Deutsche Bank Alternative Energy Utilities & Power Conference MAY 11 & 12, 2010

1. Deutsche Bank Alternative Energy Utilities & Power Conference MAY 11 & 12, 2010

2. Safe Harbor Provisions This presentation contains statements concerning NU’s expectations, beliefs, plans, objectives, goals, strategies, assumptions of future events, future financial performance or growth and other statements that are not historical facts. These statements are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. In some cases, a listener or reader can identify these forward-looking statements through the use of words or phrases such as “estimate”, “expect”, “anticipate”, “intend”, “plan”, “project”, “believe”, “forecast”, “should”, “could”, and other similar expressions. Forward-looking statements are based on the current expectations, estimates, assumptions or projections of management and are not guarantees of future performance. These expectations, estimates, assumptions or projections may vary materially from actual results. Accordingly, any such statements are qualified in their entirety by reference to, and are accompanied by, the following important factors that could cause our actual results to differ materially from those contained in our forward-looking statements, including, but not limited to,actions or inaction of local, state and federal regulatory and taxing bodies; changes in business and economic conditions, including their impact on interest rates, bad debt expense and demand for our products and services; changes in weather patterns; changes in laws, regulations or regulatory policy; changes in levels and timing of capital expenditures; disruptions in the capital markets or other events that make our access to necessary capital more difficult or costly; developments in legal or public policy doctrines; technological developments; changes in accounting standards and financial reporting regulations; fluctuations in the value of our remaining competitive electricity positions; actions of rating agencies; and other presently unknown or unforeseen factors. Other risk factors are detailed from time to time in our reports to the Securities and Exchange Commission (SEC). Any forward-looking statement speaks only as of the date on which such statement is made, and we undertake no obligation to update the information contained in any forward-looking statements to reflect developments or circumstances occurring after the statement is made or to reflect the occurrence of unanticipated events. This presentation references actual and projected EPS by business, a non-GAAP presentation, which management believes is useful to investors to evaluate the actual and projected financial performance and contribution of our businesses. This non-GAAP financial measure should not be considered as alternatives to our consolidated net income attributable to controlling interests, and EPS determined in accordance with GAAP as an indicator of operating performance. Please refer to our reports to the SEC for further details concerning the matters described in this presentation.

3. NU’s Value Proposition • A national leader in siting, building and operating electric transmission facilities • Approximately 50% of net income from transmission • Supportive federal legislation and FERC economic regulation • Significant regional opportunities still before us • Significant projects under way in generation and natural gas • Electric distribution rate cases this year should enhance profitability of underperforming segments • Attractive regulated business model with strong financial profile • 10 years of rising dividends

4. Electric Gas NU’s Attractive Regulated Business Profile Regulated companies Service territories Total customers: 2.1 million Total assets: $14.1 billion • Regulated T&D company • 1.2 million retail customers in 149 cities and towns in Connecticut The Connecticut Light and Power Company VT NH • Regulated integrated electric utility • 490,0000 retail customers in 211 cities and towns in New Hampshire • ~1,200MW of regulated generation assets Public Service Company ofNew Hampshire Electric territory The Connecticut Light andPower Company Public Service Companyof New Hampshire Western MassachusettsElectric Company Western Massachusetts Electric Company • Regulated T&D company • 205,000 retail customers in 59 cities and towns in western Massachusetts MA Gas territory Yankee GasServices Company • Regulated natural gas delivery company with significant growth potential • Largest natural gas distribution system in Connecticut as measured by number of customers (~205,000), and size of service territory (2,187 square miles) RI CT Yankee Gas Services Company

5. First Quarter Consolidated Results As Expected Earnings For Common In Millions Distribution and Generation Transmission Competitive Total Parent/Other

6. 2010 EPS Guidance Unchanged

7. Key Near-term Earnings Drivers

8. Key Longer-Term Earnings Drivers • Distribution/Generation • Earned returns in electric distribution companies • Completion of PSNH Clean Air Project and additional clean energy initiatives • Growth of natural gas business • Transmission • Continued build-out of NEEWS projects • Construction of HVDC line to Hydro-Quebec • Increasing renewable energy portfolio standards in New England ´

9. Hydro-Quebec- HVDC ´ HVDC Line between Quebec and New Hampshire 3 Southwest Connecticut Reliability: Projects Complete 1 Transmission as a Key Strategic Enabler to Solving New England’s Energy Challenges Potential Wind Sites ´ 4 Renewables & Clean Energy NEEWS Projects Under Way 2

10. NEEWS Advances Into the Siting Phase • GSRP Status • ISO confirmed need date of 2014 in October 2009 • CT approved project in March 2010; MA hearings completed and briefs filed • EFSB to review staff memorandum on May 13 • Decision expected third quarter • Construction start in late 2010/early 2011 • In-service 2013 • IRP and CCRP Status • Updated needs assessment expected by 3Q 2010 Greater Springfield Reliability Project SPRINGFIELD Interstate Reliability Project HARTFORD Central Connecticut Reliability Project 345-kV Substation Generation Station 345-kV ROW 115-kV ROW

11. ´ New HVDC Line To Connect Hydro-Quebec Generation To New England Market • To be owned by Northern Pass Transmission LLC - NU (75%) and NSTAR (25%) • 1,200 MW transfer capability • Northern terminus at Des Cantons (Québec), southern terminus in central or southern New Hampshire • Québec terminal will convert the power from AC to DC (rectifier) • US terminal will convert the power from DC to AC (inverter) • Capital cost estimate for US segment: $900 million ($675 million for NU share) • Joint Development Agreement signed; work proceeding on Transmission Services Agreement • PPAs to be offered Des Cantons HVDC Line HVDC Converter Station

12. Natural Gas Could Supply an Expanding Market in Connecticut • Connecticut depends heavily on heating oil • Natural gas has significant cost advantages at today’s prices • Natural gas offers significantly lower emissions • Vehicle transportation market may emerge • Yankee Gas’ latest expansion project now underway (Waterbury to Wallingford Line Project) N Route 68/150 intersection Cheshire/Prospect border Waterbury Yankee Gas Liquefied Natural Gas Facility Eagle St., Waterbury Prospect Cheshire Naugatuck Wallingford Project route construction planned for 2010 Project route construction planned for 2011 FIVE MILES

13. Appendix

14. Current New England Renewable Portfolio Requirements Vermont Goal: 20% by 2017 Minimum: 2005-2012. Load growth to be met with renewables and capped at 10%. Maine 40% by 2017 (currently 30%) New Hampshire 23.8% by 2025 Massachusetts Class IClass II 4% in 2009; 1% annual 3.6% kwH sales starting increments thereafter in 2009 & 3.5% kwH sales from waste energy starting in 2009 Connecticut 27% by 2020 RI 16% by 2020