On grid means that you attach your system to the utility. Off grid means that you live independent of the utility and provide all your own power.
An on-grid system doesn’t need a battery because you use electricity and sell your extra to the grid and use grid electricity when your wind system doesn’t produce enough. In effect, the grid is your safety backup.
If you disconnect from the grid, it means that you need extra capacity to make sure you can charge your batteries, and that your batteries have enough capacity to carry you through periods of no wind and no sun, if you own solar. Having wind and solar together gives you a greater chance of being able to recharge your batteries.
You have to determine the capacity of your batteries by looking at your electric usage and by knowing how long, in the worst case, you might have no wind (or no solar) energy feeding the battery. To go off-grid, you should plan on having extra energy capacity and extra battery capacity for worst case scenarios.
In an off-grid system, your wind turbine’s output passes through a charge controller into a battery and from there into an off-grid inverter, which synchronizes to the voltage (120 or 240) of your house or building without synchronizing to the grid.
|1 meter high||100 Watts||500|
|2.7 meter high||500 Watts||2,500|
|4.5 meter high||2 kilowatts||7,500|
|6 meter high||2 kilowatts||7,500|
*Price in dollars, Euros, or British pounds depending on your region
The prices above do not include shipping, taxes, and installation.
The first step is to look at your electric bill.
Here is an example of a commercial statement:
As you can see, it is not so simple. Each category has multiple charges.
On peak means the height of the day. Off peak is usually at night. Charges can go up during times of high demand (demand charge), etc. The important conclusion from this is the amount your utility officially says it is charging you is very different from the amount actually charged.
The simplest way to handle this is to take a typical billing cycle, and take the conclusions:
The number of kilowatt hours is shown as 134,550.
The total cost is $16,547.13.
The cost per kilowatt hour is $16,547.13/134,550 = $0.13 per kilowatt hour. This is the real cost in a part of the US where people may tell you that they pay only 5 cents per kilowatt hour. That may be before all the surcharges.
Here is a residential example:
Again, take the total price paid, $22.48, and divide it by the total kilowatt hours (kwh) and you get $22.48/63 = $0.36 per kilowatt hour. This is in one of the highest cost areas of the US. Note that relative costs for small users have a higher cost per kilowatt hour because of the cost of the basic service fee.
Without that fee, the cost is ($22.48-$10.44)/63 = $0.19, still very high.
In calculating the value to you of a renewable energy system, you need to consider the case where the grid offers a feed-in tariff—that is, the utility pays you a fixed price for the electricity your system produces over a long period of time, such as 20 years. Sometimes these are high.
Some utilities have net metering—what you send them cancels out what they send you.
One scheme that is currently in use in Florida, for example, is not to the advantage of the producer. The utility pays you the cost of the energy as they buy it. The utility may be able to buy coal or nuclear power for 3 cents a kilowatt hour, even if they sell it to you at double or triple the cost to them, so they offer you the cost to them.
In general, the conclusion is that you will often be best off producing your own electricity. The choice of wind or solar then comes to the resource in your home or building. An advantage of using wind and solar together is that they enable you to produce electricity at more times of the day and avoid storage and peak use costs.
You can play with your available space and the power available from the different turbines. The bigger and larger the turbines, the more cost effective, in general. One has to take installation costs into account.
Here is a table about the way to locate the different sizes, in general:
|Large (6 meters high)||Land or very strong roof|
|Medium (4.5 meters high)||Land or strong roof|
|Small (2.7 meters high)||Land or regular roof|
|Mini (1 meter high)||Personal size for a garden, a camping trip, a boat|
What size generator do you pick for the large and medium models? In general, you will get the best returns as follows:
|Wind Speed in meters per second||Generator capacity in kilowatts|
Determine the place where you want to put your turbine. An area of higher wind is almost always the best choice.
If it is on a flat area, ground or roof, you should have exact measurements of the location and the direction of where most of the wind comes from. You will ideally place your group of turbines so that they are side by side perpendicular to the direction of the wind.
To get the cluster effect, they should be at a distance from shaft to shaft of 1.2 times the turbine diameter. The spec sheet shows the turbine diameter and ideal spacing.
If you are purchasing only one turbine, it doesn’t matter, since this turbine reacts to wind from any direction.
Another consideration is to locate them close to the point of use or a point of electrical connection to the grid. This reduces expenses, usually not much, of electrical cabling.
Here is an example: You are putting the turbines on the ground and decided to use the largest size, since the larger the size, the more cost-effective, and placing them on the ground works for you.
