In calculating how much lost energy there will be from curtailment, a network company will need to make lots of assumptions. This means that 6,570MWh x 10% = 657MWh of energy output will be lost due to curtailment. For example, the same 5MW solar farm might have a predicted curtailment of 10% energy over the year. In these curtailment reports, a network company will either express the curtailment as a reduction in MWh output over a year, or as a percentage. ![]() Whilst network companies are only concerned about peak power, they will usually provide reports with their ANM connection offers (although not all DNOs provide a report) showing the predicted curtailment, in terms of energy. A 5MW solar farm with a 15% capacity factor would therefore expect an annual energy output of 5MW x (24h x 365days) x 15% = 6,570MWh. Nuclear has a capacity factor of close to 90%, baseload gas 50-60%, wind 30-40% and solar typically no more than 15%. This is influenced by many factors, such as plant reliability, maintenance schedules, market conditions, network outages, and fuel source availability, etc. All types of generation have an annual capacity factor, i.e., the likely availability during a year. This baseline figure depends on the annual capacity factor. Due to the variability of all types of generation, curtailment is normally assessed over the period of a year, so an annual baseline needs to be calculated. The million-dollar question with curtailment is clearly, ‘How much’? Before a generator or a network company can model how much curtailment there may be, a baseline figure needs to be calculated to compare against the curtailed output. For example, on a certain day a 5MW solar farm might only be able to be allowed to export 2MW due to constraints on the network, so the network company would have to issue a curtailment instruction to reduce from 5MW to 2MW.įor the generator, however, the issue is not so much having to reduce to 2MW, but the corresponding loss in MWh output (i.e., energy), because it is the sale of MWh of electrical energy by which the generator makes money. So, a network company will issue curtailment signals in terms of MW. ![]() If too many generators have a high peak power output, the total MW power flow through the network could overload something. For network companies, instantaneous power output is the key issue. What is being curtailed?ĪNM curtailment is viewed differently by network companies than by generators. This article unpacks curtailment in more detail, but first you may need to understand the difference between power and energy. ![]() Our previous article explaining ANM introduced the idea of curtailment, when the output of a site is controlled by the network company to avoid expensive upgrades to the system. When parts of the electricity network become full and reach their capacity, a network company can use an Active Network Management (ANM) scheme to control the output of a generator so that it doesn’t overload the grid.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |