Half Yearly Report

ECOFIN WATER & POWER OPPORTUNITIES PLC

Half-year Financial Results for the six months ended 31 March, 2015

Announcement of Unaudited Results

This announcement contains regulated information.

Summary of the Half-year to 31 March, 2015

• Total Shareholders' funds - net assets attributable to Ordinary and Zero Dividend Preference ("ZDP") Shares - fell by 9.5% and by 8.0% on a total return basis1

• The net asset value per Ordinary Share fell by 12.0% on a reported basis, and by 10.6% on a total return basis

• The price of an Ordinary Share declined by 7.0%. The total return per Ordinary Share (the change in the share price plus the dividends received and reinvested) was -4.7%

Performance for periods to 31 March, 2015

Ecofin Water & Power Opportunities plc (the "Company") was launched on 26 February, 2002 and its Ordinary Shares were first issued on 29 June, 2005. The performance of the Company and the indices shown below is presented on a total return basis, i.e., assuming a reinvestment of dividends. The indices are net return indices calculated assuming the reinvestment of dividends net of withholding taxes using the tax rates applicable to non-resident institutional investors.

Chairman's Statement

Net asset and share price performance

This Half-year Report covers the six month period from 30 September, 2014 to 31 March, 2015, the first half of your Company's current financial year - which will end on 30 September, 2015.

In the half-year to 31 March, 2015, the net assets of your Company attributable to both its Ordinary and Zero Dividend Preference Shareholders, that is, total Shareholders' funds, declined by 9.5%. The net asset value (NAV) per Ordinary Share fell by 12.0% or by 10.1% on a diluted basis. The price of an Ordinary Share fell by a lesser 7.0% as the discount to NAV at which Ordinary Shares traded narrowed from 24.2% to 19.8% over the period. On a total return basis, assuming that the quarterly dividends received by an Ordinary Shareholder over the period were reinvested in the Company, the NAV per Ordinary Share fell by 10.6% and the total return on an Ordinary Share was -4.7%. In comparison, in the Company's financial year ended 30 September, 2014, the NAV per Ordinary Share and the price of an Ordinary Share rose by 26.9% and 32.9%, respectively, on a total return basis.

The Company's performance over the six month period covered by this Half-year Report compared unfavourably to the performance of the broader equity markets. In this period the MSCI World Index of developed country equity markets rose by 13.4% on a total return basis and in sterling terms. The MSCI World Utility Index rose by 8.9% while the MSCI World Energy Index fell by 9.6% on the same terms over the period. These comparisons, however, are complicated by the geographical weightings of the indices and the large movements in foreign exchange rates over the period, as explained more fully in the Investment Manager's Report.

The performance of the Company and the sectors in which it invests varied considerably between the fourth quarter of 2014 and the first quarter of 2015. Most of the Company's relative underperformance occurred in the fourth quarter of 2014 and was largely attributable to the dramatic fall in the oil price over the quarter and to a broad, indiscriminate sell-off of energy companies' shares. This included Lonestar Resources, your Company's largest investment, as well as companies perceived by investors - often incorrectly - to have an exposure to falling oil prices. In the first quarter of 2015, the performance of your Company stabilised as it performed broadly in-line with the sectors in which it invests which, however, themselves lagged the broader equity markets.

Dividend increase

On 28 November, 2014 the Company paid its first dividend at the new quarterly rate of 1.8125p per Ordinary Share - an increase of 7.4% over the previous rate of 1.6875p per Ordinary Share - which is the equivalent of 7.25p per annum. At the price of an Ordinary Share on 31 March, 2015 of 150p, this represents an annual yield of 4.8%.

Outlook

The International Monetary Fund ("IMF") published its semi-annual outlook for the world economy in April 2015 forecasting world growth of 3.5% in 2015 as compared to 3.4% in 2014. It characterised the outlook for growth as "moderate but uneven" and forecast an acceleration of growth in the advanced economies and a slowing of growth in the developing economies this year. While the legacy of high levels of debt continues to restrain spending and growth, the IMF believes that the macroeconomic risks to its forecasts have decreased somewhat over the past six months due to the stimulative effect of the fall in the oil price, exchange rate depreciation in the Euro area and Japan - which should make their exports more competitive - and signs of economic recovery in the Euro area. Geopolitical risks, however, such as conflicts in the Middle East and Ukraine and the possibility of an intensifying crisis in Greece, continue to pose risks to financial markets.

World equity markets were markedly more volatile over the six months to 31 March, 2015 than they were over the Company's financial year to 30 September, 2014 and this looks set to continue as investors react to divergences in regional growth prospects. The long anticipated rise in US policy interest rates, the pace of any European recovery, the prospects for Chinese growth and moves in commodity prices and foreign exchange markets all have the potential to contribute to greater volatility in world equity markets in coming months. Large movements in the market valuations of smaller companies in your Company's portfolio - such as Lonestar Resources - also contribute to the volatility of your Company's net asset value in the short-term. The results of the UK election, however, have significantly reduced regulatory risk in the UK.

Over the longer term, however, your Company's Investment Manager believes that the structural changes taking place in the global utilities sector, the investment required to replace ageing plant and to build new utility and energy infrastructure and the growing importance of renewable energy should give rise to opportunities for your Company to earn superior equity returns.

