Hybrid Technology: Save Power Generation Cost

Donauer Al Badi Gulf is a joint venture between Germany’s Donauer and NAS International. Their latest technology is based on a hubrid solution for power generation. A state of art solution including solar based panels is developed for commercial use in Middle Eastern countries.

Due to shortage of electricity during summers, the dependency on diesel generators increases. The latest technology is a combination of disel generators and solar designs to produce electricity from the combination of the two processes. This way a saving of 30-40% generation cost will be seen. The solar process which is cheaper to produce electricity will produce electricity first. An artificial intelligence sensor will detect the deficit and automatically that demand will be fulfilled by the diesel generator.

Remote areas which are not connected to the power grid and which rely on diesel generators can also be benefitted from this technology. Also, such projects, if developed on a larger scale can produce employment for many in the villages. Compared to almost 5 years taken by diesel generator setup, solar projects can be completed in less than a year. Such innovative ideas help save the natural fuel of the nature which are presently used to generate electricity.

Development in Wave Energy Technology

The marine energy industry has been in a state of technological developments recently. Innovations to improve the existing technology we already have are growing by giant strides. The efforts of many companies are being rewarded by various Government organizations which provide financial aid to boost research so that the industry keeps developing forward.

The most recent announcement was made by the Scottish Government which said that a funding of 7.9 million pounds would be given to boost the developments of five marine energy developers. The marine energy market is developing rapidly and keeping that in mind The WATERS program (Water & Tidal Research Development and Demonstration Support) has been released. The Scottish energy market has a potential to benefit their economy by an amount of 4 billion pounds with wave technology. 

Here are some new technologies developed by big brand names in the field of marine energy development.

Albatern: WaveNET technology

Based on the technology of modules and associated nodes, this project has been granted 617,000 pounds under the WATERS2 scheme. With adevelopment and testing phase in the period of late 2012 to late 2013, this project is capable of becoming a 10MW energy proposition.

AWS Ocean Energy: AWS-III Wave Energy Converter (WEC)

Awarded with a grant of 3.9 million pounds, this project has a rated power output of 2.5MW. A full prototype plan is planned in 2014. The technology involved is a multi cell array of flexible membranes.

Nautricity:CoRMaT technology

Aimed to reduce the complexity of operations, the CoRMaT can deliver the tidal power without needing big and heavy supporting structures.

Oceanflow Energy: Oceanflow’s ‘Evopod’ tidal technology

The company’s strategy is to build an operating experience with its 35 kW mono turbine and 70 kW twin turbine Evopod units. The technology involves a semi submerged floating body that is tethered to the seabed by a multi-line spread mooring system.

Scotrenewables Tidal Power: SRTT

This technology features two contra rotating rotors that excite that extract the kinetic energy of the tidal flow, which is converted to electricity though a power take-off system.Company’s WATERS project will involve the design, construction and installation at EMEC of a commercial demonstrator SRTT rated up to 2 MW.

Future Growth

The UK has become a world leader in development of marine energy projects. The UK will be home to the first multi MW commercial array project. Tidal energy has been given due acknowledgment and is considered as a significant contributor the energy demand.Tidal power plays an important role in reducing the dependability on other sources like imported fuels.

Understanding Permanent Magnet Alternator

The output voltage of a permanent magnet alternator depends on the shaft rpm and the load. The higher the rpm, the higher is the voltage. The higher the load for a given rpm, the lower is the voltage.

Current & RPM when connected to load

The current (“amperage”) of a dc generator at any rpm is not governed by its rpm but only by the load put on it. This means that if you run a generator with no load, the current stays at zero no matter how high the rpm is. Only the Generator terminal voltage goes up, but no matter how high the voltage is, if there is no load, there is no current flow.

Frequency

Frequency is related to the rpm and the number of poles the generator has. The more the number of poles, the higher is the frequency at a given rpm.

Wind Permanent Magnet Generators: Battery Charging Application

The market for small wind turbines is providing added electrification needed in remote areas. Many parts of the world are still running on electricity from batteries rather than electrical grids laid by national power corporations.  Telecom companies who have to provide uninterrupted signals in remote areas rely on batteries and generators to get electricity. Another area that uses battery back up is Marine operations.  Off grid wind turbines are proving to be more and more valuble in these situations.

Wind speed is not always constant and it is usually highest during the night hours when people are not using much electricity. Storage of this night-time electricity can charge the battery and become an important method to utilize this electricity that could be lost.

Installing a small wind permanentmagnet generator at remote sites can provide battery charging at a much lower cost than diesel generation or charging stations. Since there are no recurring costs with wind energy, the payback period of the initial setup cost is minimal. 

 In marine environments where the sources of electricity are scarce, batteries are the only viable option and due to high wind speed at sea, these wind turbine battery charging options become a very profitable and convenient source. The overall cost of electricity is reduced. Also with battery usage the overall capacity of the site is doubled. The wind turbine produces the electricity and the battery stores the the extra electricity.

The initial setup is simple. The connection diagram is shown below.

Since the generator is a permanent magnet one, the efficiency obtained in converting mechanical energy to electrical energy is maximum. It is more than 90%, which means more than 90% of the applied mechanical force by the wind is converted into electricity. Compared to 70% provided by traditional generators the amount of wastage is minimal. With such high efficiencies in permanent magnetgenerators, the fuel savings are more, the batteries last longer and overall cost of using electricity is decreased.

