 100V controller.  That can be explained later (cold temperature Voc).  Take a look at Epever's Triron4215N controller.

Lastly, an inverter.  Lots of choice here, but if you want to run a frig, make sure you select a pure sine wave inverter.  MSW or SW inverters make motors run hot and will quickly burn them out.  They are only good for resistive loads like traditional filament lights and such.  Samlex makes a quality UL-list model, the PST-2000, that would work well for you.  The frig, having an electric motor, will have starting surge that is higher than the running watts it is rated for.  

Remember, with electronics, you get what you pay for.  Cheap overseas inverters are made with bottom rung budget parts that might barely make it through the warranty year.  Whatever you buy, make sure it is UL-listed.  You should be able to make a functional system that will work for you for ~1500$.

I have an excellent book called "Homebrew Wind Power".  It's very detailed and explains exactly how to build and generate your own electricity with a turbine.  It also says (I'm paraphrasing) "Don't use wind power unless you have no other reasonable option".  For the cost, it just isn't worth it unless you are so remotely located that you can't get electricity to your location without paying an obscene amount of money.  Interestingly, the tower is a very significant part of the cost.  They are hard to put up, hard to secure, make it hard to maintain the turbine.  My personal, and limited, opinion is that solar panels and backup batteries are more cost effective and cheaper/easier to maintain.

Hello all,

I am in Hawaii (Hawaii Oceanview, largest and oldest subdivision in the USA and the least inhabited) I have 24 solar panels (200 watts each from Renogy) that charge a bank of (48) 3.2 volt 60 amp hour lithium batteries in 12 volt pairs with a healthy BMS (from a site called battery hookup) going through (3) 10k inverters enough to power all my lights, electric stove, washer (I line dry) a ductless split a/c system (if I ever have a need to use it) and led grow lights for two enclosed 20x40 two level hydroponic grow houses (fruits and veggies only! Well maybe a plant or two for personal use😏) I seldom need to use the a/c because of the tradewinds and due to the most excellent weather my house has 6x10 sliding doors on all sides so it is open to the weather when I want it to be. I use a homemade wind mill that is three 40’ aluminum ladders set at 25’ in height tig welded in a tripod configuration (so I can climb up for repairs) with guy wires in between the ladders connected to two 250 amp ac delco alternators via direct gearing so I could change gearing to find the sweet spot for rpm. I have the windmill locked out during the day with a bicycle disc brake activated from the ground because I get so much power from the solar panels and need to keep it alive during tropical storms (and daytime wind is around 20 mph that high up during the day and averages 5-10 mph in the evening) I rarely need to engage the wind generation but it’s there as backup on overcast or rainy days. I can utilize this system because I am in a year around growing season (even at 3000’) but if you go this way you either need to build your system to withstand winter temps and ice buildup on the blades (the reason I decided to move to Hawaii, along with a year around growing season) I have it pretty sweet here compared to those living INCONUS and I salute you all for your hardwork and thriving against foul weather and predators.

Nice setup! When I visited the Hawaiian Islands years ago the steady breeze from offshore was amazing -- and a lifesaver for me since I don't do well with heat. Even a small wind generator would provide a surprising amount of power over time.