Tag Archives: steam

Green Turbine presents 15 kW turbine model at Dutch Installation Trade Fair!

Date: 10 – 12th September, 2013

Stand: AITEC hall 2, stand 204,

Trade Fair website: Evenementenhal Hardenberg

We will be showcasing our 15 kW turbine model at the stand of AITEC, a specialist in heating equipment. In turn, AITEC the dealer of Magnabosco steam boilers, will be presenting the GVR 300 model steam generator.

Our 15 kW turbine is expected to be market ready by Q4 of 2013. With this turbine it will be possible to modulate and vary the output. Each nozzle is 2.5 kW. You can also range the pressure between 1 and 10 bar abs.

You are more than welcome to come and visit us at the fair!

Both Gas- and Steam to power EV battery range?

Nick Kurczewski is writing about extremely small (gas) turbines, which can extend the travel range of electric cars in his blog on the website of Green Car Advisor. He’s talking about the Dutch company MTT en the Israeli Company EVT Motors, but he forgets to mention Green Turbine BV. Although Green Turbine is mostly suitable for hybrid cars (the turbine can use the waste heat of the motor), it also can be used in electric cars with a gas turbine, because waste heat of a gas turbine can be used to drive Green Turbine.

So, what exactly is the Green Turbine?  Well, it’s a small (slightly larger than a football), lightweight and silent micro steamturbine with an output in the range of 1-15 Kw. It converts steam to electricity and also produces heat in this process. It can be driven by any fuell type (natural gas, propane etc.), waste heat, biomass and fuel cell.

Green Turbine
Green Turbine

The turbine has been developed in the past five years by a small company called Green Turbine BV (it has also a Canadian version which is the company Green Turbine INC. info@greenturbine.net

Green Turbine is not developing a prototype, it actually has a working prototype. The only thing left, is the long term testing which is starting at the end of October.

Green Turbine can extend the efficiency of hybrid cars by 20-30%. As previously mentioned, it captures the waste heat of the engine exhaust and converts it into electricity. We calculated this percentage based on the following:

In hybrid or fuel cell cars about 10% of the waste heat can be recovered and converted to electricity. As waste heat is about 75% of the total energy input of a car, this 10% is substantial. It will boost total efficiency of a hybrid automobile between 20 – 40%.

Imagine what Green Turbine could do in an electric car, when it is placed after a gas turbine!



New geothermal heat recovery method

Bron: National renewable energy laboratory
Example of geothermal heat: Hot springs in Nevada. Source: National renewable energy laboratory

Pacific Northwest National Lab has been making progress in using a new method for capturing more heat from the low-temperature of
geothermal resources. Which it is hoped could result in generating  pollution-free electrical energy. A new liquid is used called biphasic fluid, which has the benefit of rapid expansion and contraction capabillities developed by PNNL’s conversion system. The  thermal-cycling  of the biphasic fluid, when exposed to heat and brought to the surface from water circulating in moderately hot, underground rock,  will power a turbine generating electricity.

Scientists added metal-organic heat carriers (MOHC’s)  to aid efficiency, which boost the power generation capacity to near that of a convential steam cycle.
‘Our intention is to enable generation from low-temperature geothermal resources to get a clean energy source without  any greenhouse gas emissions  which is  also a steady and dependable source of power’ said Pete McGrail, PNNL Laboratory. ‘ We accidentily discovered this by research on nanometerials used to capture dioxide from burning fossils fuel’ .

PNNL  plan  to have a functioning  bench-top prototype generating electricity by the end of the year.


Seattle steam turns to wood

The Seattle Steam Company, which operates two plants that produce steam for heating downtown Seattle office buildings, hotels and hospitals, has plans to replace a natural gas-fired boiler with one that uses recycled and waste wood as its fuel. For Seattle Steam, the move to biomass represents an initial step in the switch to renewable energy sources. The switch, according to the company will reduce Seattle Steam’s carbon emissions by about 55,000 tons annually. The plans for the conversion to wood fuel were already on the table in 2006, as it is now it looks like it will be this autumn when the boiler is ready for use.

