Prof. J.J. Leahy is an Environmental Chemist at the School of Chemical Science, University of Limerick. Here, he explains how we can cut down our energy use at home.

When we use energy in our homes or for travel we produce greenhouse gases and contribute directly to climate change and consequent habitat destruction.

In What Planet Are You On?, through the eyes of the families, we get insights into how our energy consumption is determined by our lifestyles, and as the ultimate consumers of energy, it shows us how we can make changes which can reduce our carbon footprint and have a positive impact on climate change.

Our homes are responsible for a quarter of energy-related CO2 emissions. From 2006 to 2018, there were significant reductions in the CO2 emissions from heating our homes primarily due to a shift from coal/oil to gas heating, but this downward trend was reversed from 2014 and is currently rising at 8% p.a., probably due to people having more money to spend.

Thankfully, we are on a downward trend again as people become aware of climate change and are taking greater personal responsibility. This was really noticeable with the families taking part in the series - they all want to change.

Where can we make changes?
For What Planet Are You On?, we focused on electricity usage within the home and transport outside the home.

Home heating
For most homes, heating can have almost three times the carbon footprint of electricity. The Commission for Regulation of Utilities (CRU) suggests that the average Irish household uses 11,000 kW.h of gas and 4,200 kW.h of electricity each year.

Electricity usage within homes
Actual energy usage differs depending on the size of the home and how many people live there, as well as other factors like whether the house is occupied during the day or not.

The 4,200 kW/h of electricity used by a typical Irish household compares with 4000 kW.h for the EU average but we compare poorly against the Netherlands who consume 3100 kW.h.

Some of the families such as the McNamaras electricity usage was 74 kW.h over 5 days equivalent to 5400 kW.h per annum. This is high. By having solar electric panels producing renewable electricity in their home another of our families, the Yeboahs, used as little as 12 kW.h over a similar 5 day period.

Solar panels can contribute up to 70% of electricity demand for households during summer months when sunshine is most plentiful.

I think people will be surprised to learn how much energy they consume in their tumble dryers. Would you believe it's more than twice that of a washing machine? Probably in Ireland, we wash our clothes more than is necessary because the tumble dryer provides us with a very convenient way of drying clothes.

About 30% of all electricity in Ireland is consumed within our homes. While electricity usage is rising, the associated greenhouse gas emissions have fallen by 1/3 since 2005. But this was due to reasons outside our personal control and is mostly due to the replacement of coal and oil with natural gas as well as greater use of wind for power generation.

We can contribute individually by using less electricity but we can also reduce our carbon footprint by using our large appliances such as washing machine or dishwashers at night when demand for electricity is low and there is a higher fraction of renewable power available.

All of the families who participated in the show were aware that their cars were the biggest contributors to their carbon emissions but I think they were surprised to learn that it was five times greater than that from all electricity usage in the home.

For the two rural-based families, this was not surprising as their commutes to work were very long and there was no public transport alternative. Public transport between rural and urban centres is appalling.

Later in the series, we give each family the use of a VW e-golf car and Skoda E-bike. And for these families, the electric car had a large effect in terms of reducing their carbon footprint. They were also surprised to see how economical it was compared to diesel or petrol.

The electric bike proved to be a big hit with all the families but was especially useful for our Dublin family The Yeboahs where it displaced one of their cars for a daily commute to work. The reduced effort when using electric bikes provides comfort but also allows the bike user to concentrate on safer cycling.

Watch the brand-new series of What Planet Are You On? with presenter Maia Dunphy on RTÉ One on Sunday evenings at 18.30.