The spec sheet gives the turbine diameter as 2425 mm.
The distance for ideal cluster effect is 0.1 times 2425 mm to give the space between the turbine blades when as close to each other as possible. That means each turbine’s total space is 1.1 times 2425 = 2667.5 mm. That means that a space that one could fit a row of 10 turbines in 10*2667.5 = 26,6750 mm = 26.675 meters = 87.5 feet. You should also allow more space in front and back so you have a little room to maneuver if you area is limited. Allow at least half a meter in all directions around your wind farm.
This row of turbines is ideally set perpendicular to the direction of prevailing wind direction. That is why wind information is important in setting up your wind farm. The cluster effect will still work at an angle of 45 to 135 degrees from the prevailing wind direction.
If you have wind of 6 meters per second or more and enough room, it is worthwhile to set up a second row of turbines after the first. Each turbine in the second row will produce as much energy as a single turbine all by itself because the cluster effect works in the second row also.
If you have two turbines in the front row, the third turbine in the second row should be places at the same distance from each turbine at 45 degrees from each turbine in the first row. The distance between each turbine is 0.1 times 2425 = 242.5 mm.
Here is how it would look:
On a slanted roof, you should generally have only one row, and on the very top. It is best if the angle of the roof is in line with prevailing wind.
Don’t forget to put up a fence for safety. And then get your permit.
The most important thing you can do first is measure your wind with one of many reasonably priced and commercially available kits, often called weather stations.
If the average wind speed is 6 meters per second or above, you almost always have a great return on investment. 5 meters per second usually means a good return on investment. Gusty wind is better than lower but steady wind.
Look at some free online resources to get a feeling as to whether or not you are in a high wind area. There is a caution that comes with all these resources. Wind can be very specific to a specific location and height. Many of these resources don’t tell you exactly where they were measured and at what height. They are useful as a starting approximation.
International information: Weather Underground: https://www.wunderground.com/
Enter your location, then click on Others, and scroll down to the bottom of the page for the wind graph.
International information: Meteoblue: https://www.meteoblue.com To take full advantage of this site, click on the left side bar where it says Archive Climate and then under it Weather Archive. It takes you to a page where you can get wind speed measurements or projections over the course of a year.
US Department of Energy: https://windexchange.energy.gov/
This site has useful information in general and has links to wind maps of each state. Many countries have their own meteorological services and provide data to the public.
You can take that approximation and generalize by asking yourself questions: Are those websites generally accurate about what I feel the wind is? Is my location open on all sides so the wind can come through easily? Is my location in a geographical wind tunnel that accelerates the wind and makes it higher than the norm in my area?
Ultimately, the best solution is to invest a small amount of money and get data from a weather station. Look for one that produces a spreadsheet so that the data can be analyzed. The more often the weather station can take readings, such as every 10 seconds instead of every minute, the better. We do not make these weather stations. We simply recommend any of the reputable models that are in the price range of $100- 200 each. If you are building a wind farm involving megawatts, then you should approach one of the commercial testing services.
The standard is white. You can pay extra for the color options you want. You can specify another solid color from our list of standard colors on the inside, the outside, or both inside and outside for 250 dollars or Euros. Other colors and special designs require a custom quotation.
See the page www.flowerturbines.com/customers
You need a local installer. Our current default is to ship the turbine ready to install in a single or double assembly. The main job of your installer is to prepare the installation base, and the civil engineer to tell the installer how strong to make it. After physical installation, an electrician should make the electrical installation.
See the page www.flowerturbines.com/customers . Here is a summary of some important points. In most cases, you will connect your turbine directly to the utility grid, in which case you will receive an inverter. If you want to go off-grid and supply all your energy from wind or wind plus solar, you will need a battery system (not supplied), an off grid inverter, and a charge controller to connect the turbine to the batteries. If you already have a solar system with batteries, we need to give you a charge controller that fits your current battery voltage; email us the information when you purchase. If you want such as system and have not purchased it yet, we recommend batteries with minimum voltage setup of 48 volts. If you want to connect wind and solar panels to a new system with our turbines, let us know and we will supply you with a hybrid charge controller.
In general, it is best to email us when you order and reference the order number. Information that will help us help you includes:
- Your location and how windy it is
- Your choice of on-grid or off-grid
- Whether you have or intend to get solar also, and if you do, what electronics you currently have, and what is the voltage of your batteries, if any
- Configuration of the planned location for the turbines with a simple map. Flat roof or slanted? Area available on the ground?
