Creating a low carbon home

A guide to Electricity Storage

In the last five years we’ve seen big changes in the way electricity is generated. Traditionally electricity was generated in large power stations and transmitted via the national grid to local substations and then on to homes and businesses.

The pressure to reduce carbon emissions in the electricity sector has led to many more smaller, decentralised generation sources being connected to the distribution network. These are typically on-shore or offshore wind farms, or large solar farms.

Power storage is particularly important when power is generated from variable sources, such as the sun and wind. In recent years, the technology for storing electricity has developed to the point where it has become commercially viable, so it is easier to make sure power is available when it’s required.

We don’t necessarily need to use electricity at the same time as it is generated. Electricity Storage allows us to capture the electricity as it is generated and keep it until we want to use it. Electricity Storage is particularly useful in combination with sources of renewable generation, such as solar and wind power, because it means you can use the electricity when you need it, rather than only when the sun is shining or the wind is blowing.

Electricity generation has changed enormously in the last five years.

Until recently, large power stations generated electricity and delivered it via the National Grid to substations that in turn transmitted it to homes and businesses and wherever else it was required.

Thanks to the drive to reduce carbon emissions, increasing amounts of energy from onshore and offshore wind farms and industrial solar farms are being supplied to the electricity network. One of the key challenges of these sorts of power sources has been that, because they depend on the sun and the wind, they cannot be relied upon to provide a constant supply of power.

About Electricity Storage The Electricity System

Who is this guide for?

If you are a householder or you run a small business and want to know more about generating and using electricity from renewable generation, this guide is for you. It is not a technical guide, but it explains what Electricity Storage is, how you can use it and why you might want to consider installing it. It also offers guidance on how to go about it and where to find out more information.

The benefits of Electricity Storage

You can use more of the energy you generate yourself, so your bills will be lower

You may be able to use storage as a back up in the case of a power cut

You can reduce peak demand charges that may affect small businesses (if half hourly metered)

Centralised generation

Traditional arrangement New arrangement

Centralised generation

Localised generation

Localised generation

Renewable generation

Renewable generation

Commercial property

Commercial and domestic property

Domestic property

The Electricity System

A solar panel system generates electricity during the day and a wind turbine does so when the wind blows. You can use this electricity as it is produced. If you generate more than you use, you can export the surplus power to the electricity grid.

If you have an Electricity Storage system, you are able to keep that surplus electricity and use it when it is convenient for you. This means you will need to buy less electricity from your supplier.

As an example...

The nature of power from renewable sources means that they are not constant.

The practical effect of this has been that we have not been able to be sure that we will have the electricity we need when we need it. This can be a particular problem at those times of day when demand tends to be high for everyone. Recent technological developments are solving this problem. It is now possible to store the power generated by these alternative sources for use when it is required.

How does it work?What is Electricity Storage?

1. Renewable generation (i.e. solar panel/small wind turbine) Electricity is generated from the sun or other natural source.

2. Hot water tank Water is stored and is heated using the electricity from the renewable generation.

3. Electricity Storage device Excess electricity from the renewable generation is stored ready for use when required.

4. Export Limiting System (ELS) Limits the amount of electricity exported to the electricity distribution network (outside the home).

5. Electricity service position The interface between the import and export of electricity between the home and electricity distribution network.

6. Customer Consumer Unit (CCU) This is a piece of electrical equipment which contains the switches and circuit breakers to manage and distribute the supply as it enters the property.

1

2

3 4 56

6am – 6pm

6pm – 6am

CCUELS

Excess exported

Shortfall imported

2

3 4 56

CCUELS

DNO CABLE

DNO CABLE

Is it right for me? Useful links To find out more about Electricity Storage or any of the topics in this booklet, please visit our website:

www.ukpowernetworks.co.uk

or email us at:

DG-Q&A@ukpowernetworks.co.uk

Alternatively, you can visit the Energy Networks Association website for further details on low carbon:

www.energynetworks.org

For more information on finding a reputable installer, please visit:

www.electricitystorage.co.uk

The right choice for you

Whether or not you install Electricity Storage will depend on a number of factors, some of which relate to your usage and others that are technical, engineering questions. It is important to take professional advice before you embark on installing an Electricity Storage system.

As a minimum, you need to have a working source of renewable generation. If you already have renewable generation source such as solar panels or a wind turbine installed, you must check with your local electricity distributor that you will be able to install Electricity Storage.

You must get the go-ahead from your Distribution Network Operator (DNO) and it is vital to follow the regulations that exist to protect the network from damage. The best way to do this is to use a reputable installer. A reputable installer will be able to tell you if you are able to take advantage of Electricity Storage and will ensure that you comply with the regulations related to such installations.

YES NO

Do you have renewable generation installed at your property?

Are there periods of time when the use of electricity at your

property is low/minimal? This is when electricity could be stored.

Are you considering installing renewable generation at your

property?

Storage may be of benefit to you because you are not using all of the electricity going into your property. Storage will allow you to save the electricity you haven’t used for use at another time which will save you money. A reputable installer will be able to assist you with the process and notify your DNO at the appropriate stage.

YES YES

Storage may not be right for you right now because you are using all of the electricity going into your home.

Without a source of renewable generation you are still able to install a storage unit to take account of off peak tariffs or other opportunities. A reputable installer will be able to assist you with the process and notify your DNO at the appropriate stage.

NO NO

The process for notifying the DNO of your intention to install renewable generation depends on the amount of renewable generation you intend on installing. You will find all the information you need on our Distributed Generation web-pages.Once you have the renewable generation installed you will be able to look into whether or not storage is suitable for you.

Once installed

UK Power Networks Holdings Limited Registered in England and Wales No. 7290590 Registered office: Newington House, 237 Southwark Bridge Road, London SE1 6NP

www.ukpowernetworks.co.uk

UK Power Networks Holdings Limited is the holding company of the companies in the UK Power Networks group of companies.

V1.0