Generator Blog

Every week, consumers take their portable generators to local stores hoping for good news.

They swear they’ve been performing the recommended monthly maintenance on the machines so loud, but so valued when the power goes out following a storm. But the tell-tale thick brown sludge in the generator’s carburetor gives them away.

It’s OK, say local generator store owners. There’s no need to lie — especially now that we’re in the height of the hurricane season.

The important thing, they add, is to bring in that unused generator to be serviced before a storm is on the way. For example, stores saw a flurry of business last month when the first tropical storms of the season popped up in the Atlantic.

And now, with Erika looming, they can expect a little more.

For fees typically ranging from $65 to $125 — depending on the amount of work to be done — local generator “specialists” say they can get that neglected piece of equipment back on track.

“I get a couple of generators a week that come in for maintenance,” says Justin Suggs, general manager at Stuart Lawn & Garden. “They won’t start. People have left gas in them, or they are not doing the monthly run on the engine.”

His standard generator maintenance advice: Once a month, put a half gallon of gas in your generator and run it for at least a half-hour. A month later, do the same thing.

Even a generator that’s out of gas still has vapors that create a blockage in the carburetor, says Suggs, whose also owns and operates Suggs Lawn Equipment in Royal Palm Beach.

There are easily hundreds of portable generators idled in garages and storage sheds that haven’t seen the light of day since Wilma left town four years ago. What’s more, the current recession has moved generator maintenance to the back-burner for many owners.

Still, in one week last month, customers dropped off five generators to be brought up to snuff at Blast Off Equipment Inc. in West Palm Beach, co-owner Felix Finnegan Jr. says.

He said that’s a sign that despite the recession, the storm season is making folks recognize the need for maintenance.

“People have … left gas in them and gummed up their carburetors,” Finnegan says, which can lead to a generator mechanic having to remove the fuel completely and dry out the system with an air compressor.

One area of generator sales that has jumped during the recession is “whole house” or stand-by generators.
Jon Andio, co-owner of 1 Stop Generator Shop in Palm Beach Gardens, said since people can’t sell their homes, they figure they might as well install a generator.

He says while the store sells portable generators, sales of stand-by units — which start at $8,000 — are up 65-70 percent over 2008 and make up the bulk of his business.

But, he warns that the stand-by generators, which operate automatically and start instantly in the case of a power outage, also require maintenance.

“The big ones are car engines,” he says, “And just like a car mechanic tells you to change your oil, you should change the generator’s oil every six months.”

Power station
Generator neglect is common, say mechanics. But there are some basic maintenance tips to avoid a bill that could easily top $100.

Always empty fuel from a generator when it is not in use.

Put in a half-gallon of fresh gas and run it once a month.

Plug in a lamp, drill, or a small appliance to make sure the generator works.

If it has an electric start, keep the battery charged.

Cover it when not in use to keep out dirt and dust.

Running the basics
Generator size: 5,000 watts
Price: $1,000 (average)
What it will run:

Refrigerator (1,200 watts)

Electric fry pan (1,500 watts)

Microwave (1,000 watts)

Three lamps (180 watts)

Computer and monitor (1,000 watts)

Television (300 watts)

Neglect vs. proper care
Cost of generator: $1,000
Cost of proper do-it-yourself maintenance: a half gallon of gas ($1.50) for 12 months = $18
Cost of neglect: A dead generator that takes $65-$125 in service. And if it requires parts …

New carburetor: $100 (plus labor)

New battery: $60.

New oil and air filters: $50.

A renewable energy company plans to test a new underwater generator just off the Pembrokeshire coast.

Cardiff-based Tidal Energy Ltd has planning permission for onshore works and is now seeking consent to place its DeltaStream device on the seabed.

A year-long trial is due to be held at Ramsey Sound, near St Davids.

The company said its tidal generator, capable of producing enough electricity to light around 1,000 homes, was at the cutting edge of green technology.

Invented by Pembrokeshire engineer Richard Ayre, each unit features three generators that sit on a triangular frame.

It is designed to be easily lowered onto and recovered from the seabed using a floating crane.

The company said its distinctive blade design enabled the turbine automatically to shed excess power, permitting consistently high energy conversion.

Planning approval has been granted by Pembrokeshire Coast National Park Authority for the onshore works.

The company has now applied to both the UK and Welsh assembly governments for consent for the offshore works which include laying a cable and positioning one DeltaStream device on the seabed.

Chris Williams, development director of tidal energy, said a “comprehensive” environmental impact assessment had been undertaken.

A public exhibition of the plans is due to be held later this month.

The company is hoping to start the trial in autumn next year.

Mr Williams said: “The next public exhibition is to update the local community on the project, and particularly to discuss and explain the findings of the environmental assessments.