On 13 May, 2015, the last calculation date before the publication of this report, the net asset value per Ordinary Share was 183.68p and the share price was 148p.

Ian Barby

Chairman

19 May, 2015

Investment Manager's Report

Economy and markets

Over the six months to 31 March, 2015, the global economy continued to recover from recession with growth in the developed economies accelerating somewhat while it slowed in developing economies. With generally higher growth rates, however, developing economies still accounted for an estimated 70% of world growth over the period. The United States and the United Kingdom led the recovery in the developed economies and growth in the Euro area showed signs of picking up as it benefited from lower oil prices, a larger-than-expected quantitative easing programme announced by the European Central Bank in January and a depreciating currency. Although Japan, too, commenced a quantitative easing programme during the period, Japanese growth was close to zero over the six months. In China, growth continued to slow modestly, approaching 7% per annum.

Against a background of legacy issues associated with the world financial crisis and problems in the Euro area - notably, in Europe, high levels of debt, deleveraging and weak banks - two developments during the period had major, largely favourable implications for the world economy: a sharp and surprising drop in the oil price and large movements in foreign exchange rates. Over the six months to 31 March, 2015, the Brent crude and West Texas Intermediate (WTI) oil prices fell by 41.8% and 47.8%, respectively. This has acted as a stimulus to spending in major oil importing countries; that is, in most developed countries and in China and India. Over the same period, the US dollar strengthened 17.7% against the Euro, 9.6% against the yen and 9.4% against the pound. These large moves primarily reflected differences in monetary policy, with the United States ending its quantitative easing programme during the period and signalling that policy interest rates will rise over the intermediate term. In contrast, monetary policy in the Euro area and Japan is now headed in the opposite direction. The depreciation of their currencies against the dollar as the result of quantitative easing programmes should act as a stimulus to economic growth in the Euro area and Japan.

In the financial markets, government bond yields in the United States, the Euro area - with the single exception of Greece - and Asia declined over the six month period reflecting a lowering of inflationary expectations, the easing of monetary policy in the Euro area and Japan and, in the United States, an increased demand for US dollar denominated assets by foreign investors. While global equity markets gained over the period, markets were much more volatile than they were over the Company's financial year to 30 September, 2014 and performance varied considerably by sector. Geopolitical developments including the Ebola crisis, developments in the Middle East and Ukraine and the election of a new government in Greece all contributed to the higher volatility. Over the six months to 31 March, 2015, however, the MSCI World Index of developed country equity markets rose by 13.4% on a total return basis and in sterling. The MSCI World Utilities Index rose by 8.9% while the MSCI World Energy Index fell by 9.6%, both on a total return basis and in sterling.

Performance

Following a strong performance by the Company in the financial year to 30 September, 2014, the Company's net assets fell over the six months to 31 March, 2015, underperforming the broader equity markets. While the net asset value and price per Ordinary Share of the Company rose by 26.9% and 32.9%, respectively, on a total return basis in its most recent financial year - compared to an increase of 12.6% in the MSCI World Index - the net asset value per

Ordinary Share fell by 10.6% in the six months to 31 March, 2015 compared to a rise of 13.4% in the MSCI World Index on a total return basis in sterling terms. The price of an Ordinary Share, however, fell by only 4.7% over the period on a total return basis as the discount to net asset value at which the Ordinary Shares traded narrowed from 24.2% to 19.8%. The revenue return per Ordinary Share in the six months to 31 March, 2015 was 2.16p compared to 3.41p in the six months to 31 March, 2014. This is largely attributable to a large special dividend that was received in the earlier period. At 31 March, 2015 the Company's revenue reserves stood at £18,604,000, equivalent to 8.86p per Ordinary Share.

Most of the decline in the Company's net assets occurred in the fourth quarter of 2014 when the sharp fall in the oil price precipitated a dramatic and indiscriminate sell-off of energy companies and of companies which investors - not always correctly - believed had some exposure to the falling oil price. The share price of Lonestar Resources Limited ("Lonestar"), the Company's largest holding, fell by 33.8% in the fourth quarter having fallen broadly in line with the oil price since June 2014 even though its activities are concentrated in the basin with the lowest production costs of any unconventional energy basin in the United States, the Eagle Ford in south Texas. The sell-off also affected pipeline operators such as Williams Companies, the Company's second largest holding, even though its business is the regulated transportation of gas, not oil. Some renewable energy companies were also adversely affected by the fall in the oil price, apparently in the mistaken belief that cheaper oil would make renewable energy uncompetitive - even though oil is rarely used in electricity generation in developed countries and the principal drivers of renewable energy investment in these countries are regulation and legislation.

In the first quarter of 2015, the performance of the Company stabilised and it performed broadly in line with the global utility and energy sector indices. Contributors to performance over the six months were the Company's UK and Euro area portfolios, its renewable energy holdings - as the sector rebounded in the first quarter of 2015 - and its holdings in China. Notable individual performers were the French power company Direct Energie, the Company's sixth largest investment, the US integrated utility and renewable energy developer NextEra Energy, the Company's third largest holding, and a number of Euro area infrastructure companies including the Spanish infrastructure operators Ferrovial and Acciona, the Swiss airport operator Flughafen Zuerich and the Portuguese renewable energy developer and operator EDP Renovaveis. Nevertheless, over the six month period, six of the Company's ten largest holdings declined in value. The share price of Lonestar continued to decline, falling by another 37.7% in the first quarter of 2015 and by 58.8% over the six months to 31 March, 2015.

