Grid Connecting

For the UK, as far as we are aware, the following applies to all of the Distribution Network Operators (DNOs) in the UK. Many DNOs make information available on their websites and have downloadable forms but, as usual, it is easier to obtain information from some than others, and may require a telephone call to obtain the documents.

All of the Samrey turbines fall under the G83/1regulations which cover ‘Small Scale Embedded Generation’ of up to 16A per phase connected at low voltage to the distribution network.

This means that prior consent is not required before connection BUT a notification form must be submitted on or before connection (this is a legal requirement). The form is principally concerned with the correct and safe connection to the public grid and considers the ‘installer’ to be the properly qualified electrician who makes the connection to the grid, and who must make a declaration that the installation complies with regulations. It is therefore important that a qualified electrician be used to make the grid connection and who will be able to sign the G83/1 declaration. Grid-tie inverters supplied as part of the Samrey package are fully certified as G83/1 compliant in the UK.

If multiple units or turbines larger than 2.5kW are being connected it is likely that total rating exceeds 16A. In this instance prior consent must be sought. Consent will only be granted where the network is either suitable or where it has been made suitable (generally at the cost of the applicant) and connection is safe and secure.

One of the conditions of connecting to the grid is that, if the network goes down (e.g. damage to transmission cables, maintenance, etc), the system has to disconnect from the network. This is critical to ensure the safety of anyone working on the network, but also has the effect of taking the turbine off-load so generation ceases until the inverter senses the grid is back on-line.

Renewable Obligation Certificates (ROCs)

A ROC is issued for every megawatt hour (1000 kilowatt hours), rounded up or down to the nearest whole MWh, of renewable energy by an accredited generator. Accreditation can be gained by application to Ofgem as a small generator (50kW or less). One of the key requirements to gain ROCs is to have an approved meter installed in an approved manner. Ofgem publishes a list of approved meters on their website or available by telephone from their Renewables team.

Once accredited, periodic meter readings (monthly or annually) are submitted to Ofgem who will process the data and issue the number of ROCs earned.

The Renewables Obligation has been designed to produce 20% of the UK’s energy by renewables by 2020, and ROCs act as a subsidy to encourage generation of energy from renewable sources to meet this goal. From a relatively low base, each year the proportion of energy from renewable sources is increased by regulation, and unless this level is met by energy producers, they must meet the shortfall by buying an equivalent amount of ROCs. As a result of this process, ROCs have a market value and may be sold or traded directly or via agents; although the price will vary from time to time depending on the renewable energy targets set, the supply of renewable energy and demand for ROCs. Government intends that suppliers will be subject to the scheme until 2027. For those who wish to claim the ROCs themselves Ofgem now offer an online account where ROCs can be held and traded from similar to an online share trading account.

Further information may be obtained from Ofgem at http://www.ofgem.gov.uk/Sustainability/Environmnt/RenewablObl/Documents1/FAQ_230507.pdf

Selling Electricity

With grid connection, it is possible to sell any excess electricity generated back to your electricity supplier, whether or not ROCs are being claimed. Initially, any electricity generated will be first used to meet current household demand. Any shortfall will be met from the grid, but any surplus can be sold back to your supplier. Each supplier will have its own scheme/s and specific requirements which change in response to demand and legislation. It is always a good idea to check the current schemes and terms and conditions.

Generally speaking suppliers require an approved meter recording of the amount of electricity fed back into the grid – an export meter - this is not likely to be the same as total generation required by Ofgem and will inevitably call for a second meter. Periodically the export meter is read and the unit price is paid back by the supplier. It is often the case that the suppliers will want to take in the ROCs and offer a slightly better unit rate, or give a lower return and let the generator take their luck with selling the associated ROCs, or even be appointed as agent for the sale of the ROCs irrespective of the tariff offered. The best option will depend upon many factors, not least the amount of effort to be undertaken by the owner and the requirements of the supplier (e.g. costs and installation of a specific export meter, etc.) and should be carefully assessed.

In some cases suppliers have a less formal system that assess the generation based on the capacity of the turbine. These tend to pay a lower amount per unit, but the cost of export meters and installation are avoided and may thus be suitable for smaller turbines.

Schemes and tariffs are developing and evolving in response to demand and competition, and so it is worth monitoring the offerings.