Combined heat and power (CHP) plants are characterized by high fuel efficiency and are therefore usually the thermal power producing units of choice within a district heating network.
For this reason, fast and efficient control of controllable power producing units – so-called "portfolio control" – becomes increasingly important as the ratio of renewable energy in a power system grows.
This chapter focuses on radial-inflow turbines, which first appeared as a practical power-producing unit in the hydraulic turbine field.
The use of renewable power sources increases the fluctuations in the power grid which increase the demand for highly efficient, fast-starting power-producing units that can cope with sudden production losses.
The power produced per turbine unit could be substantially improved, with little impact on total power produced by the array, by removing turbines from areas where power produced was low.
This can be explained by the facts that heating value of CNG is 12% higher than that of gasoline and it produces a comparable but lower output indicated power, therefore CNG consumes less energy per unit power produced compared to gasoline under the same engine operations.
To optimize this system, one needs to define the net power produced by the power unit (dot{W}_{text{NET}}), which is the difference between powers produced by the cycle (dot{W}_{text{cycle}}) and power consumed by the brine pump (dot{W}_{{{text{b}}.{text{p}}.}}): dot{W}_{text{NET}} = dot{W}_{text{cycle}} - dot{W}_{{{text{b}}.
Eight out of the nine cities have formulated measures that aim at increasing the share of heat and power produced in decentralised CHP units.b The actions planned by these eight municipalities differ in various ways.
They also found the generators in South Australia were able to gather much higher profit margins for each extra unit of power produced compared with other states, and that had increased significantly since May 2016.
These can have emissions intensities of around 1,000kg of CO2 per megawatt-hour (that is, the amount of carbon dioxide that is released for each unit of power produced).
