Introduction
As part of the NYSERDA NextGen Building Innovation Program, Sunamp installed its PCM heat batteries in a home in Montauk, NY, to optimize solar thermal energy use and minimize reliance on an oil-fired boiler during colder months. This project aligns with New York State’s commitment to achieving an 85% reduction in greenhouse gas emissions by 2050, demonstrating the potential of thermal storage to accelerate clean energy adoption in residential settings.
The home, occupied by two adults, previously used a solar thermal system for summer domestic hot water (DHW) and an oil-fired boiler for winter. By introducing Sunamp’s Thermino thermal storage, the project delivered significant environmental and economic benefits.
Challenges
- Seasonal dependence on an oil-fired boiler for winter DHW needs.
- Underutilization of solar thermal energy during peak production periods.
Comparing the systems
Existing system
The heat from the solar thermal array was previously stored in a 120-gallon indirect storage tank with backup provided by an oil-fired boiler with a 40-gallon indirect storage tank.
The Sunamp solution
The existing solar thermal array remains in position for use to heat the Thermino 300i P58 in order to provide domestic hot water supply. A blending valve/small tank is necessary to control the temperature of the water coming from the solar system to guarantee the integrity of the phase change material.
A heating element in the thermal battery will be used as a backup heat source to provide hot water to the house in days with solar restrictions.
The data suggests the homeowner was able to leverage the energy produced by the solar thermal system for 55% of the days in the monitoring period and relied on the backup DHW source on the remaining 45% of the days.
Estimated annualized energy consumption & GHG emissions when battery is charged from the grid:
Estimated annualized energy consumption & GHG emissions from backup DHW system and offset by solar thermal system:
The use of a thermal battery with an internal heater have a measured emissions of 0.56 tons CO2e per year, a reduction of 50% in comparison with the oil-fired boiler for the same period.
Conclusion:
Energy efficiency
- Decoupled production and usage of the energy, making better usage of the sun energy – solar thermal energy met DHW demand on 55% of days during the monitoring period.
- On the remaining 45% of days, the electric backup system ensured reliable hot water supply.
Environmental benefits
- The solar thermal system, when paired with the thermal battery, reduced overall energy consumption by an estimated 2.05 MWh per year.
- It also lowered greenhouse gas emissions by 0.50 tonnes CO2e annually compared to using a thermal battery with only an electric heater. This represents a 50% reduction in emissions compared to the previous oil-fired boiler during the same period.
- Without the solar thermal system, a thermal battery powered solely by the grid would consume 4.34 MWh per year and emit 1.06 tonnes CO2e. In contrast, the oil-fired boiler would produce 2.13 tonnes CO2e annually, highlighting a 50% reduction in emissions with the thermal battery solution.
