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Questions and Answers - Wind

Q. How much power can I get from a wind turbine?

A. The amount of power you can get out of a turbine is directly related to the cubic of the wind velocity. This means that the power increases exponentially with wind speed. The only way to know how much power you can get is to know how much wind you have.

To prepare a cost analysis we need to know the monthly average wind speed for each month of the year on your site and, ideally, at the same height of the turbine. Since the wind speeds can be radically different a few hundred feet apart, it is not a good idea to use the data from a weather station or airport several kilometers away.

You want your turbine located at least 30 feet above the tallest obstruction within 100 feet. This is to minimize turbulence in the wind and maximize the power from the turbine. Since the power will increase exponentially with wind speed, and the wind speed is faster the higher you go, we recommend mounting the wind turbine as high as possible to get the most power.


Q. How do I determine the wind speed on my site?

A. Ideally you would use an anemometer (wind meter) that can record both wind speed and wind direction. The meter would connect to a data logger that can record the information to be downloaded to a computer and then determine the average values. We have a professional wind meter with data logger that retails for about $1200. Most people choose to go with a less expensive home weather station. You can pick one of these up at your local department store for about $200-$500. You will want to get one that can track wind speed and, ideally, wind direction. You can mount the weather station on your roof and keep track of the data; they will usually have average daily or weekly values that you will need to record to determine the average monthly values that we need. Since the weather station is mounted on your roof instead of a tower 30 feet above, this method will give you a lower estimate of the wind potential for your site.


Q. How much does a wind system cost?

A. We have wind turbines that range in size from 90 - 10,000 watts, and range in price from $800 - $37,000. With these turbines you need towers, which vary in size and price as much as the turbines. Some turbines can connect directly to the utility (Grid-tie), most are designed to charge batteries. If you go with a battery system you will need batteries and an inverter to convert the DC power from the batteries to AC power for use in your home. Basically, asking how much a wind system costs is like asking how much a car costs - it depends on many factors and can vary widely.


Questions and Answers - Microhydro

Q. How much power can I get from a Microhydro turbine?

A. The amount of power you get from a turbine depends on your water resource. You will need to know the vertical distance from the highest point to the lowest point of your water resource (vertical head) and you will need to know your usable flow rate.

Potential Power = Head(ft.) x Flow rate(gpm)
8 (conversion factor)

This equation will give you a basic idea of how much power you can get. This is an upper value and you will actually get less than this in practice.

To determine your vertical head and flow rate, please view the Microhydro Survey. Sheet.

The main type of turbine we sell requires a minimum head of 10ft. and a minimum flow rate of 20gpm. We have a low head turbine that operates between 2-10ft of head and requires a minimum flow rate of 500gpm.


Q. How much does a Microhydro system cost?

A. A basic microhydro system starts at about $5000 once you add up all the components. .

With a proper water resource, microhydro can be the most power for the least amount of capital cost.


Questions and Answers - Solar

Q. How much power can I get from a Solar system?

A. The amount of power you can get from a solar system depends on the size and number of solar panels you install. In Canada, you will typically get three times more power in the summer than in the winter.


Q. How many solar panels do I need?

A. To determine how many solar panels you need and the size of the inverter you will need to convert DC power from your batteries to AC power for your home, you will need to put together an Energy Budget.

To put together an energy budget you will need to have a list of all of your household appliances, the amount of power that each one consumes, and the number of hours in a week that you expect to use them. For sizing the inverter, it is helpful to know which appliances you would want to have running all at the same time in the worse case scenario. This information will help us to determine which components will meet you needs.


Q. How can I get the most power out of my solar panels?

A. Solar panels should be mounted on an angle equal to your latitude and facing true south (north if you live below the equator).

This angle can be further adjusted for seasonal performance. In the winter you can tilt the panels forward by 15°. In the summer you can tilt the panels back by 15°.

Shading is the real problem with solar panels. You want your panels located in a place that will receive no shading for the entire day over the entire year, ideally. If you cannot find a place without shading, there is a type of solar panel called an Amorphous panel. These panels are slightly more expensive and slightly less efficient, but handle shading much better. Even so, it is still best to avoid shading as much as possible.


Questions and Answers - Grid Intertie

Q. What does grid intertie mean?

A. A grid intertie system is one that feeds electricity back into the utility power grid. There are two main types of systems, with or without battery backup. With a battery backup system you will have power when the utility goes down and you can have a smaller system with fewer solar panels. With a direct grid-tie system your power goes out just like everyone else and you need a minimum of seven solar panels. Batteries can be expensive, are hazardous goods, and are difficult to ship. A grid-tie system connects to the utility through your electricity usage meter. Depending on your local utility regulations, this will happen one of two ways: 1) Your system will tie into your existing meter and cause the meter to run slower or backwards - this is called net-metering. 2) You will need to have a new meter installed that has two digital displays. One display records the power used, the other the power produced - the difference is what you are charged on your power bill.

Download detailed information about Grid-tie in Canada


Q. How much does a grid intertie system cost?

A. A basic solar grid-tie system will cost about $15,000 for the equipment. You can also have a grid intertie system with microhydro or wind if you have a battery backup system. A few of the larger wind turbines even allow for direct grid-tie systems. A special grid-tie inverter only costs about $200 more than a similar pure sine wave inverter. Depending on your local regulations, the required meter and safety equipment can cost between $500 and $2000.


