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What we accept as evidence of green power

This page is for data center operators and web hosting providers, who want to get verified as a verified green hosting provider. On this page you will find information about the kind of evidence required in order to get verified, as well as additional information about the context of that evidence and examples to use as a guide.

Note: This is a living document. We review and update it periodically based on updates in the regulatory landscape, new scientific evidence, and changes to the way industry operates. This document was last modified on:


When wanting to get verified as a green provider, we need to see evidence of the steps you are taking to avoid, reduce, or offset the greenhouse gas emissions caused by using electricity to provide your service/s. We will expand on these terms in more detail later in this document, but to set the scene here are brief definitions of each.

  • Avoid – This means you’re running on 100% renewable power, or are operating in regions where the grid is overwhelmingly powered by renewable energy.
  • Reduce – This is when you still use fossil fuel electricity from your local grid, but account for the emissions of this energy by using vehicles like a green tariff or environment attribute certificates.
  • Offset – This means you still use fossil fuel electricity from your local grid, but account for the emissions of this energy by purchasing quality carbon offsets from a reputable provider/marketplace.

In addition to the above, we also need to see that the evidence provided is timely, makes a material difference, and whenever possible in the public domain. To better understand what each of these means, you can expand and read the sections below.

Evidence should be timely”. What does this mean?

We require all evidence to be up-to-date for the last full calendar year.  The first time you submit a verification request, we will need to see evidence related to the last full calendar year. After that, evidence also needs to be renewed on a yearly basis for the previous full calendar year.

For example: Someone who verify a new provider in 2023 would need to provide evidence of their green energy usage for the calendar year 2022. Afterwards, in 2024, they would need to renew this evidence to show their green energy usage for the calendar year 2023.

If you’re not able to find offsets that match the time period you’re accounting for, then we will also accept offsets that are local to your operations within the last three calendar years.

For example: The datacenter you operate is in Taiwan but you cannot purchase offsets for the last calendar year. We would accept offsets attributed to projects based in Taiwan that were retired in the last three calendar years instead.

Evidence should make a material difference“. What does this mean?

For providers of digital services like hosting and so on, we are primarily interested in the energy from the digital infrastructure they use for evidence of greenness. We ask for evidence that shows an organisation’s digital operations being green, and that they are taking steps to make a material difference to carbon emissions.

Of course, organisations may take other steps to be sustainable (like composting, using recycled water etc.). However, for the sake of processing verification requests we do not take these other measures into consideration.

Should evidence be public or private?

Whenever possible, we encourage evidence to be made available in the public domain. However, we understand that some evidence (like invoices, business contracts etc.) contain confidential material. 

We do not share any supporting documentation you have asked us to keep private, but we do recommend making as much as you can available, in redacted form if need be. This makes your claims easier to defend, and some users will prefer to buy from a provider that uses one way of accounting for emissions, over another.

When submitting a verification request, you can choose which information you’d like to make public or keep private. Any evidence marked as private will not be visible in our Green Web Directory, Green Web Checker or via our API.

Understanding what evidence is required for your organisation

As a hosting provider, you can determine what evidence you should include with your verification request by going through the following questions:

  1. Do you use 100% green energy from our own infrastructure?
    1. Yes! Find out what evidence is required.
    2. No. Go to question 2.
  2. Do you operate in a region that has a grid intensity of less than 20g CO2e/kWh or uses over 99% renewable power?
    1. Yes! Find out what evidence is required..
    2. No. Go to question 3.
  3. Do you directly pay for green energy to cover the non-green energy we use?
    1. Yes! You directly pay for green energy to cover the non-green energy we use. Find out what evidence is required..
    2. Yes! You purchase environment attribute certificates or have guarantees of origin. Find out what evidence is required.
    3. Yes! You directly fund renewable energy projects. Find out what evidence is required.
    4. No. Go to question 4.
  4. Do you purchase quality carbon offsets to cover the non-green energy we use?
    1. Yes! Find out what evidence is required.
    2. No. Go to question 5.
  5. Do you resell or actively use a provider that is already in our Green Web Dataset?
    1. Yes! Find out what evidence is required.
    2. No. Read through the scenarios, see the FAQ, and contact us if you still have questions.

