Ultra low head micro hydro

In this post, we will discuss Ultra Low Head Micro Hydro, low head pico hydro turbine and low head hydro turbine manufacturers. There are hundreds of low head weirs and water mills still spread across the mid-western and eastern United States, the United Kingdom, and much of Europe. These sites were used for agro-processing and to operate small industrial shops for over a hundred years. The Nautilus low head designs are intended to match these existing sites and operate in open flumes. They will tap this age old but presently unused source of renewable energy to power homes and small businesses.

Most low head mill sites started with water wheels and changed to water turbines as more power and higher shaft speeds were required to drive modern machinery and generators. These turbines were installed with vertical power shafts to get equipment above flood levels in open flumes beneath the mill (see drawing). In cases where only the weir remains, simple open flumes can be built from poured concrete or vertical corrugated steel tubes.

low head pico hydro turbine

Ultra Low Head Micro Hydro

Open Flume Diagram
Nautilus’ Ultra Low Head Turbine Line:

Nautilus offers three Francis Turbine options to meet different flow and power requirements. These designs are supplied in both regulated and unregulated configurations and are specifically designed to be installed in open flumes with a head range from 1m (3ft) to a maximum of 3.7m (12ft), in power ranges from a few hundred watts to 3000 watts. This is 72kWh per day, which is enough energy to power two average U.S. Homes

660 Ultra Low Head Turbine

The 660 Ultra Low Head turbine (660-ULH) is a 150mm (6in) diameter Francis turbine with a bronze runner and bronze and stainless steel guide vane and gate assembly. It uses a water lubricated rubber bearing below water and heavy duty spherical roller bearings above water to support the shaft and pulley assembly. The turbine case is fitted with an adjustable cylinder gate to turn the unit off and regulate flow.

The gate control is mounted on a heavy steel plate that includes the upper bearing mount which supports the main power shaft. This assembly is bolted to the floor or framework above the flume. The shafting is supplied to the correct length to fit site specifics. In the lowest head version, where the pit can be easily drained, this cylinder gate can be eliminated to reduce cost. The power range of the 660-ULH in an open flume is from 300 watts to 1200 watts.

Key Features
  • Regulation: Cylinder Gate
  • Runner Type: Francis
  • Materials: 304 S.S., Mild Steel, Cast Iron, Bronze
  • Head Range: 4ft (1.2m) to 12ft (3.7m)
  • Flow Range: 1.1 CFS (30 l/s) to 2.1 CFS (59 l/s))
  • Power Output: 300 watts to 1.2 kW

T Ultra Low Head Turbine

The T Ultra Low Head turbine (T-ULH) is the most powerful open flume turbine built by Nautilus. This unregulated design produces from 500 watts to 3,300 watts with a head range from 1m to 3.7m. Often two or three units are installed to match streamflow variation or the T-ULH is installed in combination with the Regulated CMC. For large open flume environments, where it is not possible to drain the pit, an optional cylinder gate is installed to shut down the turbine. This is an external cylinder and it helps to clean leaves and debris from the turbine when opened and closed. Like the CMC-ULH, the T-ULH is designed with runner passageways that are larger than the guide vane openings to avoid clogging.

The Nautilus T-ULH turbine is manufactured in our shop from the same high quality materials as the entire Nautilus line of turbines. It is fitted with shafting and gate controls that are mounted above the flume and out of flood range. This is the ideal turbine to capture the power available at low head weirs and mill sites.

Key Features
  • Regulation: Cylinder Gate
  • Runner Type: Francis
  • Materials: 304 S.S., Mild Steel, Cast Iron, Bronze
  • Head Range: 3ft (1m) to 12ft (3.7m)
  • Flow Range: 2.9CFS (80l/s) to 5.2CFS (146l/s)
  • Power Output: 500 watts to 3.3 kW

CMC Ultra Low Head Turbine

The regulated CMC Ultra Low Head turbine (CMC-ULH) operates in a similar power range as the 660-ULH in an open flume and produces up to 1500 watts. The CMC offers better part gate regulation and efficiency than the other cylinder gate Nautilus models.

To avoid clogging, the gate openings are larger than the passageways in the turbine runner, so anything that gets through the gates will easily pass through the runner. In addition, the closing action of the gates packs a punch and will cut up sticks and leaves that enter the turbine.

This 200mm (8in) Francis turbine is made from Stainless Steel, Bronze and Cast Iron. The heavy duty bearing configuration matches that found in the Type 660-ULH with heavier shafting. This robust design was manufactured by 3 three different companies in the US until 1940. Over 4000 were installed in the US and around the world. This simple regulated design is perfect for open flumes.

