Energy & Power
“What’s holding back co-generation?” asks IEA
By Anthony Capkun
May 21, 2014 – A new publication from the International Energy Agency (IEA) spotlights, it says, two implementable technologies that efficiently integrate heat and electricity systems, provide flexibility and enhance energy security: “Linking Heat and Electricity Systems: Cogeneration and District Heating and Cooling Solutions for a Clean Energy Future” (download PDF below).
Cogeneration (a.k.a. combined heat and power [CHP]) provides enhanced energy efficiency compared with conventional thermal generation by recovering some of the heat produced during electricity generation that otherwise would be wasted, notes IEA. Worldwide, cogeneration plants’ average conversion efficiency rate was 58% in 2011, compared with 36% for conventional thermal power plants, adds IEA.
District heating and cooling (DHC) systems, which distribute thermal energy among end users in a network, can be coupled with generation sources such as CHP or other locally available energy sources (e.g. waste heat, renewables or natural cooling from water sources) for further environmental gains. DHC networks based on these sources can be five to 10 times more efficient than traditional electricity-driven equipment, says IEA.
Despite their proven advantages, IEA notes global deployment of cogeneration and efficient DHC has been limited. A select number of countries use cogen to meet a share of their energy demand, but it has lost ground overall, declining from 14% of global electricity generation in 1990 to around 10% in 2000, and remaining stagnant since then.
“Linking Heat” looks at use of these systems in a variety of countries and applications to analyze existing barriers and opportunities. It delves into three case studies for industrial cogeneration in Mexico, Spain and Scotland and three others for efficient DHC in Denmark, France and Saudi Arabia. The analysis addresses not just the technologies’ mechanics, but the flexibility they offer, financing mechanisms, business models and policy frameworks.