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The solution to solar's oldest problem

Save your solar energy for when you need it most - Simple!

Solar Generation seldom coincides with demand.
When this happens, excess solar power is exported to the national grid resulting in a lost opportunity for savings. 

Did you know that the average home fitted with a solar PV system in the UK exports as much as 
70% of its power to the grid?

Peak generation from your solar PV system, of course, depends on the weather, but most of the time it's at about midday, but the peak energy demand in your home occurs mainly in the mornings and evenings.



The solar home's energy seesaw

balancing power is an art form

Imagine your solar home is like an energy seesaw. 
On one end is power generated from solar, and on the other, is power demand from your home. 

If more power is generated from solar than is being used in the home, the seesaw tips one way, and the extra power is exported to the grid. 


if power demand from the home is greater than that generated from solar, the seesaw tips the other way, with the rest of the power needed being imported from the grid. 


Keeping the energy seesaw balanced 

The perfect position to be in

Sundial works by diverting excess solar generated power during times when it would be exported and stores it 
into its own lithium battery pack, reducing export and balancing the energy seesaw. 

When power demand in the home is greater than solar power generation, 
Sundial releases that previously stored power back into the home, reducing import and again balancing the energy seesaw. 

When the energy seesaw is balanced, your home's energy demand is at zero, resulting in lower average energy costs.


Energy changes quickly

Sundial's advanced control system is the key to unlocking its full potential


It's not easy balancing energy that's traveling at 1.75 million miles per hour!

Sundial contains advanced, patent pending, control electronics that monitors and reacts to changes in energy levels 5 times per second
An industry first! 

This reaction speed is essential in ensuring that none of your saved energy is lost to the grid, resulting in a more effective energy store.

Input and output power is constantly adjusted to within a few watts, to perfectly balance the energy seesaw, ensuring that your solar energy is used in the most efficient way possible. 

And the best bit 
This all happens automatically, so you can use energy whenever you want, knowing that Sundial has it all in hand.

Our safe battery technology is paramount

A safer battery means greater peace of mind



The Lithium Battery Trilemma

How can you make a battery inherently safe, longer lasting and smaller. 
That's the holy grail of battery technology.



Cycle Life

A single battery cycle is defined as one full charge and discharge. The greater the cycle life the longer it lasts.

    Thermal Safety

    How temperature affects a battery when charging or discharging. Lower temperatures reduce the risk of cell damage and lead to longer cycle life.

    Energy Density

    This is the measure of a battery's energy capacity in kWh over its physical size

    Battery Chemistry

    Current battery advancements have given us Lithium Iron Phosphate (LiFePO4), 
     the battery chemistry employed within Sundial.






      Safer, longer lasting battery chemistry

      Lithium Iron Phosphate (LiFePO4) The perfect balance between safety and performance


      Sundial does not use the same Lithium ion chemistries as devices such as mobile phones, laptops and other battery storage products.

      Safety is improved with the latest Lithium Iron Phosphate battery chemistry as it has a distinct advantage due to its thermal and chemical stability.

      Combine this with Sundial's advanced battery management system (BMS), specifically designed to constantly monitor the safety and health of the battery pack over time, and the result is a safer battery with an impressive cycle life.



      Low voltage batteries are safer

      All of Sundial's safety features add up to one simple conclusion!

      We have one of the safest home battery storage solutions in the world

      Low DC battery voltages promote confidence

      Sundial's internal battery pack has been designed to be classed as extra low voltage DC, meaning increased safety. 



      The maximum internal DC voltages are less than those allowed on a telephone line!




      AC vs DC Coupled

      Two configurations of battery storage systems, which is right for you?

      Storage systems can be integrated in two different formats, 
      it's all about where the battery is sited within your system. 

      DC Coupled

      In a DC coupled system, the battery is located between the solar panels and the solar inverter, coupled on the DC side of the system.

      Advantages of a DC coupled system

      Slightly improved conversion efficiency.

      Single inverter handles AC/DC conversion for both PV and battery

      AC Coupled
      In an AC coupled system, the battery is stand alone from the solar PV system and is connected into the home like any other appliance, coupled on the AC side. 

      Advantages of an AC coupled system

      Compatible with any new or existing solar PV or wind generation system.

      Existing Feed-In-Tariffs and warranties unaffected

      integrated and quick to install.

      Easily expandable over time.



      A bigger battery isn't necessarily better!  

      This is the most common question we are asked, how much battery capacity do i need?

      PowerFlow have carefully considered the answer to this question, and have concluded that matching PV capacity with battery capacity is about the right balance of performance vs cost 

      Ultimately the more battery capacity you install the less energy you will buy, only until the point where you cannot charge or discharge it fully

      The UK receives just 10% of the suns energy in the winter compared to in the summer. 
      Installing a large capacity battery to capture exported energy, on an average sized 4kWp solar PV system, simply doesn't make sense.