The emission reduction from a heat pump and heat recovery is calculated as the difference between baseline emissions (gas or purchased heat) and project emissions (electricity for the pump and fans plus residual fuel). A heat pump does not eliminate emissions; it shifts them from Scope 1 or purchased heat to Scope 2, so the result depends heavily on the grid emission factor and the pump's coefficient of performance (COP).
What the project changes
- Heat recovery returns heat from exhaust air or process wastewater and reduces heat demand. The side effect is additional electricity use by fans and pumps.
- A heat pump produces heat from electricity by extracting low-grade heat from air, ground, water or waste heat. COP is the ratio of heat produced to electricity consumed.
- A buffer unit (storage tank) smooths out operating conditions and lets the pump run in efficient modes.
The right order of calculation: first reduce demand (heat recovery), then cover the remainder with the heat pump, then account for residual fuel for peak loads.
Formula
Reduction = (Gas_baseline × EF_gas + Heat_baseline × EF_heat) − (Elec_project × EF_grid + Gas_project × EF_gas + Heat_project × EF_heat)
Any electricity in the baseline is accounted for in the same way. All quantities must be brought to the same conditions — weather and load (see Project baseline).
Example 1. Replacing a gas-fired boiler house
For this example, we take the following factors: gas — 2.04 kg CO₂e/m³, grid electricity — 0.726 kg CO₂e/kWh (an estimated value).
Baseline: the boiler house burns 150,000 m³ of gas a year.
- 150,000 × 2.04 = 306,000 kg = 306.0 t CO₂e.
Project: heat recovery has reduced heat demand, the heat pump covers the base load, and the boiler remains for peaks.
- Electricity for the pump and fans: 250,000 kWh × 0.726 = 181,500 kg = 181.5 t.
- Residual gas: 20,000 m³ × 2.04 = 40,800 kg = 40.8 t.
- Project total: 222.3 t CO₂e.
Reduction: 306.0 − 222.3 = 83.7 t CO₂e a year.
A useful check: with these factors, each cubic meter of gas displaced “pays off” in emissions terms only if less than 2.04 / 0.726 ≈ 2.81 kWh of grid electricity is spent to replace it.
Example 2. Replacing purchased heat
The facility bought 900,000 kWh of heat. For this example, the factor for purchased heat is 0.2 kg CO₂e/kWh (an estimated value).
- Baseline: 900,000 × 0.2 = 180,000 kg = 180.0 t.
- Project with a seasonal COP of 4.5: electricity 900,000 / 4.5 = 200,000 kWh × 0.726 = 145.2 t. Reduction: 34.8 t.
- Project with a seasonal COP of 3.0: 300,000 kWh × 0.726 = 217.8 t. Emissions increased by 37.8 t.
The emissions break-even point: COP = 0.726 / 0.2 ≈ 3.63. Below this value, replacing purchased heat with a heat pump increases emissions at these factors. That is why climate projects depend on the real seasonal COP, confirmed by monitoring, and on pairing the pump with on-site generation — see Solar plants and battery storage.
What to monitor
- Electricity consumption of the heat pump and the heat recovery equipment, on separate meters.
- Residual consumption of gas or heat.
- The pump's heat output, to track COP.
- Weather data for normalization.
For more on the structure, see the article on the monitoring plan.
How it works in the platform
- The MRV contour is still in development and is marked “Soon” in the platform: a heat pump or heat recovery project with a baseline-versus-project comparison cannot yet be calculated in it.
- You can already collect the data for such a calculation in the GHG contour. In Data entry, boiler-house gas (Scope 1, stationary combustion) and purchased electricity and heat (Scope 2) are entered month by month for each facility, and invoices, certificates of completion and photos of meter readings are attached to the records.
- Emissions are calculated for each source, and every record shows the methodology applied. The company GHG page shows totals by year, a comparison with the previous year and monthly trends — they reveal how emissions shift from Scope 1 to Scope 2 once a boiler house is replaced.
Frequently asked questions
Why did Scope 2 emissions rise after the heat pump was installed?
Because gas or purchased heat has been replaced with electricity. What matters is the total across all sources: if the drop in Scope 1 or heat-related emissions exceeds the rise in Scope 2, the project reduces emissions.
Which COP should be used in the calculation — rated or actual?
For a reductions report, the actual COP derived from monitoring data for the period. The rated COP is acceptable only for a preliminary estimate.
Can heat recovery be counted separately from the heat pump?
Yes, if the effect of each measure can be isolated through measurement. The key is not to credit the same reduction in heat demand twice.