NFU Energy has warned growers with small Combined Heat and Power Plants (CHP) below 1 MW thermal capacity not to be caught out by factors which could mean that they require environmental permitting, although this is not normally required for CHP units of this size.
One common mistake is misreading the capacity. ‘Many installers and site operators focus on the output capacity of their plants when sizing their plant,’ says NFU Energy. ‘For instance, a 600 kWe (electrical capacity) CHP will have over 1 MWth input, which would classify it as a medium sized plant; therefore, requiring permitting. The electrical capacity divided by the electrical efficiency will give you the thermal input, if this is greater than 1,000kW (1MW) then you will require an environmental permit.’
Sites with more than one generating plant also have to consider the total combined thermal capacity of all plants. If above 1MW then permitting is required.
Another issue is Capacity Market Auctions. ‘If you intend to enter the 2021 capacity market auctions you will need to have an environmental permit,’ warned NFU Energy. ‘The minimum export capacity that sites can auction for is 100 kWe. Therefore, small CHPs with grid export agreements less than this will also not require permitting. Pre-2017 existing CHPs (i.e. those not yet subject to permitting until 2025 (>5MWth) or 2029 (1-5 MWth)) that plan to enter the
2021 capacity market auctions will require permitting earlier in order to take part.’