What Are the Alternatives to Heat Pumps for Low Carbon Heating?

As the UK transitions toward Net Zero emissions, heat pumps are often presented as the primary solution for decarbonizing domestic heating. But what if you're not ready to install a heat pump—due to cost, noise, space constraints, or personal preference?

This article explores the realistic alternatives to heat pumps for homeowners who still want to go Net Zero. It also considers the broader implications of each technology for the UK energy system.

1. Electric Boilers: Simple, Familiar, But Expensive to Run

✅ Pros:

• Nearly 100% efficient (1 kWh in = 1 kWh out)

• Low installation cost – no outdoor units, no garden space needed

• No major internal changes – can often replace a gas boiler directly

• Ideal for small flats or listed buildings where external units aren't allowed

  
  

❌ Cons:

• Use 3–4 times more electricity than a heat pump for the same heat

• Very expensive to run unless combined with solar PV or battery storage

• Place greater strain on the national grid and increase the need for energy generation and transmission infrastructure

  
  

Pro Tip:

Some homeowners pair electric boilers with battery systems (e.g. Tesla Powerwall) to charge up overnight using cheaper tariffs and avoid peak electricity prices.

2. Storage Heaters & Thermal Batteries: New Tech, Old Concept

Modern night storage heaters and thermal batteries are making a comeback:

• Store electricity as heat during off-peak hours

• Release warmth during the day or evening

• More controllable and efficient than older storage heaters

Options include:

• Phase change materials (e.g. Sunamp) that store and release heat at stable temperatures

• Solid-state thermal batteries and new-gen storage heaters with smarter controls

These technologies can work well in homes without outside space—but they’re still resistive heating, meaning they’re less efficient than heat pumps.

3. Biomass Boilers (Pellet or Wood Burning)

For rural homes or off-grid properties, biomass boilers—especially wood pellet systems—remain a viable alternative.

✅ Pros:

• High temperatures – can run with existing radiators and pipework

• Eligible for some subsidy schemes if off gas grid (e.g. Boiler Upgrade Scheme)

• A relatively direct swap for traditional boilers

❌ Cons:

• Emits smoke and particulates – not suitable for urban or smoke control areas

• Pellet price volatility and supply concerns (some previously imported from Russia or Canada)

• Environmental concerns about deforestation and long-term sustainability

While technically “renewable,” widespread biomass heating is unlikely to scale safely or sustainably for the entire population.

4. Biogas and LPG (Liquefied Petroleum Gas)

Some homes off the gas grid use LPG or biogas in traditional boilers. Biogas can be produced from anaerobic digestion of waste, and some suppliers now offer 100% renewable biogas blends.

✅ Pros:

• Works in existing LPG boilers with minimal adjustment

• Drop-in fuel – no need for new radiators or pipework

• Renewable biogas is net zero compatible

❌ Cons:

• Limited supply – not scalable for widespread domestic use

• Price competition from industries that also need biogas for decarbonization

• Often more expensive than grid electricity or mains gas

This can be a good transitional fuel for off-grid homes but is unlikely to be a national-scale solution.

5. Hydrogen for Home Heating? A National Decision

Some government trials considered converting entire regions to run on hydrogen gas for heating (e.g. the now-shelved Redcar hydrogen village). However, public resistance and technical inefficiencies halted most of these plans.

✅ Pros:

• Works in modified gas boilers

• Can potentially use existing gas pipe networks

❌ Cons:

• Public resistance is high—many don't want hydrogen burned in their homes

• Inefficient use of electricity (green hydrogen requires a lot of energy to produce)

• Better used for industry, aviation, and shipping—where no alternatives exist

Most energy experts agree hydrogen is best reserved for sectors where electricity won’t work—not for heating average homes.

6. Carbon Capture & Storage (CCS) – Not for Individual Homes

Some argue we could keep burning natural gas but capture the CO₂ emissions. While CCS may play a role in power generation, it’s not viable at the household level.

Why not?

• Impossible to capture CO₂ at domestic boilers

• CCS requires centralized systems, not distributed home-level applications

In scenarios where CCS is used, it's paired with gas-fired power plants to generate clean electricity, not to power individual gas boilers.

Comparing the Options: Efficiency & Feasibility

Technology	Typical Efficiency	Best Use Case	Net Zero Compatible?
Heat Pump	300–400%	Most homes with outside space	✅ Yes
Electric Boiler	100%	Flats, listed buildings, backup heating	✅ With green power
Storage Heater	100%	Small homes, off-peak usage	✅ With smart usage
Biomass Boiler	~85–90%	Rural homes, off-grid	✅ Debated
Biogas (LPG/BioLPG)	~85–90%	Off-grid homes, transitional tech	✅ Limited supply
Hydrogen Boiler	~50–60% (green H₂)	Industrial clusters, not individual homes	❌ Inefficient

There Are Alternatives—But Choose Wisely

While heat pumps remain the most efficient and scalable low-carbon heating solution, there are legitimate alternatives for specific contexts:

• Electric boilers can decarbonize hard-to-retrofit flats or listed buildings

• Thermal storage can help smooth electricity demand

• Biomass or biogas can support rural off-grid homes

• Hydrogen should be reserved for industrial use, not domestic boilers

The key takeaway: One size does not fit all. The right solution depends on your home, location, infrastructure, and personal or regional constraints.