How to Reduce Carbon Footprint With Solar and Measure It Properly

You can reduce carbon footprint with solar by replacing grid and generator electricity with power from your own roof, and you can estimate the reduction with one multiplication: solar units used × an emission factor. This guide explains the method, where the emission factor comes from, and how businesses in Pakistan can report the result honestly to buyers and auditors.

Where your electricity emissions come from

Your electricity footprint has two main sources.

Grid electricity. Pakistan's grid draws on a mix of plants: natural gas and LNG, furnace oil, imported and local coal, hydropower, nuclear and a growing share of solar. Fossil plants release CO2 for every unit they generate. The average CO2 per unit on the grid depends on which plants are running, so it changes by year and by season.

On-site fuel. Diesel, petrol and gas generators burn fuel on your premises. These are direct emissions, and in corporate reporting they count as Scope 1.

Solar panels produce no emissions while generating. Each unit of solar you use replaces a unit from the grid or from a generator.

How to reduce carbon footprint with solar: the formula

Grid electricity replaced:

CO2 avoided (kg) = solar units used on site (kWh) × grid emission factor (kg CO2 per kWh)

Generator fuel replaced:

CO2 avoided (kg) = litres of fuel no longer burned × fuel emission factor (kg CO2 per litre)

For diesel, the IPCC's default emission factors work out to roughly 2.7 kg of CO2 per litre burned. Your auditor may use a slightly different published value, so use theirs when you report.

Add the two results for your total CO2 avoided.

Getting your solar units

Do not estimate this. Your inverter records it. Sungrow inverters store daily and monthly production in Sungrow's monitoring app and web portal, and you can export the data for any period. If you export power to the grid, your DISCO bill also shows exported units, so you can subtract them to find units used on site.

Finding a grid emission factor for Pakistan

This is the hard part, and it is where many carbon claims go wrong.

We have not found a current, officially published grid emission factor for Pakistan from NEPRA, so we do not print one here. The values you will come across include:

• International datasets. The UNFCCC publishes a harmonised grid emission factor dataset agreed by international finance institutions, with values by country.
• Academic studies. Published papers have calculated factors for Pakistan's grid, but many are based on data that is now more than a decade old. The grid mix has changed a lot since then.
• Project documents. Carbon credit projects calculate their own factors using UNFCCC methods. These are specific to the project and its time period.

Your supply also matters. Most of the country buys from DISCOs such as LESCO, IESCO, FESCO or MEPCO on the national grid, while K-Electric runs its own power plants alongside supply it buys from the national grid, so its mix can differ.

If NEPRA or your DISCO publishes an emission factor for your supply, use that figure and note its source and year. If you report to a buyer or auditor, ask which factor and source they require and use that consistently. If you only want a rough internal estimate, pick one published factor, write down the source and year, and stick with it so your year-on-year numbers stay comparable.

Operating margin and combined margin

Carbon methods talk about an "operating margin" (the plants that would have run if you had not used solar) and a "build margin" (new plants being added to the system). A "combined margin" blends the two. For simple corporate reporting, a grid-average factor is the usual starting point. For carbon credit projects, the combined margin is normally required.

Worked example (hypothetical numbers)

The numbers below are for illustration only. The emission factor in this example is a placeholder, not Pakistan's official grid figure.

• Solar units used on site in a year: 14,600 kWh (example)
• Grid emission factor: 0.5 kg CO2 per kWh (placeholder)
• Diesel no longer burned: 1,000 litres (example)
• Diesel factor: about 2.7 kg CO2 per litre

Grid: 14,600 × 0.5 = 7,300 kg, or 7.3 tonnes of CO2

Generator: 1,000 × 2.7 = 2,700 kg, or 2.7 tonnes of CO2

Total avoided: about 10 tonnes of CO2 a year in this example

Swap in your own inverter data, fuel records and your chosen emission factor to get your real figure.

What counts and what does not

Item	How to treat it
Solar units you use on site	Reduces purchased grid electricity, so it lowers your Scope 2 emissions
Diesel or gas no longer burned on site	Lowers your Scope 1 emissions
Solar units exported to the grid	Under the GHG Protocol, not subtracted from your Scope 2; can be reported separately as avoided emissions
Emissions from making the panels	Part of the lifecycle footprint; usually reported separately, not in Scope 2

Be careful with claims like "carbon neutral" or "100% green" on marketing material. A rooftop system usually covers part of your load, and your buyers will check the numbers.

Ways to cut your footprint further with solar

• Keep panels clean. Dust, winter smog residue in Punjab and salt film at coastal sites reduce output, which means fewer clean units. Agree a regular cleaning schedule with your installer or a maintenance contractor.
• Add storage. A hybrid system with a battery energy storage system such as the Sigenergy SigenStack lets solar replace generator hours during load-shedding, which cuts Scope 1 emissions as well.
• Solarise pumps and tube-wells. Farms running diesel tube-wells and pumps can switch to solar pumping. See agricultural solar.
• Use the whole roof. Higher-efficiency panels such as Aiko's back-contact modules produce more units from limited roof space.
• Cut waste first. LED lighting, inverter ACs and fixing compressed-air leaks in factories reduce the load solar has to cover.

Reporting for exporters

If your buyers ask for emissions data, give them:

1. Monthly solar production and on-site use, exported from your inverter platform
2. Units purchased from your DISCO, from your bills
3. Generator fuel use, from purchase records
4. The emission factors you used, with source and year

Our article on solar energy for businesses in Pakistan covers the business case and ESG reporting in more detail.

FAQs

How much CO2 does a 10 kW solar system save in Pakistan?

It depends on how many units the system produces, how many you use on site and which emission factor you apply. Multiply your measured solar units by your chosen factor using the formula above.

Do exported units count toward my carbon reduction?

Under the GHG Protocol, exported units do not reduce your own Scope 2 emissions. You can report them separately as emissions avoided on the grid.

Is solar really zero-carbon if panels are made in factories?

Panels have a manufacturing footprint, but they produce no emissions while generating power over many years of use. Lifecycle studies consistently find solar's emissions per unit far lower than fossil fuel power.

Can I sell carbon credits from my rooftop system?

Small rooftop systems rarely qualify on their own. Carbon credit programmes require registered methods, independent verification and usually large or pooled projects. EGS does not sell carbon credits.

Get a quote for your solar equipment

Want to reduce carbon footprint with solar and have the data to prove it? Send us your load or electricity bills and we suggest Aiko panels, a Sungrow inverter that reports to Sungrow's monitoring platform, and storage where it fits, with today's price. We supply businesses across Pakistan; ask about delivery to your city. Get a quote, ask for today's price on WhatsApp, or size a system with the solar calculator.