As explained in the Investment Manager's Report in the Annual Report and Accounts for the Company's most recent financial year ended 30 September, 2014, the Company does not measure its performance against a benchmark index or indices. It invests in a universe of utility and utility-related companies - including some exposed to the energy sector - and of companies in the infrastructure sector. Most of the Company's assets are in a transatlantic portfolio of European and North American companies although the Company invests on an opportunistic basis in other OECD markets and has some investments in emerging markets. As a consequence, the Company's performance is likely to diverge from the sector indices shown above and referred to in the Chairman's statement and this report.

The increase of 8.9% in the MSCI World Utilities Index on a total return basis and in sterling terms over the six months to 31 March, 2015, for example, reflects the fact that 54.4% of the index consisted of US companies at 31 March, 2015 and that these companies, on average, performed well. Within the US component of the index, regulated, interest rate sensitive utilities performed particularly well as US government bond yields unexpectedly fell over the period. In contrast, 34.5% of the Company's portfolio was invested in US companies at 31 March, 2015. Over the period, the Company also reduced its holdings of regulated utilities - in anticipation of higher US interest rates sometime this year - in favour of those utilities and energy infrastructure companies better positioned to benefit from economic growth in the US. The large moves in foreign currency exchange rates over the period also complicates comparisons although the Company's policy of not hedging its US dollar-denominated holdings while hedging its holdings denominated in Euros served it well over the period. Although the MSCI World Utilities Index rose by 8.9% on a total return basis over the period in sterling terms, it fell by 0.5% in US dollar terms.

Portfolio developments

An analysis of the Company's investment portfolio by geography, sector or type of investment and the market capitalisation of the companies in which the Company is invested is shown on page 6 of the Half-year Report. The changes over the six month period reflect market and foreign currency movements as well as asset allocation decisions by the Investment Manager. The Company lowered its exposure to the United States, largely on valuation grounds, and increased its exposure to the Euro area - where valuations are relatively low - in expectation of higher growth as a consequence of the European Central Bank's quantitative easing programme. The Company increased its exposures to non-regulated utilities - mostly vertically integrated power companies - at the expense of regulated utilities, principally in the United States, and to alternative energy. The decline in the Company's exposure to the energy sector primarily reflects the fall in the share price of Lonestar.

The Company's ten largest holdings at 31 March, 2015 included three companies which did not feature in the ten largest holdings at 30 September, 2014 although all numbered among the Company's investments at the time: Direct Energie, the French power company, which moved into the ten largest holdings through price appreciation, and the US companies Quanta Services and NRG Energy whose inclusion reflected the Company's decision to add to its holdings in these companies on price weakness. These companies replaced the US company General Electric, a position the Company liquidated over the period; the Spanish power and gas utility Endesa which fell in value after the payment of a large special dividend; and the Spanish tube maker Tubacex following a significant reduction in the Company's holding. Major purchases over the six month period were of Centrica, Suez Environnement, CEZ, GDF Suez, Fortum and Veolia Environnement in Europe and of Calpine, Quanta Services, Pattern Energy, NextEra Energy Partners, Kinder Morgan, Williams Companies and Xcel Energy in the United States. Major sales were of RWE, Pennon, Tubacex, Drax, National Grid, Melrose Industries and Severn Trent in Europe and of General Electric, OGE Energy, Sempra Energy, Exelon, Union Pacific and Northeast Utilities in the United States.

Lonestar Resources

Lonestar, the Company's largest investment, accounted for approximately 6% of the Company's portfolio at 31 March, 2015, down from a high of 19% in June 2014 when the oil price began its dramatic decline. Lonestar's shares, denominated in Australian dollars, declined by 58.8% over the half-year to 31 March, 2015, from A$0.40 to A$0.165 per share. The fall in Lonestar's share price has left it trading at a wide valuation discount to its peer group of smaller

North American companies which are active, like Lonestar, primarily in the Eagle Ford basin in south Texas. Depending on the valuation metric used, at its recent price of A$0.20 per share Lonestar trades at an average discount of between 51% to 90% to its peers. If Lonestar were trading in line with the average valuation of its US peers it would be trading at a share price of approximately A$0.97 per share.

Lonestar is well positioned to succeed in a low oil price environment and continues to make good operational progress. Its operations are concentrated in the Eagle Ford basin of south Texas which is acknowledged to have the lowest production costs of any basin in North America; costs which are falling rapidly due to improvements in drilling techniques and increased competition among service providers. It has a policy of hedging a substantial portion of its forward oil production and has hedged approximately 50% of its 2015 production and 40% of its 2016 production at average prices of $87 and $77 per barrel, respectively. Its producing wells are generating internal rates of return in excess of 30% p.a. at current oil prices and its drilling budget for 2015 and 2016 is forecast to be matched by cash flows. Lonestar's business objective is to drive up its valuation by developing its proven acreage, adding to its proven acreage by selective drilling on its other acreage and using its financial strength to make selective 'bolt on' acquisitions of acreage from financially stretched companies while continuing to grow its production.