Key Features
  • Regulation: Register Gate
  • Runner Type: Francis
  • Materials: 304 S.S., Mild Steel, Cast Iron, Bronze
  • Head Range: 4ft (1.2m) to 12ft (3.7m)
  • Flow Range: 1.2 CFS (33 l/s) to 2 CFS (57 l/s)
  • Power Output: 290 watts to 1.5 kW

Domestic Wind Turbines – The Basics

Households can now make use of wind power technology by installing micro turbines, also known as or small-wind or ‘microwind’ turbines. When the wind is strong enough it turns the blades of the turbine, generating electricity. The U.K. climate is ideal for wind harnessing technologies as 40% of the wind in Europe is experienced here, and in the right area you should be able to see substantial savings on your electricity bills.

Pole mounted domestic wind turbine
Pole mounted domestic wind turbine

There are two types of microwind turbine:

  • Building mounted: These systems are installed on your roof, and have a fairly small capacity, averaging 1-2kW
  • Pole mounted: These installations are freestanding and have a larger capacity of around 5kW-6kW

The Energy Saving Trust has calculated that in an ideal location a roof mounted micro-turbine system could reduce your electricity bills by around £350 a year. Your system could also be eligible to receive payments for the electricity you generate through the government’s Feed-In Tariff (FIT) scheme. Here’s how the scheme works:

  • You are paid a ‘Generation Tariff’ for each unit of electricity you generate, regardless of whether you use it or not, at a tariff rate that is fixed when you make an application for the scheme. The scheme then pays you starting from when you apply to the scheme, for 20 years. A pole mounted installation in an ideal location could receive £2,700 a year at current tariff values.
  • You are also paid an ‘Export Tariff’ for any generated electricity that you don’t use. The same pole mounted installation could receive £160 a year in export payments at current tariff values.
  • The electricity that you generate is free for you to use. If you use more electricity than your system is generating at any point you will be taking it automatically from the grid as you do now, which you will pay for. Overall, however, you will still save money on your electricity bill.
  • You can get a loan to cover the cost of installing your system by instead signing up to the Green Deal scheme. The loan is recovered via your energy bill, using the money you have saved on your energy bill by using the system. This means that the installation should not cost you any additional money.

Calculate your savings now!

How Domestic Wind Turbines Work

How a domestic wind turbine feeds electricity to your home and to the national grid
How a domestic wind turbine feeds electricity to your home and to the national grid
  • When the wind turns a wind turbine’s blades this movement drives the rotating shaft the blades are attached to. This shaft sits inside a generator. Inside the generator the shaft is surrounded by a magnetic field, so that when the shaft rotates it generates an electric current. In smaller turbines the blades can be attached directly to a generator with a magnetic field.
  • The electricity the turbine produces is DC electricity. This DC electricity passes through a device called an inverter, which connects the turbine and your home’s electrical system. It converts the DC electricity to AC electricity which can be used in your home.
  • The electricity the wind turbine generates can be fed directly into your home or stored in batteries. The turbines can be connected to the national grid so that you can export any surplus electricity and receive FIT payments for your electricity, or you can keep your turbine off the grid and store your surplus using batteries, though this arrangement won’t qualify for FIT payments.
  • If your turbine is connected to the grid, any surplus electricity is automatically exported to the grid, and if you use electricity from the grid this is also supplied to your system automatically.

The providers of the FIT scheme do not currently measure how many units of electricity you export, but for microwind turbine systems it is assumed to be 75% of the electricity you generate. The capacity of a microwind turbine system to generate electricity varies according to the individual system, and can be described in kilowatts (kW). This value can range from approximately 0 to 15. The average capacity of a house mounted system is 1-2kW and the average capacity of a pole mounted system is 5-6kW.

Whilst this measure is valuable, it does not fully describe the capacity of a turbine as the wind speeds at which this capacity is reached differ from turbine to turbine. This means that the Small Wind Turbine Performance and Safety Standard is also used. Contained within this standard is the BWEA Reference Annual Energy. This is the energy in kWh that the turbine will produce annually at a consistent wind speed of 5m/s at a set turbine height. A second value, the BWEA Reference Sound Levels give the noise level of the turbine from 25 and 60m away rounded up to the nearest decibel (dB).

Installing Microwind Turbines

When considering a microwind turbine installation it is essential that you accurately measure the wind speed of your specific location. The average annual wind speed required to make wind turbines worth the investment is a minimum of 5 metres per second (11 mph), which is not usually achieved in urban or suburban areas. This is because the wind speed in urbanised areas is usually reduced by by closely arranged buildings and trees. Nearby hills can also affect wind speed, as does whether you live in a valley or not.

Building mounted domestic wind turbine
Building mounted domestic wind turbine

It is strongly recommended that before you commission a microwind installation that you accurately measure your local wind speed by buying and fitting an anemometer (wind measuring instrument). You should leave this device to carry out measurements for at least three months but ideally you should leave it for a year to get a comprehensive overview of the wind levels your property is exposed to.

