Home Battery Storage

 

 

 

Make the most of your free solar generation with a home storage solution

Battery storage has taken some huge steps forward in recent years. It can now offer you the opportunity to store your free, renewable, electricity generated from your solar pv array during the day to use at night when the panels are no longer working. Saving you importing expensive electricity from the main grid and further increasing your energy independence while decreasing your carbon emissions.

     

  1. How a Battery Storage System works

    In a conventional solar pv system the house will use all the electricity produced from the panels before it imports electricity from the gird. If the panels produce more electricity than the house is using at that point in time it will export it to the grid to be taken up by other users.

    In a battery storage solar pv system, this extra power will be diverted to the battery bank in your house and stored to use later when your house requires more energy than the array can provide and at night when the solar pv is not generating.

    The wiring of the system is such that the house will use the battery power preferentially ahead of the grid (like conventional solar), thus saving you money as you no longer need to buy as much expensive electricity from the grid. You can use your free electricity that you have already generated instead!

    If the battery bank is full, and your house demand is being met by the solar, any excess generation will still be exported to the grid, as usual, so other users can benefit.

  2. DC-Coupled vs AC-Coupled

    There are two types of battery storage solutions for solar pv arrays, DC-Coupled and AC-Coupled. All solar pv panels produce DC current and this is then changed to AC current by the inverter so the power can be used by the appliances in the house. As a result, there is a DC side and an AC side to a solar pv system. Whether a storage solution is DC-Coupled or AC-Coupled refers to which side of the inverter the battery bank is.

    In a DC-Coupled system the solar pv panels and the batteries are before the inverter and therefore the batteries can be charged directly from the panels at high efficiency as there are minimal losses. When power is required from the batteries the stored electricity then passes through the inverter to be used by the house just like normal power would from the panels.

    In an AC-Coupled system the DC current from the panels is changed to AC current by the inverter, this is then changed back to DC by a second inverter to charge the batteries. When power is required from the batteries the stored power is then passed back through the second inverter to become usable AC current again.


    DC-Couled System

    AC-Coupled System

     

    The main advantages of an AC-Coupled system are that it is easily retrofit-able to any solar pv system and simple to install and does not require altering the solar pv system already installed.

    With a DC-Coupled system there may be a need for an inverter change to make sure it is compatible with the new battery system but having one inverter increases the efficiency of the whole system and saves space which is useful in many domestic situations. This is also a great option for a new solar pv installation.

  3. Lithium Batteries

    There are two main types of batteries sold to work with solar pv systems. These are Lead-Acid batteries and Lithium-ion batteries. These two types of batteries work very differently and both have merits depending on the conditions and location of the solar system. For domestic on-grid systems Li-ion batteries represent the best solution:

    • High Energy Density (more energy per unit area)
    • High depth of discharge (DOD)
    • Higher continuous power output
    • Long battery life / high number of charge cycles
    • High efficiency between charging and discharging

Please contact us if you would like to speak to an advisor about a battery storage solution for your property.

Along with the advancing product technology the infrastructure technology for batteries is also rapidly moving forward. Utilising multi-rate tariffs with batteries can make both environmental and financial sense. A battery can be charged by the panels during the day and then overnight by a lower rate tariff for use in the morning when a higher rate tariff starts. The solar pv will minimise import during the day and the battery can then support the house in the morning and evening during high rate hours. With the roll out of smart meters, half hourly metering and tariffs are now available. Multi Rate Tariff compatible batteries are perfectly suited to discharge in peak tariff hours and charge  from the low tariff further increasing your homes efficiency and reducing your electricity bills.

Reduce your Carbon Footprint by avoiding the more expensive coal powered peak rates:

The UK electricity network uses a range of power sources to supply our homes and businesses. From dirty coal and oil which release tonnes of CO₂ into our atmosphere to wind, hydro and solar which utilise our abundant renewable natural resources, all of these technologies make up our ‘Energy Mix’. As less energy is needed at certain times of the day the grid will change what energy generators are used to make up the Energy Mix at that point in time. This is where a solar home storage solution can really make a difference.

At the times of highest electricity consumption (across the whole grid) a greater number of power generators are employed to reinforce the supply. This is when the coal (and even diesel) power generators surge, pumping out emissions to cover our peak demand. The times of highest demand are late afternoon and evening. This is also the time when your battery, which will have stored up all its solar energy during the day, is ready to discharge. Your home with its own store of renewable, CO₂-free energy will need to import little to no electricity from the grid when power is at its most carbon intensive.  As more people adopt home storage these peak hours will reduce which would benefit everyone as we would rely less on the worst polluting power stations.

UK GRID CARBON INTENSITY (gCO₂/kWh)

UK GRID CARBON INTENSITY (gCO₂/kWh)

CO₂ emissions per kWh of electricity generated from the UK grid against time of day. The red area indicates when the “dirtiest” electricity is generated.

 

Increase Your Self–Consumption

By adding a battery system to your solar pv array you are now able to store the energy that you would usually export. This energy can then be used later in the day when you would usually import from the grid. A battery system is a simple way of increasing your self-consumption of your free, renewable energy.

Lower Your Electricity Bills

By using normally exported electricity that is generated for free by your solar system, instead of purchasing electricity from the grid, you can see the savings made from your renewable energy investment rise as your electricity bill falls.

Energy Security

Unfortunately, electricity prices are only going in one direction. By utilising as much of your free, green electricity as possible you can shield your yourself from steep future price rises on your electricity bills. In the future we are likely to see ‘time of use metering’ once the roll out of smart meters is complete. With a battery storage solution you will be able to use your stored solar energy at the most expensive (and CO2 intensive) times of day.

Monitor Your Energy

All of our battery storage solutions come with a monitoring platform to allow you to track your household’s energy usage as well as monitor the solar pv generation and battery health. Having this information can allow you to alter usage habits in the property to maximise the solar and battery, and create a more environmentally friendly home that is cheaper to run.

Backup Power

Many of the battery storage products that we offer can be configured to provide backup power if there is a grid failure. This means that your battery can enable you to keep essential circuits running in the house when the grid is down.

 

Product Range