Strategy and outlook

As the Company's largest investment - and one of its most volatile - Lonestar is important to the success of the Company over the intermediate term. The Company owns 55.5% of Lonestar and another 11.4% is held by long-term investors who were investors in Lonestar's predecessor, the unquoted company Ecofin Energy Resources plc. As a result, the 'free float' in Lonestar's shares is small, the shares are reasonably illiquid and small trading volumes can have a large effect on Lonestar's share price. In addition, the primary listing for Lonestar's shares is in Australia where most of the secondary trading in its shares takes place even though the Company's operating assets are in the United States. In keeping with local Australian practice for smaller companies, Lonestar's shares have been valued in cents, not dollars.

Lonestar is making a concerted effort to cultivate US investors and to close the valuation gap at which its shares trade relative to its US peers. On 8 May, 2015 shareholders approved a consolidation of its shares in the ratio of 1 new share for fifty old shares. Based on its recent share price of A$0.20, this increases its share price to A$10.00 - approximately US$8.00 at current exchange rates - in line with US practice. Following the listing of Lonestar's shares in US dollars on the US OTCQX exchange last year, the company is looking at ways it can upgrade its US listing and increase the liquidity in its shares. Lonestar's management is also devoting more of its time to meeting US analysts, brokers and investors. The Investment Manager is confident that the valuation gap at which Lonestar trades compared to its US peers will narrow and that the Company's investment in Lonestar will be realised on attractive terms.

As already mentioned above, the Company has reduced its exposure to the US and increased its exposure to the Euro area and may continue to do so over the coming months. While the universe of companies is very large in the United States, valuations are higher than in Europe, particularly for the shares of regulated, 'bond like' utilities which have enjoyed a period of out-performance as investors have sought yield. The valuations of these companies are at risk should US interest rates rise later in the year and the Company reduced its exposure to them in the six months to 31 March, 2015. The Company's portfolio in the US is now weighted toward regulated gas pipeline and network businesses as there are still large infrastructure needs to be met as US power companies replace coal generation - which is coming under ever more restrictive regulation - with gas-fired power plants and renewables. The portfolio is also weighted towards integrated utilities which are building renewable energy generating plant. These companies should be able to participate in economic growth but have underperformed with the oil price fall - even though they may have little or no direct exposure to the oil price - and investors' recent preference for higher yielding regulated utilities. With state renewable energy standards to be met, attractive federal tax treatment of renewables and a declining long-term cost curve due to technological improvements, the renewable sector is emerging as an attractive growth sector in its own right.

In Europe, we expect the combination of quantitative easing by the European Central Bank, a depreciating currency and low oil prices to act as a stimulus to growth. In the utility sector, however, power prices remain low and the growth of renewable energy generation is challenging the business models of many utilities. As a consequence, the legislative and regulatory environment in which Continental European utilities, especially, operate is likely to change, corporate activity is likely to increase and managements' strategies are becoming a critical differentiating factor in company performance. Although valuations by some measures are very attractive, we are selective in our exposure to commodity price-driven generation groups. The Company's portfolio is weighted towards larger utility businesses with international activities which should be able to participate in global growth. The portfolio is also weighted towards infrastructure operators and service providers which should benefit from higher levels of economic activity. In the United Kingdom, the investible universe is small although reserve margins in the power industry are very low by historical standards which should support power prices.

Elsewhere in the world, the Company is increasing its exposure to Japan and to China. Japan, too, has embarked on a programme of quantitative easing which should stimulate growth and its traditional utility companies are attractive on valuation grounds. In China, the renewable energy sector continues to grow with strong government support and its world class equipment manufacturers are rapidly gaining market share.

The outlook is for more far-reaching structural changes in the global utilities, infrastructure and energy industries against a background of very large investment requirements. The structural changes are driven by a number of factors including the decline of traditional, coal-fired electricity generation due to environmental considerations, the growth in the use of natural gas and liquefied natural gas (LNG) for electricity generation and heating globally and the dramatic increase in the renewable energy sector, albeit from a small base. In the United States, the energy revolution brought about by the exploitation of unconventional, shale-based reserves of oil and gas is having a profound effect on the energy and utilities industries. These changes are driving enormous new investments in energy transportation and interconnection - both in North America and Europe - such as gas pipelines to supply electricity generators and electricity transmission networks to link renewable energy generators to consumers. These changes - along with a resumption of economic growth - are seeing an increase in corporate activity and restructurings, the introduction of new capital market instruments and wide variations in the performance of individual companies. A specialist investor, such as the Company, should be well-placed to produce good returns for Shareholders over the longer-term.

Ecofin Limited

Investment Manager

19 May, 2015

Consolidated Statement of Comprehensive Income

for the half-year ended 31 March, 2015

The total column of this statement represents the Group's profit or loss, prepared in accordance with International Financial Reporting Standards (IFRS). The supplementary revenue and capital return columns are prepared under guidance published by the Association of Investment Companies ("AIC"). All items derive from continuing operations; the Group does not have any other recognised gains or losses.

Consolidated and Company Balance Sheets

As at 31 March, 2015

* The prior year Balance Sheet was restated to split out the derivative liabilities of £5,098,000 from the total investments held at fair value through profit or loss.

Consolidated and Company Cash Flow Statements

for the six months ended 31 March, 2015

Consolidated Statement of Changes in Equity

Notes to the Financial Statements

1 Accounting policies

1.1 Basis of preparation

The Half-year Financial Statements have been prepared in accordance with International Accounting Standard ("IAS") 34 "Interim Financial Reporting" and in accordance with the Statement of Recommended Practice ("SORP") for investment trusts issued by the Association of Investment Companies (AIC) in January 2009, where the SORP is not inconsistent with IFRS.

