Many of us strive to change our personal behaviour to decrease our environmental impact, such as by reducing energy consumption. Some of us are constantly thinking of ways to improve our habits, while others might do so less frequently—perhaps triggered by reading a relevant news article or watching a documentary. And for some, of course, it may not register at all.

Perhaps the biggest question everyone has no matter where one lies on this spectrum is this: how much can individual actions make a difference? That is just what I hoped to find out through an experiment I conducted at home. My results were surprising. And I’d like to share them with the hope that others are inspired to adopt some easy, environmentally-friendly habits, while also saving their wallets in the process.

I planned two separate trial runs of selective behavioural changes to reduce my electricity usage at home. The first was to reduce my air conditioning (AC) usage, which is no easy feat living in the humidity of Florida, and the second was to reduce my electric light usage. These are the primary sources of energy consumption in residential homes in the US, with air conditioning accounting for over 50 percent of electric usage per household, while lighting is about 8 percent. 

We get our utility bill after we have already consumed the energy, which may cause many to not consider their daily usage in relation to the choices we make. To help make a proactive change with my AC usage, I looked at my current habits, the average consumer’s habits, and recommended energy saving settings. A study showed that the average thermostat cooling setting in North America is between 73–76℉ (or 22.8–24.4°C). This was right similar to my own settings, as I tend to keep it around 76℉ during the day and 73℉ at night. On the other hand, the US Department of Energy recommends keeping thermostats at home at a low of 78℉ (25.5°C) when in a cooling cycle.

The first step

Yikes, what had I gotten myself into? The recommended temperature sounded warm to me, with my personal comfort in question. But I stuck with the plan and reprogrammed my thermostat. And thus began my first 30-day trial run. The initial nights were a little uncomfortable. But this was short-lived, and a few days into the trial, I slept just fine. 

Likewise, raising my thermostat from 76℉ to 78℉ in the daytime didn’t faze me at all. I typically work from home, so although I was around during the hottest parts of the day, the indoor temperature rarely crossed my mind. After the experiment ended, I reviewed my utility bill from the same period in the previous year and noticed a drastic decrease in electricity usage. 

My daily average kilowatt-hour (kWh) usage over this period reduced by nearly 60 percent, from 19.93 to 11.83 kWh. Even better, my electricity bill dropped from $103.79 to $57.78—a decrease of around 56 percent. What’s more astonishing, this happened during an average 10-degree increase in outdoor temperature compared to the previous billing period. By turning up my thermostat by a few degrees, I not only reduced my carbon footprint, but also saved money—all while staying comfortable in my home. 

A European study showed the average carbon emissions output from electricity consumption is 0.233 kg CO2eq/kWh (so for every kWh of electricity consumed, 0.233 kg of carbon dioxide equivalent is emitted). Based on this rate, my 30-day experiment reduced my carbon footprint by 52 kg CO2eq—a decrease of around 40 percent! These results were encouraging, helping me realise that simple changes to individual habits can indeed make a difference. With this as my motivation, I took it a step further with a next 30-day experiment, where along with keeping the thermostat at the recommended temperature, I was also going to turn off the lights when not in use. 

Behavioural psychology

This new experiment was going to require a bit more effort than just changing the thermostat setting. I committed to three actions: ensuring I turned lights off when leaving a room, utilising more natural light by opening blinds, and keeping lights off when unnecessary. I thought this would be relatively easy, but this was where the psychology of behavioural change revealed itself. 

During the first few days, I constantly caught myself forgetting to turn lights off when leaving a room or even leaving the house entirely. However, I made some progress with being more intentional about light usage, ensuring I kept them off when not in use. I started to notice that when I happened to leave a light on, I’d now get up and turn it off. In the past I probably would have just left it on until returning to that area later. 

This still wasn’t quite enough to get the results I hoped for though. After returning from the grocery store one day to a well-lit house, I knew I needed to step things up. A few studies have demonstrated that environmental behaviours are frequently habitual, triggering automatic processes, which meant I needed some extra motivation to rewire my brain. A simple solution was to place brightly colored sticky notes near every light switch in the house. These helped remind me to flip those switches off. 

Finally, while working from home, I started to take advantage of opening blinds throughout the house, especially in the office, and avoided using the overhead lights when possible. I even went to small lengths such as using my phone’s flashlight when running to the bathroom or kitchen. Ultimately, it really became something of a game to use as little lighting as possible, and no, I didn’t feel like I was walking around in the dark all the time. 

After this second experiment ended, I looked to the utility bills for results. I had continued to maintain an AC temperature of 78℉ , so I wasn’t sure how much further reduction on my utility bill to expect. But I was greatly pleased to discover that my energy consumption had dropped an additional 22.4 percent, resulting in a further 5.5 kg CO2eq reduction in my carbon footprint! 

After two months of trying to reduce my energy consumption, I felt buoyed by the fact that individuals can have a direct impact without having to do a whole lot. I would encourage people to think about their own habits and how they can make changes to reduce their environmental impact. It could start small, with raising the AC temperature by one to two degrees, for example. Or by turning lights off when leaving rooms, and maybe even gamifying it, especially for kids.

Some of these changes may be hard to initiate but the benefits are great. I have stuck with these new habits for many months now. They have led to a greater sense of doing the right thing, given me hope that the environment can be protected, and even helped save money every month. 

Further Reading

Kopsakangas-Savolainen, M., M. K. Mattinen, K. Manninen and A. Nissinen. 2017. Hourly-based greenhouse gas emissions of electricity–cases demonstrating possibilities for households and companies to decrease their emissions. Journal of Cleaner Production 153: 384–396.

Ohnmacht, T., D. Schaffner, C. Weibel and H. Schad. 2017. Rethinking social psychology and intervention design: A model of energy savings and human behaviour. Energy Research & Social Science 26: 40–53.

Parker, D. 2013. Determining appropriate heating and cooling thermostat set points for building energy simulations for residential buildings in North America. Report published by the Florida Solar Energy Center. Accessed on September 3, 2025.