Renewable and Sustainable Energy Technology - International ...

The International Experience77The MDI TechnologyThe MDI engines are powered by compressed air. In order to create the compressed airthere is a wide variety of fuels that can be combusted, including the usual fossil fuels suchas petrol, diesel, natural gas and LPG. A wide range of biofuels can also be used such asgasified biomass, wood waste, ethanol, coconut oil, tallow, rapeseed oil, etc. In the verynear future direct and indirect thermal solar energy is possible. These fuels can be usedwithout changing the engine or its specifications as the combustion and/or heating used toproduce the compressed air takes place outside the MDI engines.One of the key differences between the MDI engine and a normal internal combustionengine is that combustion occurs outside the engine in an extremely efficient and clean way.Another important difference is what MDI calls the ‘active chamber’ that enables two pistondown strokes for a given volume of compressed gas instead of only one in a traditionalinternal combustion engine.In the case of biofuels there is no need for costly transformation into bio-diesel orcumbersome blending. This considerably reduces cost and makes for ease and speed ofdeployment.The design of this engine is such that it is totally scalable and replicable, as is the modelfor the manufacturing plant. This allows for a wide scope of applications. Two specificapplications for the MDI engine that are viable and available are the compressed air electricalpower generators and the compressed vehicles.Bolt-Ons – Electricity GeneratorCourtesy: IT MDI-EnergyThe compressed air generator is an MDIengine driving a bolt-on generator to createelectricity. Due to the properties of the enginedesign, this system offers more possibilitiesthan any other for co-generation. Whenintegrated with technology that enables there-use of so-called waste energy from apower generation system, it will be possibleto generate power at the point of use whilesimultaneously providing air conditioning(heating or cooling as required) hot waterand recycling grey water to spring waterquality levels.This creates the possibility of providing asustainable environmentally sound solution toclimate change and related fossil fuel issues.These compressed air generators are not just electricity generators, instead they form thebasis for a total processing system with bolt-on features. Therefore, when fully integratedin a home environment the overall energy efficiency of the system can be over 90% fromprimary source to end-use.The MDI engine alone is estimated to have overall energy efficiencies that range from45% to over 70% depending on the versions and models.