Peter VanDerWal

pollinator
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since May 28, 2017
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bee bike fish greening the desert solar woodworking
Working on setting up a sustainable household. Currently have a solar array that produces more than we use, an expanding garden, small (3000 gallon) rainwater collection system, L2L system, kitchen rinse sink grey water system. working on shower grey water, expanding rainwater collection and building an aquaponics greenhouse.
Southern Arizona. Zone 8b
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Recent posts by Peter VanDerWal

wayne fajkus wrote:This is my first year for bees so any info appreciated. Id love your opinion on langstroth vs top bar.  I did one of each thinking i would pick one for next years expansion.

By 97% do you lose 3 complete hives out of 100, or does each hive lose 3% of the bees?



Pretty sure he's talking about hives.

Individual hives lose nearly 100% of their bees every year, the queen is the only honey bee that survives for more than 4-5 months.  When the nectar is flowing, the foragers typically only live 6-7 weeks.

1 day ago
A couple things that haven't been covered well yet.

The 'power' in the wind goes up as the cube of the wind speed.  So if the wind speed doubles, the available power goes up 8x.  So a 12 mph ind might barely have enough power to be useful, a 6 mph wind will have 1/8 as much power available.  An ideal turbine can harvest maybe 40% of the available power, and that's BEFORE you convert it into electricity.

The power available also goes up as the square of the turbine diameter, double the diameter, you get 4x the power.  This is why commercial turbines are so big, and why small turbines are generally worthless.

http://windenergyfoundation.org/about-wind-energy/how-wind-works/ ; has a good overview of wind energy and

https://www.engineeringtoolbox.com/wind-power-d_1214.html  ; has a simple explanation of the calculations and a nice example.

From their calculations a 1 meter (~3 foot) turbine in a 10 meter per second (22 mph) wind will produce about 94 watts.  in a 5 m/s wind it would produce less than 10 watts, in light winds, like the above video talks about, the MAXIMUM available power is in single digits and in real life you won't be able to get even that due to losses.  Get up to 4 meters in diameters and you can produce 1,500 watts in 10 m/s (22mph) wind and perhaps 150 watts or so in 5 m/s wind.

Double the diameter (2 meters) and the power goes up 4x, but you still can't get anything from winds under 4-5 m/s because of losses etc. 
Start getting up into the 50 meter plus turbines with variable pitch props, etc. and you can start harvesting some of that energy from 4 m/s wind, but that is basically just a bonus for those turbines because they won't install one anywhere they expect to see average speeds below around 7-8 m/s, and even that is questionable.

Anyway, hopefully you can see now why wind turbines need to be at least 6 meters in diameter and have average wind speeds that are above 5 m/s (~11 mph). 

If you have the skills to build a turbine yourself, then maybe you could get by with a small 3 meter turbine.  If you are good with wood working, welding, electronics, etc. then buy Hugh Piggott's book and build one
http://scoraigwind.co.uk/a-wind-turbine-recipe-book/
1 day ago
Xzeres does an annual average.  For most people that is the more important criteria.

For someone that lives closer to the poles, the winter time average wind speed might be more important.  However, most areas tend to be windier, on average, when the weather is hot instead of when it's cold.
Still it might be different in your case.

I like the Weather Underground website: wunderground.com  They not only list weather data from the professional weather stations, but also include thousands of individual "personal" weather stations.  If you dig around that site you might be able to find a dozen or so people near you with weather data available going back a few years.  Look at what the average wind speeds are in your area during the winter time.

It's possible that you might be one of the rare exception where a small wind turbine makes sense.  it's not likely, but it's possible.

FWIW when I plug my address into Xzeres it tells me that my average wind speed is 10 mph, which means I'm just on the lower edge of a wind turbine being feasible.  But, Xzeres reccomends a 7.5 meter turbine on a 100 foot tower for me and I don't use a lot of power, about 500 kWhs per month on average. 
Xzeres also points out that the lifetime average cost of electricity for that turbine would be 34 cents per kWh, which is almost 3x what the grid charges for electricity where I live and about 2-3 times what it would cost me today to install off-solar for the same output.
1 day ago
I just watched that video and Wow!  Almost everything he says in it is wrong.  His explanation about wiring is completely wrong, AC vs DC completely wrong.  He is right about not wanting an even number of blades, but his explanation of why is wrong.

