Chief financial officer Lindis Jones said the write-down reflected the customer losses the past year but also the expectation that wholesale power pricing isn't likely to improve short-term.
The firm still believes in the case for investing in Flick and in the half-hourly price signals the Flick platform can offer, he said.
The two companies are testing a number of bundled offers so it can select the best to take to market. But he said growth rates will be slower than originally planned given the wholesale environment and the fact Flick will be competing with a more conventional fixed-priced offer.
Z Energy is the country's biggest fuel retailer. In September it cut its full-year guidance by $60m citing "unprecedented" discounting in the retail fuel sector and lower than expected margins at the Marsden Point oil refinery it part owns.
Today it reported first-half earnings before interest, tax, depreciation, amortisation and changes in financial instruments of $182m, up 4 per cent from a year earlier.
It reiterated its full-year ebitdaf guidance at $390-$430m but noted that there are potential "headwinds" to the local economy near-term from low business confidence, slowing growth and investment.
"Despite the nature of our business we are not immune to this loss of confidence in economic activity," chief executive Mike Bennetts said. "Z's focus for the second half of FY20 is on the customer; especially in our retail segment."
Should fuel margins not lift from the levels seen since August, full-year earnings are likely to be at the bottom of the forecast range, the company said.
Z shares rose 2.7 per cent to $5.40, leaving them virtually unchanged from the start of the year. The stock fell almost a dollar in the week after its September earnings downgrade.
Shane Solly, a portfolio manager at Harbour Asset Management, said he was a little surprised by the stock move today given the company's cautious outlook.
"That is a theme that has been coming through in some of the earnings. Companies are wary, or they are putting some caveats around, this slowing in activity," he told BusinessDesk.
"There may have been some people expecting a weaker set of numbers. The fact they've come out broadly in line means it's not quite as bad as they thought it might have been."
Bennetts noted that Z lost market share in petrol, diesel and fuel oil as the economy slowed and competitors discounted heavily to seize customers during changes in the firm's loyalty programmes.
While national petrol demand was flat, and diesel use down 2 per cent, Z's sales of those products fell 2 per cent and 6 per cent respectively.
Total fuel volume marketed in the six months fell 2 per cent to 1.92 billion litres, with more of that volume loss occurring within the firm's Caltex chain.
While the firm's ebitdaf was higher than it reported a year ago, Z indicated that the result would be little changed when the previous year's earnings are adjusted higher for a change in accounting standards and timing differences.
Improved margins on fuel and higher refining margins in the latest period were largely offset by higher operating expenses and a $4m loss from Flick.
Jones noted that the improved fuel and refining margins in the latest period were simply a reflection of higher costs a year earlier when the Marsden Point refinery had an extended shutdown. Higher operating costs in the latest period were mostly due to a one-off investment of about $10m putting in place the platform for the group-wide Pumped loyalty scheme introduced in August.
The company will pay a 16.5 cent interim dividend on Dec. 10 to investors registered at November 22. That is up from 12.5 cents a year earlier.
