Electric boilers cut costs of brief district heating peaks

Electric boilers are the most cost-effective option for covering short-term peaks in district heating demand, according to a study reported by ERR.

Researchers from Tallinn University of Technology and Austria’s Johannes Kepler University analysed the experiences of more than 160 specialists and researchers in the heating sector. They also calculated the cost-effectiveness and environmental impact of nearly 50 different district heating scenarios.

The study found that electric boilers are the most economical solution when additional capacity is needed only during the coldest hours and accounts for 10 to 20 percent of the heating system’s total capacity. On average, operating electric boilers costs one-fifth less than using traditional gas boilers.

When additional heat accounts for about 40 percent of system capacity and is needed for longer and more frequent periods, large heat pumps become the most practical option. They reduce primary energy use by nearly 50 percent and cut carbon emissions by more than one-third.

Biomass boilers offer the greatest environmental benefit, reducing pollution by more than 90 percent. However, operating them would cost almost three times as much as gas heating.

The researchers said the cost-effectiveness of each technology depends on the balance between initial investment, energy efficiency, and fuel and maintenance costs.

Electric boilers are relatively inexpensive to install, meaning that the initial investment can pay off even if the equipment operates for only a few dozen hours a year. Heat pumps and biomass boilers require much more capital and need longer, more continuous operating periods to recover their costs.

Because heat pumps use energy very efficiently, producing several units of heat from one unit of electricity, they are the most reliable choice for district heating networks during longer cold periods, both financially and environmentally.

The findings were published in the journal Energy Reports.