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How to use WITS to watch wholesale power prices

Keen to keep track of the spot prices on NZ’s wholesale electricity market? (Super handy if you’re one of our Home Generation Flicksters!).

You’ll find the best info on the WITS website. WITS stands for Wholesale Information Trading System, and it’s run by NZX. It contains all real-time information on wholesale electricity prices, and is a free-to-air site available to the general public.

While WITS is loaded with all the good data, it can be a tad tricky to use, so here’s our step-by-step guide to viewing your spot prices.

What’s the quickest way to view current spot prices?

Easy as. Head to the WITS dashboard. In the top right-hand corner you’ll see a grey map of Aotearoa, labelled RTD Price Map. Around the map are coloured boxes, depicting the grid points and a snapshot of market prices in real-time. FLICK0257 WITS Blog GREY 3

To get an idea of your current wholesale price, pick the grid point nearest your region. The price shown in the box is $/MWh, so simply move the decimal point one space to the left to find your c/kWh price – for example, Stratford shows 121.00 $/MWh which equates to 12 c/kWh.

What’s the current spot price at my specific Grid Exit Point?

Grid Exit Points (also known as GXP or POC) are the connection points to the national grid, where electricity flows from the grid to local networks. There are lots of GXPs around Aotearoa.

To see prices at a specific GXP, you’ll first need to know its reference (e.g. HAY0111). If you’ve got access to the Electricity Registry you’ll be able to find this in the ‘Network’ section of the Registry, however most people don’t have access to the Registry, so simply get in touch with us and we’ll find it for you.

Once you’ve got your GXP, head to the WITS dashboard. You’ll notice the menu runs vertically down the left side of the page. Click on the second tab, ‘Market Prices’ (the dollar sign!). FLICK0257 WITS Blog GREY 4

On the ‘Market Prices’ page, scroll to the ‘Grid Point’ section.

You’ll see that it automatically populates data for Benmore (BEN2201), Haywards (HAY2201) and Otahuhu (OTA2201), so you can delete these if they’re not the GXPs you’re looking for by clicking on the ‘X’.

Enter your GXP into the ‘Grid Points’ field, click the applicable result and make sure you hit ‘Refresh Results’. FLICK0257 WITS Blog GREY 8

And voila! You should see a graph showing today’s prices as well as forecast prices for the rest of the day. FLICK0257 WITS Blog GREY 7

What are the historical spot prices at my Grid Exit Point?

(Heads up - to find this info, you’ll need your GXP reference again).

On the WITS dashboard menu, scroll down to the ‘Historical Data’ tab (the clock icon). FLICK0257 WITS Blog GREY 6

On the ‘Historical Data’ page, follow the same process as above and scroll down to the ‘Grid Point’ section.

Again, delete the GXPs that aren’t relevant, enter the GXP/POC into the ‘Grid Points’ field and click ‘Refresh Results’. FLICK0257 WITS Blog GREY 5

On the next screen, you’ll be able to select the month or year that you want data for. Once you’ve entered your dates, hit ‘Refresh’ again, and on the right you should see the relevant date and a downloadable file. FLICK0257 WITS Blog GREY 1

Download it, open the unzipped file, and you’ll be able to see all spot prices for your selected dates in column ‘D’.

To see the average spot price for that period, click on column ‘D’ to highlight the entire column of spot prices.

In the bottom right-hand corner, you can view the sum and the average. Remember to move the decimal point one place to the left to find the average c/kWh spot price. FLICK0257 WITS Blog GREY 2

So in this example, the average spot price was 8.76 c/kWh.

Still got WITS questions, or want some helping walking through each step? No problemo – hit the ‘Contact Us’ button below!