Green web hosting is website hosting from a provider that powers its servers with renewable or other fossil-free electricity and runs its data centers efficiently. To verify a claim, look for a published Power Usage Effectiveness (PUE) figure, a clear source of renewable power (own generation, a power purchase agreement or a green tariff), and a listing in the Green Web Foundation’s dataset. Carbon offsets alone do not make a host green.
Key Takeaways
- According to the International Energy Agency (IEA), data centers used around 415 TWh of electricity in 2024, about 1.5% of global electricity, and the IEA’s Base Case projects around 945 TWh by 2030.
- Power Usage Effectiveness (PUE) compares a data center’s total energy use with the energy delivered to its computing equipment; 1.0 is the theoretical ideal.
- Google reports a fleet-wide PUE of 1.09 for 2025, against an industry average of 1.54 from the Uptime Institute’s 2025 Global Data Center Survey.
- The Green Web Foundation does not accept carbon offsets as evidence of green hosting; it accepts own generation, direct power purchase agreements, green tariffs and energy certificates.
- Renewable energy certificates (RECs) represent 1 MWh of renewable generation each, but critics say unbundled certificates can let two parties claim the same clean power.
What Should You Know About Green Web Hosting
Green website hosting means buying your website hosting from a company that uses electricity efficiently and avoids wasting power. Ideally, the company also runs on renewable or other fossil-free power, either by generating it, buying it directly from a project, or using a green electricity tariff. Your website host is using servers and a network in order to give you website hosting.
The servers are just like very big computers, but they have a lot of processing power and memory. This sort of technology needs a lot of power in order to make it work. Not only does it need the power to run the servers and the network, but also to cool the servers because they produce a lot of heat that is counterproductive to their working. A company that is also able to cool its servers in an eco-friendly way is also good.
Cooling servers in an eco-friendly manner
Some companies have found very clever ways of doing this. There are companies that run stream water through their cooling system. Other companies use cold outside air to cool their servers, a method known as free cooling. And, there are companies that siphon off some of the warm air to heat the office buildings above. Green website hosts will often find more energy efficient and green ways of cooling their servers.
Do servers use that much power?
A server running on electricity from a fossil-fuel source such as a coal power station has a real carbon footprint; one often-repeated comparison likens a single server’s emissions to those of an SUV, though that figure has not been independently verified and depends on the server and the local power grid. Any one host is going to have a lot of servers, which is similar to them having their own collection of delivery trucks running in diesel.
Are there energy efficient servers?
It is a hard question to answer because it is very subjective. Just know that there are some servers that are more wasteful than others. It is a little like cars: a small, fuel-efficient petrol car such as a Smart car is more efficient than a large regular car, but it will never be as energy efficient as walking or cycling.
So do not be bowled over by companies that claim they have energy efficient servers. It is a good start, but it is not enough to cut emissions enough to warrant bragging rights. They should be taking further steps, including optimizing workloads so that servers are not left running idle with unused processing power (servers cannot be put on standby the way a home computer can).
Using wind power to cool servers
Supplemental renewable generators, such as wind turbines or solar panels, may be set up near to the data center. They may provide additional energy in order to power the cooling systems. This trickle of energy can save the host company money, while slightly reducing the data center’s demand on the power grid.
Is the company bragging about it?
If they are bragging about how green they are, then pay attention. It is good to support companies that are green. The only trouble is that the online world is a place where lies become facts. Unverified claims spread easily online, so green marketing claims deserve the same scrutiny as any other claim. If the company is bragging about it, then there is a chance that they have taken steps to be greener. They may also be lying, and it is hard to find the truth.
Still, if they are bragging about their green policy, then they are more likely to have actually taken steps than a company that does not mention its green policy.
Why should I care?
Some estimates put the emissions of information and communication technology (ICT) on a par with, or above, those of the aviation industry: a 2021 study by Freitag and colleagues estimated ICT’s share of global greenhouse gas emissions at 1.8-2.8%, and possibly as high as 2.1-3.9%, while Our World in Data reports that aviation accounted for 2.5% of CO2 emissions in 2019. Older estimates compared the Internet’s power use with that of a country such as Poland or Turkey and put its emissions at around 300m tonnes of CO2 a year; these figures could not be independently verified, and current measures differ. The IEA estimates that data centers alone used around 415 TWh of electricity in 2024.
