Mercury Energy is one of New Zealand’s four major gentailers, generating electricity primarily from hydro stations in the Waikato and geothermal plants in the Bay of Plenty/Taupō region. Their generation fleet is approximately 90%+ renewable. They have a strong following in the Waikato region and are well-regarded for their EV charging plans.
Type: Gentailer (generates + retails)
Generation: Hydro (Waikato River) + geothermal (~90%+ renewable)
Plan types: Fixed-term, variable, EV night rate
Notable: Strong in Waikato/BOP; best gentailer EV charging plan
Mercury Energy Plans (2026)
Standard Variable Plan
- Unit rate: approximately 31–37c/kWh (major urban areas, incl. GST)
- Daily charge: approximately 50–75c/day
- Open-term, no lock-in
Fixed-Term Plans (12 or 24 months)
- Rate locked for contract period
- Break fee applies if you leave early
EV Night Rate Plan
Mercury’s standout offering for EV owners:
- Discounted overnight rate (typically 11pm–7am) for all electricity — not just EV charging
- Ideal for households that shift dishwasher, washing machine, and EV charging to overnight periods
- Requires a smart meter
Mercury’s Strengths
1. Strong renewable generation Mercury generates ~90%+ of their electricity from renewable sources — the Waikato River hydro chain (8 stations from Whakamaru to Karapiro) and the Kawerau and Rotokawa geothermal plants in the Bay of Plenty. Their renewable credentials are strong.
2. Best gentailer EV plan Mercury’s overnight rate plan is one of the best structured EV charging deals from a major gentailer. The discounted overnight rate applies to all electricity during those hours (not just EV-specific meter channels), so households that shift their general load overnight benefit fully.
3. Competitive for small households Mercury’s Low User plan options tend to be competitive for 1–2 person households with below-average consumption.
4. Good online tools and app Mercury’s digital account management is solid — usage tracking, billing management, and plan comparison are all accessible.
5. Strong regional presence Mercury is particularly well-priced in Waikato, Bay of Plenty, and Taranaki regions where their generation assets are located.
Mercury’s Weaknesses
1. Not always competitive outside core regions In Auckland, Wellington, and Christchurch, Mercury doesn’t always appear near the top of Powerswitch comparisons. Independent retailers often match or beat them.
2. No broadband bundle Mercury doesn’t offer broadband services. If you want a power + broadband package, Electric Kiwi or Contact Energy are better options.
3. Standard pricing is middle-of-the-road On a pure price basis (excluding the EV plan benefit), Mercury is competitive but not exceptional. Independent retailers often offer lower unit rates.
Who Is Mercury Energy Best For?
- EV owners — Mercury’s overnight rate plan is one of the best for households charging an EV
- Waikato and Bay of Plenty households — Mercury is often genuinely competitive in their home regions
- Small households (1–2 people) using under 8,000 kWh/year
- Households who want strong renewable generation credentials from a gentailer
Mercury vs Electric Kiwi for EV Owners
Both are frequently recommended for EV owners:
| Feature | Mercury | Electric Kiwi |
|---|---|---|
| EV-specific plan | Yes (overnight rate) | Yes (EV MoveMaster + Hour of Power) |
| Off-peak structure | Fixed overnight rate | Fixed rate + 1 free hour |
| Broadband bundle | No | Yes |
| Contract | Optional fixed or open-term | No contract |
| Generation | ~90%+ renewable | Grid mix (buys wholesale) |
For most EV owners, Electric Kiwi’s combination of competitive rates + Hour of Power + broadband bundle gives a slight edge in total value — but Mercury is the best gentailer option.
Verdict
Mercury Energy is a solid choice for EV owners and households in the Waikato/BOP region. Their high renewable generation and competitive overnight rate plan make them one of the more appealing gentailers. For other regions or households without EVs, always check Powerswitch to see if Mercury is competitive at your address.
Rating: 3.5/5 — Good for EV owners and Waikato/BOP households; compare for other situations.