In general terms, efficiency is the output of a process compared to the input. In the context of a power plant we have three types of efficiencies.
- Economic efficiency
- 运营效率
- 活力efficiency
Economic efficiency of a power plant
Economic efficiency is essentially the specific cost of producing useful output and tends to be the main driver behind shaping process plant design and operation.
运营效率of a power plant
操作效率通常称为“容量因子”或有时“负载因子”，并与潜在的最大输出相比，测量从过程的实际输出。
发电厂的能量效率
能量效率是指在考虑混合输入和输出时使用“能量转换效率”的有用工作输出的比率。
Heat rate
活力efficiency is closely related to the 'Heat rate'. Heat rate is the quantity of heat required to produce an unit of useful output and therefore a lower heat rate is more efficient and gives a higher percentage energy efficiency. The relationship most frequently used to describe heat rate and efficiency in respect of electrical power generation is:
能量效率= 3600 /热速率
其中在KJ / kWh，MJ / MWH或GJ / GWH中测量热速率。
能源相关分析通常是指热效率，无论是漏洞等术语。
热效率
"Thermal efficiency” is strictly defined as the useful output energy for a given quantity of gross input heat energy and is therefore subtly different from energy conversion efficiency, which might include both heat and power as inputs and outputs.
漏洞
“Deergy”被定义为系统工作的潜力的衡量标准。一个关于储层的系统的Deergy'B'是系统在变换过程中由系统完成的最大工作，使其与储存器均衡。在工业生态领域中使用了Deerveny分析作为既有工具的工具，减少流程所需的漏洞量，并更有效地使用过量。高级效率也称为二级效率，因为它通过考虑anergy来计算过程的效率。
anergy
“无力”,是互补的部分(热)energy that cannot be converted into work.
考虑第二热力学定律。一个过程的能量E和Adergy B平衡是：
EINPUT = EIN产品+ ELOSS
Binput = Bin product + Bloss + Bdestroyed
可以使用热力学电位E或B描述该方法的效率η。效率是进入产品的潜力的一部分。
设备供应商引用的效率通常是能量转换或一流的热力学效率。这表明特定设备将一种能量转换为另一个形式的特定设备如何，但它并不显示该设备如何与替代能量转换过程进行比较。
可用于说明能量转换效率和高级效率之间的差异的例子是天然气的燃烧仅加热水。虽然这具有很高的一法效率，但它具有较低的二级效率，浪费了大量的高温，高质量的能量来加热相对冷的水。
典型的电厂效率
Efficiencies of Different types of Power generation sources:
| 类型 | 效率 | Operating Condition |
| 亚临界热厂 | 35-38％ | 170巴，570˚C |
| 超级缩减热植物 | 42％ | 220 bar, 600˚C |
| Ultra Super Critical | 45-48％ | 300bar,600˚C |
| IGCC | 45-55％ | |
| Hydro Power Plant | 85-90％ | |
| Wind turbine | 30-45％ | |
| 太阳能热系统 | 每年12％ | |
| Geo热系统 | 35％ | |
| 核电站 | 0.27％ | |
| 柴油发动机 | 35-42％ |
燃煤发电厂的效率
Coal fired power plant operates on modified Rankine cycle. Its efficiency is decided by parameters of this cycle. The changes of efficiency of different power plant attributes mostly to different temperature , pressure, superheat steam and Reheat steam temperatures. Conventional power plants operate at 170 bar and 570˚C superheat steam parameters. Their efficiency lies between 35-38% depending upon nature of coal. Super Critical thermal power plant operates 220 bar and 600˚C and their efficiency is generally 42%. While Ultra super critical plant parameters are 300bar and 600˚C and efficiencies are around 45-48%.
2nd燃煤电厂的类型是IGCC（综合气化联合循环）这些植物的效率在45-55％之间，这取决于煤炭质量和过程选择气化。
可再生能源发电厂的效率
- 水力发电厂具有最高的效率。水的潜在头靠近涡轮机，所以只有损耗发生一些涡轮机损失。效率位于85-90％之间。
- 风力发电机总转换效率为30-45％。
- 太阳能热系统可以实现高达20％。但是，阳光的天气和移动路径的变化使其每年达到12％的效率。
- Geo热系统uses the rankine cycle with steam temperature at saturation point. It usually achieves around 35% efficiency.
效率in a Nuclear Plant
核电站的效率几乎不同。在蒸汽轮机侧，它们在饱和点使用蒸汽温度的兰敏循环。这使它们效率aroung 38％。能量释放nuclear fission非常高，非常小的散发，加热蒸汽。因此整体效率通常超过0.27％。
柴油发动机产生的力量效率
The large capacity industrialdiesel enginesoperates between 35-42% efficiency。
