1) AES Tietê's energy generation in 1Q11 was 36% higher than its physical guarantee. It invested R$35 million in modernizing three power plants. 2) Net revenue decreased 9% to R$416 million in 1Q11 compared to 1Q10. EBITDA was R$338 million with an 81% margin. 3) Reservoirs for AES Tietê's power plants were at high levels, reflecting good rainfall in 1Q11. The company distributed R$212 million in dividends for 1Q11 results.

1. 1Q11 Results
May, 2011

2. 1Q11 Highlights
 Energy generation 36% higher than physical guarantee
Operational
Operational  R$ 35 million invested, mainly, in the modernization of the Nova Avanhandava (347 MW),
Ibitinga (132 MW) and Caconde (80 MW) power plants
 Net revenue of R$ 416 million, down 9% compared to 1Q10
Finance
Finance
 5% decrease in costs and operational expenses
 Ebitda reached R$ 338 million, with margin of 81%
 Net income of $ 193 million is in line with the 1Q10 recurring net income1
Subsequent
Subsequent  Dividends distribution of R$ 212.3 million related to 1Q11 results, corresponding to R$ 0.53 per
Event
Event common share and R$ 0.58 per preferred share
1 – Excluding the non-recurring event in the 1Q10 relating to the legal dispute with Furnas, in the amount of R$ 28 million, net of taxes. 2

3. Brazilian reservoirs in comfortable levels
due to good rainfall
Water inflow (LT Avg1) Reservoirs level
190%
158%
145%
124%
99%
99%
92%
92%
92%
85%
98%
85%
79%
83%
87%
83%
81%
66%
73%
76%
73%
61%
47%
51%
Southeast South Northeast North Southeast South Northeast North
1Q09 1Q10 1Q11
1 – Long term average 3

4. High level of AES Tietê’s reservoirs
reflects the good rainfall level during 1Q11
Reservoirs level of AES Tietê’s power plants1
100%
100%
99%
99%
98%
100%
98%
93%
94%
95%
90%
94%
Caconde HPP
Caconde Água Barra Bonita Promissão
Vermelha
1Q09 1Q10 1Q11
1 – As of 03/31/2011 4

5. Maintenance of high operational availability with generated
energy 36% higher than physical guarantee in 1Q11
Energy Generation (MW Avg.1)
143%
136%
130%
125%
118%
1,979
1,665 1,599 1,612
1,512
2008 2009 2010 1Q10 1Q11
Generation - MWAvg Generation/Physical guarantee
1 – Generated energy divided by the amount of period hours
5

6. Reduction of energy billed in the
1Q11 to AES Eletropaulo
Billed Energy (GWh)
-15%
4,276
3,645
52
643 108
566 424
587
3,015 2,526
1Q10 1Q11
AES Eletropaulo Energy Reallocation Mechanism Spot Market Other Bilateral Contracts
6

7. Investments in the modernization of Nova Avanhandava,
Ibitinga and Caconde power plants
Investments1 (R$ million) 2011 Investments
89%
158
6
82
57 12 5% 6%
13 152 35
70 4
8
43
30
1
7 Equipment and Modernization
2009 2010 2011 (e) 1Q10 1Q11
2 New SHPPs
Investments New SHPPs
1 - Do not include capitalization of interests during plants modernization and development of projects IT projects
2 - Small Hydro Power Plants 7

8. Expansion of 550 MW of installed capacity
through the Termo SP Project
Plant localization (Canas/SP)
• Project objectives
- Expansion of installed capacity in the State of São Paulo
- Offering competitively energy prices
• Project features
- Combined cycle using natural gas
- 2 gas turbines, 2 heat recovery boilers and 1 turbine steam
- Estimated investment of R$ 1.1 billion
- Natural gas consumption: 2.5 million m3/day
• Expected Timetable
- May 26, 2011: Public Hearing
- July/11: Expectation of issuance of Prior License (expected)
- 2nd half of 2011: Power Auction realization (expected)
Project Website: www.aestiete.com.br/termosaopaulo
8

9. 9% reduction of net revenue reflecting the
volume of sales to AES Eletropaulo
Net revenue (R$ million)
- 9%
460
416
7
16 14
17
437
385
1Q10 1Q11
AES Eletropaulo Spot/Energy Reallocation Mechanism Other bilateral contracts
9

10. 5% reduction in costs and expenses due to locks’
bi-annual maintenance occurred in 2010
Costs and operational expenses1 (R$ million)
4.0
2.6 4.8
0.8 1.1
82
78
1Q10 Financ. Comp. Transmission Energy Locks Others PMSO 1Q11
for Use of and Purchased for
Water Res. Connection Resale
1 – Do not include depreciation and amortization 10

11. Ebitda margin stable in 81%
Ebitda (R$ million)
82% 81%
- 10%
378
338
1Q10 1Q11
EBITDA Margin Ebitda
11

12. Financial result benefited by Furnas revenue and
by the lower expense due to exchange of debt
(R$21 million)
Financial Results Financial Results with non-recurring effect
(R$ million) (R$ million)
1Q10 1Q11 1Q10 1Q11
(0.2)
(11) (11)
- 74%
(42.8)
 Non-recurring effect of the 1Q10 relating to the legal
dispute with Furnas in the amount of 42.6 million
12

13. Recurring net income stable reflecting good
performance in costs and expenses
Net Income (R$ million)
1
109% 110%
3.4% 2.5%
220  Distribution of R$ 212 million in dividends
28 related to 1Q11:
- R$0.53 per common share
- R$0.58 per preferred share
192 193 - Ex-dividends: May 13, 2011
- Date of payment: May 26, 2011
1Q10 1Q11
2
Pay-out Non-recurring effect
Yield PN Net Income
1 – Pay-out referred to dividends paid in the 1Q10 in relation to the net income adjusted by the IFRS 2 – 1Q10 non-recurring effect related to Furnas, net of tax 13

14. Reduction of final cash balance influenced by lower volume of
sales in the 1Q11 and by the Furnas revenue in the 1Q101
Operating Cash Flow (R$ million) Final Cash Balance (R$ million)
-18% -13%
366 574
499
299
1Q10 1Q11
1Q10 1Q11
1 – Non-recurring event relating to the legal dispute with Furnas in the amount of R$ 43 million 14

15. Exchange of debt allowed the reduction of
average cost and extension of term
Net Debt (R$ billion) Average Cost and Average Term (Principal)
0.4x 3.1
0.3x
1.8
0.5
0.4 124.8% 113.9%
1Q10 1Q11 1Q10 1Q11
14.9% Effective Rate 14.0%
1
Net debt Net debt / EBITDA Average Term CDI
1 – Percentage of CDI 15

16. 1Q11 Results
The statements contained in this document with regard to the
business prospects, projected operating and financial results,
and growth potential are merely forecasts based on the
expectations of the Company’s Management in relation to its
future performance.
Such estimates are highly dependent on market behavior and
on the conditions affecting Brazil’s macroeconomic
performance as well as the electric sector and international
market, and they are therefore subject to changes.