Increasing energy generation from renewables is forcing traditional power companies and the National Grid to quickly adapt to new challenges, according to energy data specialist EnAppS.
Its recent reort says that with the recent growth of renewables and solar PV in particular far exceeding previous expectations, new challenges are emerging that have serious implications for traditional fossil fuel generators and the National Grid’s ability to manage supply-side issues.
Overall renewable generation in May, including estimates for unmetered wind, solar, biomass and hydro, was 23% of the total power supply – up from a previous high of 21% in mid-winter when wind’s contribution was particularly high.
As a result of these trends, together with imports of power from the Continent, fossil fuel’s share of generation is reducing.
From around 80% in January 2009, the contribution of conventional coal- and gas-fired power stations to the UK’s power generation fell to less than 50% during May 2015.
In terms of daily contributions, figures show that solar PV generation appeared to provide 6% of total power output on 23 and 30 May, with peak output levels reaching 15% of half-hourly generation and almost 5GW of power on the 23rd.
As a guide to the unexpected nature of this increase, in its 2014 Future Energy Scenarios report, the National Grid said it expected to see the 6.5GW generation threshold breached by 2018/19 at the earliest and by 2025/26 at the latest – putting current solar output levels nearly 10 years ahead of schedule.
EnAppSys director Paul Verrill said: “The recent increased levels of solar PV generation is a scenario that is demanding a new approach from the traditional power generators and the National Grid.
“The National Grid now needs to quickly adapt to reduced generation from other power sources during the middle of the day, and the existing generators will have to adjust to a midday depression of energy prices, with these prices now reducing close to the low prices experienced overnight.
“If solar capacity continues to grow, this will see a large depression in levels of demand for electricity generation from conventional power sources in the middle of the day and a challenge for National Grid to manage the system without the inherent ‘inertia’ provided by large thermal power stations.”