Carrie Goetz, principal, and CTO of StrategITcom looks at the challenges faced in increasing renewable energy production to meet future energy demands
Much stall has been put on renewable energy as the answer to our climate change woes, but there are some problems surrounding its continued growth. To meet the demands of world energy consumption through renewables would require ten times our habitable landmass for wind and about half of it for solar.
So, what are the figures behind this proclamation? Bear with me while I go through the math. The estimated US energy usage is 92,943,042,000,000,000 BTU or 470,319,634 KW/year. It takes 2.5 acres per MW for 1kW of solar and 60 acres per MW for wind. To run fully renewable in the US, that would require 1,175,799,085 acres for solar with a development cost of about $3 million per MW and 28,219,178,040 acres for wind at about $2million per MW onshore and $3-$4 million per MW offshore. The entire US is about 2.27 billion acres, of which 108 million are developed urban areas. The remaining is either unhabitable, undeveloped, or farmlands.
The total land surface area of Earth is about 57,308,738 square miles, of which about 33 per cent is desert and about 24 per cent is mountainous. Subtracting this uninhabitable 57 per cent (32,665,981 mi2) from the total land area leaves 24,642,757 square miles or 15,770,000,000 acres of habitable land. 2018 world energy use is about 23398 billion kWh hours or 2,671,004,566.2 kW, which would require 6,677,511,415 acres for solar (half of the world’s habitable landmass) and 160,260,273,960 acres for wind which would mean trouble for the Earth’s inhabitants.
While we are making strides towards renewables, it is clear from consumption to landmass ratios that we are not able to move entirely to renewables. The recent pandemic caused power consumption to decrease in 2020. This decrease was primarily due to quarantines and people working from home. However, that decrease will reverse as people return to work.
Solar electricity rose by a record 20 per cent, with estimated capacity sitting at 127 GW; however, wind provided the most significant contribution to renewables growth, adding 111GW worldwide. As a result, overall renewables in power generation increased from 10.3 per cent to 11.7 per cent, displacing 1.3 per cent of coal generation globally.
Across the entire energy sector, ICT, including data centres, accounts for about four per cent of all energy usage worldwide. While this is a large number, the numbers reported as to the energy usage of our sector are greatly exaggerated. For example, in 2019, a report by the Shift Project found that ‘the emissions generated by watching 30 minutes of Netflix is the same as driving about four miles’. As stated in this report, streaming alone was responsible for more than 300 million metric tons of CO2 in 2018, equivalent to the entire emissions of France. This number, picked up by several news outlets to fuel the climate crisis, is cited often. However, for this to literally be true, this would mean that this one streaming service would have to consume 370 TWh of electricity each year. That number is nearly double the electricity used by all data centres globally. Yet, across the entire data centre sector in the same year, that consumption was only 205TWh according to ITIF’s Sorry Wrong Number.
According to IEA and Carbon Brief, this study makes several flawed assumptions. For starters, it inaccurately estimated the bitrate at 24Mb/s when for 4k, it is 16Mb/s, and weighted by viewing device and stream on average is closer to 4.1Mb/s. In short, they confused bits for bytes. They also overestimated the power of the viewing device using TVs as their bellwether, failing to account for phones, tablets, and other far more energy-efficient viewing devices. In fact, an IEA analysis found that video streaming consumes .12-.24 kWh of electricity per viewing hour which is about 25-53 times less than many of the Shift project assumptions. In 2020, the Shift Project acknowledged their error with bits and bytes. The damage, however, was already done as their original numbers were widely echoed in the mainstream media without fact checks.
According to the same ITIF report, this is not the only time we have seen wrong numbers. Bitcoins expected usage is another, along with their estimated CO2 emissions. These studies failed to incorporate the number of renewables in the bitcoin mining sector. And another incorrect yet widely reported statistic surrounds the YouTube downloads and views of the song ‘Despacito’, stating that the downloads alone were equal to the electricity consumed by several African countries. Those estimates mistakenly assert that this song alone was responsible for a seventh of Google’s total electricity use. We all know that song just is not that good. When Ericsson fact-checked this claim in its report ‘A quick guide to your digital carbon footprint’, the download of one song to a smartphone requires about 0.001 kWh, so the five billion downloads of the song would be about .005TWh or 120 times less than reported estimates.
According to IEA, Internet traffic has tripled since 2015 and is expected to double again by 2025 as more devices and households in developing nations come online. While people in our industry generally discuss Moore’s law, we rarely discuss Koomy’s law which states, “the number of computations per kWh of electricity has doubled every ~1.6 years”. Many of these studies forget to consider all the work being done to increase energy efficiency within our industry. Yet one problem remains, stranded, or wasted power.
Stranded power is the dirty little secret of the data centre industry. While we work tirelessly at uptime, we forget the price of stranded power. Coupling power demands with land demands creates quite the conundrum. We simply must look to carbon removal strategies as stepping stones to renewables. Carbon capture and carbon sequestration remove the unwanted CO2 emissions from natural gas production and can be equally crucial to environmental stewardship in our industry.