Transpower says electricity use has ticked up compared to last winter due to new work patterns.
Chief executive Alison Andrew said power use dipped sharply as businesses cut use during the level 4 lockdown but since restrictions have been lifted there's been a slight increase in use.
Although the data is early, she said this could be attributed to large numbers of people still working from home - and turning on heaters while workplaces are also up and running and using the usual amount of electricity.
The state-owned enterprise released a major report on the country's energy future in the week after it went into lockdown and she said while it was still too early to know if forecasts needed to be updated, there were clear lessons the country could learn from Covid-19.
Transpower believes the economy will be increasingly electrified, driven mainly by the rapid shift to electric vehicles and away from coal boilers and heaters in public buildings and factories.
Andrew said now was the ideal time to act on climate change by capitalising on New Zealand's renewable energy advantage, even if it was difficult to see beyond the impact of the pandemic.
''It's acute, it's right here, right now and it's in our face. Something like climate change is chronic - it's going to be as dramatic if not more but it's taking time to build,'' she said.
''I'm hoping that people will be able to maintain that 'and' perspective rather than the 'or' perspective.''
A contestable public fund could provide capital for the large green projects that were needed as power use started to climb from 2025.
The report states household energy bills will fall by as much as 25 per cent, driven by the falling cost of transport due to a forecast rapid uptake of electric vehicles.
New Zealand has a target of 100 per cent renewable generation by 2035.
It showed that about 40 new, grid-scale generation and batteries projects would be required before 2035 and this would allow generation to be around 95 per cent renewable by 2035, moving to 100 per cent by 2050, to meet government targets.
But the demand outlook has fallen since a similar report two years ago. It forecasts lower electricity demand growth of 70 per cent to 2050, compared with 100 per cent in the 2018 report, due to widespread uptake of energy efficiency measures. If Rio Tinto shut its Tiwai Point aluminium smelter this would mean another 12 per cent of existing electricity supply feeding into the system.
A review by Rio was due by the end of March but there had been no update, said Andrew.
A smart grid - made up of millions of smart appliances and smart electric vehicle chargers plus many small-scale solar photovoltaic and battery systems in 2035 - would ease the need for more generation and network investment, the report says.
Nearly 60 per cent of the country's total energy requirements will be from electricity in 2050, up from 25 per cent in 2016.
While there are just 20,000 electric vehicles (EVs) on the road now, the report forecasts there will be about 1.5 million of them by 2035 and they will comprise nearly 100 per cent of the fleet in 2050.
She said government subsidies would not be so important for uptake as the price came closer to petrol vehicles and they would be a quarter to a third the cost to run.
Average, two-car households (with one an EV) would have their total energy bill cut by 25 per cent or $1631 in 2035.
This will require an additional 4 TWh of electricity by 2035 and 12 TWh by 2050.
Current coal and gas use for process heat had to be around 50 per cent electrified by 2035 with significant uptake in low-temperature process heat.
Andrew said that during lockdown major grid work went on, even under level 4 restrictions, as staff could work safely.
Transpower had not been caught out by not having the right expertise from overseas yet although other parts of the system have had to get exemptions for essential workers.