Do Solar Panels and Battery Storage Save You Money?

Yes, they do. Let's dive into the details and see how.

I had my solar panels installed in December 2021, followed by a battery installation in June 2022. Initially, let's focus on the impact of the solar panels alone. My household has a high electricity usage due to working from home and running multiple devices around the clock. Additionally, we own an electric car, resulting in an annual electricity demand of about 10,000 kWh.

I am on the Octopus Go tariff, designed for electric car owners, offering significantly reduced rates during off-peak hours (12:30 AM to 4:30 AM). Shifting energy usage to these off-peak hours for activities like running the dishwasher, washing machine, and electric water heater can substantially lower your bills. With solar panels, any excess electricity generated during the day further reduces the amount you draw from the grid, resulting in even lower bills.

Electricity Usage Breakdown:

Before installing solar panels, my entire electricity demand was met by the grid. For example, in November 2021, I used 476 kWh during peak hours (more expensive) and 401 kWh during off-peak hours. All of this energy was purchased from the grid.

After installing the solar panels in December 2021, even though it was a dull and rainy month, I started using less grid electricity. As time progressed and the days became sunnier, the amount of electricity I drew from the grid continued to decrease, while my overall electricity demand remained relatively stable. The difference between my total energy usage and what I took from the grid represents the electricity provided by my solar panels, resulting in cost savings.

How Solar Panels Save Money:

Let's look at the data. In December 2021, the percentage of electricity drawn from the grid began to decrease. As the months went on, this trend continued, showing clear savings. The more sunlight available, the less grid electricity you need to buy. A typical 3.9 kWp solar installation can generate around 3,500 kWh annually, which would cover roughly a third of my total energy needs.

Introducing Battery Storage:

Batteries can further enhance savings. They store excess solar power generated during the day for use during peak hours or at night, significantly reducing the amount of expensive peak-time electricity drawn from the grid. For instance, in June 2022, after installing the battery, my peak grid usage dropped dramatically, while my off-peak usage increased slightly as the battery topped up overnight.

Financial Impact:

Assuming a fictional energy tariff similar to Octopus Go, where peak electricity costs 28p per kWh and off-peak costs 7.5p per kWh, the savings are clear. In November, fully reliant on the grid, the cost was £63. By June to August, with solar panels and battery storage, the monthly bills dropped to between £40 and £50, less than a third of the original cost.

This dramatic decrease in electricity bills demonstrates the financial viability of investing in solar panels and battery storage. Additionally, this doesn't account for the environmental benefits, which further enhance the value of these systems.

Conclusion:

Solar panels and battery storage can indeed save you money on electricity bills. While the exact savings depend on several factors, including energy costs, the size of the solar installation, and your specific energy usage patterns, the financial and environmental benefits make it a worthwhile investment.