National Grid recently released its Electricity Ten Year Statement (ETYS) detailing the key challenges the UK grid operator expects to face over the next decade. Currently, the UK grid is under considerable strain as the margin between supply and demand continues to narrow. This has led to the recent bout of alarming headlines warning of potential blackouts this winter. This supply problem is looking as if it will continue to compound as the planned closure of fossil fuel plants approaches and the amount of intermittent, embedded generation connecting to the distribution network is forecast to increase exponentially.
According to National Grid’s ‘Gone Green’ scenario, the growth of embedded generation over the next decade will be unprecedented. Although connected at the distribution level, en masse embedded generation can have a significant knock-on effect on the transmission network and therefore on overall energy system reliability. [Internet Of Things Is Faster Than Power Stations]
Solar is mainly to blame
The main embedded generation asset type National Grid has identified as a challenge is solar panels, specifically those expected to be installed in the south of England. These would place increased stress on the local network and would also necessitate grid reinforcement as there currently isn’t sufficient capacity or infrastructure to transport the anticipated future supply from Scotland, where the majority of wind power is produced, to the south where demand will be highest.
Closure of traditional fossil fuel plants not only creates issues in terms of reactive to active power balance on the grid, but also removes generation sources currently responsible for supplying the vast majority of UK energy system flexibility. In this instance, flexibility refers to the ability of generators to ramp up/down or customers to decrease/increase energy usage in response to a grid signal. Flexibility in the energy system is vital to maintaining grid balance and for integrating intermittent, renewable generation onto the network.
Renewable generation by its very nature is intermittent and therefore other generation assets and customers need to provide the flexibility required to adjust export/import levels at short notice to accommodate a change in energy supply when the wind blows or the sun shines. This would otherwise cause a mismatch of supply with demand, resulting in lights out.
Meeting grid challenges with VPPs
These substantial challenges can be met with the implementation of Virtual Power Plants (VPPs) in areas of high embedded generation density.
Supported by cloud-based software, monitoring and automation equipment and an optimisation engine, VPPs are able to extract flexibility out of small scale generators and customers, allowing them to respond to varying amounts of renewable supply on the system whilst compensating them for doing so.
This benefits grid operators as they are able to delay, or completely avoid, costly and carbon intensive grid reinforcement by unlocking existing capacity.
Limejump is currently partnering with National Grid to provide grid balancing services when the energy system is most in need. If a stress event were to occur on the grid, Limejump’s customers enrolled within our VPP would be able to power 50,000 homes for over an hour. Limejump’s award winning VPP technology is helping to meet the ETYS challenges head on.