DC Coupled Solar to Battery Solution: Unlocking Solar PV Potential on Grid Constrained sites
Commercial organisations in the UK seeking to deploy solar PV systems face significant challenges due to restrictions imposed by the UK National Grid, which typically limits Grid capacity to 950kW. At this level, the constraint caps solar array capacity at a maximum of 1.425MW (1.5 times the Grid limit).
For many organisations, this limit is grossly inadequate to meet their energy load demands behind the meter, especially for those with high energy consumption needs. As a result, they are unable to fully maximise the potential of solar energy to offset their consumption or reduce reliance on Grid-supplied electricity. This limitation not only prevents them from achieving cost savings through renewable energy but also hinders their efforts to reduce carbon footprints and meet sustainability targets. The inability to fully utilise the available solar resource impacts energy efficiency, leading to missed opportunities for increased energy independence and lower operational costs.
Addressing this issue is critical for organisations aiming to optimise renewable energy use while navigating Grid constraints and advancing their sustainability agendas.
Grid constraints create a cascade of limitations that prevent UK businesses from achieving their full renewable energy potential and sustainability objectives.
UK National Grid capacity restriction
Capped at 1.5× Grid limit
For organizations needing 5MW+
The solution lies in enabling commercial organisations to deploy as much solar PV as needed to fully meet their energy demands, despite Grid limitations. Innovative approaches such as DC-coupling solar directly to battery energy storage systems (BESS) allow businesses to deploy as much solar as required, while also enabling the storage of excess solar energy in the BESS for later use to better manage energy flows within allowable limits, empowering organisations to fully exploit their renewable energy potential and achieve true energy independence.
AceOn offers a game-changing solution for UK businesses facing Grid limitations that restrict solar PV capacity. Our DC Coupled Solar to Battery Storage System enables organisations to install larger solar arrays, store excess energy, and use it when needed, maximising energy efficiency and significantly reducing your Opex costs.
AceOn can DC-couple unlimited amounts of solar PV directly to the DC Bus of a suitably sized battery energy storage system using DC-DC string optimisers. These optimisers—and the entire solar PV system—are controlled by AceOn's proprietary, intelligent controller and energy management system. The battery energy storage system is equipped with a DC-to-AC inverter connected to the Grid and sized according to Grid limitations.
By using DC-DC optimisers, we eliminate the need for AC-coupled solar inverters, therefore only needing to declare one inverter capacity to the DNO. By directly coupling the solar array with the Battery in DC form, the system minimises energy losses and maximises storage efficiency. The stored energy is then converted to AC via an inverter that operates behind the meter, ensuring that the system complies with Grid export limits while maintaining optimal energy flow within the facility.
This approach allows businesses to reduce reliance on expensive Grid electricity, increase energy self-sufficiency, and fully leverage their solar PV investment, even when Grid restrictions are in place.
Install larger solar PV systems and store surplus energy for later use, overcoming Grid limitations.
Reduce reliance on Grid electricity, achieving lower energy costs, and achieve a faster return on your solar investment.
Fully utilise renewable energy, significantly reduce your carbon footprint, and meet sustainability goals.
Achieve greater energy autonomy by producing, storing, and consuming your own solar power to be used when you need it.
Powered by best-in-class partners like Tier 1 Energy Storage Manufacturer (Bloomberg New Energy Finance) and AMPT and backed by AceOn's expertise in controller programming and energy management, we deliver a proven, reliable, and scalable energy solution that meets your business needs.
The innovative technology that unlocks unlimited solar capacity
Solar PV panels generate direct current (DC), which typically connects to a DC/AC inverter in standard solar installations. In these systems, the inverter's capacity must be declared to the Distribution Network Operator (DNO). Since batteries also store energy as DC, the solar PV array is connected directly to the DC Bus of a suitably sized battery system. This configuration eliminates the need for traditional solar AC inverters, which would otherwise count toward the Grid connection limit.
Instead, we use DC-DC optimisers which do not require DNO declaration, allowing a solar PV array of any size to connect directly to the battery storage system.
AceOn then links the battery to the electricity network using a battery storage DC/AC inverter that matches the grid connection size agreed upon with the DNO.
In this example, an AC-coupled system with a 50kWh battery and a 70MW solar PV array would require a 100MW grid connection. In contrast, our DC-coupled system would only require a 50MW connection.
AceOn offers a revolutionary solution to UK businesses struggling with Grid restrictions that limit the scalability of solar PV systems. With AceOn's DC-DC Coupled Solar Battery Storage System (BESS), your business can transcend Grid limitations and deploy as much solar as necessary to meet your full energy demands—without compromise.
AceOn's DC-Coupled Solar & Battery Energy Storage System (BESS) empowers businesses to maximise the utility of their solar PV investments by efficiently storing excess solar energy generated during peak production times and making it available when consumption is high, or Grid capacity is constrained. This enables increased energy self-sufficiency, reducing reliance on the Grid while lowering costs and emissions.