Linear Permanent Magnet Generator

Wave energy and tidal power have always been an area of interest in many nations since there is an immense potential  in these energy sources. But, the problem of energy conversion has always been a daunting issue. The traditional energy conversion devices use rotary generators which are high speed  and convert the mechanical force to electricity.

To combat these adversities, growing interest has begun in linear permanent magnet generator for energy conversion. The motion of the rotor in a linear generator is unlike the traditional rotary generator. The  main difference between the two is the motion is going straight up and down  in a linear generator. Because of this linear feature it is possible to couple the motion of the rotor to the reciprocating vertical motion of the ocean waves. By coupling, we can eliminate the use of gearboxes and power take off schemes.  A linear alternator is most commonly used to convert reciprocating (i.e. back-and-forth) motion directly into electrical energy. Because of this ability, this type of permanent magnet alternator is suitable for tidal action and production of electricity from that motion.

Still many considerations are to be taken into account to get the desired efficiency. If the rotor speed is low then i.e. if the frequency is low then a larger construction is required which increases the overall cost. Hence newer designs are required which increases the efficiency along with smaller designs. The linear permanent magnet can be designed in a tubular form as well as a flat structure depending upon the application. Leakage is limited in flat type generators due to symmetrical structure. 

There are several factors which are important to the output of the generator of this type:

·         Number of turns

·         Area of magnetic surface

·         Revolutions/second

·         Tesla of the magnet ( flux intensity)

·         Number of poles

Harnessing the ocean energy has been escalating  since the developments of newer technologies like the permanent magnet alternators. Due to a lack of gearboxes, the maintenance has become easy and inexpensive. The efficiency has increased which has made the overall projects profitable and attractive for people to invest in. 

10 kW Permanent Magnet Generator

10kW Design

The 10kW permanentmagnet generator finds its applications in residential houses on country sides, farming sites, small business setups etc. This has empowered owners to a great extent to reduce utility bills. Other than these, 10kW wind turbine setups are very famous in telecom sector, on or off grid residential areas, rural schools etc. Areas with no electricity grids or with unreliable grids depend on wind energy most of the time.

Very high efficiency and long lasting design have made 10kW system a favorite amongst rural   land owners and farmers. Farmers can expect a very short payback period of less than 5 years which makes their fuel cost go down.

 When designing a 10kW wind turbine, many considerations have to be kept in mind. This is not a very small setup. Issues like weight of the whole turbine, tower, braking system etc play an important role while designing. These windmills have to be made to withstand strong wind conditions since potential of generating electricity during high wind conditions are much more.  Also during strong wind conditions the design and strength of the whole setup comes into play. These winds can damage strong structures easily, hence the material of the wind blades and the tower strength have to be strong enough to withstand winds at 150 km/hr. 10 KW designs have to be robust and dependable for these wind conditions. With a yield of 40,000 -60,000 kWh, users can increase their benefits by selling back the electricity to the national grids. 

10kW Generators in Telecom

During past seven years the installation of telecom grids all over the world has increased many folds. During these competitive times, the telecom companies are expanding their networks to regions where there are no electric grids also. The small wind industry is a key player in this field. Wind turbines like 10kW turbines find a huge potential in these areas by providing uninterrupted power supply throughout the day 365 days a year.

Direct Drive 10kW

The many advantages of 10kWpermanent magnet generator especially a 10 kW are reliability, efficiency and reduction in the overall cost of producing electricity. In the direct drive method power is taken directly from the wind turbine without any reductions which was earlier provided by a gearbox.

A 10kW turbine fitted with a direct driven mechanism offers many advantages:

·         More efficient – No power wastage from belts, chains, gearbox etc

·         Drive Stiffness – Avoiding gearbox results in removal of mechanical backlash, hysteresis and elasticity

·         High torque at low speed

·         Noise reduction

·         Increased lifetime

·         The positioning is faster and accurate

Other features of a 10kW design:

Since a 10kW wind generator becomes a large unit and weight is more, the mounting arrangement like tower is made from high tensile foundations. Mechanical fail safe braking system is incorporated for to stop the turbine operations. Heat sensors, over voltage sensors etc are fitted to keep the machinery safe from any damage. At very high wind speeds which can be a danger to the setup, wind shutdown mechanisms are installed to keep the kit from getting blown away.  

Grid Tie Inverter

The Grid Tie Inverter or synchronous inverter is a special type of power inverter that converts DC electricity into alternating current. A special feature of these types of inverters is that it can feed AC into the existing electrical grid. GTIs are often used to convert DC electricity produced by renewable sources of energy like small wind turbines using permanent magnet generators into AC used to power homes and businesses.

During the period of overproduction from the permanent magnet source, power is routed back to the state grid and hence sold to the local power corporations. But these types of arrangements are possible with special type of grid networks only. These grids are specially manufactured to allow ease of distribution and back feeding.  Residential areas and businesses connected with grid-tied electrical system are permitted in many countries most popular being North America and Europe. There are different compensating ways in which different governments pay the individuals for feeding back the power like “Net metering” or “Feed-in-tariff”. 

Due to this system, the payback period of the renewable energy source like a windpermanent magnet generator decreases and hence the inflow of money is increased for the consumer. Hence using a wind permanent magnet generator is becoming a popular way of generating the power in many nations.

More on Permanent magnet generators and grid tie inverters to come……..Keep following.