The most cost efficient way to utilise renewable energy is to use it to replace the electricity currently purchased from your electricity supplier. This works best if the renewable technology is designed to match your current electricity demand.

Use the calculator tool below to get an accurate prediction of the potential savings from investing in renewable energy.

If selling electricity ‘locally’ under a private agreement the customer will need to be local. The benefits of this are:

• Generator will achieve ‘near’ wholesale market prices
• Generator will share in the customers savings in not having to pay transmission and distribution charges

You can sell the ‘spill’ – the electricity you are generating either in excess of your demands OR generated at times when your demand is low (for example from a wind turbine at night time).

If selling to the grid you will need:

• An electricity supply from the company you wish to sell to (usually)
• To be producing more than 500kWh per annum.
• accreditation by OFGEM to receive ROCs (Renewable Obligation Certificates)
• Compliance from your local distribution company for connection of the renewable generator to the national grid.

You will also need:

• An OFGEM approved gross generation meter that measures all the output of your system
• An export meter to register the amount of electricity you feed into the electricity network.
• An inverter to synchronise the varying voltage from your supply to the stable grid supply. This is individually programmed on-site to optimise power exported to the grid and to ensure network safety by disconnecting if the grid fails.

If over 5kW is being produced the local grid may need to be strengthened. The cost can vary greatly depending on the extent of the work needed and the distance to the high voltage supply.

What are they?

ROCs were introduced in 2002 by the government to encourage the development of renewable technologies in the UK and to help reduce carbon emissions.

An annual obligation is placed on all electricity suppliers in the UK to demonstrate to the government that they have purchased a % of their electricity from renewable sources. This % increases annually by about 1%, starting at 7.8% in March 2008 and peaking at 15.4% in 2016.

Suppliers demonstrate their obligation by declaring ROCs to Ofgem who administer the scheme.

Electricity suppliers can therefore meet their obligations by buying ROCs from generators, creating their own renewable energy or paying the buy out (penalty) amount for that year.

ROCs can be awarded for all renewable electricity used in a permitted way – that is consumed on site, OR is provided via a distribution system for supply to customers AND / OR exported to the grid.

How much are they worth?

• In 2002 government set the value at £30
• This increases annually with inflation
• April 07– March 08 ‘Buy out price’ is £34.30
• However ROCs are traded on a daily basis and current values are higher than the ‘buy out price’

How many ROCs can I get?

• These Certificates are bought by suppliers who use them to prove to Customs and Excise that they have supplied Levy Exempt electricity to industrial customers.
• A LEC is currently worth £4.41 and this increases each year with RPI.
• A supplier will pay 95% of this value to the Generator (Just over £4 / MWh).
• Ofgem issues one LEC for every MWh of renewable electricity generated. Industrial customers who consume non-renewable fossil fuel electricity rather than renewable electricity are charged a levy for this electricity. If customers purchase green electricity with attached LECs then they do not pay the levy.

Use the calculator tool below to get an accurate prediction of the potential income from investing in renewable energy.