Energy and water wasted in the lab can quickly outweigh household use

An image showing three scientists unplugging two plugs

Source: © M-H Jeeves

Pull the plug on wasting energy

You cannot open a newspaper, turn on the television or use social media without being reminded of the consequences of the defining issue of our time: the climate crisis. From rising sea levels, escalating emissions of heat-trapping greenhouse gases and an increase in global average temperature, it is more apparent than ever that to sustain the planet for future generations, humankind must make changes to slow down the global warming process. For scientists, this responsibility is closer to home than many may think. 

Those working in a chemistry lab know that a day’s work requires just as much use of machines as it does chemicals and glassware. From weighing and stirring to heating and washing, we use a substantial amount of energy and water for the smallest of tasks.

Over time, as I have worked on my synthetic chemistry PhD project, using a range of specialised laboratory equipment has become second nature to me. Along with familiarity comes complacency. I’ve noticed myself leaving equipment on overnight without a second thought. After coming into the lab one morning and discovering I had left the cold tap running through an unused condenser, I realised my only concern was flooding my fumehood, with a complete disregard for the amount of water I had just wasted. I thought to myself, how many taps have I left running for days without noticing? How many times have I left electrical equipment on overnight, and how many other students at institutions all over the world are going to do the same tonight?

As individuals who work in a laboratory use much more energy and water than those who work solely in an office environment, I think it’s extremely important that we have a better understanding of our energy and water consumption so we can do our part to reduce usage. I find it can help to compare lab usage to common household activities. For example, consider the first part of any chemical reaction: weighing out reagents, which is usually done on an electric analytical balance. The laboratory I work in has four of these balances, none of which are switched off overnight in order to maintain a constant temperature. If they were, we would save the same amount of energy a year that it takes to boil a kettle over 420 times.

As turning off an analytical balance overnight would affect the calibration of the instrument, it’s clear that some energy usage within the lab is unavoidable. Since compromises have to be made for the sake of research, identifying opportunities to reduce energy usage in other areas is therefore crucial.

Chemical reactions are often stirred to promote dissolution and heated to give the system sufficient energy to react, both of which are achieved using magnetic stirrer hotplates. It’s easy enough to forget to turn off a switch, but neglecting to turn off a stirrer hotplate for just one night wastes enough energy to run a washing machine over 15 times. In my lab alone there are 14 postgraduates that undertake synthetic work, each of whom have two hotplates, so energy consumption can quickly add up.

But it’s not just forgetfulness that is a source of wasted energy. In a synthetic lab, most fumehoods contain a Schlenk line: apparatus used for air- and moisture-sensitive reactions that allows chemists to easily switch between introducing an inert gas into the system and reducing the pressure using a vacuum pump. It happens often that chemists set up their Schlenk line in the morning and use it sporadically throughout the day. Sometimes they may even use it only once, and still not disassemble it until the end of the day. The vacuum pump is on at all times while assembled, so leaving your line up and unused for the full working day – 8 hours – wastes the same amount of energy it takes to toast 220 pieces of bread.

It’s not just energy that’s wasted in the lab. Most chemists are familiar with reflux apparatus: cold water runs through tubing connected to the bottom of a glass condenser, up the apparatus and out into a sink. Depending on the flow rate, it’s estimated that this process can use between one and four litres of water per minute. This means that when I forgot to turn the tap off overnight, I could have wasted up to 5760 litres of water. Once I realised this value is more than 30 times the amount of water the average person uses in their house per day, I knew something had to change.

As all of the comparisons with household use show, it is imperative we track our energy consumption and water use in the lab and minimise both. An easy way to start is to make sure you’re not running equipment unnecessarily. In the lab I work in, my group have implemented a rule in which the last researcher working must check all equipment is off before they leave at the end of the day, and this has instilled a more conscientious attitude into us all.

Although climate change may be inevitable, individually we can begin to take action to slow down this change. If we are to prevail in the battle to save planet Earth, we must all play our part – researchers too.