eCactus Solar

Economy 7 Battery Storage System: Uses and Benefits

Table of Contents

This article is a gateway to better understanding battery energy storage systems. We will focus specifically on how these systems work alongside Economy 7. In addition to exploring their uses and benefits, we will look at the technical aspects.

Economy 7 refers to a UK off-peak electricity price scheme. Consumers are encouraged to use more off-peak electricity and less peak-time electricity (peak shaving) for grid load balancing. This applies to commercial and domestic users. To benefit from Economy 7, you need a smart meter, that applies to retail or business users.

If your business or organisation cannot get a smart meter or Economy 7, look at your on-peak/off-peak pricing from your energy supplier. If there is a differential and opportunity for cheaper electricity at night, keep reading as the principles will be the same.

We are now seeing the mass adoption of PV Solar, electric vehicles and battery storage systems. Load-shifting and preset battery storage and release times inside your building or house are key considerations for saving energy bills.

Even if you have no solar PV, a battery can help you benefit more from Economy 7, provide uninterrupted or emergency power in a blackout, and give you more options for the future.

(If you are not in the UK, the same logic applies within your country, organisation or home.)

Understanding Economy 7

Economy 7 is an electricity tariff that offers lower rates during off-peak hours and higher rates during peak hours.

Your supplier will indicate the seven off-peak hours. These typically operate from midnight to 7 am. However, this may vary depending on your region and supplier.

Switching to an Economy 7 tariff can save you money if you use more energy after midnight. However, if your energy habits lean towards the daytime, watch out for those higher rates. The ideal solution is to store affordable nighttime electricity so that you can use most of your power during the day. 

Battery Storage Systems for Peak Shaving

Rechargeable batteries in battery energy storage systems are essential for storing energy from solar panels or wind turbines. Battery storage systems deliver this stored energy to consumers when needed.

These systems also use advanced technologies to handle various functions like load shifting, peak shaving, integrating renewable energy, and serving as an emergency backup.

Peak shaving involves reducing the energy drawn from the grid during busy times. (For example, between 6-8 pm when families come home from work and school). Peak shaving is critical to help us transition to a green economy.

Battery Storage System: Making the Most of Economy 7

When combined, battery energy storage and Economy 7 tariffs present a range of uses and benefits that can truly transform how you manage your energy usage.

Load Shifting 

Battery energy storage enables electricity consumers to adjust their energy consumption from peak hours to off-peak hours. This load-shifting method saves money and lowers grid stress during peak demand hours.

Environmental Impact

Environmental Impact of economy 7 battery storage system

Lower energy consumption during peak hours can lead to lower greenhouse gas emissions. The adoption of battery energy storage systems by homeowners and businesses aligns with sustainable practices, which supports today’s eco-conscious society. 


Homeowners can significantly cut their energy expenses by charging battery storage devices during off-peak hours when power rates are low and utilising that stored energy during peak hours. This benefits companies that rely on electricity, such as factories and research centres.

The price of commercial and industrial battery storage systems decreased significantly in 2023. That means that payback periods are realistic, and consumers of every size can profit. In previous years, battery storage on large projects was done for practical and environmental reasons, not so much for financial ones. This all changed in 2023, and we are excited about the implications!

Emergency Backup

The sun may not shine 24/7, but a battery storage system is an electricity safety net, providing constant power whenever needed.

Improved Lifestyle 

The battery storage system improves your lifestyle through energy independence and backup power during power outages.

Renewable Source Integration

Battery storage boosts renewable energy sources by storing excess green energy.

Performance through the seasons 

Seasonal variation is one of the most critical aspects of the Economy 7 battery storage system. With shorter days in winter, solar energy production may be cut short. This makes it the perfect time to use the energy the overnight charging system has accumulated. However, in the summer, when there is plenty of sunlight, solar panels can provide enough electricity to power a house during the day while also charging the battery. Understanding and reacting to seasonal fluctuations is thus essential.

EV Optimization

Battery storage enables load balancing and intelligent charging for consumers who own electric vehicles (EVs). EV owners can programme their car chargers to take electricity from the battery during off-peak hours, lowering overall charging costs and reducing grid pressure.

Key Considerations

  1. There are a variety of battery types in the market. Different batteries have different lifespans and efficiency. Lithium-ion batteries are more efficient and long-lasting than other battery types.
  2. Temperature rating is one of the most critical factors when purchasing a battery energy storage system. Systems with wide temperature ranges are more effective, especially in harsh weather conditions, and provide consistent output all year.
  3. Switching time defines how quickly a system shifts between different energy sources. It enables a transition from a power grid to a backup system during a power outage.
  4. The noise level of the battery storage system should be as low as possible.
  5. Depth of Discharge specifies the quantity of stored energy customers can use before recharging the battery system. A high DoD system allows you to use considerable energy, maximising power efficiency.
  6. When selecting battery storage systems, it is critical to evaluate their temperature ratings. Systems with a wider temperature range can function effectively in adverse situations and maintain consistent performance.

Bright future of battery storage system 

According to a recent McKinsey research, the worldwide battery business will double in size between 2022 and 2030, topping $400 billion/£312billion in value. 

Multiple factors have triggered this rise in demand. For starters, batteries are becoming more affordable and efficient. Second, the growing need for renewable energy sources needs reliable energy storage, which batteries play an essential part in. Finally, governments worldwide are boosting their support for battery research and development and reducing reliance on fossil fuels.


Perfectly suited and fully certified for the UK market, eCactus systems align with Economy 7 tariffs and integrate seamlessly with renewable energy sources like solar panels.

eCactus offers a powerful and easy-to-install energy storage product – the Agave series. These are top-tier hybrid (DC and AC coupled) all-in-one systems suitable for homeowners and small businesses. They fully meet daily charging requirements with high battery capacity and efficiency.

As shown above, these can be connected in parallel to achieve between 10.24 and 51.2 kWh of storage. Most residential installations would require one all-in-one unit (in the image above, there are three).

The App Advantage

The eCactus ECOS app is the perfect way to optimise most of your battery storage system. It allows you to track the system quickly and provides valuable data about your energy usage.

Monitor Energy Consumption

Users can track their electrical usage in real-time, knowing when and how they utilise electricity. This information assists in making informed choices regarding energy management.

Smart Usage Strategy

Using modern apps, users can program their battery storage systems to function automatically during off-peak hours. This level of automation ensures that energy is used optimally without requiring frequent manual intervention.

With our ECOS app, there are settings such as state of charge and maximum discharge. There are five presets within 24 hours to adjust for usage patterns.

Distributor and Installer Support

The eCactus ECOS home energy management app enables professionals to assist end users remotely. This entails providing timely updates, troubleshooting, and optimising system performance without requiring physical visits.