Yet, the problem is so much easier to solve than vehicle emissions, airplane emissions and cattle emissions. All the hosting companies need to do is start powering their centers with renewable energy. Cost is an incentive: according to IRENA, 91% of newly commissioned utility-scale renewable capacity in 2024 delivered power at a lower cost than the cheapest new fossil-fuel alternative, and utility-scale solar’s installed cost fell 87% between 2010 and 2024.
Improving the efficiency of data centers is going to save the hosting company some money, and is going to help save the earth at the same time. It is win-win, but it does require an investment on the part of the hosting company. Which means that Mother Nature is still taking one for the team until we start buying from green-only companies.
What Makes a Web Host Genuinely Green?
A genuinely green web host does two things: it uses less energy for the same work, and it gets that energy from fossil-free sources. The Green Web Foundation, an independent non-profit with offices in Amsterdam and Berlin that tracks how much of the internet runs on green energy, accepts five kinds of evidence for green power.
- Self generation: the provider generates its own fossil-free electricity.
- Direct procurement: the provider buys power from a fossil-free project under a dedicated power purchase agreement (PPA).
- Green tariffs: the provider actively buys a fossil-free tariff from its electricity supplier.
- Unbundled certificates: the provider buys certificates of fossil-free generation separately from the power it uses.
- Passive procurement: the provider operates where certificates are bundled with power by default.
The Green Web Foundation counts solar, wind, geothermal, ocean energy, hydropower and nuclear energy as fossil-free sources. It states that carbon offsets cannot be used as a valid basis for verification, because its goal is phasing out fossil fuels rather than offsetting them.
How Much Electricity Do Data Centers Use?
Data centers used around 415 terawatt hours (TWh) of electricity in 2024, about 1.5% of global electricity consumption, according to the International Energy Agency’s Energy and AI report. In the IEA’s Base Case, that figure roughly doubles to around 945 TWh by 2030, just under 3% of global electricity consumption.
Electricity is not the only resource involved. Wikipedia’s data center article notes that most large data centers use water for evaporative cooling, and that Virginia’s data centers consumed about 2.1 billion gallons of water in 2023.
What Is PUE and What Is a Good Score?
Power Usage Effectiveness (PUE) is the ratio of the total energy used by a data center facility to the energy delivered to its computing equipment. The Green Grid, a non-profit of IT professionals, developed PUE in 2006, and it was published as the international standard ISO/IEC 30134-2:2016.
A PUE of 1.0 is the theoretical ideal, meaning every unit of energy reaches the computing equipment. A PUE of 1.5 means that for every unit of energy the servers use, another half unit goes on cooling, power conversion and other overhead.
| Benchmark | PUE | Source |
|---|---|---|
| Theoretical ideal | 1.0 | Definition of PUE |
| Google fleet-wide, trailing twelve months, 2025 | 1.09 | Google data centers efficiency page |
| Industry average, 2025 | 1.54 | Uptime Institute 2025 Global Data Center Survey, as cited by Google |
| Two-phase immersion cooling, best reported | as low as 1.01 | Wikipedia, Data center |
PUE measures facility efficiency only. A data center with an excellent PUE can still run on coal power, so check the energy source as well as the PUE.
Real Examples of Greener Data Center Cooling
Large operators already use the cooling methods described above. Google’s data center in Hamina, Finland, uses seawater from the Bay of Finland for cooling, and Google describes an offsite heat recovery project there with Haminan Energia, its first offsite heat recovery project, expected to meet an estimated 80% of the local demand for warming homes and businesses.
In Denmark, Meta’s Tietgenbyen data center in Odense sends surplus heat to the local district heating network. According to the engineering firm Ramboll, the energy center operated by Fjernvarme Fyn recovers 215,000 MWh of energy a year from the data center and supplied heat to more than 12,000 homes in 2023.