The financial information contained in this Half-year Report does not constitute statutory accounts as defined in Section 434 of the Companies Act 2006. The financial information for the periods ended 31 March, 2015 and 31 March, 2014 have not been audited. The financial information for the year ended 30 September, 2014 has been extracted from the latest published audited accounts. Those accounts have been filed with the Registrar of Companies and included the Independent Auditor's Report which, in respect of both sets of accounts, was unqualified, did not contain an emphasis of matter reference, and did not contain a statement under Section 498(2) or (3) of the Companies Act 2006. Those statutory accounts were prepared in accordance with IFRS, as adopted by the European Union.

The functional currency of the Company is sterling as this is the currency of the primary economic environment in which the Company operates. Accordingly, the Financial Statements are presented in sterling rounded to the nearest thousand pounds.

The same accounting policies, presentation and methods of computation have been followed in these Financial Statements as were applied in the preparation of the Company's Financial Statements for the previous accounting periods.

IFRS 10 Consolidated Financial Statements

The Financial Statements in these accounts reflect the adoption of IFRS 10 (including the Investment Entities amendment) which requires investment companies to value subsidiaries (except for those providing investment related services) at fair value through profit and loss rather than consolidate them. The Directors, having assessed the criteria, believe that the Group meets the criteria to be an investment entity under IFRS 10 and that this accounting treatment better reflects the Company's activities as an investment trust. Therefore all investments in subsidiaries (with the exception of EW&PO Finance plc) are carried at fair value through profit and loss in accordance with IAS 39.

EW&PO Finance plc, which is controlled by the Company, holds the ZDP Shares and has lent the proceeds to the Company. It is considered to provide investment related services to the Group and is therefore required to be consolidated under the IFRS 10 Investment Entities amendment. EW&PO Finance plc has been consolidated in these Financial Statements using consistent accounting policies to those applied by the Company.

1.2 Presentation of Statement of Comprehensive Income

In order to better reflect the activities of the Company as an investment trust company, and in accordance with guidance issued by the AIC, supplementary information which analyses the Consolidated Statement of Comprehensive Income between items of a revenue and capital nature has been presented alongside the Consolidated Statement of Comprehensive Income. In accordance with the Company's Articles of Association, net capital returns may not be distributed by way of dividend. Additionally, net revenue is the measure the Directors believe appropriate in assessing the Company's compliance with certain requirements set out in Section 1159 of the Corporation Tax Act 2010.

1.3 Going concern

The Directors have carefully reviewed the Company's current financial resources, the majority of net assets being securities which are traded on recognised stock exchanges, and the projected expenses for the next 12 months. They have also taken into consideration the Company's investment policy, its risk management policies, and its borrowing facilities. On the basis of that review, the Directors are satisfied that the Company's resources are adequate for the Company to continue in business for the foreseeable future and that, accordingly, it is appropriate to prepare the Financial Statements on a going concern basis.

1.4 Use of estimates

The preparation of Financial Statements requires the Company to make estimates and assumptions that affect the items reported in the Balance Sheet and Statement of Comprehensive Income and the disclosure of contingent assets and liabilities at the date of the Financial Statements. Although these estimates are based on management's best knowledge of current facts, circumstances and, to some extent, future events and actions, the Company's actual results may ultimately differ from those estimates, possibly by a significant amount. The investments in the equity and fixed-interest stocks of unquoted companies that the Company holds are not traded and as such the prices are more uncertain than those of more widely traded securities. The unquoted investments are valued by reference to valuation techniques approved by the Directors and in accordance with the International Private Equity and Venture Capital Valuation ("IPEV") Guidelines and IFRS 13.

1.5 Segmental reporting

The chief operating decision maker has been identified as the Board of the Company. The Board reviews the Company's internal management accounts in order to analyse performance. The Directors are of the opinion that the Company is engaged in one segment of business, being the investment business. Geographical segmental analysis has not been disclosed because the Directors are of the opinion that as an investment company the geographical sources of revenues received by the Company are incidental to its investment activity. The geographical allocation of the investments from which income is received and to which non-current assets relate is given on page 6 of the Half-year Report.

2 Income

3 Net asset value

Diluted NAV

The diluted NAV per Ordinary Share has been calculated on the assumption that the £79,830,923 (31 March 2014: £79,949,563 and 30 September, 2014: £79,909,563) nominal amount of CULS was fully converted on a 57.92:100 basis into 46,240,067 additional Ordinary Shares (31 March, 2014: 46,308,781 and 30 September, 2014: 46,285,613). This results in adjusted net assets, as noted above.

4 Return per class of share

The total return per Ordinary Share shown above can be further analysed between revenue and capital, as below:

Diluted return per Ordinary Share

The diluted return per Ordinary Share is calculated on the assumption that the CULS is converted at the beginning of the financial period on 30 September, 2014 into additional Ordinary Shares and that earnings reflect the savings in finance costs on the CULS after taxation. This results in an adjusted revenue return of £5,254,000 (31 March, 2014: £7,881,000 and 30 September, 2014: £16,313,000), an adjusted capital loss of £(48,393,000) (31 March, 2014: £39,219,000 and 30 September, 2014: £85,767,000) and adjusted weighted average shares in issue of 256,118,264 (31 March, 2014 and 30 September, 2014: 256,118,264).

