As the name implies, a micro turbine is a small gas fuelled turbine engine attached to a high speed generator and power electronics to produce usable electrical and thermal energy in distributed generation applications.
In recent years a slow deregulation of the power generation market has taken place throughout the world. Now, markets are open to anyone to produce their own electricity and to export it to others on the grid. The market is also open to international corporations and state-owned monopolies in many countries are being sold off and broken up. The power corporations that produce energy in large complex facilities are now exposed to competition from small-scale production of power on site where the need is, and State-owned power companies that were controlled by the government are now sold out on the stock market. The new owners tend to have a shorter perspective and value short- or medium-time profits so long-term infrastructure investments are less frequent. The private companies do not want to maintain a large production buffer to assure that enough power is produced in case of extreme weather or other crisis.
The power demand changes quickly in both size and location. The prize on power changes also rapidly world wide due to speculations, politics and natural disasters. All these changes make it harder for companies to justify the investments that a new full-scale power plant requires. An interesting example is California, USA where almost no new power plants have been built during the years since the power market was deregulated in 1996; a situation which made the power shortages during January in 2001 more severe.
This development has lead to a new interest in small-scale power plants that are easy and quick to install, with low cost and a short payback time. The power production can be adjusted to the current demand and if the demand increases over time, another turbine can be installed. The companies do not need to take the full investment that a larger power plant would take, and small-scale power production can be viewed with the motto: invest as you grow.
Small-scale power plants are nothing new. But now it can be combined with water heating, thus increasing the total efficiency from 30 to 80%! The combination of power and heat (CHP) generation is therefore essential to the success of the micro-turbine system.
The development of small-size on-site power plants increases also the flexibility in the power generation, e.g. when they are placed in clusters and connected into networks to serve many customers at many different locations. These distributed micro-grids can be operated as centralized systems monitored from a single location.
Micro turbines are one of the most important technologies that can be efficiently employed to address the global problems of increasing electrical demand and greenhouse gas emissions. Micro turbines have much lower emissions than traditional technologies and, unlike reciprocating gensets, are highly durable and capable of operating for extended periods of time at full power without shutdown maintenance.
Global interest in distributed generation, and micro turbines has been boosted by the spread of natural gas networks and by the fact that power transmission losses are avoided if power is produced locally. Average efficiency of national electric power grids has stagnated at around 30% prior to accounting for transmission losses – by generating electricity on-site, operators can achieve a similar level of electrical efficiency and capture the waste heat to perform valuable work. By combining heating/cooling and power in a single combustion process, operators can achieve total efficiencies approaching 80%.
Micro turbines offer considerable advantages when compared to alternative distributed generation technologies:
Compact size – less than half that of an equivalent reciprocating engine
Low weight per unit of power leading to reduced civil works costs
Smaller number of moving parts and thus lower maintenance costs
Low noise levels so they can be located in sensitive sites
So, by using a gas fired micro-turbine, building owners and operators can generate and control their own electrical needs on site – and the thermal energy used for heating and cooling applications is free!
As the name implies, a micro turbine is a small gas fuelled turbine engine attached to a high speed generator and power electronics to produce usable electrical and thermal energy in distributed generation applications.