“Areas that have been assessed are far-reaching, ranging from bird life, to mammals, tourism and ecology.

“We invite anyone with an interest in the project to come along and talk with us about the details of the proposed 12-month test.”

The exhibition will be held from 1400 to 1700 GMT on Friday, 20 November and 1000 to 1300 GMT on Saturday, 21 November at Curtis House on Bryn Road in St Davids.

Siemens Energy has received an order from the Russian company OOO RN-Tuapsinskiy NPZ, a fully owned subsidiary of OAO Rosneft, for the supply of six industrial gas turbine generators. The SGT-800 gas turbine-generators each rated at 47 megawatts will be operated in the Tuapse refinery located on the Black Sea. The first three gas turbines are scheduled for delivery by late 2010, with the remaining three units to follow by the end of 2012. The order is valued at approximately EUR 90 million.

The order encompasses six gas turbines and six generators that are needed for the generation of electricity and steam to accommodate expansion of the Tuapse refinery’s capacity. Tuapse is an important petroleum port on the Black Sea. The customer OOO RN-Tuapsinskiy NPZ is currently undertaking extensive expansion and upgrading projects at the refinery to increase the plant’s capacity from a current 5 million to about 12 million metric tons (38 million to 88 million barrels). At the same time refining depth will be increased from 56 to 95 percent.

The SGT-800 stands out with its first-class efficiency, high availability and reliability, and low life cycle costs. NOX emissions are minimized thanks to its Dry Low Emissions (DLE) combustion system. A critical project requirement for the gas turbines being supplied to the Tuapse refinery is their capability to operate on various fuels. The SGT-800’s DLE system is unique in that it can achieve low emissions on a wide variety of fuels.

Including this order, 29 SGT-800 gas turbines have already been ordered by customers from Russia or have been delivered to Russia. For instance, between 2007 and 2008 Siemens received orders from Rosneft for a total of seven SGT-800’ machines for the gas turbine power plant at the Priobskoye oil field.

In June 2009, the Kolomenskoe gas turbine power plant in Moscow, supplied by Siemens with three SGT-800 machines, was able to start commercial operation. The cogeneration power plant supplies the Russian capital with 136 megawatts of electricity as well as 171 Gcal/hour of district heat. Overall plant efficiency is 83 percent.

(The SGT-800 gas turbine features high efficiency and low life-cycle costs. It is used for simple cycle power generation, for combined cycle power generation (CCPP) and because of its excellent waste heat recovery potential it is ideal for combined heat and power (CHP). The photo shows the SGT-800 gas turbine with a capacity of 47 megawatts at the Finspong plant in Sweden.)

An induction generator is a type of electrical generator that is mechanically and electrically similar to a polyphase induction motor. Induction generators produce electrical power when their shaft is rotated faster than the synchronous frequency of the equivalent induction motor. An electric voltage (electromotive force) is induced in a conducting loop (or coil) when there is a change in the number of magnetic field lines (or magnetic flux) passing through the loop. When the loop is closed by connecting the ends through an external load, the induced voltage will cause an electric current to flow through the loop and load. Thus rotational energy is converted into electrical energy.

 

Induction generators are often used in wind turbines and some micro hydro installations due to their ability to produce useful power at varying rotor speeds. Induction generators are mechanically and electrically simpler than other generator types. They are also more rugged, requiring no brushes or commutators.

 

Induction generators are not self-exciting, meaning they require an external supply to produce a rotating magnetic flux. The external supply can be supplied from the electrical grid or from the generator itself, once it starts producing power. The rotating magnetic flux from the stator induces currents in the rotor, which also produces a magnetic field. If the rotor turns slower than the rate of the rotating flux, the machine acts like an induction motor. If the rotor is turned faster, it acts like a generator, producing power at the synchronous frequency.

 

In fact, an induction generator may operate as a motor or a generator. For instance, a standard, 3 phases, AC motor may be powered from the 50 Hz grid, with the motor speed “slipping” at less than for 50 Hz synchronism. If this motor is itself forced to rotate at more than for 50Hz synchronism by a rotating power source, (e.g. a diesel engine or wind turbine), while connected to the grid, it delivers current to the grid as a generator. The current flow is proportional to the slip, i.e. the small difference, 3%, between synchronised rpm and the actual rpm. This slip is too small to notice as a speed change of a wind turbine rotor, so induction generators are classed, somewhat erroneously, as fixed-speed generators. This type of generator is very simple, rugged, and relatively cheap. Usually it is “excited” into operation.

 

In induction generators the magnetizing flux is established by a capacitor bank connected to the machine in case of stand alone system and in case of grid connection it draws magnetizing current from the grid. It is mostly suitable for wind generating stations as in this case speed is always a variable factor.