The articles in English are the definite article the and the indefinite articles a and an (and sometimes some). Use of the definite article implies that the speaker assumes the listener knows the identity of the noun's referent (because it is obvious, because it is common knowledge, or because it was mentioned in the same sentence or an earlier sentence). Use of an indefinite article implies that the speaker assumes the listener does not have to know the identity of the referent. In some no article is ..
Cogeneration or combined heat and power ( CHP) is the use of a heat engine Cogeneration and Cogeneration Schematic, www.clarke-energy.com, retrieved 26.11.11 or power station to simultaneously generate electricity and useful heat. Trigeneration or combined cooling, heat and power ( CCHP) refers to the simultaneous generation of electricity and useful heating and cooling from the combustion of a fuel or a solar heat collector. A plant producing electricity, heat and cold is called a trigeneration or poly..