Yeah, sure his turbines start spinning at low wind speeds, but so what?  They don't produce any usable power at low wind speeds.  There are plenty of explanations online about why chassing after low wind speeds is worthless, but basically it comes down to there isn't any useful power to capture at low wind speeds.

There are two signs that someone selling turbines is trying to scam you.  Anyone that suggests mounting turbines on roof top is targeting ignorant consumers.  Anyone that suggests their turbine is superior because it works at wind speeds below 10 mph is targeting ignorant consumers.  I'm not using 'ignorant' here as an insult, but rather to describe someone that isn't educated on the subject (the actual definition of the word)

As for the guy in the video, Google "Missouri Wind and Solar reviews" and you will come across hundreds of websites complaining about his fraudulent advertising.

If you want a good wind turbine company that consistently get's good reviews and really knows what they are doing, I'd recommend Southwest Windpower.  I have no affiliation with the company, I have never even purchased any of their products.  However, as I said I read lots of good things about them, including the fact that they would rather lose a sale than sell you a turbine when they know it won't work well for you.  If you insist, they will sell you one, but they'll tell you up front that you won't likely be happy with it.

They don't recommend mounting turbines on roof tops, and they will tell you that it's worthless trying to get power out of low speed winds that simply don't have any useful power to extract.

Check out:
http://www.windenergy.com/products/skystream

and read the section "Will it work for me?"

and then follow their link to:
http://www.xzeres.com/buy-direct/wind-report-project/
to see if your area is a good wind resource.
1 day ago
It's kind of difficult to answer your question since we have no idea where you live.

However, as a general answer, Honey bees will generally forage for nectar within a 2 mile radius of their hive.
2 days ago
Every time I look into bitcoin these days, I come to the conclusion that even if your energy is free, you won't make a profit if you have to purchase the miners.

If you're willing to spend a 20-30 thousand or more on miners and have LOTS of free power, then maybe.

Cracking water into hydrogen is a possibility, but again the equipment is expensive and the profits are small.  If you don't care about efficiency (the energy is going to get wasted anyway) then you could build your own electrolyzer, but then the problem is compression the H2 for storage.  That part is dangerous and dozens, possibly hundreds, of people have killed themselves and others trying to do it.

If you make pottery, then running an electric kiln when you have surplus power might be a possibility.  Of if you do woodworking and metal working, then running the high draw equipment only when you have surplus power might work.
2 days ago

Devin Lavign wrote:

Shawn Klassen-Koop wrote:

Devin Lavign wrote:I would highly suggest you look into combo off grid power. Solar and wind. If you have running water on your property add in micro hydro.

Solar is great but has draw backs. Adding wind and/or micro hydro helps fill those draw backs. Wind usually picks up on the cloudy days when there is no sun. Micro hydro never gives a lot of power but is a consistent constant power source, which you know can power X amount of appliances.

2nd is a big thing I see with people wanting to go off grid is not reducing power consumption first.



Hi Devin, I'm a little worried about wind. This article really made me consider that it might not be a good fit, despite that in the end it does actually advocate a hybrid system.

https://www.solacity.com/small-wind-turbine-truth/

I don't really want a massive tower in my yard. What kind of wind system do you recommend for off-gridders doing a wind/solar hybrid?

Micro hydro is great but we don't have micro hydro.

Reducing power consumption first - bingo. Hence car dilemma.



Well I can tell you that article was not a very fair objective one. Not sure why they are so down on wind power, but looking at the wind generators they sell I see they don't have good high quality wind generators for home power use. You see the 3 blade wind generators are mostly used for marine use. People on boats or the coast where they get strong winds. For inland home power use you would want a 5-9 blade wind generator.

