With electricity bills doubling between late 2021 and early 2023, homeowners have come under increasing pressure to make ends meet, writes Ken Bruton. Where once the average annual cost of electricity was approximately €1,000 per annum, it is now routinely close to €2,000. The government has acted to try to ease this burden with various energy credits, but this still leaves homeowners responsible for the shortfall.

Gerald Bruton is 80 years young. His journey to reduce his energy consumption began in early 2022 and was driven more by cost reduction than environmental aspirations. His house is like many others in the country, a 1970s three-bedroom semi-detached located in a western residential housing estate of Cork city. (Full disclosure, Gerald is my dad.)

Bruton had already improved the wall and attic insulation in a bid to reduce heating oil consumption when news of the first significant electricity price increase came in early 2022. His unit costs quickly went from 21c/kWh in January 2022 to 30c/kWh by April 2022 (see Figure 1). 

Figure 1: Gerald Bruton's average electricity cost per day from Jan 2022 to Oct 2023.

His reaction to these substantial price increases was twofold: monitor and reduce his electricity consumption and potentially install renewable energy generation technology. He identified that the tumble dryer, electric shower and the dreaded (to Irish people anyway!) immersion heater were the ones to watch closely.

He had always been an advocate of the clothes line to dry the washing. With the tumble dryer on the banned list, he began to use the less energy intensive dehumidifier as a tool to assist his clothes drying needs, even if it did take a little longer and a bit more planning to achieve.

Bruton cut his electric shower durations to a strict five minutes and cut out the use of the immersion heater. These behaviour changes resulted in a 10% reduction in electricity consumption in his May 2022 electricity bill. 

Buoyed by this initial success, he sought quotations for solar photovoltaic (PV) panels to both provide electricity as well as hot water via a solar fed electric heating element. After research, he went for a 2.56kW, eight 320W panel system.

Due to southern aspect roof area constraints, he located four panels on the southern side of the house with four others on the western side. This did slightly reduce the overall expected yield of the system by about 10%, but it did elongate the daily generation window by making use of the evening sun.

A 30% reduction in grid procured electricity

The solar PV system was installed in June 2022 with the support of an SEAI grant of €1,800. Bruton immediately saw a reduction in grid-procured electricity and the PV system delivered a 30% reduction in grid procured electricity over the course of the next year.

One of the keys to maximising these savings was the generation of hot water via the electric heating element diversion from the solar system. This saw him move from electric showers to domestic hot water system fed showers.

The solar PV system installation, coupled with the energy efficiency improvements that he made, meant that he was able to navigate the further 45% increase in electricity unit costs to 44c/kWh in March 2023 without seeing a drastic increase in his monthly bills.

In early 2023, Bruton made the decision to switch from a petrol to an electric car. He received delivery of the new car in June 2023 supported by an SEAI grant of €5,000. He signed up to a smart tariff, where one of the benefits was free electricity on a Saturday between 9am and 5pm (fair usage cap of 100kWh per month). He has since adapted his driving behaviour in line with that of his EV, and charges it every Saturday. 

Figure 2: Bruton's grid, solar & EV kWh consumption per month.

Bruton has since adapted his driving behaviour in line with that of his EV, and charges it every Saturday. He is also careful not to encroach on the peak demand period between 5pm and 7pm each day where a unit cost of 57 c/kWh is charged by ensuring that he has his dinner in the oven and on the table before 5pm each day!

He now remarkably consumes 20% less electricity to run his household and charge his EV per month than he did prior to beginning his energy management journey (figure 2).

He is also investigating replacing his oil boiler. However, this is not straightforward due to the need to upgrade the airtightness of the house while also potentially increasing radiator areas to deliver lower temperature hot water if a heat pump is procured. He has however already seen a reduction in his monthly household electricity and transport related CO2 emissions of 75% (figure 3). 

Figure 3: Gerald's monthly household electricity and transport CO2 emissions.

Bruton's energy management journey has many lessons. While renewable technologies have the power to assist the transition to a more sustainable future, a significant amount of behavioural change and flexibility is also required. More importantly, we can see that age is not a barrier to emissions reduction. 

Author: Ken Bruton, University College Cork. This article first appeared on RTÉ's Brainstorm.