Avoiding greenhouse gas emissions from your operations

Your organisation avoids greenhouse gas emissions caused by using electricity to provide your service/s. This can be either by using 100% renewable power, or by operating in regions where the grid is overwhelmingly powered by renewable energy.

Scenario 1: We use 100% green energy from our own infrastructure

In the last full calendar year, your organisation has drawn all its power from renewable sources all the time, and did not draw power from the grid.

Evidence required

  • Evidence that you have facilities onsite to make this possible. This can include:
    • Power generation and usage data from renewable energy infrastructure.
    • A public, verified third-party audit showing that all power comes from the claimed renewable source.

Still got questions? See the FAQ.

Scenario 2: We operate in a region that has an annual average grid intensity of less than 20g CO2e/kWh or uses over 99% renewable power.

In the last full calendar year, your organisation operated in a region where the grid was on average as close to completely green as possible. For us, that means it had an annual average grid intensity of less than 20g CO2e/kWh or generating over 99% of its electricity from renewable sources.

These are currently rare, but as more countries transition their own grids to renewables we expect to see this scenario more often.

Evidence required

  • A statement from the government, or regional energy provider, about the generation of renewable energy in that area.
  • Pointing to annual average grid intensity figures from a reputable source like Ember Climate, or Electricity Maps.

Example

The province of Quebec, Canada. Here, the government put out a statement about the generation of renewable energy in the province, mostly from hydropower, stating that grid intensity was 1.3 grams of CO2e per kilowatt-hour.

Still got questions? See the FAQ.

Reducing greenhouse gas emissions from your operations

Your organisation reduces greenhouse gas emissions caused by using electricity to provide your service/s. This can be by purchasing green energy tariffs, or environment attribute certificates. Or, this could be through funding renewable energy projects.

Scenario 1: We directly pay for green energy to cover the non-green energy we use

In the last full calendar year, your organisation has drawn power from the energy grid in regions you operate, but you accounted for the amount of power coming from fossil fuels by directly purchasing that amount of renewable energy. This is usually called a green tariff.

Evidence required

  • A document showing you are using a green tariff. We strongly recommend making this public.

Example

Hetzner uses green energy tariffs for their data centres in Germany and Finland.

Still got questions? See the FAQ.

Scenario 2: We purchase environmental attribute certificates or have guarantees of origin

In the last full calendar year, your organisation has drawn power from the energy grid in regions you operate, but you can prove that you are generating an equivalent amount of green energy to cover the power coming from fossil fuels in that grid. This can be through environment attribute certificates, or guarantees of origin.

You can show you are paying to put at least as much green power into the grid as you use.

Evidence required

  • Evidence of how much fossil fuel energy your organisation has consumed.
  • Evidence to show that you have accounted for this.
    • A purchased environment attribute certificate (EAC).
    • A document showing guarantee of origin for any green power purchased.

Example

Greengeeks uses renewable energy certificates to account for the fossil fuel energy used by their operations.

Still got questions? See the FAQ.

Scenario 3: We directly fund renewable energy projects

In the last full calendar year, your organisation has drawn power from the energy grid in regions you operate, but you can prove that you funded renewable energy projects that generated an equivalent amount of green energy to cover the power coming from fossil fuels in that grid.

Evidence required

  • Evidence of how much fossil fuel energy your organisation has consumed.
  • Evidence to show that you have accounted for this.
    • An official document, invoice, or other similar evidence from a renewable energy project you have funded. This should include the amount of renewable energy the project puts/will put onto the grid.

Example

Ripple Energy crowdfunded the construction of Craig Fatha, a consumer owned wind turbine, to account for the fossil fuel energy used by their operations.

Still got questions? See the FAQ.

Offsetting greenhouse gas emissions from your operations

Your organisation offsets greenhouse gas emissions caused by using electricity to provide your service/s. This can be by purchasing quality carbon offsets from a reputable provider/marketplace.

We recommend using offsets only as a last resort. If you are not able to directly purchase renewable energy, a green tariff, or renewable energy credits then offsets can be used as evidence when seeking to be a verified provider.

In other instances, you don’t know exactly how much fossil fuel energy usage you need to account for. We often see this when upstream providers do not disclose where the power used to deliver your services comes from. In this case, you can purchase offsets to make up for this.

Scenario 1: We purchase quality carbon offsets to cover the non-green energy we use.

