Жаңа Зеландия электр нарығының жұмыс принципі

The New Zealand electricity market (NZEM) is a decentralised electricity market regulated by the Electricity Industry Participation Code administered by the Electricity Authority (EA). The authority was established in November 2010 to replace the Electricity Commission.

Electricity is traded at a wholesale level in a spot market. The market operation is managed by several service providers under agreements with the Electricity Authority. The physical operation of the market is managed by Transpower in its role as system operator. Generators submit offers through a Wholesale Information and Trading System (WITS). Each offer covers a future half hour period (called a trading period) and is an offer to generate a specified quantity at that time in return for a nominated price. The System Operator (Transpower) uses a scheduling, pricing and dispatch (SPD) system to rank offers, submitted through WITS, in order of price, and selects the lowest cost combination of offers from the generators to satisfy demand. The market pricing principle is known as bid based security constrained economic dispatch with nodal prices. The highest priced bid offered by a generator required to meet demand for a given half hour sets the spot price for that trading period. Electricity spot prices can vary significantly across trading periods, reflecting factors such as changing demand (e. g. lower prices in summer when demand is subdued) and supply (e. g. higher prices when hydro lakes and inflows are below average). Spot prices can also vary significantly across locations, reflecting electrical losses and constraints on the transmission system (e. g. higher prices in locations further from generating stations). Trades take place at approximately 285 nodes (grid injection points and grid exit points) across New Zealand every half hour. Generators make offers to supply electricity at 59 grid injection points (GIPs) at power stations, while retailers and major users make bids to buy electricity at 226 grid exit points (GXPs) on the national grid. Final prices at each node, taking account of grid losses and constraints, are processed and confirmed the following day. All electricity generated is required to be traded through the central pool, with the exception of small generating stations of less than 10MW. Bilateral and other hedge arrangements are possible, but function as separate financial contracts. Trading develops by bids (purchaser/demand) and offers (generator/supply) for 48 half hour periods for each pricing nodes on the national grid. Bids and offers start 36 hours before the actual real time consumption or trading period. Up to four hours (pre dispatch) before the trading period starts a new forecast price is calculated to guide participants in the market. From four hours to the start of the trading period every half hour a dispatch price is calculated and communicated. One hour before the start of the trading period bids and offers can no longer be revised (with some exceptions) and the new prices reflect Transpower's adjustments in load forecasts and system availability. During each half hour period Transpower publishes a new real time price every five minutes, and a time weighted 30 minute average price. The real time prices are used by some large direct connect consumers to adapt their demand. The prices are however guidelines only as the final prices are calculated ex post—normally around 10:00am the following day, unless there are irregularities or disputes. Using the offer prices as established two hours before the trading period and volumes as established during the trading period. Differences between forecast, dispatch, real time and final prices can be significant.

In 2009, the Commerce Commission released a report by Stanford economist Frank Wolak on the ability of the four largest electricity suppliers to exercise unilateral market power in the wholesale electricity market and the economic rents (any payment in excess of the cost of production) that may have resulted. Using empirical industrial organization techniques, Wolak estimates these rents to be $4.3billion over the 7 years he studied when compared with a perfectly competitive market. The methodology he used and the results are also described in a working paper. His report was criticised for aspects of its methodology, with the Electricity Technical Advisory Group (ETAG), Ministry of Economic Development, claiming that there is no evidence of the sustained exercise of market power. An agent based model (ABM) developed at Auckland University was used to analyse the New Zealand wholesale electricity market. The model suggests considerable market abuse and quantified the combined market rents for 2006 and 2008 to be $2.6billion, when compared with a perfectly competitive market as counterfactual. In terms of residential electricity prices, a 2015 report found these were twice as high under retail competition.