Peak production storage
High-demand availability
Lower costs & emissions
Energy self-sufficiency
The system works by integrating a DC-coupled solar array with DC-DC string optimizers that stabilise the voltage from each solar PV string, connecting directly to the DC Bus of the battery storage system. Each solar PV string is connected to an Ampt DC-DC optimizer, which stabilises the variable input voltage from the PV module strings and outputs a consistent DC voltage. Maximum Power Point Tracking (MPPT) on each string eliminates power mismatch, allowing the system to capture maximum energy from each panel. This high, fixed DC voltage is then delivered directly to the battery system without immediate conversion to AC, which minimises energy losses during the charging process. By using DC-DC optimizers, the need for AC solar inverters is eliminated, allowing for a larger PV capacity to be stored than typically permitted by DNO Grid limits.
AceOn's proprietary controller and energy management system seamlessly integrate solar generation with battery storage, precisely controlling energy flow to and from the battery and ensuring compliance with Grid export limits. The stored energy can be converted to AC through a BESS inverter when needed for facility use, with the inverter operating within the facility's internal system rather than feeding directly into the Grid. This setup ensures that the facility adheres to Grid export limits, preventing more than the allowed maximum (typically 950kW) from being uploaded back to the Grid, in line with UK National Grid regulations.
Additionally, the BESS can be charged from the Grid or other onsite sources during off-peak periods when energy costs are lower, ensuring that stored power is available for high-demand periods or when solar generation dips due to weather.
The DC-coupled design of AceOn's system improves efficiency by 8-24% over traditional AC-coupled systems, further enhancing operational efficiency and energy capture.
By combining solar PV with advanced battery storage, AceOn's solution enables businesses to achieve energy independence and flexibility, meeting high demand without relying on costly, carbon-intensive Grid electricity. This innovative system also helps businesses meet Grid compliance requirements while gaining substantial energy savings, enabling them to reach sustainability targets while reducing operational costs and emissions.
Example shows how to install a 5MWp Solar PV array and 5MWh Battery Storage System on a 950kW grid connection. AceOn will accurately size the PV and Battery for each site using our Battery simulation software.
Performance increase opportunity compared to AC-coupled solutions
Reduced number of combiners and minimised cabling to lower costs
Transform your energy strategy with proven advantages that deliver real business value
AceOn's DC-to-DC coupled system is powered by top-tier partnerships, including Tier 1 Energy Storage Manufacturer (Bloomberg New Energy Finance) and AMPT, which ensure that you receive a proven, scalable, and cost-effective energy solution.
At the heart of AceOn's solution is our deep expertise in programming the Controller, the critical component that brings together solar generation, battery storage, and energy management systems into a seamless, high-performance process. This level of integration ensures that every system functions at its highest possible efficiency.
AceOn's controller expertise allows us to harness the technologies from our key partners and combine them into a unified energy management solution. Our technical knowledge and hands-on experience ensure that your solar and storage system operates smoothly, delivering maximum output while meeting regulatory standards.
Our team has a deep understanding of power generation, distribution, and storage. This expertise ensures that your system is finely tuned for reliability and performance, guaranteeing seamless integration across all components of the solar and storage system.
Familiarity with UK energy standards and sustainability goals is a cornerstone of AceOn's approach. We ensure that our Energy Management Systems (EMS) are fully aligned with local and national regulations, as well as the specific sustainability targets of your business.
This technical proficiency allows AceOn to build a solar and battery storage system that not only meets the energy demands of your business but also complies with all regulatory frameworks, giving you the peace of mind that your solution is futureproof.
As a global leader in battery energy storage solutions, our partner brings cutting-edge, scalable, and efficient energy storage systems that can handle the demands of large-scale solar PV installations.
Their robust offerings include liquid-cooled and air-cooled systems that have passed critical certifications, ensuring safety and performance.
With a turnover of £4 billion and projected growth in battery energy storage systems, our partner is well-positioned to support large-scale projects.
With over 350MW of battery energy systems installed in the UK and 1.7GW worldwide, our partner provides unmatched technical expertise, making them a trusted partner in utility-scale energy storage projects.
Established in 2007 in Fort Collins, Colorado AMPT's innovative approach and partnerships have made them a leader in utility-scale solar optimisation focusing on power conversion technology within the sector, the main objective being to enhance the efficiency of photovoltaic (PV) systems.
With over $50 million in funding raised, including a recent $15 million round, AMPT is positioned for global expansion, driven by strong growth and demand for its market leading solar optimisation technology.
AMPT has operations and partnerships across North America, Europe, Asia, Australia, and the Middle East, focusing on reducing solar project costs and improving return on investment (ROI).
AMPT's string optimisers increase energy output and lower system costs, making them an ideal partner for AceOn's DC coupled storage systems. This integration supports efficient energy conversion and cost savings in largescale solar projects.
This technology operates the DC bus at a fixed voltage higher than the battery voltage, eliminating 50% of the battery converter's power circuitry and enhancing power density. This innovation cuts costs and provides a more affordable solution for solar projects.
Contact AceOn today to learn how our DC Coupled Solar Battery Storage System can help your organisation overcome Grid constraints and achieve true energy independence.