Highly placed industry sources said the State power utility had stopped ring-fenced guarantees with customers amid consistent failure to guarantee supply, even though customers pay in hard currency.
Zesa is battling to meet demand for power, which stands at 1 800MW at peak of demand against internal generation capacity of 800MW, at best, with its capacity heavily constrained by drought.
The majority of consumers that are not ring-fenced, considered non-critical and households endure long hours of power cuts, usually 18 hours, seriously disrupts their activities.
The power utility has ring-fenced arrangements with miners and critical industry, which are prioritised with power anchored on imports, but industry says Zesa is failing to abide by the binding agreements.
"Zesa has stopped ring-fenced power supply agreements because the situation just doesn't allow it to do so. The shortage of power is acute and imports cannot be guaranteed, so it is not tenable," a sourced said.
Zesa spokesman Fullard Gwasira said in instances, regional suppliers declare emergencies and that means power becomes available, but at a steep cost of US31 cents per kilowatt hour.
"Zesa still has arrangements with ring-fenced customers that are anchored by imports and these imports only disrupt if there are power supply challenges in the electricity grid due to internal challenges of neighbouring or utilities that supply us with electricity to augment local production," he said.
In such instances, the State power utility says, ring-fenced customers are informed and asked to reduce their consumption or even stop operations in order to avoid collapsing the national grid.
"The power utility prioritises miners, exporters and industry under this arrangement owing to their strategic importance and contribution to the national economy. Such customers are part of the plus or minus 400MW provision by Zesa," Mr Gwasira said.
With Zimbabwe experiencing acute shortage of foreign currency, the State power utility also faces serious challenges just securing the financial resources needed to import power.
Further, regional countries from where Zimbabwe must import power have also recently been facing supply challenges of their own due to plant breakdowns and drought that has handicapped Zambia, which generates on Kariba's northern bank.
While Zimbabwe already had power deficits due to reduced generation capacity caused by lack of further investment in power infrastructure, the drought last year has made the situation worse.
The drought that hit most parts of the Southern African region have reduced water flows down south, seriously affecting Lake Kariba's water level, which has dropped to critical levels.
Kariba South, a hydro power plant, is Zimbabwe's largest power station with capacity to churn out 1 500MW, but production has been limited to less than a third to avoid depleting the dam.
The country's second largest power plant, Hwange, has not made the situation any better as its advanced age sees producing 450MW to 500MW at best against rated capacity of 900MW. Break downs are also frequent.
