Sustainable Energy Solution for a Fast-Food Drive-Thru in England

Introduction

The energy consumption of commercial establishments, particularly those in the fast-food industry, has become a significant challenge in the modern world, where both operational costs and environmental concerns are on the rise. This case study examines the successful implementation of a smart energy management solution for a fast-food drive-thru located in England. The business faced critical energy challenges, including rising electricity costs and insufficient grid supply to meet its high energy demand. EQONIC was commissioned to provide a solution that would address these issues through renewable energy integration and battery storage systems.

This report details the specific challenges faced by the establishment, the solutions proposed and implemented by EQONIC, and the impressive results that followed. We will explore the technical specifications of the solution, the financial investment, and the environmental and economic returns over the long term.

Location and Background

The fast-food drive-thru is located in a busy commercial area in England, serving hundreds of customers daily. With the high operational demands typical of such establishments, energy consumption is naturally high. The business uses around 500 MWh annually, which creates a significant operational expense. Furthermore, the drive-thru relies on a grid connection with a limited capacity of 350 kVA, which is insufficient to meet its energy needs, especially during peak operating hours.

Compounding the challenge is the limited rooftop space available for renewable energy installation. The building’s roof is covered with sedum, a type of green roofing system designed to promote biodiversity and stormwater management. While beneficial for the environment, the sedum roof poses a structural challenge for mounting solar panels, as it requires an elevated design to prevent damage to the roof and avoid sinking of the panels into the substrate.

The Challenge: Rising Energy Costs and Grid Limitations

Energy expenses have been a growing concern for the fast-food industry as a whole, and this drive-thru location was no exception. The establishment's 500 MWh annual energy consumption significantly exceeded the capacity of its 350 kVA grid connection, leading to periodic energy shortages and high costs. The owners sought a sustainable and cost-effective energy solution to reduce their dependency on grid power, especially during peak hours when tariffs are highest.

Additionally, the business owners wanted to take advantage of renewable energy through photovoltaic (PV) systems. However, the limited rooftop space, combined with the sedum roof, created design challenges for installing an effective solar energy solution. The green roof's weight and structure demanded a specialised mounting system that would not compromise the roof’s integrity or functionality.

Without a viable solution, the business risked continuing to face exorbitant electricity bills and potential energy shortages, making long-term sustainability and profitability a concern.

The Solution: EQONIC’s Hybrid Energy System

To address these energy challenges, EQONIC recommended the installation of a smart hybrid energy system comprising solar panels, a hybrid inverter, and battery storage units. The proposed system was specifically designed to fit within the constraints of the available space and overcome the challenges presented by the sedum roof.

1. Solar PV System

Given the limited rooftop area, EQONIC recommended a 57.4 kWp PV system featuring 475W Monocrystalline solar panels. Monocrystalline panels were chosen due to their high efficiency and superior performance in limited space environments. With their ability to generate more energy per square meter than other types of panels, these were the ideal choice to maximise the available rooftop area.

2. Hybrid Inverter

A critical component of the system was the EQONIC 500kW PCS 3ph hybrid inverter. This device serves as the brain of the energy system, allowing the seamless integration of solar energy, grid power, and battery storage. The inverter ensures that the establishment can prioritise the use of solar power when available, and switch to battery power or the grid as needed.

The hybrid inverter also enables the batteries to charge during off-peak hours at night when electricity tariffs are lower. This stored energy is then discharged during the day to supplement grid supply and solar generation, thereby reducing reliance on expensive daytime electricity rates.

3. Battery Storage

Four EQONIC 389kWh high-voltage batteries were installed, providing a total storage capacity of 1.556 MWh. This allows the establishment to store excess solar energy generated during the day and discharge it during periods of high demand or when solar generation is insufficient. The battery storage system not only reduces reliance on the grid but also provides backup power in case of outages.

4. Sedum Roof Mounting System

The final challenge was designing a mounting system that would allow the solar panels to be installed without damaging the sedum roof. EQONIC proposed the use of Renusol Console 100kg ballast mounts, which elevate the solar panels above the sedum layer. This prevents the panels from sinking into the green roof and ensures proper airflow around the panels for maximum efficiency.

The mounting system was also designed to minimize penetration of the roof membrane, reducing the risk of leaks or damage to the structure.

Financial Investment and Cost Breakdown

The total cost of the system, including the solar panels, hybrid inverter, battery storage, and mounting system, came to £583,275 (excluding VAT). This investment was carefully calculated to provide the best return over the long term, taking into account both the reduction in energy costs and the environmental benefits.

Although the initial cost may seem high, the system’s ability to reduce energy expenses by 55% annually and the long-term savings potential make it a financially sound investment. By charging the batteries at night when tariffs are lower and discharging them during the day, the establishment is able to significantly cut down on its energy bills. The system also helps protect the business from future increases in electricity prices, providing additional financial security.

Environmental Impact and Sustainability

In addition to the financial benefits, the new energy system has a positive impact on the environment. The solar PV system generates clean, renewable energy, reducing the establishment’s reliance on grid power, much of which comes from non-renewable sources.

The system reduces the establishment’s carbon footprint by approximately 13,700 kg of CO2 per year, contributing to a more sustainable future. Over the system’s expected 25-year lifespan, this will result in a total reduction of 343,000 kg of CO2, making a significant contribution to the fight against climate change.

Results and Long-Term Benefits

The implementation of the EQONIC hybrid energy system has been a resounding success. The establishment has achieved a 55% reduction in annual energy costs, thanks to the combination of solar energy, battery storage, and strategic use of grid power. Over the course of 25 years, the system is expected to save the business approximately £3.5 million, taking into account inflation and rising electricity prices.

The environmental benefits are equally impressive, with the system reducing the establishment’s carbon footprint by 13,700 kgCO2 per year. This not only helps the business meet its sustainability goals but also improves its reputation as an environmentally conscious company.

In addition, the system’s battery storage provides the establishment with greater energy independence, reducing the risk of outages and ensuring a more reliable power supply during peak hours.

Conclusion

The successful implementation of the EQONIC hybrid energy system for this fast-food drive-thru in England demonstrates the power of innovative energy solutions in reducing operational costs and environmental impact. By combining solar power, battery storage, and smart energy management, the establishment has not only reduced its energy expenses but also made a significant contribution to sustainability.

This case study highlights the importance of tailoring energy solutions to the unique challenges of each location, whether it’s a limited rooftop area, a green roof, or a constrained grid connection. EQONIC’s expertise in designing and implementing such systems has resulted in a financially and environmentally beneficial solution that will provide long-term value for the business.