The assumed conversion was dilutive for the half-year ended 31 March, 2015 and for the financial periods ended 30 September, 2014 and 31 March, 2014.

5 Dividends on Ordinary Shares

IAS 10 "Events after the Balance Sheet Date" requires dividends to be recognised in the period in which they are paid. The Company increased the quarterly dividend payable to Ordinary Shareholders from 1.6875p to 1.8125p per share with effect from the quarterly dividend paid on 28 November, 2014. The current dividend policy is to pay four quarterly dividends of 1.8125p per share to Ordinary Shareholders totalling 7.25p per share per year, markets permitting.

Amounts recognised as distributed to Ordinary Shareholders in the half-year to 31 March, 2015 are as follows:

6 Share capital

Ordinary Shares

At 31 March, 2015 there were 209,878,197 Ordinary Shares in issue (31 March, 2014: 209,809,483 and 30 September, 2014: 209,832,651) and 568,409 Ordinary Shares held in Treasury (31 March, 2014 and 30 September, 2014: 568,409).

During the six months to 31 March, 2015 the Company issued 45,546 Ordinary Shares following receipt of elections to convert by holders of the Company's CULS.

7 Non-current liabilities

6% Convertible Unsecured Subordinated Loan Stock 2016 (CULS)

On 29 July, 2009, the Company issued £80,000,000 nominal amount of CULS. The loan stock can be converted at the election of holders into Ordinary Shares during the months of May and November each year until May 2016 at a rate of 1 Ordinary Share for every 172.6445p nominal of CULS. It may also become compulsory for holders to convert their loan stock into Ordinary Shares of the Company at the conversion price then applicable if 80% or more of the nominal amount of the CULS issued has already been converted or has otherwise ceased to be in issue. Interest is paid on the CULS on 31 May and 30 November each year. The interest is charged 25% to revenue and 75% to capital within the Consolidated Statement of Comprehensive Income, in line with the Board's expected long-term split of returns from the investment portfolio of the Company.

As at 31 March, 2015 the nominal amount of CULS in issue was £79,830,923 (31 March, 2014: £79,949,563 and 30 September, 2014: £79,909,563).

CULS issued by the Company is regarded as a compound instrument, consisting of a liability component and an equity component. At the date of issue, the fair value of the liability component was estimated by assuming that an equivalent but non-convertible obligation of the Company would have a coupon rate of 7%. The difference between the proceeds of issue of the CULS and the fair value assigned to the liability component, representing the embedded option to convert the liability into equity of the Company, is included in equity. The liability is subsequently measured at amortised cost using the effective interest rate. Expenses associated with the issue are netted from the carrying value of the CULS and are amortised over the life of the CULS.

Zero Dividend Preference Shares (ZDP Shares)

On 29 July, 2009, the Company's subsidiary, EW&PO Finance plc, issued 60 million ZDP Shares at a price of 100p per share. The ZDP Shares will mature on 31 July, 2016 and had a gross redemption yield of 7% per annum at issue; that is, investors will receive 160.70p on 31 July, 2016 for every 100p invested. As at 31 March, 2015, there were 60 million ZDP Shares in issue (31 March, 2014 and 30 September, 2014: 60 million).

The Company issued to its subsidiary, EW&PO Finance plc, a non-interest bearing Subordinated Unsecured Loan Note 2016 ("Loan Note") equal to the net proceeds of the ZDP Share issue which were lent by the subsidiary to the Company under an agreement dated 29 September, 2009. This will be repaid or redeemed at par on 31 July, 2016 or earlier on demand by the subsidiary. The Company also entered into a subsidiary capital contribution agreement whereby the Company will undertake to contribute such funds to the subsidiary as will ensure that the subsidiary will have, after the repayment of the Loan Note by the Company, sufficient assets to satisfy the final capital entitlement of the ZDP Shares.

8 Effective rate of tax

The effective rate of tax reported in the revenue column of the Consolidated Statement of Comprehensive Income for the half-year ended 31 March, 2015 is 13% (half-year to 31 March, 2014: 10% and year to 30 September, 2014: 10%) based on a revenue return before tax of £5,190,000 (half-year to 31 March, 2014: £8,787,000 and year to 30 September, 2014: £16,590,000). This differs from the standard rate of tax of 20.5% (31 March, 2014: 23% and 30 September, 2014: 22%) as a result of income not taxable for corporation tax purposes.

9 Principal risks

The principal risks facing the Company along with, where appropriate, the steps taken by the Company's Board to mitigate such risks are summarised on pages 20 to 22 and note 20 to the Financial Statements in the Annual Report and Accounts for the year ended 30 September, 2014 (available on the Investment Manager's web pages (www.ecofin.co.uk) and from the Company Secretary). These include investment performance and market risk, income risk, liquidity risk, the Company's investment in majority-owned Lonestar, operational risks, and a loss of key investment personnel or clients by the Investment Manager which may impair its ability to manage the Company's assets. Additional risks relate to the Company's capital structure and use of gearing, investment in unquoted securities and securities of companies incorporated in non-OECD or emerging markets, and foreign exchange risk. A further risk relates to the interaction of supply and demand and general market or sector sentiment, as reflected in the discount to NAV at which the Ordinary Shares trade in the secondary market.