Q. How much power can I get from a grid intertie system?

A. It depends on your charging source. Virtually unlimited, only by your pocketbook.


Questions and Answers - Battery Backup Systems

Q. What is a battery backup system?

A. This system may, or may not, have an alternative charging source. They are generally designed to run a few emergency loads in case of a power failure and will not run all appliances in a home. They usually connect to the power utility as a charging source, but also work very well with a generator.

When the utility power goes out, the system will automatically take over and begin powering essential loads from the batteries. The loads are connected to an emergency breaker panel.

When the utility comes online, the system will automatically switch back to regular power and begin charging the batteries back to full.


Q. How can a battery backup system greatly improve my generator backup?

A. A generator will give you close to full power as soon as it is started up. If you are only using the power to run a few lights or a radio, you will be wasting a lot of energy and a lot of fuel.

With a battery backup and inverter, the system will provide you with the power you're using and no more. When the batteries get low, you can charge them with the generator. The batteries will take all of the power that the generator can create. When the batteries are fully charged, you can turn off the generator. No waste of fuel, lower operating costs, lower maintenance costs, less noise, and a much more efficient system.


Q. Can I use a battery backup system to lower the cost of my power bill?

A. A backup can be designed to only come on when the power is out, or it can be programmed to run loads until the batteries are at a certain level (such as 60% capacity) and then go into charging. Unless you have time of day power savings, this might not be a good idea. Due to conversion efficiency losses, it takes more power to charge a battery than what is actually stored. With time of day savings, you can run the batteries in the day and charge them at night, possibly realizing a savings. The other option is to add a charging source such as solar, wind, or microhydro.


Questions and Answers - Misc.

Q. What kind of appliances can I operate on an Alternative Energy system?

A. Since most of our systems use batteries as the main power source; the batteries limit the amount of electricity you can consume. It is not practical to run loads that consume more than 1000W of power on a continuous basis. For example: water heater, stove, baseboard heater, clothes dryer (or any large resistive heat sources), air conditioner, older model fridges and deep freezes, etc. The system will often run these loads fine, but the loads will drain the batteries faster than they can be recharged. A microwave will typically use more than 1000W, but will only run for a few minutes a day and will work fine. Likewise, newer Energuide rated, high efficiency refrigerators will work fine on these systems. Generally, we recommend going with propane, natural gas, or biomass to provide heating sources. For large loads with occasional use, a generator will usually work well to augment the system. With solar systems, we usually recommend going with a backup generator for the wintertime when there is less sun available.


Q. What is the difference between Modified Sine Wave and Pure Sine Wave power?

A. An inverter is an integral part of any battery-based system. It transforms the direct current (DC) electricity in the batteries into alternating current (AC) for powering your home appliances. AC power alternates between positive and negative voltage peaks and forms a wave pattern. When this wave has smooth curves, it is called pure sine - this is what you get from the power utility. A less expensive way to produce power is to approximate the smooth curve with many rectangles. The more rectangles, or steps, that are used the smoother, or cleaner, the wave output becomes - this is called a modified, or square waveform. Modified sine wave power will operate 95% of all loads exactly the same as pure sine wave power. Some loads won't work at all, but usually the load just doesn't work as expected. Digital clocks for instance use the peaks of the alternating current to keep time, a modified sine wave will confuse the location of the peak and cause the clock to lose or gain time unpredictably. Some televisions will display interference lines; some power tool battery chargers will overheat and should always be monitored. Often the same appliance by a different manufacturer will be effected differently or not at all. For the most part, appliances are not designed with the intention of using modified sine power and so the results, if any, are often unpredictable.


Q. What is the payback period for a system?

A. The only way to put this question into perspective is to ask another question:

• What's the payback period on your car?

Your car will dramatically reduce in value the minute you drive out of the dealership, will not last as long as one of these power systems, and will often cost more. I guarantee that all of our systems are better value than your car.

• How much is our environment worth?

Every one of our systems will reduce your impact on the environment. Since we cannot live without the environment, it is absolutely priceless. Which means that all of our systems are priceless and beyond value or payback periods.

Wind

Q. How much power can I get from a wind turbine?

Q. How do I determine the wind speed on my site?

Q. How much does a wind system cost?

Microhydro

Q. How much power can I get from a Microhydro turbine?

Q. How much does a Microhydro system cost?

Solar

Q. How much power can I get from a Solar system?

Q. How many solar panels do I need?

Q. How can I get the most power out of my solar panels?

Solar Grid-intertie

Q. What does grid intertie mean?

Q. How much does a grid intertie system cost?

Q. How much power can I get from a grid intertie system?

Battery Backup

Q. What is a battery backup system?

Q. How can a battery backup system greatly improve my generator backup?

Q. Can I use a battery backup system to lower the cost of my power bill?

Miscellaneous Questions

Q. What kind of appliances can I operate on an Alternative Energy system?

Q. What is the difference between Modified Sine Wave and Pure Sine Wave power?

Q. What is the payback period for a system?


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