National Grid is already experiencing issues caused by the changing nature of our energy system, such as the increasing amount of electricity that is being provided by distributed generation (DG). Distributed generation, from Combined Heat and Power (CHP) plants to solar panels, currently supplies around 10GW at times of peak demand, which is around 17 per cent of total demand. National Grid are struggling to access data from smaller DG sources, which makes it more challenging to accurately assess capacity levels and ensure security of supply.
It’s clear that as our heating and transport systems become increasingly electrified, the grid will need to be reformed in order to meet the increasing demands upon it. Could microgrids be the answer? Let’s take a look…
What is a microgrid?
A microgrid is a collection of small generators that combine to make a small, freestanding grid. Microgrids are embedded within the larger grid, but they can also switch off from the larger grid in the event of an issue such as a blackout, so those within the microgrid are still provided with power.
How are we currently using microgrids?
At present, there’s still plenty of unexplored potential in microgrids. Most of our existing microgrids are on a relatively small scale, such as hospitals, or large industrial sites with an onsite CHP facility.
Microgrid users typically operate in parallel to the grid, so that the grid can provide instant back-up in the event of a generator tripping. They also tend to be fuelled by natural gas and, thanks to the decarbonisation of grid electricity, are often a less green option. However, there are microgrids emerging that are much more sustainable. Renewable microgrids – involving solar panels and batteries – have already been successful in bringing power to remote African villages that do not have access to grid electricity.
A great example of this in the UK is the Scottish Island of Eigg. This operates an electricity network that includes 3 small hydro-electric schemes, small wind turbines and a solar installation in addition to diesel generators and a battery storage system.
How could microgrids improve our future energy system?
As distributed generation continues to account for a greater share of our electricity supply, it’s likely that we’ll see the number of microgrids increase as well.
Options for small-scale, community electricity generators are becoming greener and more diverse – many business and domestic premises now have solar panels, for example, and while small-scale wind turbines, CHP and natural gas generators are also becoming more prevalent. The price of batteries, which are vital for microgrids to provide power without depending on a centralised power plant, is also falling.
With more renewable options for small-scale generation available, and the cost of energy storage falling, microgrids will become more commercially viable and at some point in the future, we could see microgrids forming a significant part of our electricity network. These microgrids could help us to:
Become more resilient
As microgrids can either manually or automatically flip a switch to disconnect from the larger grid, having a network of microgrids would mean that if something went wrong with part of the main grid, microgrid users should be protected. They will still be provided with power until the issue with the main grid is resolved.
The ability of microgrids to isolate themselves from the wider grid could also improve the cybersecurity of our energy system. In the event of a cybersecurity attack on the larger grid or a specific microgrid, each microgrid could isolate itself to ensure that the threat remains localised.
Balance supply and demand
We’re relying on renewable sources more than ever, and our dependence on them will only increase as we strive to reach our commitments to sustainability. While the benefits of going green are clear, renewable generation is notoriously intermittent, making it challenging for National Grid to accurately balance supply and demand.
As microgrids contain at least one energy storage solution within their grid, they can help to mitigate the intermittency of renewable energy by providing the larger grid with spare capacity when it’s needed, or turning down when demand is low.
Bring costs down
The energy storage element of microgrids could also bring costs down for those that use them. If there’s a large spike in demand on the larger grid, the microgrid can make money by selling any excess power it has stored to the utilities. Having integrated energy storage within the grid could also help to bring costs down for those within it as they can buy and store energy while costs are low, for use when costs rise again.
Manage the grid more easily
As we know, the National Grid is finding it difficult to predict capacity levels due to the growth of distributed generation. Microgrids can help National Grid by aggregating all of the small-scale resources within them, from solar panels to batteries, and presenting them as a single entity. This means that National Grid won’t have to communicate directly with each individual generator, user etc., and should make it easier for the operator to manage and predict supply and demand.
If you’d like to find out more about how microgrids could help your organisation, or you’d like to speak to an expert about your energy procurement call us on 08451 46 36 26 or email firstname.lastname@example.org.