Peak Shaving with Battery Storage: Cut Your Business Electricity Bill
If your business is on a half-hourly metered electricity supply, you are probably paying more than you realise during peak demand periods. Demand charges, also known as capacity charges or availability charges, can account for 15-30% of your total electricity bill. Peak shaving with commercial battery storage is one of the most effective strategies to slash these costs, and the technology has reached a point where the financial case is compelling for most commercial properties.
Understanding Demand Charges
Most commercial electricity tariffs have two main cost components. The first is the unit rate: the price per kWh of electricity consumed. The second is the demand charge, which is based on your maximum power draw (measured in kW or kVA) during specific periods. Your demand charge is typically calculated based on the highest half-hour of consumption during the billing period or during designated peak windows.
This means that even a brief spike in electricity demand, perhaps when multiple pieces of equipment start simultaneously, or when your heating and cooling systems run at full capacity on a cold morning, can set your demand charge for the entire billing period. You effectively pay a premium for your highest moment of consumption, regardless of how brief it is.
For Essex businesses, peak demand charges are particularly significant between November and February when heating loads combine with earlier darkness requiring more lighting. A factory running production equipment, heating and lighting on a January morning can easily see demand spikes 30-50% above their average consumption.
How Peak Shaving Works
Peak shaving uses a battery storage system to cap your maximum grid demand at a predetermined level. The process is straightforward:
- Off-peak charging: The battery charges during periods when electricity is cheapest, typically overnight between 00:00 and 07:00, or during mid-afternoon when solar generation may be available.
- Demand monitoring: Smart control systems continuously monitor your building's electricity demand in real time, tracking the power being drawn from the grid.
- Automatic discharge: When demand approaches your target ceiling, the battery automatically begins discharging, supplementing grid supply with stored energy to prevent the demand spike from being recorded.
- Cost reduction: By capping your peak demand, you reduce both the demand charge component of your bill and the unit rate cost of peak electricity.
The beauty of peak shaving is that it does not require you to change your operations. Your machinery, heating and lighting continue to run as normal. The battery simply acts as a buffer, absorbing the cost difference between off-peak and peak electricity.
The Financial Impact
Let us look at a real-world example. Consider a medium-sized warehouse operation in Essex with the following electricity profile:
- Annual electricity consumption: 250,000 kWh
- Average demand: 60kW
- Peak demand: 110kW (occurring during winter mornings)
- Annual electricity cost: £75,000 (including approximately £15,000 in demand charges)
By installing a 100kWh battery system and capping peak demand at 70kW, this business could reduce demand charges by approximately £8,000-£10,000 annually. Additional savings from tariff arbitrage (buying electricity cheap at night and using it during the day) could add another £4,000-£6,000. Total annual savings of £12,000-£16,000 against a battery system cost of £40,000-£55,000 delivers a payback period of 3-4 years.
Industries That Benefit Most
While peak shaving benefits any business with variable demand, certain industries see particularly strong returns:
Cold Storage and Refrigeration
Cold storage facilities have high baseline electricity consumption with significant demand spikes when compressors cycle on simultaneously. Battery storage can manage these spikes while maintaining uninterrupted refrigeration, making it one of the best applications for peak shaving technology.
Manufacturing
Factories with heavy machinery that starts up in the morning create pronounced demand peaks. Peak shaving allows production to begin without penalising the business through elevated demand charges for the rest of the billing period.
Hotels and Leisure
Hotels with extensive HVAC systems, kitchens, laundry facilities and spa equipment experience significant demand variation throughout the day. Peak shaving smooths the demand profile and reduces costs during high-occupancy periods.
EV Charging Hubs
As businesses install multiple EV chargers, the potential for demand spikes increases dramatically. A bank of rapid chargers operating simultaneously can draw 150kW or more. Battery-buffered charging allows businesses to offer fast charging without the grid upgrade costs and demand charges that would otherwise apply.
Combining Peak Shaving with Solar
The combination of solar panels and battery storage for peak shaving is particularly powerful. During daylight hours, solar generation directly reduces grid demand. Excess solar energy charges the battery rather than being exported at low SEG rates. The battery then discharges during evening and morning peaks when solar is unavailable but demand is highest.
This combined approach delivers three revenue streams: reduced unit rate costs from solar self-consumption, reduced demand charges from peak shaving, and export income from any surplus generation. For businesses operating during standard daytime hours, this combination typically delivers the fastest return on investment of any commercial energy strategy.
Choosing the Right Battery System
Effective peak shaving requires a battery system with specific characteristics. High power output (measured in kW) is more important than capacity (measured in kWh) for demand management. The system must be able to discharge quickly enough to respond to sudden demand spikes. Lithium iron phosphate (LFP) batteries are the preferred choice due to their high cycle life, as peak shaving involves daily charging and discharging cycles.
Smart energy management software is equally important. The system needs to predict demand patterns, optimise charging schedules around tariff structures, and respond in real time to changing loads. Modern systems from manufacturers like GivEnergy include sophisticated algorithms that learn your building's demand patterns and continuously optimise their strategy.
For guidance on choosing between the leading commercial battery brands, see our GivEnergy vs Tesla Powerwall comparison.
Getting Started with Peak Shaving
The first step is understanding your current demand profile. If you are on a half-hourly metered supply, your energy supplier can provide half-hourly consumption data that reveals your peak demand patterns. At EC Eco Energy, we analyse this data as part of our free site survey to design a battery system optimised for your specific demand profile and tariff structure.
We handle everything from initial assessment through to installation, commissioning and ongoing monitoring. Our systems include cloud-based dashboards so you can see exactly how much your battery is saving in real time.
Frequently Asked Questions
Peak shaving is the practice of reducing your highest electricity demand periods by discharging stored battery energy during peak times instead of drawing from the grid. The battery charges during off-peak hours when electricity is cheapest and discharges during expensive peak periods, effectively 'shaving' the peaks from your demand profile and reducing both your unit rate costs and demand charges.
Peak shaving typically saves commercial businesses 20-40% on their electricity bills, depending on the tariff structure, consumption patterns and battery size. Businesses on half-hourly metered supplies with significant demand charges see the greatest savings. A medium-sized commercial property spending £30,000 annually on electricity could save £6,000-£12,000 per year through peak shaving.
The ideal battery size for peak shaving depends on your peak demand duration and magnitude. As a general guide, you need enough storage capacity to cover 2-4 hours of the difference between your peak demand and your desired demand ceiling. A business with a peak demand of 100kW wanting to cap at 60kW would need approximately 80-160kWh of battery storage.
Yes, combining peak shaving with solar panels is highly effective. Solar panels reduce your daytime grid import, while the battery handles peak demand management. During sunny periods, the battery can charge from solar rather than the grid, further reducing costs. This combined approach typically delivers the fastest return on investment for commercial properties.