Psce 2011 Article final

focused on the principle of so called measurement and 
verification. The application of the proposed methodology can 
lead to continuous efficiency improvement programs both for 
cogeneration plants and generator groups connected to a grid. Its 
benefits are even beyond the generation agents purposes. Once 
generators develop a new paradigm of transparency, with real 
time performance data that can be accessed by other interested 
agents, such as customers or grid administrators, a contribution
to the concept of smart grids will be made whilst relevant supply 
side performance information is disclosed to other parties. 
Index Terms—Cogeneration, Energy management, Energy 
conservation, Power generation. 
I. N
OMENCLATURE
ANEEL: Electrical Energy National Agency – The Regulator 
BPSTG: Back Pressure Steam Turbine Generator 
CDM: 
Clean Development Mechanism 
CHP: 
Combined Heat and Power plant 
EC: 
European Community 
LHV: 
Lower Heating Value 
MME: 
Mines and Energy Ministry - Brazil 
M&V: 
Measurement and Verification 
PDCA: 
Plan-Do-Check-Act quality management cycle 
PFD: 
Process Flow Diagram 
TP:
Turbo Pump 
A. C. Paro is with University of São Paulo, and Promon Engeering Ltd., 
São Paulo, Brazil (e-mail: [e-mail]). 
E. A. F. A. Fadigas is with the Energy and Automation Department – 
Polytechnic School, University of São Paulo, São Paulo, Brazil (e-mail: 
[e-mail]).
II. I
NTRODUCTION
uring the last few years, the term energy efficiency has 
been present in many discussions involving the industry 
sector, the civil society and climate change researchers. 
The growing concern about the contribution of this subject to 
better energy use forms in all these sectors has permitted the 
development of many studies which proposed solutions for 
energy savings. In many countries, these discussions have 
brought advances in public policies implementation dedicated 
to achieving global energy savings for integrated systems. 
However, it is interesting to notice that many of those policies 
are oriented towards the end use of electricity, the so called 
demand side management, applied to industry, commercial 
installations and households. Another approach to the energy 
efficiency assessment emerges from the reckoning of a huge 
amount of energy being wasted prior to its end use, for 
example due to low efficiency thermodynamic cycles working 
in many power plants around the world. Far from being a new 
issue, this subject is under continuous discussion and many 
advances have been achieved. Combined cycle gas power 
plants, cogeneration with combined heat and power (CHP) 
plants and other technologies can be mentioned as the latest 
energy efficiency improvement results on supply side. But 
there is still a huge amount of wasted energy lying under low 
efficient thermoelectric plants and even CHP plants operating 
under low pressure steam Rankine cycle.
In order to achieve the better use for the energy of all those 
fuels used in thermoelectric plants, from coal to oil, gas and 
lately biomass, a new approach emerges. This approach has 
been called as supply side management and is still under early 
definition compared to the end uses approach in the energy 
efficiency domain. In this context, the purpose of this article is 
to propose a methodology for: 
-
calculation of design predicted CHP plant overall 
energy efficiency; 
-
measurement and verification of operational energy 
efficiency. 
The latest released public policies regarding supply side 
energy efficiency in the USA, Europe and Brazil are 
presented. Besides government’s initiatives, the released draft 
standard ISO/DIS-50001, intended to certificate energy 
management systems, is also presented and discussed. 
A Methodology for Biomass Cogeneration 
Plants Overall Energy Efficiency Calculation 
and Measurement – a Basis for Generators Real 
Time Efficiency Data Disclosure 
A.
C. Paro, Member, IEEE, and E. A. F. A. Fadigas 
D

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2 
Based on this global scenario of developing public policies 
and standardization initiatives, the methodology is presented 
and discussed in order to better understand its intent and 
applicability. The benefits of a standardized methodology for 
calculating and measuring generation plants energy efficiency 
are then discussed. 
At the end, other limitations and future steps for 
development of supply side energy efficiency management are 
then put to further discussion. 
III. P
UBLIC POLICIES REGARDING 
C
OGENERATION
This item presents a brief status of public policies related to 
cogeneration sector in each in the USA, Europe and Brazil. 
In USA, most of the cogeneration plants are derived from 
fossil fueled plants. The USA regulation regarding 
cogeneration returned to the scene with the publication of 
PURPA to law in 1978. The most recent publications are the 
Energy Policy Act - EPA 2005, that defined incentives for 
micro-cogeneration 
and 
established 
termination 
with 
mandatory purchase and sale requirements from cogeneration; 
and later the Energy Independence and Security Act - EISA 
2007, that considered cogeneration officially as energy saving 
practice [1]-[2]. One of the most important requirements was 
the 
minimum 
necessary 
efficiency 
for 
qualifying 
cogenerations. Based on the fact that the average efficiency 
range of fossil fueled electricity plants is 35-40%, the 
minimum required efficiency for qualifying cogenerations was 
established at 42,5% [3]-[4]. It represented an important 
initiative towards a supply side energy management policy. At 
the end of 2008, cogeneration represented 6.55% of the total 
electricity capacity in USA [3]. 
In Europe’s recent cogeneration related public policy, the 
document 
Directive 
2004/8/EC, 
from 
the 
European 
Community (EC), was published with the intent of promoting 
cogeneration [5]. It established rules to classify cogeneration 
plants and calculate efficiency and related energy savings. 
Furthermore, the “Action Plan for Energy Efficiency” released 
in 2006 by EC brought numbers on the current average energy 
transformation efficiency of around 40%, with vast 
improvement potential. Besides, as only 13% of energy in 
Europe comes from, supposed to be more efficient, 
cogenerations, there are indications of unused potential [6]. 
However, these regulatory incentives seem not to be enough 
yet. The COGEN Europe Position Paper in response to 
European Commission consultation on the review of 
COM(2006)545 indicates that the actions stated in that 
document were not executed and the plan to double CHP