We offer 4 sizes. Most people ordering online will want the “residential” size, around 2.7 meters high and 1 meter in diameter, which is made for lighter roofs, or for the ground. In general, for strong roofs or the ground, we recommend the larger sizes for greater efficiency. For corporate sales of wind farms of more than 5, contact us by email.
We are allowing pre-ordering of turbines in order for you to reserve one you like and be the first in your area to have one.
The first served are those that buy a turbine outright.
The second served are those that reserve a turbine with a deposit. We will alert you when it is the time to top off your payment.
Pre-ordering and reservations are only for those turbines you reserve, not additional ones. As a reminder, you will get much more energy and cost-effectiveness from more than one at a time when grouped together in a cluster.
We try to solve all the issues of small wind turbines that could prevent them from being used in a tight environment, near people, and near and on buildings. As a starter, they must be quiet and pleasing to the eye.
This table shows some basic characteristics:
|Horizontal axis||30%+||High||Dangerous||3 meters per second|
|Vertical axis lift||15-25%||High||Dangerous||3 meters per second|
|Vertical axis helix||5-10%||Medium||Dangerous||5 meters per second|
|Vertical axis drag||7-10%||Low||Safe||2-3 meters per second|
|Flower Turbines||35% alone*||Low||Safe||1.2 meters per second|
*when including the cluster effect, the performance increases so that our turbines perform 20-50% better; technically, that is not “efficiency”
This is a common question. Let’s answer it in a few ways:
1. Do you mean that you want to take your house off the grid and that will be your only source of power?
If so, you need to have extra capacity from the turbines and the batteries to make sure you are covered during times of no wind.
To do this you need to calculate or estimate:
a. How many kilowatt hours do you use each day? You can usually estimate this from finding the number of kilowatt hours used on your utility bill and dividing that number by the number of days on a bill. Make sure you do this for the most energy intensive time of the year as a safety margin. Then take this figure, multiply it by 365, and you have the amount of kilowatt hours you need to prepare for in the course of the year. This is a slight overestimate because you are multiplying the time of most intense use by 365.
b. Determine your average wind speed.
c. Look at the Excel sheet we provide on the web site that shows the number of kilowatt hours per year for each type of turbine. Pick the size of turbine appropriate for you, whether you can cluster them, etc., and see how many kilowatt hours per year you can expect from each. Then get enough turbines to provide a wide safety margin of a few thousand kilowatt-hours.
d. Prepare for the possibility that you may have to depend on battery power for a few days of no wind. Use the figure you obtained above for the most intense use of energy and multiply it by the number of days your area could go without much wind. For example, if you use 5 kilowatt hours per day and you want to have the safety of 5 days backup, then you should pick a battery system that has 25 kilowatt-hours storage as a minimum. Take into account that battery capacities can be affected by multiple cycles, so always overbuy!
In that case, your system consists of the turbine or turbines, a charge controller for each turbine, a battery pack, and an off grid inverter.
2. Do you mean that you want to be carbon neutral?
In that case, you want to send your electricity to the grid when you produce and buy it from the grid when you don’t produce, and you don’t need a set of batteries in your system. In that case, take your electric bills and determine the number of kilowatt hours you use each year, and make a general match with the spreadsheet of kilowatt-hours per year for each turbine.
In that case, we may occasionally recommend a charge controller with a small battery system along with an on-grid inverter. The reason might be to enable picking up power from low wind speeds.
3. Do you really mean that you just want a good investment?
Very often, building owners, such as an owner of a tall office building, will ask whether they can power the whole building from it. The answer is almost always no. The point is that, if you are in a windy area, it will almost certainly be profitable in itself. For a building owner, it has additional benefits such as greater energy security, more points on LEEDS certification, and image. In these cases, the recommendation is that you be realistic that you may not be able to run your building from the electricity produced, but that you can reduce your electric bill profitably, and the cumulative effect on the climate of many people doing this is significant.
Another question that is often asked: Why should we get these small turbines when offshore turbines are producing electricity so cheaply?
The answer is that you would be surprised at the markup. Offshore wind can now be produced for a few cents per kilowatt hour, but, by the time it reaches your home or office, it is usually 10-20 cents. Our turbines are highly competitive against that real consumer price. In addition, beware that, if you search for an answer on what a utility charges per kilowatt hour, you didn’t get the full story. There are many taxes and fees above that.