The Financial Benefits: Exporting Your Excess Energy and Battery Storage

One of the most attractive aspects of solar ownership in the UK is the ability to earn money by exporting excess electricity back to the grid through the Smart Export Guarantee (SEG). While the exact rate can vary between providers, currently, you can expect to be paid around £0.15 per kWh for your exported power.

Let’s look at the potential income and battery requirements:

• 5kW Continuous Export System (24 hours): To export 5kW for 24 hours, you’d be looking at a total of 5 kW×24 hours=120 kWh of exportable energy per day. This is a very substantial amount of energy, and to generate this from solar alone would require a very large solar array. For example, a 5kW inverter can manage a maximum of around 6.5kW of solar panels. To generate 120 kWh in a typical UK day, you’d likely need an array significantly larger than 15-20 kWp, depending on sunlight hours and panel efficiency. If you manage to export 120 kWh per day, this could generate an income of 120 kWh×£0.15/kWh=£18.00 per day, or approximately £540 per month. To support this level of continuous export and/or self-consumption, you would need a very large battery storage system. A battery around 120 kWh would be required to hold 24 hours’ worth of this energy, either to feed the export or to power your home when solar isn’t available. This capacity would allow you to store a full day’s worth of generation for export or consumption when needed.
• 8kW Continuous Export System (24 hours): Exporting 8kW for 24 hours means a total of 8 kW×24 hours=192 kWh of exportable energy per day. This would require an even larger solar array, likely in excess of 25-30 kWp, combined with significant battery storage. Exporting 192 kWh per day could generate an income of 192 kWh×£0.15/kWh=£28.80 per day, or approximately £864 per month. For this scale of operation, a battery system of around 192 kWh would be necessary to ensure 24-hour power availability and/or export capability, assuming no grid top-up during off-peak times.

Battery Storage: Beyond Solar Export

To truly maximize your export income and achieve greater energy independence, a battery storage system is crucial. This allows you to store excess solar generation during the day and use it during the evening or on cloudy days, rather than buying from the grid.

However, battery storage isn’t just for solar owners. Even without solar panels, a large battery system can significantly reduce your electricity bills by taking advantage of off-peak charging rates, which can be as low as £0.07 per kWh. You can charge your battery during these cheaper periods and then power your home from the battery during peak times when electricity prices are much higher.

RenewSolar offers a wide range of battery options to complement your energy setup. Their 50kWh battery is currently on offer for £4,250. This sizable battery could provide substantial power storage. For instance, if you charged this 50kWh battery during off-peak hours at £0.07/kWh, it would cost £3.50 to fully charge. If you then used this power during peak hours when the rate might be £0.30/kWh, you could save £11.50 per cycle (50 kWh×(£0.30−£0.07)) per full charge cycle. With a suitable inverter, this could power your way to significant savings and even a monthly income by enabling you to maximize self-consumption and export.

For the higher energy requirements of an 8kW continuous export system, multiple 50kWh RenewSolar batteries, or a larger custom solution, would be needed to reach the 192kWh capacity required for 24-hour operation from storage.

Understanding Your Installation: Grid-Tied vs. Off-Grid

There are two primary types of solar installations:

• Grid-Attached (On-Grid) Systems: These systems remain connected to the national electricity grid. You don’t necessarily export power, but you retain the connection for charging your battery and for drawing power during winter months or periods of low solar generation. This type of system often features a “pass-through” functionality, allowing you to seamlessly switch between grid power and PV power to run your home. Many grid-attached systems also offer a “back-up power” mode, where your system can continue to supply power to essential circuits during a power cut. A common operating mode is “PV Priority,” where your home is primarily powered by solar, then by the battery if solar is insufficient. Grid power is only drawn if both solar and battery power are unavailable. For DIY grid-attached installations, you can have a qualified electrician install an AC Isolator and a Bi-directional Dual Pole RCBO. These devices allow you to safely connect your inverter to your existing electrical installation. It is legal to use existing circuits for this connection, but it is paramount that you understand the limits and requirements of the installation and how the additional power source can affect your electrical system’s safety and integrity. All electrical work must comply with current IET Wiring Regulations (BS 7671) and building regulations (Part P). While DIY is permissible, any work on the main electrical system should be undertaken by or signed off by a competent person.
• Off-Grid Systems: These systems are entirely independent of the national grid. They require a robust battery bank and often a generator for backup during extended periods of low sunlight. Crucially, for off-grid installations, you need to install a PEM (Protective Earth Main) or PE (Protective Earth) earthing system to protect your home and appliances. Most inverters are TT type, meaning they require a separate earth electrode at the installation site, independent of any existing grid earthing. This ensures safety by providing a direct path to the earth for fault currents, protecting against electric shock. Proper earthing is fundamental for the safety of your off-grid electrical system.

