Mr Mackenzie, 52, from Monard, near Tipperary, requires four-hour haemodialysis treatments to stay alive after being treated for kidney cancer five years ago.
“Our electricity bills have already more than doubled since last year and will continue to rise,” he said.
He sits at the machine for four hours every two days, but the machine runs for much longer than that, drawing electricity to clean and perform other essential functions.
He was also recently diagnosed with cancer in his lymph nodes and is considering alternative treatments.
“My condition makes me really cold and I'm worried about the cost of oil. I need to keep warm,” he added.
He is particularly worried about the possibility of a power outage and how this would affect his ability to receive vital dialysis. He has opted to do dialysis at home instead of going to hospital, which saves money for the HSE, but the uncertainty about power outages is a major concern.
MacKenzie, a father of two, was forced to give up his job because his wife, Sheila, works outside the home and is entitled to claim a 20 percent tax refund on their electricity bills.
This is welcome, but at just around €2,000 it is a tiny fraction of what is currently being paid and what will be paid over the winter. He said those working from home could claim 30% and that the difference was one measure the Government should consider.
“I changed suppliers but they're all now increasing prices. If you register as a vulnerable customer your electricity won't be cut off over the winter but you will be billed for any outstanding balance,” Mr McKenzie said.
His concerns are echoed by those of Dr Margaret Kennedy, 69, from Greystones, Co Wicklow, who suffers from Parkinson's disease and other conditions and is permanently wheelchair bound.
“I have an electric hospital bed and if the power goes out it stops working. My sister is on a sleep apnea machine and needs power,” said Dr Kennedy, who lives with her twin sister Ann, who is also disabled.
“I'm still trying to figure out what to do about heating. It's very stressful.”
The Irish Kidney Association said that while some people can claim back some of their energy costs from the tax they pay, the refund is only available after 12 months and is not viable unless they can afford to pay the bill up front.
The association's chief executive, Carol Moore, is calling for a campaign to get energy suppliers to register people who rely on electricity for their health and survival as vulnerable customers.
The association is also calling for 100% subsidies to install renewable energy systems in the homes of patients with complex medical needs.
