N.H. Admin. Code § Puc 902.04
"Combined Heat and Power System" means a "combined heat and power system" as defined in RSA 362-A:1-a, I-d, namely "a new system installed after July 1, 2011, that produces heat and electricity from one fuel input using an eligible fuel, without restriction to generating technology, has an electric generating capacity rating of at least one kilowatt and not more than 30 kilowatts and a fuel system efficiency of not less than 80 percent in the production of heat and electricity, or has an electric generating capacity greater than 30 kilowatts and not more than one megawatt and a fuel system efficiency of not less than 65 percent in the production of heat and electricity. Fuel system efficiency shall be measured as usable thermal and electrical output in BTUs divided by fuel input in BTUs."
N.H. Admin. Code § Puc 902.04