The specific financial risks associated with foreign currencies, interest rates, market prices, liquidity, credit, valuations and the use of derivatives - which may or may not be material to the Company - are described below:

Foreign currency risk

The value of the Company's assets and the total return earned by Shareholders can be significantly affected by foreign exchange movements as most of the Company's investments are denominated and quoted in currencies other than sterling, the currency in which the Company's Financial Statements are prepared. The Company's exposure to fluctuations in exchange rates will, to some extent, be mitigated by any borrowings in currencies other than sterling and any long-term currency hedges.

Interest rate risk

The Company is only exposed to significant interest rate risk through its prime brokerage borrowings with Citigroup Global Markets Limited and through the fair value of investments in fixed-interest rate securities. Prime brokerage borrowings varied during the half-year and at 31 March, 2015 amounted to £48,206,000 in a variety of currencies. The Company's fixed-income portfolio at 31 March, 2015 was valued at £9,318,000 compared with £8,812,000 as at 30 September, 2014.

Market price risk

The Company's investment portfolio is subject to fluctuations, volatility and the vagaries of market prices. The Directors receive regular updates on the Company's investment portfolio and seek to mitigate this risk by ensuring proper controls exist through the Investment Management Agreement for maintaining a diversified portfolio of securities of utility and utility-related companies and by ensuring that there are balances within the portfolio by geography, sub-sector and types of instrument. Please refer to the Portfolio Analysis on page 6 of the Half-year Report.

The ZDP Shares and the CULS provide gearing which is used to enhance returns although this also increases the Ordinary Shareholders' exposure to market risk, resulting in greater volatility in the net assets attributable to Ordinary Shareholders.

Liquidity risk

The Company's assets mainly comprise readily realisable securities which can easily be sold to meet funding commitments if necessary.

Unlisted investments in the portfolio are, however, subject to liquidity risk, as are thinly traded securities such as Lonestar. A liquidity analysis is prepared on at least a quarterly basis as part of the Investment Manager's Report and the liquidity profile of all securities, including unquoted and thinly traded securities, is reviewed by the Board. The Investment Manager reviews the liquidity profile of investments continuously.

Credit risk

Credit risk is mitigated by diversifying the counterparties with which the Investment Manager conducts investment transactions. The credit standing of all counterparties is reviewed periodically with limits set on amounts due from any one broker.

10 Fair values of financial assets and financial liabilities

Except for the Company's CULS and ZDP Shares which are measured at amortised cost as shown below, financial assets and financial liabilities of the Company are carried in the Balance Sheet at their fair value (investments and derivatives) or an amount which is a reasonable approximation of fair value (due from brokers, dividends receivable, accrued income, cash at bank, due to brokers and prime brokerage borrowings). The fair value is the amount at which the asset could be sold or the liability transferred in a current transaction between the market participants other than a forced or liquidation sale.

* This includes the equity component of the CULS of £5,410,000 (31 March, 2014: £5,417,000 and 30 September, 2014: £5,415,000).

** Market values have been used to determine the fair values of the Company's CULS and its ZDP Shares shown in the table above.

Amortised cost is derived using valuation techniques in accordance with a Level 3 investment, whereas fair value is derived using quoted prices in accordance with a Level 1 investment.

Fair values

The Company measures fair values using a three-level fair value hierarchy that reflects the level of judgement involved in estimating fair value. The hierarchy categorises the inputs used in valuation techniques into three levels:

Level 1: Investments valued using quoted market prices, unadjusted, in active markets for identical assets are included in Level 1.

Level 2: Financial instruments that are valued using observable inputs, i.e. quoted market prices, dealer quotations or alternative pricing sources supported by observable inputs, are classified as Level 2. Level 2 investments include the Company's forward currency contracts; these are valued using quotations provided by the Prime Broker which uses spot foreign exchange rates and interest rates in the respective currencies to provide the quotations.

Level 3: Investments classified as Level 3 have unobservable inputs and these include the Company's unquoted investments (equity, equity-related and debt instruments of unquoted companies). These types of securities are generally subject to higher valuation uncertainties and liquidity risks than securities listed or traded on a regulated market.

Level 3 fair values are determined by the Directors using valuation methodologies in accordance with the IPEV Guidelines and IFRS 13. Significant inputs include investment cost, the value of the most recent capital raising, the adjusted net asset value of funds and the Ecofin Pricing Committee's valuations. In accordance with IPEV Guidelines, new investments are carried at cost, the price of the most recent investment being a good indication of fair value. Thereafter, fair value is the amount deemed to be the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

The tables below set out fair value measurements of the Company's financial assets as at 31 March, 2015 according to this fair value hierarchy. There were no transfers during the period between Levels 1 and 2 and no transfers into or out of Level 3.

At 31 March, 2015, the Company's Level 3 investments accounted for 4.7% (31 March, 2014: 6.9% and 30 September, 2014: 4.8%) of its gross assets. Investments accounting for 3.2% of gross assets were in funds managed by third-party managers which value their funds at fair value. The Directors value these investments at net asset value, adjusted if necessary. In the case of two of the funds, the Directors have elected to apply a discount of 25% to the valuations supplied by the third-party managers in recognition of the illiquidity of the investments. Direct investments in the equity, equity-related or fixed-income securities of unquoted companies accounted for 1.5% of the Company's gross assets at 31 March, 2015. The Directors valued these investments at the price of the most recent investment or a percentage of this price.