There have been long standing concerns about the potential for market abuse under nodal pricing, particularly when the transmission system becomes congested. Genesis Energy was "net pivotal" north of Hamilton on 26 March 2011. The HVAC network was under scheduled maintenance with 2 of 6 220kV lines out and 3 of 5 110kV lines out, thereby restricting supply from the South Island. Extreme bids by Genesis Energy sent Auckland spot prices to $23047/MWh (€15000/MWh), these prices later returned $197/MWh (€125/MWh) – a factor of 117×. The Electricity Authority declared a UTS (undesirable trading situation) and subsequently dropped the final price to $3000/MWh (€2000/MWh). The Electricity Authority decision was challenged and the High Court of New Zealand found in favor of the regulator. There were 29 recommendations arising from the review. One of the key recommendations approved by Cabinet was the transfer of ownership and operation of some power stations between Genesis Energy and Meridian Energy in order to increase retailer competition in both islands and to give Genesis a South Island generating base. It was decided that Genesis would receive the Tekapo A and Tekapo B hydroelectric power stations from Meridian, and Meridian would receive the Whirinaki Power Station from the government (although Meridian eventually declined to accept). The transfer of Tekapo A and B was completed on 1 June 2011. On 1 November 2010, the Electricity Authority commenced operations, taking over from the Electricity Commission. In April 2013, the Labour Party and the Green Party said if they were to win the 2014 election, they would introduce a single buyer for electricity, in order to cut retail costs. The government responded by calling it "economic vandalism", comparing it to the Soviet Union, but Greens co leader Russel Norman said it would boost the economy and create jobs. By the following day, shares in privately owned power company Contact Energy had fallen by more than 10 percent. The general election held on 20 September 2014 was won by the National Party. Share prices of listed electricity companies rose significantly when the share market opened on the Monday following the election.

The New Zealand electricity market is split into the following areas: administration and market clearing, regulation, generation, transmission, distribution and retailing. The current legislation (Electricity Industry Reform Act 1998) prevents the ownership of cross sector investment (that is energy and lines functions). This means a generation company cannot own or have an interest in a distribution company and a distribution company cannot retail electricity or deal in electricity hedges. There are two exceptions to the regulations: generation companies can own the lines required to transport electricity from their power stations to the grid or local distribution network; and distribution companies can own a small amount of conventional generation capacity within their network but are not limited in the level of renewable generation capacity. There is no barrier to vertical integration from generation to retail. The overall arrangement of the industry creates some very interesting market behaviour amongst the players. Generation is dominated by five companies: Contact Energy, Genesis Energy, Mercury Energy, Meridian Energy, and Trustpower.

The retailers are: Contact Energy, Ecotricity, Electra Energy, Electric Kiwi, Energy Direct, Energy Online, Flick Electric, Genesis Energy, Giving Energy, GLOBUG, King Country Energy, , Mercury Energy, Meridian Energy, Nova Energy, Opunake Hydro, Paua to the People, Payless Energy, Powershop, Pulse Energy, Tiny Mighty Power and Trustpower. Many of the retailers are owned by generating companies. For example, Mercury Energy owns GLOBUG and Tiny Mighty Power. Some retailers are restricted to certain geographical locations, such as King Country Energy which supplies to the King Country region of the Waikato. + Market share of electricity retailers as at 30 June 2021 Company New Zealand North Island South Island ICP count ICP share ICP count ICP share ICP count ICP share Genesis Energy 488,416 22.07% 411,547 25.22% 76,844 13.22% Contact Energy 419,992 18.98% 269,998 16.55% 149,966 25.80% Meridian Energy 349,677 15.80% 196,262 12.03% 153,368 26.38% Mercury Energy 330,955 14.95% 293,279 17.97% 37,647 6.48% Trustpower 266,349 12.03% 196,262 12.04% 69,832 12.01% Nova Energy 112,640 5.09% 98,090 6.01% 14,534 2.50% Pulse Energy 84,472 3.82% 52,487 3.22% 31,984 5.50% Electric Kiwi 78,349 3.54% 55,353 3.39% 22,996 3.96% Vocus 39,163 1.77% 30,147 1.85% 9,011 1.55% Flick Electric 26,672 1.21% 16,784 1.03% 9,888 1.70% Other retailers 16,626 0.75%