How to make a hosting company carbon neutral РRen̩ Wienholtz of Strato

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Episode 4 of the GreenMonk Podcasts – 36 mins 28 secs

My guest on this podcast is Strato’s Executive Director for Information Technology and Innovation Rene Wienholtz.

Strato are Europe’s second largest hosting company and Strato are also carbon neutral! Amazingly they achieved this without buying any offsets. How did they do it?

Listen to René explain it.

Here are the questions I asked René and the approx. times I asked them:

Can you tell us something about your own background first and who are Strato? – 00:34

If I heard you correctly you are now the largest hosting company in Europe? – 02:28

You guys are a bit like RackSpace in the sense that you don’t do co-location, you rent space on your servers, id that right? – 02:38

You mentioned that you decided to re-architect the setup in Strato and reduce your carbon footprint, was this for environmental reasons or business reasons? – 03:34

Questions from readers:

Jiri Ludvik
what percentage in carbon reduction they achieved by each of the step you mention? – 05:48

Do you use underfloor plenums as well to direct the air to the cold aisles? – 21:47

Can you talk to us too about the energy savings you are getting from buying CO2 free energy? – 25:44

Have you negotiated a set price from your clean energy supplier for a set period? – 29:36

Can you tell me how long this price is guaranteed for? – 30:15

Have you had any independent 3rd party certify that you are carbon neutral? – 30:27

More questions from readers:

Jim Hughes
Has the carbon saving had a real cost benefit? Or have the lower power costs been exceeded by the premium for carbon neutral electricity? – 31:42

Would you recommend other hosting providers take the same route? – 32:53

Do you think environmental awareness is an area where European hosting companies have a head start over the US? – 34:47

Download the entire interview here
(33.4mb mp3)


  1. says

    Thanks to you and Rene for an excellent podcast. I think that Strato is doing great things and should be commended for that. However I have a problem with the concept of buying carbon neutral power.

    Let me start by giving you an analogy. Imagine a natural disaster affecting an area. On the runway at the local airport is an aircraft with 100 seats filled with injured children to be flown out for medical attention. A well meaning company decides to pay to help ten injured children get on the aircraft. They pay the airline operator to take ten injured children off the plane to replace them with the ten that they want saved. The sponsor company can claim to have saved ten children but no extra children were saved by their action. It is better to pay to have a bigger airplane rather that to but the actual seats on an existing aeroplane.

    How does this analogy apply? Almost every electrical grid has some renewables in the generation mix. Because of the design of every grid there is only a defined percentage of renewables that can be accomodated. Renewables such as wind and solar etc. are weather dependant. This means that the infill is supplied from traditional energy sources. Accomodating increased renewables on the grid involves the use of super grid interconnects, storage such as CAES or pumped hydro, and demand response (ie demand that tracks renewable supply).

    If you buy your electricity from a grid that has a design of say 10% renewables then you are consuming 10% renewables. If you pay a supplier that has purchase agreements with renewable generators you can claim to be using renewable energy. However if the wind isn’t blowing that supplier is supplying you with energy from burning carbon based fuel. He may replace it later with wind energy but that is just rearranging the seating on the plane.

    Buying a few seats on the aircraft doesn’t save extra children. Claiming that you buy only renewable energy is an accounting trick perpetrated by electricity suppliers. Renewable energy isn’t always available so they shift their purchases in the market. The nett effect is that the grid doesn’t get anymore renewable energy. Other consumers get a lower percentage.

    If you want to lower carbon production then facilitate renewable penetration onto the grid rather than ‘buy’ renewable energy. Make more seats rather than buy up the available ones.

    As a consumer the only way to do this is to get your usage to track renewable production on your grid. Funnily enough this happens to match when wholesale electricity prices are lowest (renewables are price takers because the incremental cost of production is zero). So the way to get more seats on the plane is to buy cheap electricity.

    I know this sounds corny but trust me I have been researching it for a long time. This idea is part of a new concept of electricity production and consumption starting to be called Grid 2.0.

    In summary, if you burn electricity you create carbon. The amount of carbon repemds on the fuel mix at the time you burn the electricity. No amount of financial/market wizardry gets over this fact.

    So let me give you a practical example of how Strato might do this. If they invested in an ice bank storage unit and bought electricity when it is cheap (= wind is blowing and/or most efficient base load generation is in use) and then used that melting ice to cool their data centres when electricity is dear (= least efficient fossil fuel plants in use) they would be adding seats to the aircraft instead of using existing ones.