Domestic Wind Turbine Installation Checklist

There are a few important things to consider:

  • Building mounted or pole mounted: Building mounted systems have a lower capacity than pole mounted systems, meaning that they will generate less electricity and are cheaper to install
  • Whether you want to connect to the grid: Currently you will need to connect to the grid toreceive FIT payments. Contact your local DNO (District Network Operator) to arrange connecting your turbine to the grid
  • Whether your local area is prone to power cuts: When the power in an area fails all inverters connected to the grid are switched off, meaning that your system will stop working. You can install batteries with your turbine to provide a back-up electricity store – ask your installer for more information
  • Roof integrity: If you are intending to install a building mounted turbine it’s wise to consult your installer on whether your house is durable enough to support the turbine – they can be heavy and vibrate when in use
  • Planning permission: There are currently permitted development rights granted for domestic wind turbine systems in England, which should mean that you won’t need planning permission for your installation. However, the criteria for this are complex and there are varying needs for planning permission across the rest of the U.K. It is therefore wise to check the planning permissions for your installation with your local authority well in advance. You will have to supply a number of documents as well as paying an application fee of £150. It is a good idea to meet with a local planning officer before submitting your application so you know exactly what is required, as is consulting with any third parties such as neighbours who may be affected by your installation. Some installers will provide information and support with filling out planning applications
  • Environmental permissions: If your planned turbine is over 15m tall or you are planning to install two turbines you may be required to commission a bat or bird survey of the area
  • Your energy supplier: The larger energy companies have a legal obligation to be registered FIT suppliers but for smaller companies this is optional. Check with your energy supplier to see what they provide regarding FIT
  • Are you carrying out other building projects? You might be able to reduce the size of your installation bill by carrying out the work at the same time as any other building or landscaping work you are planning

Installation Time

The time your system will take to install will vary with your specific circumstances, particularly if you decide to carry out the installation at the same time as other building work.

Domestic Wind Turbine Installers

If you intend to apply to the FIT payments scheme you will need to ensure that your installation is carried out by an MCS accredited installer using parts that meet MCS standards. When your installer signs off your installation as being MCS compliant they will give you an MCS certificate that you will need when applying for the scheme. If you are financing your installation through the Green Deal you will need to instead use an authorised Green Deal installer.

Domestic Wind Turbine Costs

A standard 1kW building mounted turbine installation costs around £2000, with a 2.5kW turbine costing around £15,000 and a 6kW around £23,000 including installation costs.

Pole mounted domestic wind turbine
Pole mounted domestic wind turbine

Typically larger systems cost more to install but can generate more electricity, delivering you bigger energy savings and larger tariff payments. An average system working in a 5 m/s wind speed location can save you around £350 on your electricity bill and pay you £160 in Export Tariff payments and £2,700 in Generation Tariff payments every year. You will be paid these tariffs from the date you register for FIT payments for 20 years.https://googleads.g.doubleclick.net/pagead/ads?guci=!2&btvi=1&fsb=1&xpc=ZReE55zIJo&p=https%3A//www.diydoctor.org.uk&dtd=14797

The system will run for at least 20 years, and as the tariff value is set at the start of payments and index linked it is likely that the system will pay for itself in 7 years or less. After this point you will be receiving savings on your electricity bills and payments for around 13 years. For more information on the FIT scheme you can visit our Feed-In Tariff (FIT) page.

If you cannot afford to pay for the installation yourself the Green Deal scheme provides long term finance to cover all or part of your costs. These costs are recovered through your electricity bills using the savings you have made by using the turbine. Because the payment value should not exceed your saving this should mean that the installation doesn’t cost you additional money over what you would usually spend on your electricity bill. The scheme does include 7% interest in the payments however, so you will make more of a saving overall if you can afford to pay for the installation upfront. To find out more about the Green Deal, visit our Green Deal page.

In terms of maintenance, your installer will be able to give you specific guidance on any maintenance checks that need to be carried out. Usually it is recommended that you get your system professionally checked yearly at a cost of £100-£200. The turbine system comes with a lifetime warranty but the inverter may need replacing during that time at a cost of £1,000-£2,000 for larger systems. Any batteries used with the system will usually have to be replaced every 6-10 years.Find an MCS accredited local installer

low head hydro turbine manufacturers

The Benefits of Domestic Wind Turbines

An average household installing a well-sited domestic wind turbine system could benefit by over £3,200 a year. This includes the money you could save on your electricity bill as well as the Generation Tariff and Export Tariff payments you could receive from the FIT scheme. Our Feed-In Tariff scheme page contains more information on this new initiative. Domestic wind turbines deliver additional benefits:

  • Reduce your carbon footprint: A 6kW pole-mounted wind turbine system can save around 5.2 tonnes of CO2 a year.
  • Pays for itself quickly: Larger systems have a payback time of around 7 years at current tariff rates, meaning that your system’s payback time could be similar or less.

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