Mercury NZ Limited

The Business

Mercury generates electricity from nine hydro stations on the Waikato River (1,120MW), geothermal fields, and wind farms, then sells that power to retail and business customers under the Mercury and Trustpower brands. It is a vertically integrated "gentailer," both generator and retailer, a structure shared by New Zealand's four major electricity companies. The Crown holds a legislated minimum 51% stake, which underpins the balance sheet but also caps takeover speculation and limits acquisition flexibility. Mercury carries the largest new-generation pipeline of the four gentailers.

Recent Performance

FY26 revenue jumped 23%, but that was flattered by Waikato inflows near the top of the historical range, not by underlying demand growth. EBITDAF (earnings before interest, tax, depreciation, amortisation, and fair value changes) reached $1,068 million on that tailwind. The strong year has helped support a share price of A$5.63, but it also sets a difficult comparison: our FY27 forecast assumes hydro reverts toward its long-run average, and revenue is expected to fall as a result.

Outlook

Growth resumes from FY28 as new geothermal and wind capacity comes online, with revenue expected to return to mid-single-digit annual growth. EBITDAF margins are expected to drift modestly lower over the same period as fixed costs absorb a normalising revenue base. Earnings per share are likely to dip in FY27 before growing again, and the dividend is on track to extend its 18-year run of increases as the capital-spending cycle eases and free cash flow improves.

Key Risks

A forced structural separation of generation and retail, under review by the Competition Task Force, could permanently cut Mercury's margins by removing the natural hedge between its generation and retail businesses. Oversupply from the roughly 3GW of new renewable capacity under construction across the sector could push wholesale prices materially lower and compress earnings sector-wide, not just for Mercury. A multi-year drought affecting Waikato inflows would strip a further layer of earnings from the base case, a risk that is harder to offset than a single dry year because it reflects a structural shift in rainfall patterns rather than a temporary one.

What to Watch

The thesis-defining event is the Competition Task Force's interim report, expected mid-2027, which will confirm whether the integrated gentailer model survives intact or faces structural reform.

• Q2 CY2027 Competition Task Force interim report — a separation recommendation would be a permanent de-rating event; confirmation of status quo removes the largest overhang.
• Q4 CY2026 NZ Official Cash Rate decision — a rate cut lowers the discount rate applied to Mercury's long-life assets, a meaningful input to how the market prices the stock.

Company Description

Mercury's generation fleet is anchored by nine hydro stations on the Waikato River, supplemented by geothermal plants at Kawerau and Rotokawa and a growing wind portfolio. This 100% renewable mix carries zero fuel cost and zero fossil-fuel transition risk. The retail division serves roughly 590,000 residential and business connections under the Mercury and Trustpower brands, providing a natural hedge: when wholesale prices rise, generation profits offset retail margin pressure, and vice versa. Mercury also supplies large industrial customers directly. The company is listed on the NZX with an ASX foreign-exempt listing, and reports in New Zealand dollars.

Where the Growth Is

The growth pipeline, centred on Mahinerangi Stage 2 and further geothermal and wind extensions, targets 3.5TWh of new generation capacity by 2030, the largest such pipeline among New Zealand's four gentailers. Delivered on schedule, this supports trading margin growth of 3% to 5% into the terminal period, and execution running ahead of plan would be a meaningful positive for the earnings trajectory beyond FY30.

Competitive Position

Mercury's core advantage is physical, not strategic: the Waikato hydro scheme and its geothermal resource consents cannot be replicated by a competitor, and both carry asset lives of 50 to 100-plus years. Against peers, Mercury trades at 9.9 times EV/EBITDAF, below Contact Energy's 10.5 times and Meridian's 12.0 times, but above Genesis Energy's 8.5 times, a fair reflection of its mid-pack scale within a four-player market that controls the vast majority of NZ generation and retail supply. This advantage looks durable over the medium term, though a regulatory reset of the gentailer structure is the one lever that could erode it faster than the assets themselves would suggest.

Management & Capital Discipline

Management has delivered more than $1 billion in major projects on budget and on time, held operating costs flat at $370 million despite sector-wide cost inflation, and extended an 18-year run of consecutive dividend increases. One point worth flagging directly: management's commentary implicitly credits roughly half of the FY26 earnings outperformance to internal execution, but our assessment attributes closer to two-thirds of that beat to favourable hydrology, a factor outside management's control. That does not undermine the execution track record, but it does mean investors should not extrapolate FY26's growth rate.

Financial Position

Mercury's balance sheet is rated strong, with net debt held around two times EBITDAF and an investment-grade credit rating that benefits from an implicit uplift tied to Crown ownership. Liquidity headroom comfortably covers near-term capital commitments. As the growth-capex cycle peaks and then eases toward FY30, free cash flow is set to strengthen, giving Mercury capacity to fund its pipeline and its dividend without stretching the balance sheet through a weather-driven earnings downturn.