Financial Risk Management Objectives

TrustPower's activities expose it to a variety of financial risks: electricity price risk, interest rate risk, exchange rate risk, liquidity risk and credit risk. The Group's overall risk management programme focuses on the unpredictability of financial markets and seeks to minimise potential adverse effects on the Group's financial performance. The Group uses derivative financial instruments to hedge certain risk exposures. Risk management is carried out under policies approved by the Board.

(a) Electricity Price Risk

The Group typically sells more electricity at fixed prices than it generates. As a result the Group is required to purchase a percentage of its electricity sold off the electricity spot market. This leaves the Group exposed to fluctuations in the spot price of electricity where it sells electricity at a fixed price. The Group operates under an energy trading policy which limits the exposure the Group may have in any future period. Future exposure is estimated based on expected fixed price sales and generation output. The Group has entered into a number of electricity hedge contracts to reduce the commodity price risk from price fluctuations on the electricity spot market. These hedge contracts establish the price at which future specified quantities of electricity are purchased. Any resulting differential to be paid or received is recognised as a component of energy costs through the term of the contract. The Group has elected to apply cash flow hedge accounting to those instruments it deems material and which qualify as cash flow hedges while immaterial contracts are not hedge accounted.

The aggregate notional volume of the outstanding electricity derivatives at 31 March 2011 was 900GWh (31 March 2010: 1,146GWh).

The hedged anticipated electricity purchase transactions are expected to occur continuously throughout the next five years from the end of the reporting period consistent with the Group's forecast electricity generation and retail electricity sales. Gains and losses recognised in the cash flow hedge reserve on electricity derivatives as of 31 March 2011 will be continuously released to the income statement in each period in which the underlying purchase transactions are recognised in the income statement.

Sensitivity analysis

The following tables summarise the impact of increases/decreases of the relevant forward electricity prices on the Group's post-tax profit for the year and on other components of equity. The sensitivity analysis is based on the assumption that the relevant forward electricity prices had increased/decreased with all other variables held constant as a result of the fair value change in electricity price derivatives.

(b) Interest Rate Risk

The Group's bank borrowings are all on floating interest rates exposing it to the risk that rising interest rates will increase the Group's interest expense and, hence, reduce its profitability. The Group operates under a treasury policy which prescribes the proportion of fixed interest rate cover the Group must hold in relation to its future borrowings. This proportion is calculated based on the actual fixed rate cover held and the forecast debt levels of the Group. The Group has various interest rate financial instruments to manage exposure to fluctuations in interest rates. Any resulting differential to be paid or received on the instruments is recognised as a component of interest paid. The Group has elected to hedge account only a limited number of these instruments.

The aggregate notional principal amounts of the outstanding interest rate derivative instruments at
31 March 2011 was $440,415,000 (31 March 2010: $563,197,000).

Interest payment transactions are expected to occur at various dates between one month and nine years from the end of the reporting period consistent with the Group's forecast total borrowings.

Effective interest rates for the Parent and the Group are disclosed in note 25.

Sensitivity analysis

At 31 March 2011, if interest rates at that date had been 100 basis points higher/lower with all other variables held constant, post-tax profit for the year and other components of equity would have been adjusted by the amounts in the table below, as a result of the fair value change in interest rate derivative instruments.

(c) Exchange Rate Risk

During the course of business the Group may enter into contracts for the construction of generation assets and the sale of carbon credits to be settled in a foreign currency in the future. This exposes the Group to movements in foreign exchange rates. The Group operates under a treasury policy which requires all foreign currency transactions over certain limits to be 100% hedged. Compliance with this policy is measured by forecasting future foreign currency transactions and ensuring that the exchange rate has been fixed. The Group enters into forward exchange contracts to reduce the risk from price fluctuations of foreign currency costs associated with the construction of property, plant and equipment or income associated with the sale of carbon credits. Any resulting differential to be paid or received is recognised as a component of the cost of the project for the construction of generation assets and as a part of revenue for the sale of carbon credits. The Group has elected to apply cash flow hedge accounting to these instruments.

The aggregate notional principal amounts of the outstanding forward foreign exchange contracts at
31 March 2011 was $20,689,000 (31 March 2010: $25,062,000).

The hedged anticipated transactions denominated in foreign currency are expected to occur at various dates between one month and two years from the end of the reporting period. Gains and losses recognised in the cash flow hedge reserve in equity on forward foreign exchange contracts as at 31 March 2011 will be recycled to revenue from the sale of carbon credits when the credits are sold.

Sensitivity analysis

At 31 March 2011, if the New Zealand dollar had weakened/strengthened by 10 per cent against the currencies with which the Group has foreign currency risk with all other variables held constant, post-tax profit for the year would not have been materially different.

Other components of equity would have been $(1,387,000)/$1,458,000 (lower)/higher (31 March 2010: $(2,248,000)/$2,041,000 (lower)/higher), arising from foreign exchange gains/losses on revaluation of foreign exchange contracts in a cash flow hedge relationship.