In the last full calendar year, your organisation has drawn power from the energy grid in regions you operate, but purchased quality carbon offsets that reduce/remove/prevent a realistically equivalent amount of carbon dioxide to cover the power coming from fossil fuels you use.

Evidence required

  • Evidence of the emissions associated with your operations. Your upstream provider should be able to provide you with this information. Alternatively, you can use open source tools like Cloud Carbon Footprint to surface this information yourself.
  • Evidence that the offsets you have purchased match the quantity of emissions associated with your operations.
  • Evidence of the ‘vintage’ – what time period these offsets apply to. Offsets need to apply for the last full calendar years or newer. That means, in 2023 we would accept offsets for the year 2022 or 2023.
  • A certificate from the provider of the offsets, which shows:
    • A serial number or identifier for the given scheme.
    • Public evidence of the offsets coming from a recognised scheme – VCS, Gold Standard, or another. You should provide a link to the scheme, which will be shown in our Directory.

Example

You are hosting with Amazon Web Services, and using services in regions where they do not make claims about accounting for the fossil energy they use (see I use Amazon Web Services (AWS), am I a green site/service? for a list of these regions).

You use the open source Cloud Carbon Footprint, to quantify the emissions caused, and you pay to account for the carbon emissions.

You can then purchase offsets matching or exceeding that amount of carbon emissions.

Still got questions? See the FAQ.

Reselling or using an existing green provider.

If you are a reseller for or are an active customer of a provider which is already listed in our Green Web Dataset, then we need you to provide the following evidence:

  • Technical evidence that you use the upstream providers services, either via matching AS numbers or IP ranges. OR, 
  • An invoice from the provider to your organisation showing the infrastructure and services you are using (like hiring server racks, or virtual private servers).

Commercially sensitive information can be obfuscated, as long as we are still able to clearly see the relationship that exists and the services that are being utilised.

Still got questions? See the FAQ.

Ready to get verified?

Are you a hosting provider ready to become included in the Green Web Dataset?

If you have further questions

The FAQs below might help to answer some questions that you may have after going through the content above.

Our organisation has just started business this year. Do I still need to show evidence for the last calendar year?

No, in a situation like this where you have only started operating the current calendar year we would not require you to retroactively account for emissions that were never produced.
For cases like this, we would accept evidence that dates back to the time at which you began your operations. For example, a green tariff that dates back to the start of the calendar year would be acceptable.

Our organisation is a data center operator. We take steps to ensure our PUE is as low as possible, and have numerous energy efficiency measures in place. Can this be used as evidence?

No, not in isolation. Our verification process is focused recognising quantifiable steps an organisation has taken to reduce the carbon emissions produced from the services they provide. With our mission in mind, we focus on those steps that organisations take to avoid, reduce, or offset those emissions.

While improving the energy efficiency of your operations is a terrific step, and probably will help to reduce your overall carbon emissions, it is likely that you will still be generating some carbon emissions by providing your services. You would still need to account for these emissions using one of the methods covered in the article above.

Our organisation has obtained an ISO 14001 certification. Can this be used as evidence?

No, not in isolation. Our verification process is focused recognising quantifiable steps an organisation has taken to reduce the carbon emissions produced from the services they provide. With our mission in mind, we focus on those steps that organisations take to avoid, reduce, or offset those emissions.

While an ISO 14001 certificate recognises steps you are taking to be an environmentally responsible organisation, it is likely that you will still be generating some carbon emissions by providing your services. You would still need to account for these emissions using one of the methods covered in the article above.

We dedicate 1% of our revenues to the elimination of CO2 through the Stripe Climate fund, or a similar program. Can this be used as evidence?

In order to use such a scheme as evidence, you would need to provide quantifiable proof of the emissions you are accounting for (how much CO2 did you generate by providing your services in the last calendar year), and also evidence that shows a matching amount of carbon removal through your contributions.

We currently try to balance accessibility to as many organisations as possible, with rigour – having some defensible basis for issuing our green results, and the criteria are based on principles outlined in existing, established working groups.

We also base this on published work from groups like The Renewable Energy buyers Alliance Future Internet of Power Report, and our own membership of associations like Green Software Foundation, the Open Energy project with Icebreaker One , and the Sustainable Digital Infrastructure Alliance.

If you have further questions, please get in touch!