Longevity and Investment Payback

Installing your own solar system is a long-term investment. The costs are typically paid back over the life of the system through reduced electricity bills and export income. Most solar systems are designed to last longer than 10 years, and with many systems from RenewSolar, you can expect a lifetime of 16 to 25 years, providing substantial returns on your initial investment.
RenewSolar targets returns on a 1 year and 4 year basis as part of the tag line “make solar work for you”.
If we take the 8kw inverter, the income available here is £864 per month. Which over a 4 year period would amount to £41,472

A system from RenewSolar would cost £1,700 for the inverter, and £4,100 per battery, where 4 would amount to a hardware investment of £18,100. The ROI is 2 years and 4 months. Other costs for installation, MSC, need to be added to the costs and extend the ROI time.

The life time of the system will bring a total income amount received over 16 years would be £165,888. The annual growth rate being 14.66%.

Where to Mount Your Panels: Beyond the Roof

While rooftop installations are the most common image that comes to mind, they are not the only option. The amount of power you can produce from your solar array depends significantly on factors like roof angles, direction, and pitch, which affect seasonal power production due to the sun’s angle and height in the sky.

Consider these alternative mounting types:

• Roof-Mounted Systems:
  • Pros: Utilizes existing structure, often out of the way, generally good sun exposure depending on orientation and pitch.
  • Cons: Can be limited by roof size, angle, and shading from chimneys or other structures. Installation can be more complex and require scaffolding. Aesthetic concerns for some homeowners.
    
• Ground-Mounted Systems:
  • Pros: Optimal tilt and azimuth (direction) can be achieved for maximum averaged energy harvest. Easier to install and maintain (cleaning, repairs). Can accommodate more panels if space allows.
  • Cons: Requires available land, may impact landscaping, potentially more visible, and can be more expensive due to groundworks and additional racking, planning required.
    
• Fence-Mounted Systems:
  • Pros: Utilizes existing vertical structures, good for properties with limited roof or ground space, can capture early morning and late afternoon sun more effectively with bifacial panels.
  • Cons: Limited by fence height and length, can be prone to shading from surrounding objects, may have aesthetic considerations, and may require stronger fence structures. Lesser summer performance.
    
• Pergola-Mounted Systems:
  • Pros: Creates a functional outdoor living space while generating power, aesthetically pleasing, can be integrated into garden design.
  • Cons: Power output is limited by the pergola’s size and available surface area, may require specific design for panel integration, and can be more costly than basic roof mounts.
    
• Garage-Mounted Systems:
  • Pros: Often have simpler roof structures for easier installation, can be a good option if the main house roof is unsuitable, potentially lower access costs for installation.
  • Cons: Typically smaller roof areas limit system size, may be more susceptible to shading from the main house or trees, and may require extending electrical cabling from/to the main property.
    
• Solar Trackers:
  • Pros: Maximizes energy production by constantly orienting panels towards the sun, significantly higher yield compared to fixed systems.
  • Cons: Significantly more expensive due to complex mechanical components and motors, requires more maintenance, and typically more suited for larger commercial or off-grid installations rather than typical residential DIY. may require planning.

By carefully considering your property’s unique characteristics and your energy goals, you can choose the ideal mounting solution for your DIY solar installation, putting you firmly in charge of your energy bills and contributing to a sustainable future. With MSC for SEG export payments, its clear that earning money and gaining a return and even profits over a shorter period than most investment opportunities Rate 23%.

Clearly a solar investment is worth the value and return when we look at the figures it is one of the better investment opportunity even on smaller scale.
RenewSolar while targeting domestic installations for economic good, They do offer a wider investment for commercial generation up to grid scale.
With full project management services from RenewSolar for your next large solar energy projects, you can reap rewards with minimal input.