(d) Credit Risk

The Group has no significant concentrations of credit risk (2010: none). It has policies in place to ensure that sales are made to customers with an appropriate credit history. Where a potential customer does not have a suitable credit history a bond is required before the customer is accepted. Derivative counterparties and cash transactions are limited to high credit quality financial institutions with a minimum Standard & Poor's long-term credit rating of A+ and other large electricity market participants (all have a Standard & Poor's long-term credit rating of at least BBB). Where a potential counterparty does not meet these credit criteria the maximum level of credit exposure is set individually by the Board. The Group has policies that limit the amount of credit exposure to any counterparty.

The carrying amounts of financial assets recognised in the statement of financial position best represents the Group's maximum exposure to credit risk at the reporting date without taking account of the value of any collateral obtained. As shown in note 19, the reported accounts receivable balance includes a provision for doubtful debts of $1,800,000 (2010: $2,000,000).

The Group has around 221,000 customers (2010: 225,000), only four (2010: four) of which make up more than one per cent of the Group's total accounts receivable balance. The largest of these customers accounts for 4 per cent (2010: 7 per cent) of the Group's total accounts receivable.

As of 31 March 2011, trade receivables relating to the Group and the Parent of $3,589,000
(2010: $4,447,000) were past due but not impaired. The ageing analysis of these trade receivables
is as follows:

As of 31 March 2011, trade receivables relating to the Group and the Parent of $1,800,000 (2010: $2,000,000) were past due and impaired.

The ageing analysis of these trade receivables is as follows:

For details of the receivables considered impaired refer to note 2.4.

Movements on the provision for impairment of trade receivables are as follows:

(e) Liquidity Risk

The Group's ability to readily attract cost effective funding is largely driven by its credit standing.

Prudent liquidity risk management implies maintaining sufficient cash and marketable securities, the availability of funding through an adequate amount of committed credit facilities and the spreading of debt maturities. The Group operates under a treasury policy which dictates the level of available committed facility to be maintained to provide cover for reasonably conceivable adverse conditions. This is measured by forecasting debt levels under various adverse scenarios and comparing this to committed facility levels. The treasury policy also requires a spread of debt maturities which is measured by the proportion of debt maturing in various time bands.

The tables below analyse the Group's and the Parent's financial liabilities excluding gross settled derivative financial liabilities into relevant maturity groupings based on the remaining period to the earliest possible contractual maturity date at the period end date. The amounts in the tables are contractual undiscounted cash flows.

Fair Values

Except for subordinated bonds and senior bonds (see notes 26 and 27), the carrying amount of financial assets and financial liabilities recorded in the financial statements approximates their fair values.

Estimation of Fair Values

The fair values of financial assets and financial liabilities are determined as follows:

• The fair value of financial assets and liabilities with standard terms and conditions and traded on active liquid markets are determined with reference to quoted market prices.

• The fair value of other financial assets and liabilities are calculated using discounted cash flow analysis based on market-quoted rates.

• The fair value of derivative financial instruments are calculated using quoted prices. Where such prices are not available, use is made of discounted cash flow analysis using the applicable yield curve or available forward price data for the duration of the instruments.

Where the fair value of a derivative is calculated as the present value of the estimated future cash flows of the instrument, the two key types of variables used by the valuation techniques are:

• forward price curve (as described below); and

• discount rates.

The selection of variables requires significant judgement and therefore there is a range of reasonably possible assumptions in respect of these variables that could be used in estimating the fair value of these derivatives. Maximum use is made of observable market data when selecting variables and developing assumptions for the valuation techniques. See earlier in this note for sensitivity analysis.

NZ IFRS 7 requires that financial instruments that are measured in the statement of financial position at fair value, this requires disclosure of fair value measurements by level of the following fair value measurement hierarchy:

• Quoted prices (unadjusted) in active markets for identical assets or liabilities (level 1)

• Inputs other than quoted prices included within level 1 that are observable for the asset or liability, either directly (that is, as prices) or indirectly (that is, derived from prices) (level 2)

• Inputs for the asset or liability that are not based on observable market data (that is, unobservable inputs) (level 3).

The following tables present the Group's and Parent's financial assets and liabilities that are measured at fair value.

Electricity price derivatives are classified as Level 3 because the assumed location factors which are used to adjust the forward price path are unobservable.

A sensitivity analysis showing the effect on the value of the electricity price derivatives of reasonably possible alternative price path assumptions is shown in section (a) of this note.

Capital Risk Management Objectives

The Group's objectives when managing capital are to safeguard the Group's ability to continue as a going concern so that it can continue to provide returns for shareholders and benefits for other stakeholders and to maintain an optimal capital structure to reduce the cost of capital.

In order to maintain or adjust the capital structure, the Group may adjust the amount of dividends paid to shareholders, return capital to shareholders, issue new shares or sell assets to reduce debt.

Consistent with others in the industry, the Group monitors capital on the basis of the gearing ratio. This ratio is calculated as net debt divided by total capital.

• Net debt is calculated as total borrowings less short term deposits. Total borrowings are calculated using a value of unsecured bank loans plus unsecured subordinated and senior bonds.

• Total capital funding is calculated as total equity as shown in the statement of financial position, adjusted for the fair value of financial instruments, plus net debt.

The gearing ratio is calculated below: