Executive Summary

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The purpose of this paper is to provide the reader with an overview of the main factors associated with the many low-carbon technology options available and the confluence of features that influence decision-making associated with a particular technology. Reduced Greenhouse Gas (GHG) emissions and revenue-generating opportunities can coincide when low-carbon technologies combine with demand-side response. The falling costs of low-carbon distributed energy systems provide data center operators with opportunities to satisfy the requirements of hyper-scale end-users with ambitions for a Zero Carbon Solution. The drivers for change incorporate a wide range of commercial, operational, and environmental elements, with end-users demanding reduced costs and carbon neutrality.

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Content

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i. Introduction

ii. Demand-Side Response and Sustainable Energy Trading

iii. Data Centres as Bidirectional and Unidirectional Microgrids

iv. System Selection Criteria

v. Future Papers by the i3 EYP GHG Abatement Group

vi. Glossary

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1. Introduction

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Government regulation is driving data center owners to consider the impact of their business on climate change. Globally, large economies have declared their intention to decarbonize grid generation using low-carbon energy sources such as nuclear and hydro, and adding renewable sources, primarily wind, solar and tidal power.

 

The energy sector appears to be responding. Figures released in February 2021 by the IEA (International Energy Agency) revealed that “Global emissions from the electricity sector dropped by 450 million tonnes in 2020. This resulted partly from lower electricity demand but also from increases in electricity generation by solar PV and wind.”

 

However, overall the IEA figures showed a carbon bounce due to rebounding economic activity at the end of 2020. The IEA said: Emissions in China for the whole of 2020 increased by 0.8%, or 75 million tonnes, from 2019 levels driven by China’s economic recovery over the course of the year. Emissions in the United States fell by 10% in 2020. But on a monthly basis, after hitting their lowest levels in the spring, they started to bounce back with December 2020 emissions matching those of the previous year.

 

Dr Fatih Birol, the IEA Executive Director, said: “In March 2020, the IEA urged governments to put clean energy at the heart of their economic stimulus plans to ensure a sustainable recovery. But our numbers show we are returning to carbon-intensive business-as-usual… these latest numbers are a sharp reminder of the immense challenge we face in rapidly transforming the global energy system.”

 

Renewable energy brings enormous benefits. However, the energy output from solar and wind is intermittent, and tidal energy is periodic. Furthermore, renewables could de-stabilize the grid if large blocks of power are added or removed.

 

Paradoxically, this presents both challenges to the utility providers as well as new revenue opportunities to data centre owners. Data centers with low-carbon generation sources and sufficient energy storage can assist in backfill grid capacity shortfalls by interacting with the grid. Embedded generation grid integration is well established amongst existing distributed generation companies.

 

Historically almost all data centers have used UPS to condition utility power and provide 5 – 10 minutes of IT power together with diesel generators to supply 24 to 72 hours of standby power during a utility power failure. In countries with reliable grids, diesel generators usually operate just a few hours each year. Diesel engines have high emission factors and therefore are unsuitable as a sustainable energy source for grid support.

 

Substituting diesel engines with low-carbon alternatives such as gas reciprocating engines or turbines in conjunction with sustainable energy storage devices will enable many data center

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owners to reduce their carbon footprint, and gain additional income derived from the various grid support schemes discussed in Section 2. Gas-driven generators have low NOx and SOx emissions, so they are generally permitted for unlimited use. Conversely, standby diesel generators are generally required to operate for only a few hours a year, so their overall carbon contribution is rather insignificant. The high emissions associated with diesel generators is the reason they are only permitted to run for few hours. Each country has a different grid generation fuel mix. Each type of generation has an associated emission factor, typically referred to as equivalent carbon footprint which includes the effect of all GHG emissions including CO2, SOx, NOx and F-gases. 

 

Figure 1 illustrates the 2019 GEF (Grid Emission Factor) data for some countries.

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