Idle reduction systems - Systems that rely on electric and small diesel powered heating units to maintain desired engine temperatures, both coolant and lube oil, while the locomotive is shut down.

Improved irrigation - Irrigation solutions (such as sprinkler or drip irrigation) that use water more efficiently than China’s conventional irrigation methods with equal or greater benefit to the user.

Incineration energy recovery - Waste to energy solution that generates power from the combustion of solid waste.

Industrial heat - Burning of biomass to generate heat to be used for industrial purposes.

Industrial solid waste - Garbage, refuse, sludge and other solid materials discarded as a result of industrial operations. Commonly understood to exclude biodegradable and hazardous waste.

Industrial symbiosis - Form of industrial organization where waste from one production process can be used as an input in producing another good, thus maximizing resource efficiency and minimizing industrial waste.

Industrial wastewater systems - Systems used at industrial sites to treat water after use prior to either reuse or release into the natural environment.

Industrial water reuse - Process whereby certain pollutants are removed from industrial wastewater so that the water can be recycled for further uses at the same site.

Influent - Water flowing into wastewater treatment plants.

Installed capacity - Theoretical production capacity of the total equipment that is installed, as opposed to the effective capacity which is the actual optimal production.

Integrated design - Approach that brings together all the stakeholders in the building process at an early stage to maximize building comfort and usability while minimizing resource use.

Integrated gasification combined cycle (IGCC) - System that turns coal into synthesis gas and removes impurities before combusting it in gas turbines; the waste heat is captured and passed to a steam turbine system for energy recovery.

Integrated rainwater collection - System that collects and stores rainwater from the rooftop of a building to be used locally.

Internal combustion engines (ICE) - Engines in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an ICE, the expansion of the high temperature and pressure gases directly apply force to a movable component of the engine, such as the pistons or turbine blade.

IP-based automatic meter reading (AMR) - Solutions that automatically gather data from energy metering devices and transmit to a central processing facility where billing is handled and consumption patterns are analyzed.