7 Matching Annotations
  1. Mar 2023
    1. A country’s residual mix represents the shares of electricity generation attributes available for disclosure, after the use of explicit tracking systems, such as GO, havebeen accounted for.Without a residual mix, renewable electricity sold with GOs would be double counted because the same electricity would be disclosed to consumers buying “regular” electricity

      This is how green the power is, once the certificates that can be transferred have been transferred. So, when a country has lots of green energy but sells off it's "greenness", this is what the actual carbon intensity should be. Norway is the perennial example.

    1. Google, with their Apollo project, has developed a non-blocking 136x136 optical circuit switch that is both forward and backward-compatible with any bandwidth or wavelength Google uses or will use in its data centers. This switch, according to Google, only uses 108 watts of power consumption. Compared to a standard 136 port EPS switch, which would be in the 3,000 watts range. So while there are disadvantages to OCS, Google has created a solution that has far more upsides than there are downsides for them. And over the past 5 years, “tens of thousands of 136x136 port OCS (eight spare ports) were manufactured and deployed.” Google has created a system that works incredibly very well for them.In the future, Google is looking at a larger port count OCS for further scale-out capabilities as well as faster switching speeds to allow wider adoption of OCS in the lower layers of the network. This broader adoption would be tremendously negative to Broadcom, the leader in hyperscale networking switches. Furthermore, Google says they will also continue to improve reliability and lower insertion/return loss.

      30x power usage improvement

    2. The low latency of OCS comes from the fact that OCS does not have to decode packets; all they have to do is bounce the incoming light from the source port to the destination port.

      There's no conversion back and forth between light and packets. It's a bit like the serialisation / deserialisation cost higher up the stack

    3. Before diving too deep into how their custom networking stack works, let’s quickly discuss what it does and the industry implications. First off, Google claims their custom network improves throughput by 30%, use 40% less power, incurs 30% less Capex, reduces flow completion by 10%, and delivers 50x less downtime across their network.

      These are wild figures. What is the counterfactual?

  2. Feb 2023
    1. Attributes (and certificates) must be sourced and purchased from within the same defined geographic region that constitutes a “market” for the purpose of transacting and claiming attributes. Ideally this “market boundary” would be clearly defined, but in general it refers to an area in which the laws and regulatory framework governing the electricity sector are sufficiently consistent between the areas of production and consumption. As such, transactions that are both international and intercontinental are not usually appropriate unless there is physical interconnection (indicating a level of system-wide coordination between countries) and ideally if these countries’ utilities or energy suppliers recognize each other’s instruments

      The RE100 says it's a bit rich to try buying credits in say… the Nordics to account for Asia

    1. Alphabet Inc.’s renewable energy methodology is a custom calculation and is based on a global approach. The numerator includes all renewable energy procured, regardless of the market in which the renewable energy was consumed. Additional details on Alphabet Inc.’s criteria and methodology can be found in theAchieving Our 100% Renewable Energy Purchasing Goal and Going Beyonddisclosure

      This is basically like buying extra green energy where it's cheap and plentiful (i.e. the Nordics), to cancel out where it's not (i.e. lots of parts of Asia)

  3. Jan 2021