Bron: Wikipedia
Bron: Wikipedia

This 115 year old privately owned company now provides steam generated from burning natural gases, diesel and oil. This supplies heat through 18 miles of steam pipeline to 200 of downtown Seattle’s largest buildings. It also uses steam for generating hot water and humidity control. Because of rising gas prices as well as Seattle Steam being the biggest single natural gas consumer in the state, the company decided to make the switch to give it a more competitive edge. Subsequently, in its effort to reduce carbon emissions, it plans to fire up a new boiler which will allow it to derive more than half of its source fuel from wood waste. The wood coming from crates, packaging material and tree trimmings will be reduced to chips 3 inches or smaller.

Some have said the choice of wood is not a particularly sensible one. It might be a lot cheaper than natural gas, but burning wood will actually release more carbon emissions than the burning of natural gas. Still, advocates of the switch say this is not entirely true. A tree absorbs as much carbon (or carbon dioxide) in its lifetime as it releases when burnt. Wood burning does not release more carbon dioxide than during it’s biodegradation (i.e. rotting). Wood burning can therefore be called “carbon neutral”. Of course, harvesting and transport operations can produce significant amounts of greenhouse gas pollution, but considering that Seattle Steam plans to use ‘urban’ wood it seems to work out in it’s favour.

Seattle Steam’s use of biomass will reduce its use of natural gas by 60% and reduce it’s carbon footprint – and subsequently the footprints of its customers – by 50% the company says. This is an enormous step in the early days of carbon recognition. Stan Gent, president of Seattle Steam explains; ‘It will move us to beyond where the State’s goal is for 2050 and we will achieve that in 2009’. The company won’t stop here in its efforts to continue the search for more alternative fuel stocks. The use of glycerol, instead of the remaining natural gas, might be a next step. Although research is still in somewhat experimental stage at this point in time, Stan Gent has high hopes for the future: ’The process of burning glycerol might be commercially available within five years, if that’s the case we have every expectation that our carbon footprint will approach zero by 2020.’

The case for steam

Say: “Micro turbine” and people think of jet engines. And how small is micro anyhow? The smallest micro turbines (gas turbines that is) are still at least 30 kW: enough for a good sized apartment building.  http://www.capstoneturbine.com/
Making smaller gas turbines is hard to do, engineers face extreme stresses and temperatures in rotors and bearings. The laws of fluid dynamics can not always be scaled down easily.
So, a real micro turbine in the range of 1-5kW having a long working life, a good efficiency and burning all types of fuel is still a promise.
But if we want a decentralized power system, where every household can make its own power, that is exactly what we need.

More than a century ago, Mr. De Laval, a genial Swedish engineer, invented a small steam turbine. To be more precise: he invented THE steam turbine (although Mr. Parsons deserves some credit here too)
For some mysterious reasons, soon afterwards all research efforts were focused on developing large and even huge steam turbines. Mainly because very big steam engines of the reciprocating type were hard to manufacture and unsuited for driving generators. Because now we had a second industrial revolution at hand: electricity!

What happened in the past century was that enormous amounts of money and effort were spent on the development of gas engines (the automobile industry), gas turbines (jet engines, the aircraft industry) and very little in developing steam turbines. There are a handful of manufacturers of steam turbines in this world. They all build large and very large machines. A company like Elliott promotes small steam turbines: from 500kW upwards!

If I am not mistaken, this state of affairs is likely to end. After 5 years of research a company called “Green Turbine” has developed a micro steam turbine in the range of 1-15 kW. Their 1 kW and 2,5 kW versions are working prototypes and will be rigorously tested.  www.microturbine.eu

The Green Turbine is not only a turbine, but a compact, completely sealed turbo generator. The turbine runs with 30.000 rpm and on account of this high speed is very compact and only 7 kg in weight.
The novel design (patented) and modern materials like plastics gives Green Turbines excellent specifications. The efficiency seems to be as good as steam turbines of a much higher output.
The design is aimed at low production costs. Compared with gas turbines the Green Turbine is almost silent.
A very important feature is the low temperature requirement of the steam; 200 C is enough. So waste heat is an obvious source of energy.