I would highly suggest you check out the wind generators at http://mwands.com/store/wind-turbine-products and watch their wind generators for beginners video



These guys are great and really know what they are talking about. As well as completely willing to be honest and not over hype things. They cut through the BS and myths as well as the hype and outright lies.

As for wind generator towers, yes they can be a bit of an eye sore and issue but most residential wind generators don't need a huge tower. Yes higher up you put a wind generator more likely you will get good power. But then you also can't go too high or you will get loss running the power down the line. For smaller wind turbines (depending on the wind in your area) you don't need to go up too high. Maybe 30-60 ft or you might be able to do a roof mount. A lot depends on your location. How high are the trees around you, what sort of wind blocks are around, etc...

I would suggest you call or email Missouri Wind and Solar and discuss your needs with them. Even if you don't buy from them they are helpful and knowledgeable folks who will give you the right info about what is possible and needed.



First of all, Small turbines are not going to be cost effective no matter what they say.  It's a simple matter of physics.  There are a few places where they kind of make sense, but not many.

Second, the more blades a turbine has, the lower it's efficiency, that's why the really huge turbines only have two blades.  Again this is a matter of physics.  Not only do more blades have lower efficiency, they also spin at lower speeds (reducing your TSR) which makes them less desirable for generating electricity.  The only 'advantage' they have, if you want to call it that, is because they have poor efficiency and a low TSR, they are less likely to over-spin in high winds so you don't necessarily need any mechanism to turn them out of the wind, etc.
The hucksters will claim this is an advantage because instead of turning out of the wind you can make energy during high winds.  The problem with that logic is that high winds happen so rarely that it doesn't make any sense to sacrifice efficiency at lower (much more common) wind speeds to make them work in the rare high wind speeds.


There are circumstances where turbines with large numbers of blades make sense.  While turbine with lots of blades spin slower, they have higher torque.  This makes them useful when you want low speed and high torque, pumping water for example.  However, electric generators generally work more efficiently at high RPMs with relatively low torque.  In fact even many two bladed (high TSR, i.e. faster) turbines have a gearbox, chain drive, etc. to increase the RPMs of the generator.  The higher the ratio of the transmission, the lower it's efficiency.  So again, that's a knock against large numbers of blades on a turbine designed to generate electrical power.

For smaller turbines, the ideal number of blades is 3.  Two is slightly more efficient but has problems if it needs to yaw (turn) into the wind while it's spinning.  Because of gyroscopic forces, turbines with an even number of blades tend to cog or vibrate badly when yawing while spinning. I.e. with two blades there is very little resistance to turning while the blades are parallel to the tower, but high resistance when they are at right angles to the tower.  With an odd number of blades you end up with more blades that are not parallel than are at any given point in rotation so the vibration isn't as severe.
3 days ago
Should be 'possible', not sure it's economical.  Egg shells are almost pure calcium carbonate,  so grind them up into a fine power and then cook the powder at 1000°C for an hour or so.

That last bit is the hard part.
3 days ago

Eliot Mason wrote:

And...
Peter VanDerWal wrote:

I would put off getting a fully electric car until you are sure you won't need to drive 100 miles a day.



The issue isn't about finding a vehicle that can provide the range, the issue is the cost of a solar array to charge that vehicle during the winter when they only get 3 hours of sunlight.
You're talking a > $120,000 solar array just to charge the vehicle for a 100 mile daily commute.
4 days ago
Edit:  Just saw that Mike already suggested this, so call this a second vote for monofillament

My mom has had great success using fishing line.  You just string it out like a fence about chest high on the deer.  Deer are usually out in twilight and can't see the fishing line.  they don't trust it when they can feel something they can't see so they won't try jumping over it.

Best to string two strands, one a few feet in front of the other, just in case one of the lines breaks.

My mom started doing this probably 15 years ago and hasn't had any problems with deer since, she regularly gets them wandering around her yard (outside the fishing line fence)
4 days ago