Bivalent and hybrid heating systems combine a heat pump with a secondary heat source, such as an existing gas, oil, biomass or electric boiler. This approach allows businesses to use the heat pump for a significant proportion of their heating demand (>90%) while retaining the existing or secondary heat source to provide additional capacity when required.
For some buildings, a complete transition to heat pump heating may not be practical or cost-effective at this stage. This can be due to high-temperature heating requirements, limited electrical capacity, existing plant that is still relatively new, space constraints, operational requirements or the cost of a full heating system replacement. Some public buildings are designated National Emergency Response Centre’s and are expected to shelter staff and citizen’s during local and national emergencies. These Emergency Response Centres and even hospitals and day-care centres require robust and resilient heating systems with back-up sources of energy. Bivalent or hybrid energy systems that are powered by electricity and a back-up fuel meet that requirement, while also meeting carbon reduction targets in a more structured way, providing important security of supply for emergency response scenarios, such as weather events, landslides, flooding, wild-fires, etc.
A bivalent or hybrid solution can provide a phased approach to decarbonisation, reducing fossil-fuel use while maintaining the resilience and flexibility of the existing heating system, delivering enhanced security of supply.
Bivalent Heating Systems
A bivalent system uses two independent heat sources that work together depending on outdoor temperature and heat demand.
- The heat pump provides the majority of heating during mild and moderate weather.
- The boiler or secondary system activates only when temperatures drop below a set point (the “bivalence point”) or when high temperatures are required.
This approach maximises efficiency while ensuring reliable performance in colder conditions or older buildings.
For example a low carbon bivalent system might include a Biomass boiler, a Heat-pump, a Solar PV installation with Batteries to deliver renewable power and heating needs for a building and electric transport to / from that building.
Hybrid Heat Pump Systems
Hybrid systems integrate a heat pump and boiler into a single, intelligent control system. The system automatically selects the most cost‑effective or energy‑efficient heat source at any given time.
- The heat pump runs when it is cheaper or more efficient.
- The boiler supports peak loads or provides high‑temperature water when needed.
- Controls optimise performance based on electricity prices, outdoor temperature, and building demand.
Hybrid systems are ideal for businesses that want to reduce carbon emissions and energy costs without fully replacing existing boiler infrastructure.
For example a Hybrid or Bivalent system can include a combination of energy technologies to meet your decarbonisation needs.
How can TEA help?
We provide an independent assessment of your existing heating system and develop a heating strategy suited to your building and operational requirements.
Our assessment considers:
- Existing heating plant and condition
- Building fabric and heat loss
- Heat demand and operating profile
- Required heating and flow temperatures
- Heat pump sizing and performance
- Existing electrical capacity
- Available space and site constraints
- Capital investment and operating costs
- Energy and carbon savings
- Future decarbonisation requirements
We can then compare options and develop a solution that balances energy efficiency, carbon reduction, capital cost, operational resilience and long-term value.
Feature
Bivalent System
Hybrid System
Heat Source
Heat pump and separate boiler
Heat pump and integrated boiler system
Operation
Switches between sources based on temperature
Automatically optimises between sources based on cost and efficiency
Installation cost
Moderate to high (depends on boiler condition)
Moderate (often uses existing boiler)
Best for
Large buildings, high heat demand
Businesses wanting carbon reduction without major retrofit
Space requirements
Requires space for two systems
Uses existing boiler space
Carbon Savings
High
High
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Looking for the right solution for your facility? Contact us today to discuss your needs and see how we can support your goals.