The Directors may consider adjustments to these valuations. The range of possible adjustments could be large, depending on the circumstances. In the past, the Directors have accepted the recommendation of the Investment Manager and have made adjustments to the valuation of unquoted investments which have ranged up to 100% of their valuation as proposed by a third-party. For the purposes of sensitivity analysis, a 10% adjustment could be considered reasonable. A 10% adjustment to the valuation of all Level 3 investments would result in a movement in the Company's net assets of less than 1%.

A reconciliation of fair value measurements in Level 3 is set out below.

11 Financial commitments and contingent liabilities

As at 31 March, 2015, the Company had a commitment to invest $985,376 (30 September, 2014: $982,215) in Intergradora de Servicios Petroleros Oro Negro, S.A.P.I. De C.V. ("Oro Negro"), a Mexican oilfield services company.

12 Related party disclosure

Ecofin Limited acts as Investment Manager to the Company. Details of the relationship between the Company and the Investment Manager are set out in the Strategic Report, Directors' Report and note 6 to the Financial Statements in the Annual Report and Accounts to 30 September, 2014. Management fees for the half-year to 31 March, 2015 amounted to £3,505,000 (half-year to 31 March, 2014: £3,378,000 and year to 30 September, 2014: £7,219,000). Amounts still outstanding and included within other financial liabilities on the Balance Sheet were £1,746,000 (half-year to 31 March, 2014: £1,752,000 and year to 30 September, 2014: £1,902,000).

The Company owns the whole of the ordinary share capital (£50,000) of EW&PO Finance plc, a company which has issued the Group's ZDP Shares and is the holder of the Loan Note. The movement in the Loan Note during the period amounted to £2,917,000 (half-year to 31 March, 2014: £2,801,000 and year to 30 September, 2014: £5,714,000) and the balance outstanding at the half-year end included on the Balance Sheet was £87,826,000 (half-year to 31 March, 2014: £81,996,000 and year to 30 September, 2014: £84,909,000).

Bernard Lambilliotte is a Director of Lonestar, the Company's largest investment; he is also a Director of Oro Negro in which the Company has an investment.

Fees paid to Directors of the Company during the six months to 31 March, 2015 totalled £73,000 (half-year to 31 March, 2014: £73,000 and year to 30 September, 2014: £150,000).

Support

The Company has no contractual commitments or current intentions to provide any other financial or other support to its unconsolidated subsidiaries.

Restrictions

There are no restrictions on the Company's ability to access or use the assets of its wholly-owned subsidiary EW&PO Finance plc to settle the liabilities of the Group. The Company has no ability to access or use the assets of its unconsolidated subsidiary Lonestar and Lonestar has no ability to access the assets of the Company.

Interim Management Report

Except for those transactions disclosed in note 12, there have been no related party transactions undertaken by the Company in the first six months of the current financial year and there have been no changes to the related party disclosures described in the Annual Report and Accounts of the Company for the year to 30 September, 2014.

The Directors consider that the Chairman's Statement and the Investment Manager's Report on pages 2 to 5 of the Half-year Report, the above disclosure on related party transactions and the Directors' Responsibility Statement below, together constitute the Interim Management Report of the Company for the half-year to 31 March, 2015 and satisfy the requirements of Disclosure and Transparency Rules 4.2.3 to 4.2.11 of the Financial Conduct Authority. Ernst & Young LLP, the Company's Auditor, has reviewed this Half-year Report for the six months to 31 March, 2015.

Directors' Responsibility Statement

The Directors listed on page 27 of the Half-year Report confirm that to the best of their knowledge:

(i) the condensed set of Financial Statements within the Half-year Report has been prepared in accordance with IAS 34, "Interim Financial Reporting", as adopted by the European Union;

(ii) the Interim Management Report includes a fair review, as required by Disclosure and Transparency Rule 4.2.7 R, of important events that have occurred during the six months to 31 March, 2015 and their impact on the condensed set of Financial Statements, and a description of the principal risks and uncertainties for the remaining six months of the financial year; and

(iii) the Interim Management Report includes a fair review of the information concerning related party transactions as required by Disclosure and Transparency Rule 4.2.8 R.

This Half-year Report was approved by the Board on 19 May, 2015 and the above Directors' Responsibility Statement was signed on its behalf by:

Ian Barby

Chairman

19 May, 2015

Half-yearly Report 2015

The Company's Half-year Report for the six months ended 31 March, 2015 will be posted to Shareholders in May 2015. Copies of the Half-year Report and Financial Statements will be available from the Registered Office of the Company at 55 Moorgate, London EC2R 6PA and on the website, www.ecofin.co.uk, which is a website maintained by the Company's Investment Manager, Ecofin Limited. A copy of the Half-year Report for the six months ended 31 March, 2015 has been submitted to the National Storage Mechanism of the UK Listing Authority and will shortly be available for inspection at: www.Hemscott.com/nsm.do.

For further information, please contact:

Nariman Ghandhi

Company Secretary

For and on behalf of

BNP Paribas Secretarial Services Limited

Tel: 020 7410 5971

19 May, 2015