The field of application requires some “out of the box” thinking.

Where do we find a lot of waste heat: cars! Power a Green Turbine with the waste heat of a (hybrid) car and savings of 20% in fuel are easy to get.
How about yachts and small ships?

Micro CHP (Combined Heat and Power) is another obvious application. Better than a heavy Stirling engine or gas engine.

Solar energy? Yes, capture the heat, make steam and your turbine will run. Use the low temperature heat of the turbine to heat your house or swimming pool .

And, yes, also the waste heat of a fuel cell or micro gas turbine can drive Green Turbine.
We closed the circle!

The rebirth of steam

Could it be a good idea to power our future cars utilizing steam? It might sound a bit unlikely or perhaps even outdated (as it’s certainly been tried before), but according to modern-day scientists and car manufacturers , BMW being one of them, the steam engine could very well make a comeback. A well designed steam engine is considered as a potential alternative to the internal combustion engines used today. The re-introduction of this technique could be very promising to the powering of cars, rockets and maybe even space vessels in the (near) future. So how does it work?

First a bit of history. Steam force is the oldest form of mechanical traction. Although the first applications of steam in propelling a road vehicle were attempted in the 17th century, it was not until the advent of high pressure steam engines, in the early 1800s, that such vehicles became a practical proposition. Limitations in manufacturing technology and the poor condition of road surfaces, meant that nothing that could be realistically regarded as a ‘steam car’, in the sense of a car being suitable for personal transportation, was created until the end of the 19th century. That century was seen as the heyday of steam power, when steam locomotives dominated the railways.  The Stanley, produced by the Stanley Motor Car and Carriage Company, which still holds the land speed record for a steam powered automobile, was the last steam car taken out of production in 1925, when eventually being overtaken technologically by the internal combustion engine.  It wasn’t until the second half of the 20th century when the conversion from steam on the rail took place and steam powered locomotives began to vanish. For a long time the steam powered engines were cumbersome. The old generators had the capacity of a few hundred megawatts. Technological developments and improvements in manufacturing techniques (partly brought about by the adoption of the steam engine as a power source) resulted in the design of more efficient engines that were smaller, faster, or more powerful, depending on the intended application. These steam powered generators can sometimes still be found in power plants and in sea vessels.

To indicate that a steam engine is viable today in cars, the German car manufacturer BMW is now developing a hybrid system that is powered by a steam engine. They named it the ‘Turbosteamer’ and it’s based on the same principle as the steam engine:  liquid is heated to form steam in two circuits and this is used to power the engine. The primary energy supplier is the high-temperature circuit which uses exhaust heat from the internal combustion engine as an energy source via heat exchangers. More than 80 percent of the heat energy contained in the exhaust gases is recycled using this technology. The steam is then conducted directly into an expansion unit linked to the crankshaft of the internal combustion engine. Most of the remaining residual heat is absorbed by the cooling circuit of the engine, which acts as the second energy supply for the Turbosteamer.

The modern usage of steam has several advantages over the use of other power sources. There is waste heat, from the burner exhaust and from the spent steam, which can be converted using thermo-electrics into extra electricity to increase the efficiency of the system. With the combustion taking place externally and being continuous and more easily regulated for temperature, oxidizers and fuel amount, these lower combustion temperatures and pressures create less toxic and exotic exhaust gases. Another benefit is that the engine requires no oil as the steam itself lubricates the moving parts. Problems with oil depletion and oil dependency could be battled using this technique. Environmental taxes therefore will also be considerably less as opposed to other mechanical techniques. So exploring the possibilities of steam powered techniques could be, once again, a profitable endeavor.