Some retailers, including Amber Electric and Arcline from RACV offer an innovative 'wholesale pass-through' pricing model where they charge their customers variable wholesale rates for energy, plus a fixed monthly membership charge.

Although the actual price per kWh varies every 30 minutes, retailers offering this pricing model are still obliged to publish Fact Sheets for their plans that quote conventional prices per kWh. Bill Hero uses those official Fact Sheet prices to calculate the comparison prices for these plans that are included in our full-market comparison. When a Bill Hero subscriber uploads one of these dynamicly priced bills to be compared, we use the consumption data and final bill to calculate how it compares to the other conventionally priced plans available in the market.

In theory, for most products, access to wholesale rates is very attractive. This is true in principle for energy as well. However, it does come with some additional risk and complexity for energy consumers.

Wholesale energy spot prices change every 30 minutes and can be subject to extreme volatility. Aside from actually collecting the payments that fund the entire energy economy, one of the main roles of an energy retailer is to absorb wholesale price volatility so that energy consumers can pay predictable rates for the energy they use.

Under a wholesale pass-through model, you're directly exposed to the full spot market volatility. AEMO sets limits on how high and low the spot price can vary - currently, this is up to $17,500 per mWh, or $17.50 per kWh, and down to -$1,000 per mWh, or -$1.00 per kWh.

The effective per-kWh price you'd pay under a wholesale passthrough bill depends on the prevailing wholesale spot price for each 30-minute window when you consume electricity.

If you're willing and able to track the spot price and adjust your usage accordingly, this kind of plan can yield great price results. If you have solar and a battery, you can act as an energy trader and pursue an arbitrage strategy by soaking up cheap power in your battery when it's available and then exporting it when the price is high.

Amber offers a mobile app that can help you understand and predict price fluctuations so you can adjust your usage accordingly.

Even if you diligently follow the market to minimise your high-priced usage, you can undo all that good work by overusing power at a peak time when the price spikes. If you're not able or willing to pay attention to the market and adjust your usage, you could wind up being charged more than you would under a conventional plan.

Amber plans include insurance that guarantees that even if you overuse at expensive times and run up high bills, the insurance will compensate you if you've been charged more than Default Offer equivalent rates. This is a good feature and reduces the risk to consumers, but it does mean that you'd be out of pocket until the insurance rebate kicks in, effectively giving an interest-free loan to Amber.

In general, a wholesale pass-through plan is most suitable for energy consumers who are motivated to watch the market more or less constantly and are able to adjust their usage opportunistically, e.g. by running the washing machine and dishwasher at different times of day whenever the price is lowest, and by going out of the house when prices are highest - eg go to your local cinema or shopping centre to enjoy their air conditioning on a very hot day rather than consuming high-priced energy to run your own.