Renewable Energy Certificates vs Real Renewable Power
A renewable energy certificate (REC) in the United States is a tradable certificate representing proof that 1 megawatt-hour (MWh) of electricity was generated from an eligible renewable source. Many hosts that advertise renewable power rely partly on certificates like these.
Certificates are not all equal. Critics point out that when certificates are sold separately from the electricity, two parties can end up claiming credit for the same clean power, and research on voluntary solar REC purchases from 2004 to 2011 found no significant additional renewable investment or generation. A host that generates its own power or signs a direct PPA is usually making a stronger claim than one relying only on unbundled certificates.
Do Governments Regulate Data Center Energy Reporting?
In the European Union, the revised Energy Efficiency Directive (EU) 2023/1791 and Delegated Regulation (EU) 2024/1364 require data centers with an installed IT power demand of at least 500 kW to report energy performance information and key performance indicators to a European database. Most small hosting customers will never see these filings, but they make large providers’ efficiency claims easier to check.
How to Check Whether a Web Host Is Green
- Run the Green Web Check. Enter the website’s address in the Green Web Foundation’s Green Web Check to see whether it runs on 100% green energy, and view the public evidence behind the provider’s claim.
- Ask for the PUE. A provider that measures efficiency should be able to give a PUE figure and say which year it covers.
- Ask how the power is sourced. Own generation, a direct PPA or a green tariff is stronger evidence than certificates alone; offsets alone are not evidence of green power.
- Look for published reports. A sustainability report with dated figures is more useful than a green leaf logo with no data.
- Compare features and price as usual. A green host still needs to meet your speed, support and uptime needs; see our guide on finding a good web hosting provider.
Green Hosting Claims Compared
| Claim you may see | What it usually means | How strong it is |
|---|---|---|
| Powered by our own solar or wind | Self generation | Strong, if the share of total power is stated |
| Power purchase agreement (PPA) | Direct contract with a fossil-free project | Strong |
| Green electricity tariff | Fossil-free tariff from a supplier | Accepted by the Green Web Foundation |
| 100% matched with certificates | Unbundled RECs or similar | Accepted, but criticized for double counting |
| Carbon neutral through offsets | Emissions offset, not avoided | Not accepted by the Green Web Foundation |
Choosing the Right Type of Green Hosting
The type of hosting also affects how efficiently your site uses servers. Shared and cloud hosting spread server capacity across many customers, while a dedicated server runs for one customer whether it is busy or idle. Our guides on how web hosting works, the benefits of cloud hosting and colocation hosting explain the options. If you run your own hardware, knowing when to upgrade data center servers helps you replace inefficient equipment at the right time.
Frequently Asked Questions
What is green web hosting?
Green web hosting is website hosting from a provider that runs its servers efficiently and powers them with renewable or other fossil-free electricity. Strong evidence includes own generation, direct power purchase agreements or green tariffs, together with a published PUE figure.
Is green hosting more expensive?
Green hosting is not necessarily more expensive; prices vary by provider and plan, so compare current prices directly. Renewable power itself is cost-competitive: IRENA reports that 91% of newly commissioned utility-scale renewable capacity in 2024 was cheaper than the cheapest new fossil-fuel alternative.
How can I tell if my website uses green hosting?
The Green Web Foundation’s Green Web Check shows whether a website runs on green energy and lets you view public evidence of the provider’s claims. You can also ask your host for its PUE and how it sources its electricity.
Do carbon offsets make a host green?
Carbon offsets alone do not make a host green under the Green Web Foundation’s rules, which state that offsets cannot be used as a valid basis for verification. Offsets compensate for emissions rather than replacing fossil-fuel power.
What is a good PUE for a data center?
A PUE closer to 1.0 is better. Google reports 1.09 across its fleet for 2025, while the Uptime Institute’s 2025 survey, as cited by Google, puts the industry average at 1.54.
How much electricity do data centers use?
Data centers used around 415 TWh of electricity in 2024, about 1.5% of global electricity, according to the IEA. The IEA’s Base Case projects around 945 TWh by 2030.
